Classification and Diagnosis - Teeth are classified as developing, erupted, embedded, or impacted. - Wisdom teeth are the most likely to become impacted. - Impacted wisdom teeth develop between the ages of 14 and 25. - Impacted wisdom teeth can be classified by direction, depth, available space for eruption, and the amount of soft tissue or bone covering them. - Classification helps estimate the risks and complications associated with wisdom teeth removal. - Impaction can be diagnosed clinically by assessing the angulation, depth, and eruption potential. - Panoramic radiographs or cone-beam CT scans are used to diagnose impaction when the tooth cannot be assessed clinically. - Predictors for impacted wisdom teeth include the ratio of space between the tooth crown length and available space, and the angle of the teeth compared to other teeth. - The ratio of space available to the length of the crown of the tooth is a reliable predictor of impaction. - Screening at a younger age may be necessary if the second molars fail to erupt. - Radiographs can be avoided if the majority of the tooth is visible in the mouth.

Signs, Symptoms, and Causes - Impacted wisdom teeth without communication to the mouth rarely have symptoms. - Impacted wisdom teeth that communicate with the mouth can cause pain, swelling, and bleeding. - Low-grade chronic periodontitis can occur on impacted wisdom teeth or the second molar. - Asymptomatic wisdom teeth can still be infected for many years before symptoms develop. - Symptoms of impacted wisdom teeth can include bad breath and bleeding from the gums. - Wisdom teeth become impacted when there is not enough room in the jaws for them to erupt. - Genetic predisposition plays a role in tooth impaction. - Jaw and tooth size, as well as tooth eruption potential, are influenced by genetics. - Some believe that a decrease in jaw size is due to modern diets that are softer and less coarse. - Insufficient room in the jaws leads to the wisdom teeth becoming impacted.

Complications and Treatment - Cysts or tumors can develop over time around impacted teeth. - Estimates suggest that the incidence of cysts or neoplasms around impacted teeth is around 3%, mostly seen in people under 40. - Pericoronitis, or infection of the gum tissue over the impacted tooth, is the most common pathology in partially impacted teeth in individuals over 20 years old. - Bacteria associated with infections include Peptostreptococcus, Fusobacterium, and Bacteroides. - Cavities on the wisdom tooth or adjacent second molar occur in 15% of people with retained wisdom teeth exposed to the mouth. - Roughly 25% of patients with retained, asymptomatic wisdom teeth have gum infections (periodontal disease). - Teeth with periodontal pockets greater than 5mm have tooth loss rates starting at 10 teeth lost per 1000 teeth per year. - Wisdom teeth removal is the most common treatment for impacted wisdom teeth. - The procedure can be simple or surgical, depending on the depth of impaction and angle of the tooth. - Pericoronitis can be treated with local cleaning, antiseptic rinse, and antibiotics if severe.

Historical Context and Medical Considerations - Wisdom teeth have been mentioned in ancient texts and works of philosophers, scientists, and dentists throughout history. - The management of impacted wisdom teeth became more routine with the development of sterile technique, radiology, and anaesthesia. - Plato, Hippocrates, Darwin, and early manuals of operative dentistry discussed wisdom teeth. - The late 19th and early 20th centuries saw advancements that allowed for the easier management of impacted wisdom teeth. - The understanding and treatment of impacted wisdom teeth have evolved over time. - ICD-10 Diagnosis Code K01.1 is used for impacted teeth. - NICE provides guidance on the extraction of wisdom teeth. - Impacted wisdom teeth can cause complications like nerve injury and jaw fracture. - Wisdom teeth can lead to crowding of other teeth. - Mandibular third molar impaction is classified in the literature. - John Tomes' 1873 text describes techniques for removal of wisdom teeth. - Techniques include descriptions of nerve injury, jaw fracture, and pupil dilation. - Other texts from the late 19th and early 20th centuries discuss de-evolution of wisdom teeth. - Evolution of surgical techniques for wisdom teeth removal.

Prognosis, Epidemiology, and Controversies - Risk of cyst or neoplasm forming in tissues around the tooth. - Chance of disease or symptoms increases with age. - 30% - 60% of people with previously asymptomatic impacted wisdom teeth will have them extracted due to symptoms or disease. - Extraction improves periodontal status of the second molar. - Benefit diminishes beyond the age of 25. - Missing third molars (excluding wisdom teeth) occur in 9-30% of populations. - Eruption rate of wisdom teeth in maxilla and mandible. - Frequency of impacted lower third molars in a Swedish study. - Frequency of retained impacted wisdom teeth without disease and symptoms. - Incidence of wisdom tooth removal in England and Wales. - Prophylactic extraction of third molars debated. - Surveillance as a management strategy for retained wisdom teeth. - Trigeminal nerve injuries following third molar removal. - Recommendations from organizations like NICE and American Public Health Association. - Coronectomy as an alternative management option for impacted wisdom teeth.