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Impacted wisdom teeth
Impacted wisdom teeth
Impacted wisdom teeth
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Impacted wisdom teeth
Other namesImpacted third molars
Impacted third molar
3D CT of an impacted wisdom tooth adjacent the inferior alveolar nerve prior to removal of wisdom tooth
SpecialtyDentistry, oral and maxillofacial surgery
SymptomsLocalized pain and swelling behind the last teeth
ComplicationsInfections, loss of adjacent teeth, cysts
Usual onsetLate teens, early 20s
TypesFull vs partially impacted, direction of impaction
CausesCongenital
Diagnostic methodExamination, x-ray
Differential diagnosisOther causes for dental pain, TMJ pain
TreatmentGood dental care, periodic monitoring, removal of wisdom teeth
Frequency70-75% of the population

Impacted wisdom teeth is a condition where the third molars (wisdom teeth) are prevented from erupting into the mouth.[1] This can be caused by a physical barrier, such as other teeth, or when the tooth is angled away from a vertical position.[2] Completely unerupted wisdom teeth usually result in no symptoms, although they can sometimes develop cysts or neoplasms. Partially erupted wisdom teeth or wisdom teeth that are not erupted but are exposed to oral bacteria through deep periodontal pocket, can develop cavities or pericoronitis. Removal of impacted wisdom teeth is advised for the future prevention of or in the current presence of certain pathologies, such as caries (dental decay), periodontal disease or cysts. Prophylactic (preventative) extraction of wisdom teeth is preferred to be done at a younger age (middle to late teenage years) to take advantage of incomplete root development, which is associated with an easier surgical procedure and less probability of complications. However, in recent decades the preventive removal of impacted wisdom teeth has come into question, and some health organizations have issued guidelines calling to only remove impacted wisdom teeth in the case of current issues.[3][4]

Impacted wisdom teeth are classified by their direction of impaction, their depth compared to the biting surface of adjacent teeth and the amount of the tooth's crown that extends through gum tissue or bone. Impacted wisdom teeth can also be classified by the presence or absence of symptoms and disease. Screening for the presence of wisdom teeth often begins in late adolescence when a partially developed tooth may become impacted. Screening commonly includes a clinical examination as well as x-rays such as panoramic radiographs.

Infection resulting from impacted wisdom teeth can be initially treated with antibiotics, local debridement or surgical removal of the gum overlying the tooth. Over time, most of these treatments tend to fail and patients develop recurrent symptoms. The most common treatment for recurrent pericoronitis is wisdom tooth removal. The risks of wisdom tooth removal are roughly proportional to the difficulty of the extraction. Sometimes, when there is a high risk to the inferior alveolar nerve, only the crown of the tooth will be removed (intentionally leaving the roots) in a procedure called a coronectomy. The long-term risk of coronectomy is that chronic infection can persist from the tooth remnants. The prognosis for the second molar is good following the wisdom teeth removal with the likelihood of bone loss after surgery increased when the extractions are completed in people who are 25 years of age or older. A treatment controversy exists about the need for and timing of the removal of disease-free impacted wisdom teeth. Supporters of early removal cite the increasing risks for extraction over time and the costs of monitoring the wisdom teeth. Supporters for retaining wisdom teeth cite the risk and cost of unnecessary surgery.

The condition can be common, with up to 72% of the Swedish population affected.[5] Wisdom teeth have been described in the ancient texts of Plato and Hippocrates, the works of Charles Darwin and in the earliest manuals of operative dentistry. It was the meeting of sterile technique, radiology, and anesthesia in the late 19th and early 20th centuries that allowed the more routine management of impacted wisdom teeth.

Classification

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All teeth are classified as either developing, erupted (into the mouth), embedded (failure to erupt despite lack of blockage from another tooth), or impacted. Impacted teeth are ones that fail to erupt due to blockage from other teeth. Wisdom teeth, as the last teeth to erupt in the mouth are the most likely to become impacted. They develop between the ages of 14 and 25, with 50% of root formation completed by age 16, and 95% of all teeth erupted by the age of 25, however, some tooth movement can continue beyond the age of 25.[6]: 140 

Impacted wisdom teeth are classified by the direction and depth of impaction, the amount of available space for tooth eruption, and the amount of soft tissue or bone (or both) that covers them. The classification structure helps clinicians estimate the risks for impaction, infections and complications associated with wisdom teeth removal.[7] Wisdom teeth are also classified by the presence (or absence) of symptoms and disease.[8]

Impacted wisdom teeth are often described by the direction of their impaction (forward tilting, or mesioangular being the most common), the depth of impaction and the age of the patient as well as other factors such as pre-existing infection or the presence of pathology (cysts, tumors or other disease).[6]: 143–144  Each of these factors is used to predict the difficulty (and rate of complications) when removing an impacted tooth, with age being the most reliable predictor[9] rather than the orientation of the impaction.[10]

Impacted wisdom tooth with a backward tilt (distoangular impaction) and chronic infection to back of crown (green arrow)
Impacted wisdom tooth with no tilt (vertical impaction)
Impacted wisdom tooth that is tilted forward (mesioangular impaction)
Impacted wisdom tooth with a horizontal orientation (horizontal impaction)

Another classification system often taught in U.S. dental schools is known as Pell and Gregory Classification. This system includes a horizontal and vertical component to classify the location of third molars (predominately applicable to lower third molars): the third molar's relationship to the level of the teeth already in the mouth, being the vertical or x-component and to the anterior border of the ramus being the horizontal or y-component.[11]

Signs and symptoms

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Pericoronitis (green arrow) in lower right wisdom tooth

Impacted wisdom teeth without communication to the mouth,[jargon] that have no pathology associated with the tooth, and have not caused tooth resorption on the blocking tooth, rarely have symptoms.[12] The chances of developing pathology on an impacted wisdom tooth that is not communicating with the mouth is approximately 12%.[12] However, when impacted wisdom teeth communicate with the mouth, food and bacteria penetrate to the space around the tooth and cause symptoms such as localized pain, swelling and bleeding of the tissue overlying the tooth. The tissue overlying the tooth is called the operculum, and the disorder is called pericoronitis which means inflammation around the crown of the tooth.[6]: 141  Low grade chronic periodontitis commonly occurs on either the wisdom tooth or the second molar, causing less obvious symptoms such as bad breath and bleeding from the gums. The teeth can also remain asymptomatic (pain free), even with disease.[8]

The term asymptomatic means that the person has no symptoms. The term asymptomatic should not be equated with absence of disease. Most diseases have no symptoms early in the disease process. A pain-free or asymptomatic tooth can still be infected for many years before pain symptoms develop.[8]

Causes

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Impacted wisdom tooth

Wisdom teeth become impacted when there is not enough room in the jaws to allow for all of the teeth to erupt into the mouth. Because the wisdom teeth are the last to erupt, due to insufficient room in the jaws to accommodate more teeth, the wisdom teeth become stuck in the jaws, i.e., impacted. There is a genetic predisposition to tooth impaction. Genetics plays an important, albeit unpredictable role in dictating jaw and tooth size and tooth eruption potential of the teeth. Studies have shown that impacted teeth, and crowded teeth in general, arose in humans in the move from hunter-gatherers to farmers,[13] and increased with the industrial revolution, as well it has been shown that young animals fed on uncooked vegetables as opposed to cooked ones have larger jaws.[14] This suggests that it is industrialized soft and processed diets that cause impacted wisdom teeth.

Pathophysiology

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Impacted wisdom tooth with caries and cyst (green arrow) displacing inferior alveolar nerve (blue)

Impactions completely covered by bone and soft tissue, do not communicate with the mouth, and have a low rate of clinically significant infection. Since the tooth never erupts, the dental follicle that surrounds the tooth does not degenerate during eruption, and can develop cysts or uncommon tumors over time.[6]: 141  Estimates of the incidence of cysts or other neoplasms (almost all benign) around impacted teeth average at 3%, usually seen in people under the age of 40. This suggests that the chance of tumor formation decreases with age.[6]: 141 

Bacteroides fragilis bacteria under microscope

For partially impacted teeth in those over 20 year of age, the most common pathology seen, and the most common reason for wisdom teeth removal, is pericoronitis or infection of the gum tissue over the impacted tooth. The bacteria associated with infections include Peptostreptococcus, Fusobacterium, and Bacteroides bacteria. The next most common pathology seen is cavities or tooth decay. Fifteen percent of people with retained wisdom teeth exposed to the mouth have cavities on the wisdom tooth or adjacent second molar due to a wisdom tooth. The rate of cavities on the back of the second molar has been reported anywhere from 1% to 19% with the wide variation attributed to increased age.[15]

In five percent of cases, advanced periodontitis or gum inflammation between the second and third molars precipitates the removal of wisdom teeth.[6]: 141 [7] Among patients with retained, asymptomatic wisdom teeth, roughly 25% have gum infections (periodontal disease).[16]: ch13  Teeth with periodontal pockets of greater than 5mm have tooth loss rates that start at 10 teeth lost per 1000 teeth per year at 5mm to a rate of 70 teeth lost per year per 1000 teeth at 11mm.[17]: 57  The risk of periodontal disease and caries on third molars increases with age with a small minority (less than 2%) of adults age 65 years or older maintaining the teeth without caries or periodontal disease and 13% maintaining unimpacted wisdom teeth without caries or periodontal disease.[18] Periodontal probing depths increase over time to greater than 4 mm in a significant proportion of young adults with retained impacted wisdom teeth which is associated with increases in serum inflammatory markers such as interleukin-6, soluble intracellular adhesion molecule-1 and C-reactive protein.[19]

Crowding of the front teeth is not believed to be caused by the eruption of wisdom teeth although this is a reason many dental clinicians use to justify wisdom teeth extraction.[6]: 141 ,[20]

Diagnosis

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Panoramic radiograph of impacted lower wisdom teeth (green arrows) in a 26-year-old with dental caries (red arrows) on the adjacent teeth

The diagnosis of impaction can be made clinically if enough of the wisdom tooth is visible to determine its angulation, depth, and if the patient is old enough that further eruption or uprighting is unlikely. Wisdom teeth continue to move to the age of 25 years old due to eruption, and then continue some later movement owing to periodontal disease.[21]

If the tooth cannot be assessed with clinical exam alone, the diagnosis is made using either a panoramic radiograph or cone-beam CT. Where unerupted wisdom teeth still have eruption potential several predictors are used to determine the chance of the teeth becoming impacted. The ratio of space between the tooth crown length and the amount of space available, the angle of the teeth compared to the other teeth are the two most commonly used predictors, with the space ratio being the most accurate. Despite the capacity for movement into early adulthood, the likelihood that the tooth will become impacted can be predicted when the ratio of space available to the length of the crown of the tooth is under 1.[6]: 141 

Screening

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Impacted 2nd molar (red arrow) with developing wisdom tooth (green arrow)

There is no standard to screen for wisdom teeth. It has been suggested, absent evidence to support routinely retaining or removing wisdom teeth, that evaluation with panoramic radiograph, starting between the ages of 16 and 25 be completed every 3 years. Once there is the possibility of the teeth developing disease, then a discussion about the operative risks versus long-term risk of retention with an oral and maxillofacial surgeon or other clinician trained to evaluate wisdom teeth is recommended. These recommendations are based on expert opinion level evidence.[22] Screening at a younger age may be required if the second molars (the "12-year molars") fail to erupt as ectopic positioning of the wisdom teeth can prevent their eruption. Radiographs can be avoided if the majority of the tooth is visible in the mouth.[medical citation needed]

Treatment

[edit]

Wisdom teeth that are fully erupted and in normal function need no special attention and should be treated just like any other tooth. It is more challenging to make treatment decisions with asymptomatic, disease-free wisdom teeth where there is a high probability that the teeth will develop disease over time, but none exists on examination, or on x-rays (see Treatment controversy below).[5]

Understanding the process, from preparation to recovery, can help ease anxiety and ensure a smooth experience.[23]

Local treatment

[edit]
An operculum (green arrow) over a partially erupted lower left third molar with inflammation and pus (right of green arrow under tissue)
Main article: Pericoronitis

Pericoronitis is an infection of the operculum of a partially impacted wisdom tooth. It can be treated with local cleaning, an antiseptic rinse of the area and antibiotics if severe. Definitive treatment can be excision of the operculum, however, recurrence of these infections is high. Pericoronitis, while a small area of tissue, should be viewed with caution, because it lies near the anatomic planes of the neck and can progress to life-threatening neck infections.[17]: 440–441 

Wisdom teeth removal

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Wisdom teeth removal (extraction) is the most common treatment for impacted wisdom teeth. In the US, 10 million wisdom teeth are removed annually.[24] The procedure can be either simple or surgical, depending on the depth of the impaction and angle of the tooth. Surgical removal is to create an incision in the mucosa of the mouth, remove bone of the mandible or maxilla adjacent the tooth, extract it or possibly section the tooth and extract it in pieces. This can be completed under local anaesthetic, sedation or general anaesthetic.[6] As of 2020, the evidence is insufficient to recommend one type of surgical practice over another.[25]

Radiograph of symptomatic and infected impacted wisdom tooth near inferior alveolar nerve
Nerve (green arrow) pierces the root of impacted wisdom tooth. Tooth sectioned from around nerve
Socket of wisdom tooth with skeletonized inferior alveolar nerve (green arrow) intact

Recovery, risks and complications

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Most people will experience pain and swelling (worst on the first post-operative day) then return to work after 2 to 3 days with the rate of discomfort decreased to about 25% by post-operative day 7 unless affected by dry socket: a disorder of wound healing that prolongs post-operative pain. It can be 4 to 6 weeks before patients are fully recovered with a full range of jaw movements.[26]

A Cochrane investigation found that the use of antibiotics either just before or just after surgery reduced the risk of infection, pain and dry socket after wisdom teeth are removed by oral surgeons, but that using antibiotics also causes more side effects for these patients. Nineteen patients needed to receive antibiotics to prevent one infection. The conclusion of the review was that antibiotics given to healthy people to prevent infections may cause more harm than benefit to both the individual patients and the population as a whole.[27] Another Cochrane Investigation has found post-operative pain is effectively managed with either ibuprofen, or ibuprofen in combination with acetaminophen.[28]

Long-term complications can include periodontal complications such as bone loss on the second molar following wisdom teeth removal. Bone loss as a complication after wisdom teeth removal is uncommon in the young but present in 43% of those of 25 years of age or older.[26] Injury to the inferior alveolar nerve resulting in numbness or partial numbness of the lower lip and chin has reported rates that vary widely from 0.04% to 5%.[26] The largest study is from a survey of 535 oral and maxillofacial surgeons in California, where a rate of 1:2,500 was reported.[29]

The large variation in report rates is attributed to variations in technique, the patient pool and surgeon experience. Other complications that are uncommon have been reported including persistent sinus communication, damage to adjacent teeth, lingual nerve injury, displaced teeth, osteomyelitis and jaw fracture.[26] Alveolar osteitis, post-operative infection, excessive bleeding may also be expected.[20]

Treatment controversy

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Many impacted wisdom teeth are extracted prior to the age of 25, when full eruption can be reasonably expected and before symptoms or disease have begun. This has led to a treatment controversy generally referred to as the extraction of asymptomatic, disease-free wisdom teeth.

In 2000, the National Institute for Clinical Excellence (NICE) of the United Kingdom set guidelines to discontinue the removal of asymptomatic disease-free third molars in the UK National Health Service, stating that there was no reliable research evidence to support a health benefit to patients from the prophylactic removal of pathology-free impacted third molar teeth, in addition to the risks of removal and cost to the service.[30] Advocates of the policy point out that the impacted wisdom teeth can be monitored and avoidance of surgery also means avoidance of the recovery, risks, complications and costs associated with it. Following implementation of the NICE guidelines the UK saw a decrease in the number of impacted third molar operations between 2000 and 2006 and a rise in the average age at extraction from 25 to 31 years.[15] The American Public Health Association (APHA) has adopted a similar policy.[31]

Those who argue against a blanket moratorium on the extraction of asymptomatic, disease-free wisdom teeth point out that wisdom teeth commonly develop periodontal disease or cavities which may eventually damage the second molars and that there are costs associated with monitoring wisdom teeth. They also point to the fact that there is an increase in the rate of post-operative periodontal disease on the second molar,[8] difficulty of surgery and post-operative recovery time with age.[9] The UK has also seen an increase in the rate of dental caries on the lower second molars increasing from 4–5% prior to the NICE guideline to 19% after its adoption.[15] However, a study in 2014 found that the rates of hospitalizations for the removal of impacted wisdom teeth in the UK is 5 times smaller than in France and 7 times smaller than in Australia, which the authors said could be because of the UK's guidelines against the preventive removal of impacted wisdom teeth.[32]

Although most studies arrive at the conclusion of negative long-term outcomes e.g. increased pocketing and attachment loss after surgery, it is clear that early removal (before 25 years old), good post-operative hygiene and plaque control, and lack of pre-existing periodontal pathology before surgery are the most crucial factors that minimise the probability of adverse post-surgical outcomes.[33]

Asymptomatic disease-free impacted wisdom teeth in a 21-year-old

The Cochrane review of surgical removal versus retention of asymptomatic disease-free impacted wisdom teeth suggests that the presence of asymptomatic impacted wisdom teeth may be associated with increased risk of periodontal disease affecting adjacent 2nd molar (measured by distal probing depth > 4 mm on that tooth) in the long term. Few studies, however, met the criteria to be included in the Cochrane review and those that were included provided very low quality evidence and had a high risk of bias. Another study which was at high risk of bias, found no evidence to suggest that removal of asymptomatic disease-free impacted wisdom teeth has an effect on crowding in the dental arch. There is also insufficient evidence to highlight a difference in risk of decay with or without impacted wisdom teeth.[20]

One trial in adolescents who had orthodontic treatment comparing the removal of impacted lower wisdom teeth with retention was identified. It only examined the effect on late lower incisor crowding and was rated 'highly biased' by the authors. The authors concluded that there is not enough evidence to support either the routine removal or retention of asymptomatic impacted wisdom teeth.[34][needs update] Another randomised controlled trial done in the UK has suggested that it is not reasonable to remove asymptomatic disease-free impacted wisdom tooth merely to prevent incisor crowding as there is not strong enough evidence to show this association.[35]

Due to the lack of sufficient evidence to determine whether such teeth should be removed or not, the patient's preference and values should be taken into account with clinical expertise exercised and careful consideration of risks and benefits to determine treatment.[33] If it is decided to retain asymptomatic disease-free impacted wisdom teeth, clinical assessment at regular intervals is advisable to prevent undesirable outcomes (pericoronitis, root resorption, cyst formation, tumour formation, inflammation/infection).[20]

Coronectomy

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Main article: Coronectomy
Coronectomy of impacted wisdom tooth post-op xray showing root remnants (red arrow) and inferior alveolar nerve (green arrow)

Coronectomy is a procedure where the crown of the impacted wisdom tooth is removed, but the roots are intentionally left in place. It is indicated when there is no disease of the dental pulp or infection around the crown of the tooth, and there is a high risk of inferior alveolar nerve injury.[36]

Coronectomy, while lessening the immediate risk to the inferior alveolar nerve function has its own complication rates and can result in repeated surgeries. Between 2.3% and 38.3% of roots loosen during the procedure and need to be removed and up to 4.9% of cases require reoperation due to persistent pain, root exposure or persistent infection. The roots have also been reported to migrate in 13.2% to 85.9% of cases.[36]

Prognosis

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The prognosis for impacted wisdom teeth depends on the depth of the impaction. When they lack a communication to the mouth, the main risk is the chance of a cyst or neoplasm forming in the tissues around the tooth (such as the dental follicle), which is relatively uncommon.[5]

Once communicating with the mouth, the onset of disease or symptoms cannot be predicted but the chance of it does increase with age. Less than 2% of wisdom teeth are free of either periodontal disease or caries by age 65.[18] Further, a systemic review found that between 30% – 60% of people with previously asymptomatic impacted wisdom teeth will have them extracted due to symptoms or disease, 4–12 years after initial examination.[5]

Extraction of the wisdom teeth removes the disease on the wisdom tooth itself and also appears to improve the periodontal status of the second molar, although this benefit diminishes beyond the age of 25.[18]

Epidemiology

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Few studies have looked at the percentage of the time wisdom teeth are present or the rate of wisdom teeth eruption. The lack of up to five teeth (excluding third molars, i.e. wisdom teeth) is termed hypodontia. Missing third molars occur in 9-30% of studied populations. One large scale study on a group of young adults in New Zealand showed 95.6% had at least 1 wisdom tooth with an eruption rate of 15% in the maxilla and 20% in the mandible.[37] Another study on 5000 army recruits found 10,767 impacted wisdom teeth.[38]: 246  The frequency of impacted lower third molars was found to be 72% in a Swedish study,[5] and the frequency of retained impacted wisdom teeth that are free of disease and symptoms is estimated to be between 11.6% to 29%, a percentage which drops with age.[37]

The incidence of wisdom tooth removal was estimated to be 4 per 1000 person years in England and Wales prior to the 2000 NICE guidelines.[5]

History

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Farmer at the dentist, Johann Liss, c. 1616–17

Wisdom teeth have been described in the ancient texts of Plato and Hippocrates. "Teeth of wisdom" being from the Latin, dentes sapientiæ, which in turn is derived from the Hippocratic term, sophronisteres, from the Greek sophron, meaning prudent.[39]

Charles Darwin believed the wisdom teeth to be in decline with evolution, a theory which his contemporary, Paolo Mantegazza, later proved to be false when he discovered Darwin was not opening the jawbones of specimens to find the impacted tooth stuck in the jaw.[40]

In the late 19th and early 20th centuries, the collision of sterile technique, anaesthesia and radiology made routine surgery on the wisdom teeth possible. John Tomes's 1873 text A System of Dental Surgery describes techniques for removal of "third molars, or dentes sapientiæ" including descriptions of inferior alveolar nerve injury, jaw fracture and pupil dilation after opium is placed in the socket.[41] Other texts from about this time speculate on their de-evolution, that they are prone to decay and discussion on whether or not they lead to crowding of the other teeth.[42]

References

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[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Impacted wisdom teeth

View on Grokipedia
from Grokipedia
Impacted wisdom teeth, also known as impacted third molars, are the last set of molars that fail to fully erupt through the into their proper position in the , typically occurring between the ages of 17 and 25 due to insufficient space, obstruction by other teeth, or abnormal angulation such as horizontal or vertical impaction. These teeth, which evolved in humans for grinding plant-based diets but are now often vestigial in modern populations with softer foods, can remain partially or fully embedded in the bone or , affecting up to 80% of young adults in with at least one impacted wisdom tooth, and showing a prevalence of 72% for lower wisdom teeth in Swedish individuals aged 20-30. The primary causes of impaction stem from evolutionary and anatomical factors, including a smaller modern size relative to earlier ancestors, leading to where the teeth lack the necessary room to emerge upright. Additional contributors include physical barriers from adjacent second molars or , as well as atypical tooth positioning that prevents normal eruption. Risk factors are more pronounced in individuals with congenitally small s or crowded , and impactions are more common in the lower than the upper. While many cases are , particularly if fully impacted and unerupted, others manifest with noticeable signs such as localized pain or tenderness in the and gums, swelling, redness, (halitosis), an unpleasant taste in the mouth, difficulty opening the mouth fully (), prolonged headaches, or visible gaps between teeth. Complications from untreated impacted wisdom teeth can significantly impact oral health, including the development of (inflammation around a partially erupted tooth), recurrent infections, formation, and chronic discomfort. These teeth may also promote plaque accumulation and , with studies showing probing depths greater than 5 mm in 25% of asymptomatic cases, alongside increased risk of caries or root resorption in adjacent second molars. More severe issues include damage to surrounding and soft tissues or misalignment () of other teeth. Overall, impacted wisdom teeth represent a common dental concern, with extraction rates around 4 per 1,000 person-years in regions like , underscoring their .

Anatomy and Classification

Wisdom Teeth Overview

Third molars, commonly known as wisdom teeth, are the last set of to develop and erupt, typically emerging between the ages of 17 and 25 years, though variations can occur. Most individuals possess four third molars—two in the maxillary (upper) and two in the mandibular (lower) —positioned at the posterior end of the , immediately distal to the second molars. Their development begins , with starting around ages 7 to 10, followed by a prolonged maturation period that aligns with their late eruption timing. In normal eruption, third molars follow an upright path through the alveolar bone, emerging into the oral cavity to align with the opposing , where they contribute minimally to mastication in modern humans due to evolutionary reductions in jaw size and dietary shifts toward softer foods. The crowns of third molars exhibit variable shapes, often square or triangular with irregular occlusal surfaces featuring multiple cusps adapted for grinding, though smaller and less defined than those of anterior molars. Root morphology is complex and highly variable: maxillary third molars typically have three roots (two buccal and one palatal), which may be separate or fused, while mandibular third molars usually feature two roots (mesial and distal) that can diverge or fuse, occasionally forming C-shaped configurations. These roots are in close proximity to adjacent structures, such as the second molars anteriorly and the canal in the , which runs inferiorly along the root apices. From an evolutionary perspective, third molars represent vestigial structures inherited from ancestral hominins with larger jaws suited for coarse, unprocessed diets; in contemporary humans, reduced mandibular dimensions often limit their functional integration, sometimes resulting in incomplete eruption known as impaction.

Types of Impaction

Impacted wisdom teeth, or third molars, are classified primarily by their angulation relative to the second molar, depth within the bone, and degree of eruption, which helps assess surgical complexity and potential complications. Angulation is determined using Winter's classification system, introduced in the early , which categorizes the tooth's inclination to the long axis of the adjacent second molar. Under Winter's classification, vertical impactions occur when the third molar is aligned parallel to the second molar, allowing potential eruption if space permits; these are the most common in the maxilla, comprising about 56.5% of cases there. Mesioangular impactions, where the tooth tilts forward (mesially) at 11° to 79° toward the second molar, are the most prevalent overall, especially in the mandible, accounting for 40-50% of impactions. Horizontal impactions feature the tooth lying parallel to the occlusal plane, often at a 90° angle, making extraction more challenging due to proximity to the second molar roots. Distoangular impactions tilt backward (distally) at 80° to 100°, frequently seen in the maxilla at around 31.9%. Inverted impactions, where the tooth is upside down, and buccolingual impactions, tilted toward the cheek or tongue, are rarer variants. Depth and position are classified using the Pell-Gregory system, developed in , which divides impactions into vertical depth (Classes 1, 2, or 3) and horizontal position (A, B, or C). Class 1 indicates the third molar's occlusal surface is at or above the second molar's level; Class 2 places it between the occlusal and cervical lines; and Class 3 positions it below the cervical line, often requiring more invasive surgery. Horizontally, position A aligns the tooth with the second molar, B places it posterior but overlapping, and C situates it mostly within the mandibular ramus. This system is widely used for mandibular third molars, with Class 2B a frequently observed configuration in various populations. Impactions are further categorized as partial or complete based on eruption status. Partial impactions allow partial emergence through the gum, while complete impactions prevent any eruption. Regarding tissue coverage, impactions involve only gingival covering without obstruction; partial bony impactions feature partially embedded in but visible through ; and full bony impactions encase the entire in , often necessitating surgical exposure. These distinctions influence treatment , with full bony types posing higher risks. Mandibular third molars exhibit higher impaction rates than maxillary ones, with studies reporting mandibular impactions comprising approximately 60% of cases compared to 40% in the , attributed to narrower space and denser in the lower . Maxillary impactions tend toward vertical or distoangular orientations, while mandibular ones favor mesioangular or horizontal.

Etiology and

Causes and Risk Factors

The primary cause of impacted wisdom teeth is insufficient space within the to accommodate the eruption of the third molars, often resulting from the evolutionary reduction in human size over time. This shrinkage is attributed to dietary shifts in modern humans, where softer, processed foods and the use of cooking tools reduced the need for robust , leading to smaller jaws compared to ancestral populations who consumed tougher, unprocessed diets that promoted larger growth. Genetic factors play a significant role in the development and impaction of wisdom teeth, with additive genetic influences accounting for up to 88% of variation in tooth angulation and 71% in eruption level. Inheritance patterns contribute to differences in morphology and tooth positioning, increasing susceptibility to impaction. Certain genetic syndromes, such as , are associated with dental anomalies including microdontia, , smaller maxillary dimensions, and retained teeth that can contribute to crowding. Obstructive factors further contribute to impaction by physically hindering tooth emergence, including crowding from adjacent second molars, abnormal eruption paths, or the presence of supernumerary teeth that occupy space in the jaw. Several risk factors heighten the likelihood of impaction, with the condition most commonly manifesting during late adolescence when third molars typically attempt to erupt between ages 17 and 25. Females face a slightly elevated risk compared to males, with an odds ratio of approximately 1.17, possibly due to generally smaller jaw sizes. Prevalence varies by ethnicity, showing higher rates in certain populations such as Asians and Caucasians relative to those of African descent, influenced by genetic variations in jaw development and tooth eruption timing. Environmental influences, particularly poor nutrition during childhood, also affect formation; for instance, deficiencies in are linked to smaller, irregularly shaped jaws and wider tooth roots, limiting space for teeth.

Pathophysiological Processes

Impacted teeth, or third molars, initiate pathophysiological processes primarily through mechanical pressure and secondary inflammatory responses. The surrounding an unerupted third molar can undergo pathological expansion when fluid accumulates between the reduced enamel epithelium and the crown, forming a . This expansion exerts continuous pressure on surrounding bone and adjacent teeth, promoting localized via activation and remodeling. In cases of partial eruption, the operculum (overlying flap) traps food debris and bacteria, facilitating microbial invasion and leading to acute or chronic inflammation known as . This condition involves an inflammatory cascade triggered by bacterial pathogens, resulting in release (e.g., IL-1, TNF-α) and infiltration, which can extend to periodontal tissues and cause localized periodontitis. Dentigerous cysts associated with impacted third molars are relatively uncommon, with cysts and tumors occurring in approximately 2-6% of cases, as evidenced by radiographic and histopathological studies, and arise from the separation of the follicle from the crown due to inflammatory or developmental factors. These cysts further amplify and may displace adjacent structures, including the second molar. Bacterial proliferation in pericoronal pockets also heightens the risk of cyst transformation or secondary infections, perpetuating tissue breakdown through enzymatic degradation and immune-mediated responses. Proximity of the impacted tooth to the (IAN) within the can induce compressive neuropathy, potentially leading to via direct mechanical irritation or ischemic effects from vascular compression, even prior to any intervention. The inflammatory processes extend to adjacent teeth, where chronic pressure from the impacted third molar induces external root resorption of the second molar through odontoclastic activity and chronic low-grade inflammation. This resorption involves the release of pro-inflammatory mediators that erode and , compromising tooth integrity. Over time, these changes contribute to altered occlusion by shifting dental alignment and increasing biomechanical stress on the (TMJ), potentially exacerbating joint loading and degenerative remodeling in susceptible individuals.

Clinical Presentation

Signs

Impacted wisdom teeth may present with observable gum swelling or tenderness over the affected area, often due to the formation of an operculum, which is the soft tissue flap partially covering the erupting tooth. This swelling can be localized and erythematous, indicating inflammation around the partially erupted crown. Visible partial eruption of the tooth may also occur, creating gingival pockets where food debris becomes trapped, promoting bacterial accumulation and potential infection. Radiographic imaging reveals key objective indicators, such as the tooth's abnormal angulation or horizontal positioning relative to the adjacent second molar, and close proximity of the roots to vital structures like the . These findings are typically identified on panoramic radiographs, showing the tooth embedded within the bone or soft tissue without full eruption. Secondary signs include the development of caries or external root resorption on the distal aspect of the adjacent second molar, resulting from prolonged contact or food impaction facilitating decay. Additionally, may disclose shadows, such as well-defined radiolucencies surrounding the crown indicative of dentigerous cysts, which arise from pathological fluid accumulation around the unerupted tooth. Many cases of impacted wisdom teeth remain and are detected incidentally during routine dental examinations or unrelated , highlighting the importance of proactive screening to identify subclinical impactions before complications arise. These signs often stem from underlying pathophysiological processes like insufficient arch space and abnormal eruption trajectories that hinder proper tooth alignment.

Symptoms

Impacted wisdom teeth often present with subjective symptoms that significantly affect daily activities and , stemming from pressure on adjacent structures or secondary infections. is the most common complaint, ranging from a persistent dull ache to intense, throbbing discomfort localized to the posterior . This pain frequently radiates to the , , or face due to shared pathways, and may intensify with jaw movement or chewing. Patients commonly report functional limitations, including difficulty chewing hard or tough foods, restricted mouth opening known as , and jaw stiffness that hinders normal activities. Halitosis and an unpleasant taste in the mouth often arise from food debris trapped around the partially erupted tooth, exacerbating discomfort. Headaches, particularly tension-type, can occur from muscle strain in the temporomandibular region, while in the upper may occasionally mimic sinus congestion or pressure. Acute episodes, such as from bacterial invasion of the gum flap, lead to more severe symptoms including fever, heightened pain around the affected area, a sensation of pus discharge or drainage, and discomfort when swallowing. These recurrent infections can disrupt sleep, eating, and , profoundly impacting well-being. In contrast, many impacted wisdom teeth remain chronic and minimally symptomatic, with many cases asymptomatic or causing only mild, intermittent symptoms, allowing patients to function without noticeable issues.

Diagnosis and Screening

Diagnostic Methods

Diagnosis of impacted wisdom teeth typically begins with a thorough clinical examination to assess the presence and extent of impaction. This involves a detailed history taking regarding dental symptoms and general health, followed by visual inspection and palpation of the posterior oral cavity to identify swelling, tenderness, or partially erupted teeth. Probing of the gingival tissue, particularly the distal aspect of the adjacent second molar and any operculum covering the wisdom tooth, helps determine the degree of eruption, pocket depth, and potential communication with the oral cavity, which may indicate infection or food impaction. Imaging plays a central role in confirming impaction and evaluating its anatomical relationships. Panoramic radiographs, also known as orthopantomograms (OPG), provide an initial two-dimensional overview of the wisdom teeth's position relative to adjacent structures, including the and , allowing visualization of impaction type and potential complications like root resorption. For more complex cases, such as those with suspected proximity to the or sinus involvement, cone-beam computed tomography (CBCT) is recommended, offering three-dimensional for precise nerve mapping and assessment of bone morphology with lower radiation exposure than traditional CT. During diagnosis, classification systems are employed to gauge the complexity of impaction and predict surgical difficulty. The Pederson scale, based on radiographic assessment of tooth angulation (vertical, horizontal, mesioangular, distoangular, or inverted) and depth of impaction relative to the occlusal plane, categorizes cases as easy, moderately difficult, or very difficult, aiding in treatment planning. Recent advancements incorporate (AI)-supported tools to enhance diagnostic accuracy from radiographs. AI models, such as those using frameworks like YOLO11 on panoramic images, predict extraction difficulty by classifying impactions according to scales like Pederson, achieving accuracies exceeding 85% in identifying high-risk cases as of 2024. These tools analyze features like root morphology and nerve proximity, supporting clinicians in high-volume settings. In rare instances, where imaging suggests associated such as cysts or tumors (occurring in approximately 2-6% of cases), a may be performed to confirm the diagnosis. This involves excisional or incisional sampling of the lesion during or prior to extraction, with histopathological analysis to rule out odontogenic keratocysts or ameloblastomas.

Screening Recommendations

Screening for impacted wisdom teeth typically involves routine clinical evaluation and radiographic imaging to identify potential impaction before symptoms arise, with the American Association of Oral and Maxillofacial Surgeons (AAOMS) recommending assessment by an oral and maxillofacial surgeon by young adulthood, typically in the late teens to early 20s, using panoramic X-rays to visualize tooth position, development, and proximity to adjacent structures. This timing allows for proactive management, as wisdom teeth often begin erupting in late , and early detection can inform decisions on retention or removal prior to root completion, which occurs around age 18 to 25. Individuals at higher risk for impaction, such as those with insufficient space, physical blockages from adjacent teeth, or pre-existing crowding, warrant earlier or more targeted screening; orthodontic patients undergoing treatment for misalignment and those with congenital conditions like small or supernumerary teeth are particularly vulnerable, as these factors increase the likelihood of eruption failure. For patients electing retention of asymptomatic third molars, AAOMS guidelines advise ongoing monitoring with annual clinical examinations and periodic radiographic imaging during young adulthood to detect emerging , such as caries, , or formation. Early screening proves cost-effective by mitigating severe complications like , development, or damage to neighboring teeth, potentially lowering long-term treatment expenses through simpler interventions when issues are identified proactively rather than reactively. Recent advancements from 2023 to 2025 include the integration of into dental software for automated analysis of panoramic radiographs, enabling precise detection of wisdom teeth positions and extraction difficulty assessments with high accuracy (over 95% in for extraction difficulty).

Treatment Approaches

Conservative Management

Conservative management is the preferred approach for impacted wisdom teeth that are and free of associated , such as , caries, or formation, which applies to the majority of cases where no immediate intervention is warranted. This strategy aims to avoid unnecessary surgical risks while preserving the teeth through proactive monitoring and preventive care. Observation involves regular clinical examinations and radiographic evaluations to detect any emerging issues early, with follow-up visits typically occurring every 6 to 12 months depending on risk factors like position and age. are educated on recognizing symptoms such as pain or swelling, and imaging, such as panoramic X-rays, helps assess changes in position, root development, or proximity to adjacent structures. The 2024 AAOMS emphasizes for retention with active monitoring in cases. Maintaining optimal is essential to prevent or periodontal issues around partially erupted teeth; this includes gentle brushing, flossing, and irrigation of gingival pockets to remove debris, along with the use of antimicrobial rinses like 0.12% gluconate twice daily for short-term application when is present. These measures reduce bacterial accumulation and promote gingival health without invasive procedures. For mild discomfort in borderline cases, over-the-counter non-steroidal drugs (NSAIDs), such as ibuprofen at 400-600 mg every 6-8 hours as needed, provide effective and effects. Antibiotics, such as amoxicillin, are reserved exclusively for acute infections like and should not be used prophylactically in asymptomatic scenarios to avoid resistance. In select rare situations, orthodontic assistance may be considered to create eruptive space through appliances or extractions of other teeth, potentially aiding uprighting of the impacted third molar, though this is infrequently feasible due to the posterior location and limited space availability.

Surgical Extraction

Surgical extraction of impacted wisdom teeth is indicated for cases where conservative management fails or when symptoms such as , , or cyst formation arise from the impaction. This procedure is more complex and thus more expensive than the removal of fully erupted wisdom teeth, which typically involves simple extraction without incisions or bone removal. Preoperative assessment includes a thorough evaluation of the patient's to identify high-risk individuals, such as those with prosthetic heart valves, prior , certain congenital heart defects, or cardiac transplants with valvular disease, who may require prophylaxis to prevent . For these patients, a single dose of amoxicillin (2 g orally for adults, 50 mg/kg for children) is administered 30-60 minutes prior to the procedure; alternatives like (500 mg for adults, 15 mg/kg for children) are used for penicillin-allergic individuals. Radiographic imaging, such as panoramic X-rays or cone-beam computed tomography, guides the planning to assess impaction type, root morphology, and proximity to adjacent structures like the . The procedure typically begins with anesthesia administration, tailored to complexity and patient anxiety: local anesthesia numbs the area while keeping the patient awake; sedation via intravenous medication induces relaxation and ; or general anesthesia renders the patient unconscious, often with an endotracheal tube for airway protection in extensive cases. A mucoperiosteal flap is then elevated using a to expose the impacted and overlying . Bone removal follows with a high-speed handpiece and or to access the crown and roots, minimizing damage to surrounding structures. For horizontally or deeply impacted teeth, sectioning the into segments—such as separating the crown from roots or dividing the mesiodistally—facilitates piecemeal removal with elevators and , reducing force on adjacent teeth and . The socket is irrigated to remove debris, and the flap is sutured if necessary, with placed to promote and clot formation. Advancements in minimally invasive techniques have enhanced precision and reduced tissue trauma. Piezosurgery employs ultrasonic vibrations to selectively cut bone while sparing soft tissues, resulting in significantly lower postoperative , , and compared to conventional rotary instruments. Laser-assisted extraction, using Er:YAG or similar wavelengths, allows for precise and with minimal thermal damage, leading to reduced , , and muscle in the early postoperative period. Emerging robotic assistance, such as digital robot-guided systems, enables minimally invasive approaches for complex impactions by providing haptic feedback and real-time navigation, improving accuracy in bone removal and tooth sectioning while minimizing iatrogenic injury. The procedure is performed on an outpatient basis and typically lasts 20-60 minutes per tooth, depending on impaction severity and whether multiple teeth are addressed simultaneously.

Alternative Procedures

is a specialized surgical technique involving the intentional partial removal of only the crown of an impacted mandibular third molar, leaving the roots to minimize the risk of (IAN) injury when the roots are in close proximity to the nerve. This procedure is particularly indicated for cases where cone-beam computed (CBCT) reveals root apices within 1 mm of the IAN or direct superimposition, and the pulp remains vital to reduce postoperative risk. Unlike standard surgical extraction, serves as a conservative alternative in high-risk scenarios. Recent meta-analyses indicate that achieves an approximately 84% reduction in IAN injury risk compared to full extraction, with transient neuropathy rates as low as 0.59% and no reported permanent IAN damage in multiple studies. A 2025 retrospective analysis further confirms its safety, reporting low complication rates and neurovascular injury incidence below 5%. Outcomes of coronectomy include root migration in 30% to 85% of cases, typically occurring within the first 6 to 12 months postoperatively, which often directs roots away from the canal and may necessitate follow-up and potential reintervention in about 3% to 12% of patients for symptoms like or . Success rates for the procedure exceed 90%, with intra-operative failures around 3.6%, emphasizing the need for meticulous sectioning and pulp extirpation to prevent retained root complications. Enucleation represents another alternative for managing s associated with impacted wisdom teeth, such as dentigerous or epidermoid s, where the cyst lining is surgically removed without necessarily extracting the entire if the impacted molar's position allows preservation. This approach is suitable for smaller s or those not aggressively encroaching on vital structures, aiming to decompress and resolve the while monitoring the 's . For instance, in cases of intraosseous epidermoid s linked to impacted mandibular third molars, complete enucleation via an intraoral approach has demonstrated effective resolution without full odontectomy, preserving bone integrity. Orthodontic eruption aids offer a rare, non-extraction option for select impacted wisdom teeth that are partially erupted or favorably positioned, utilizing brackets, chains, or braces to apply guided traction and facilitate eruption into the . This method is indicated when the tooth has sufficient space and vitality, often combined with surgical exposure to expose for bonding. Such techniques, though more commonly applied to canines, have been adapted for third molars in younger patients to avoid impaction-related complications like resorption of adjacent teeth. Success depends on early intervention and orthodontic planning, with follow-up to ensure proper alignment and prevent relapse.

Recovery, Risks, and Complications

Recovery from impacted wisdom teeth extraction typically involves a structured postoperative period focused on minimizing discomfort and promoting . Patients are advised to rest on the day of and gradually resume normal activities the following day, while avoiding strenuous exercise for at least one week to prevent complications such as increased bleeding or swelling. Swelling often peaks within 48 hours post-procedure and begins to subside over the next 2-3 days, with the application of ice packs intermittently for the first 24-48 hours recommended to reduce and pain. After the procedure, patients should avoid eating for the first 2 hours post-extraction to allow initial clot formation. Thereafter, a soft, cool diet is recommended for the first few days to promote healing and avoid complications like dry socket. For the first 24-48 hours, focus on liquids and very soft foods at room temperature or cool, including water, apple juice, milkshakes or smoothies (without using a straw), yogurt, pudding, applesauce, ice cream, Jell-O, mashed potatoes, scrambled eggs, cooled broth-based soups, porridge, and noodles. Chewing should be avoided on the extraction side. Foods and habits to avoid during this initial period include hot foods and drinks, spicy or acidic foods, hard or crunchy items (such as nuts, chips, or popcorn), sticky foods (such as caramel or gum), alcohol, carbonated beverages, using straws, and smoking or tobacco products. Cool foods like ice cream may be consumed in moderation to help stop bleeding and reduce swelling. From days 3 to 7, patients can gradually introduce softer solid foods as tolerated, such as pasta, soft bread, cooked vegetables, soft fruits (e.g., bananas), fish, well-cooked rice, and fluffy pancakes (prepared moist, cut into small pieces to minimize chewing, and initially avoiding sticky toppings such as syrup to prevent irritation or dislodging blood clots). Patients should resume their normal diet as comfort allows, usually within 1-2 weeks, but continue to avoid chewing directly on the surgical site. Staying hydrated and consuming nutritious foods support recovery. Always follow the specific postoperative instructions provided by the oral surgeon. To manage potential food particles in the extraction socket, patients are advised to gently rinse with warm saltwater after eating, starting after the first 24 hours. If particles remain stuck after a day or two of gentle rinsing, or if signs of infection such as increasing pain, swelling, bad taste, odor, or other symptoms appear, contact an oral surgeon or dentist for proper cleaning or evaluation. Full generally occurs within 1-2 weeks, though complete bone regeneration in the socket may take several months. Several risks are associated with the procedure, including dry socket, , and . Dry socket, or , arises when the blood clot at the extraction site dislodges or fails to form, exposing bone and ; it affects approximately 2-5% of extractions and is more prevalent following wisdom teeth removal, particularly in the lower jaw. Postoperative occurs in about 1-5% of cases, manifesting as fever, persistent swelling, or , and is often managed with antibiotics if it develops. , primarily to the inferior alveolar or lingual nerves, can lead to temporary (numbness or tingling) in the lip, tongue, or chin, with rates ranging from 0.5-5%; most cases resolve within weeks to months, though permanent damage is rare at under 1%. Complications may include hemorrhage, sinus communication, and delayed healing, particularly in certain patient groups. Minor bleeding is common immediately after surgery and typically resolves with pressure application, but excessive hemorrhage is uncommon and requires prompt medical attention. For maxillary extractions, oroantral communication—a small opening between the mouth and maxillary sinus—can occur due to the proximity of tooth roots to the sinus floor, potentially leading to sinus infections if not properly managed; it often heals spontaneously but may necessitate closure in larger cases. Smoking and vaping significantly delay healing by constricting blood vessels and increasing dry socket risk, with patients advised to abstain for at least 72 hours and ideally longer to support optimal recovery. For individuals seeking alternatives to vaping post-extraction, those using cannabis or THC should consider edibles, sublingual tinctures, or topicals to avoid mouth suction and heat that could dislodge the blood clot or cause irritation. For nicotine users, nicotine patches may serve as a safer option than vaping, though nicotine can slightly delay healing by reducing blood flow; consultation with a healthcare provider is recommended. Mitigation strategies emphasize and advanced techniques to reduce anxiety and adverse events. Improved options, such as infusions administered via intravenous routes, enhance patient comfort and minimize movement during , thereby lowering the risk of intraoperative complications like nerve trauma. Long-term complications are infrequent but can include or (TMJ) issues. , a deep , is a rare occurring in less than 1% of cases, often linked to untreated or immunocompromise, and may require prolonged antibiotic therapy or surgical . TMJ disorders, such as pain or dysfunction, can occasionally arise from surgical trauma or preexisting conditions exacerbated by the procedure, though they affect a small minority and are typically managed conservatively.

Treatment Controversies

The debate surrounding prophylactic removal of impacted wisdom teeth centers on whether cases should be extracted to avert potential future complications. The American Association of Oral and Maxillofacial Surgeons (AAOMS) advocates for early evaluation and often recommends removal of asymptomatic third molars, citing risks such as formation, , and damage to adjacent teeth if left in place. In contrast, the UK's National Institute for Health and Care Excellence (NICE) guidelines explicitly oppose routine prophylactic extraction of disease-free impacted wisdom teeth, arguing that the procedure's risks outweigh benefits in the absence of symptoms, and recommending monitoring instead. This divergence reflects differing interpretations of long-term risks, with AAOMS emphasizing preventive intervention based on observed complication rates in retained teeth. Timing of intervention remains contentious, particularly regarding optimal age. Proponents of early removal suggest performing extractions before age 25, when are less fully developed and jawbone is lower, thereby reducing risks of complications like injury, which occurs in up to 8% of cases in older patients. Conversely, critics argue for delaying until manifests, as premature may expose young patients to unnecessary and surgical risks without guaranteed benefits. Recent studies highlight evidence gaps in predicting outcomes for impactions. Analyses from 2023 to 2025 indicate low-certainty evidence linking retained third molars to increased risks, with many cases—potentially over half—remaining stable over decades under monitoring, challenging assumptions of inevitable progression. These findings underscore the need for individualized rather than blanket policies. Ethical concerns arise from potential overtreatment, including inadequate and substantial economic burdens. Patients may receive unsubstantiated claims about future risks, undermining valid consent and exposing them to avoidable harms like or . In the , widespread prophylactic extractions contribute to high healthcare expenditures, with estimates suggesting billions in annual costs for procedures that may not prevent . Globally, approaches vary: the favors aggressive removal, aligning with AAOMS, while European guidelines, influenced by , prioritize conservative management to minimize unnecessary interventions.

Outcomes and Epidemiology

Prognosis

The prognosis for impacted wisdom teeth varies significantly depending on whether they are left untreated or managed through extraction. When left untreated, approximately 25% of cases develop periodontal , such as pocket depths of 5 mm or greater on adjacent second molars, within about 5 years, potentially progressing to more severe issues like cysts or caries in the surrounding structures. Cysts, though less common (with incidences ranging from 2% to 6.2% across studies), can form around impacted teeth and lead to destruction if undetected. Overall, untreated impactions carry a notable of evolving into symptomatic conditions, including infections and decay, emphasizing the importance of monitoring. Surgical extraction generally yields a favorable , with success rates exceeding 95% in uncomplicated cases. Post-extraction outcomes contribute to improved long-term oral health by preventing recurrent issues like or damage to adjacent teeth, with enhancements observed in the majority of patients through reduced and better hygiene access. Pain relief is particularly pronounced in symptomatic individuals, with 90-95% reporting significant alleviation following the procedure. Several patient-specific factors influence . Age plays a critical role, as extractions after 25 years are associated with higher complication risks and poorer recovery compared to earlier interventions in late adolescence or early adulthood. substantially worsens outcomes by more than tripling the odds of dry socket and elevating risk, thereby delaying healing. Patient compliance with postoperative care, such as adhering to instructions, further enhances recovery and minimizes complications like . Recent advancements, including AI-driven tools for preoperative , are improving prognostic accuracy and surgical planning for impacted third molar extractions, with some models achieving up to 98% accuracy in predicting outcomes and thereby elevating overall success rates. These technologies help tailor interventions, reducing complications and supporting better long-term results as of 2025.

Epidemiological Patterns

Impacted third molars, commonly known as wisdom teeth, affect a substantial portion of the global population. A 2024 and of 98 studies involving 183,828 individuals reported a pooled of 36.9% (95% CI: 33.1–40.7%) for at least one impacted third molar per subject, with a higher tooth-level of 46.4% (95% CI: 36.7–56.1%). This condition is more prevalent in certain regions, with rates reaching 43.1% in and 36.5% in the , compared to 24.5% in and 33.5% in . The higher incidence in populations with smaller sizes, often linked to modern dietary patterns favoring softer foods, contributes to these geographic disparities. Demographically, impacted third molars are more common in the than the , with mandibular impactions accounting for approximately 57% of cases across multiple studies. peaks in the 17–25 age group, where up to 61% of individuals may have at least one impacted , declining with advancing age as eruption or extraction occurs. Females exhibit a slightly higher of 1.173 (95% CI: 1.021–1.347) for impaction compared to males, potentially due to differences in development. Ethnic variations further influence patterns, with higher rates observed in Asian populations (43.1%) and lower in European groups (24.5%), reflecting genetic and dietary influences on morphology. Over time, the prevalence of impacted wisdom teeth has increased due to evolutionary dietary shifts toward processed, softer foods that result in reduced jaw growth and space for eruption. This trend is more pronounced in developed countries with such dietary habits, exacerbating impaction rates compared to populations with traditional harder diets. Socioeconomic factors play a critical role, as lower status is associated with delayed treatment and higher complication rates from untreated impactions, such as infections or damage to adjacent teeth; improved access to dental care mitigates these risks by enabling timely interventions. Between 2023 and 2025, advancements in , including AI-assisted radiographic analysis, have led to increased detection of asymptomatic cases, with studies showing significant improvements in identifying impacted teeth on panoramic images.

Historical and Contemporary Developments

Historical Evolution

The recognition of dental issues related to third molars, now known as wisdom teeth, traces back to ancient civilizations where jaw pain and eruption difficulties were documented. In , the , composed around 1550 BCE, describes various oral ailments including treatments for swollen gums, abscesses, and jaw pain through herbal remedies and incantations, indicating early awareness of conditions that could stem from impacted or erupting teeth. Similarly, the Greek physician (c. 460–370 BCE) referenced third molars in his writings, terming them sophronisteres—meaning "teeth of prudence"—due to their emergence during late adolescence or early adulthood, a period associated with gaining wisdom. These ancient accounts highlight symptomatic management rather than surgical intervention, reflecting limited anatomical understanding at the time. The term "wisdom teeth" itself emerged in 17th-century , derived from the Latin dentes sapientiae ("teeth of wisdom"), a of linking third molar eruption to maturity and intellectual growth. By the , , often called the father of modern dentistry, advanced extraction techniques in his 1728 Le Chirurgien Dentiste, describing methods for removing problematic teeth, including those with impaction, using and elevators to address pain and infection. This marked a shift toward systematic surgical approaches, though without imaging, procedures relied on clinical examination alone. The late brought radiographic diagnosis following Wilhelm Röntgen's 1895 discovery of X-rays; by 1896, the first dental radiographs were produced, allowing visualization of impacted third molars and their relation to adjacent structures, fundamentally improving preoperative planning. In the mid-20th century, particularly after , the rise of correlated with a surge in prophylactic removal of impacted wisdom teeth, driven by concerns over crowding and misalignment in modern diets with softer foods. Key milestones included the 1933 Pell-Gregory classification system, which categorized impactions by depth (relative to the second molar) and position (anteroposterior to the ramus), aiding surgeons in predicting extraction difficulty. During the 1980s, the American Association of Oral and Maxillofacial Surgeons (AAOMS) initiated efforts toward standardized guidelines, including support for the first major on third molar management, promoting evaluation and removal based on risk factors like pathology and age. These developments established foundational practices for contemporary care.

Recent Advances

Recent advances in the management of impacted wisdom teeth have focused on integrating advanced imaging, , and minimally invasive surgical technologies to improve precision, reduce complications, and enhance patient outcomes. Cone-beam computed tomography (CBCT) has become widespread for preoperative planning, allowing detailed three-dimensional visualization of tooth position relative to vital structures like the . Combined with of patient-specific surgical guides, this approach enables precise osteotomies and minimizes bone removal during extraction, leading to shorter operative times and better preservation of surrounding tissues. For instance, a technical report demonstrated successful use of CBCT-derived 3D-printed guides in deeply impacted mandibular third molar cases, resulting in timesaving procedures and complete bone reossification within one year. Artificial intelligence (AI) applications have emerged as tools for predicting extraction difficulty, aiding clinicians in risk stratification and treatment planning. Machine learning models trained on panoramic radiographs can classify impaction types and forecast surgical challenges with high accuracy. A 2025 study developed an AI tool using YOLO11 sub-models that achieved over 90% accuracy in assessing mandibular third molar extraction difficulty, facilitating personalized surgical strategies and reducing unanticipated complications. These models integrate factors such as angulation, depth, and morphology to provide objective predictions, supporting evidence-based decision-making. Surgical technologies have advanced with the adoption of piezosurgery and robotic assistance, enhancing safety and efficiency. Piezosurgery employs ultrasonic vibrations for selective bone cutting, sparing soft tissues and reducing postoperative pain, swelling, and compared to traditional rotary instruments. A 2024 reported significantly lower pain scores and faster recovery in piezosurgery-assisted impacted lower third molar removals. Robotic systems, such as those using digital navigation, offer millimeter-level precision for minimally invasive extractions. In a 2024 study, robot-assisted techniques for impacted teeth extraction shortened procedure duration and lowered tissue trauma. Pharmacological innovations include enhanced recovery protocols incorporating biologics to accelerate healing. (PRP) and other biologic adjuncts applied at extraction sites promote faster closure and regeneration while decreasing risk. A 2024 review highlighted PRP's role in reducing postoperative rates and enhancing formation following removal, integrating into multimodal analgesia regimens for optimized recovery. Ongoing research, including 2025 longitudinal studies, reinforces the viability of conservative management for low-risk impacted wisdom teeth cases. A and compared prophylactic extraction to observation, finding no significant long-term benefits from routine surgery in patients, thus supporting to avoid unnecessary interventions. These findings align with updated guidelines emphasizing individualized approaches based on evidence from extended follow-up data.

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