title: Influence of angular position and degree of impaction of third molars on development of symptoms: long-term follow-up under good oral hygiene conditions.
abstract: To determine the risk of developing symptoms due to the presence of maxillary and mandibular third molars, we analyzed a reliable population sample by age, and according to third-molar position and impaction level using long-term follow-up data under conditions of good oral hygiene. Of 308 graduates from our dental school, a total of 776 third molars were followed up for periods of 11 to 27 years by means of intraoral radiographs. The development of symptoms, the participant's age, and third-molar angular position and degree of impaction were investigated. For both maxillary and mandibular third molars, the risk of developing a symptom correlated neither with angular position nor with impaction level. The first symptom associated with a third molar developed most frequently in their 20's for both maxilla (16.2%) and mandible (17.5%), with the next highest frequency being in their 30's (12.6%, maxilla; 13.0%, mandible). The status of third molars shows no relation to the subsequent development of symptoms if good oral hygiene is maintained. The low rates of symptom-development do not support removal of asymptomatic third molars.
authors.affiliation: Department of Oral Diagnosis and Radiology, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan. sasano@mail.cc.tohoku.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasano
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Kuribara
authors.forename: Masahiro
authors.initials: M
authors.lastname: Iikubo
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshida
authors.forename: Shizuko
authors.initials: S
authors.lastname: Satoh-Kuiriwada
authors.forename: Noriaki
authors.initials: N
authors.lastname: Shoji
authors.forename: Maya
authors.initials: M
authors.lastname: Sakamoto
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008964:Molar, Third / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D009909:Oral Health; D009910:Oral Hygiene / Q000379:methods*; D010510:Periodontal Diseases / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D011859:Radiography; D014095:Tooth, Impacted / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery