Tohoku J. Exp. Med., 2003, 200 (2)

Influence of Angular Position and Degree of Impaction of Third Molars
on Development of Symptoms: Long-Term Follow-up
under Good Oral Hygiene Conditions

TAKASHI SASANO, NAOYUKI KURIBARA, MASAHIRO IIKUBO, ATSUSHI YOSHIDA,
SHIZUKO SATOH-KUIRIWADA, NORIAKI SHOJI and MAYA SAKAMOTO

Department of Oral Diagnosis and Radiology, Tohoku University Graduate School of Dentistry, Sendai 980-8575

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.

keywords —— third molar symptoms; criteria for third molar extraction; long-term follow-up

© 2003 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2003, 200, 75-83

Address for reprints: Takashi Sasano, Department of Oral Diagnosis and Radiology, Tohoku University Graduate School of Dentistry, 4-1 Seiryomachi, Aoba-ku, Sendai 980-8575, Japan.

e-mail: sasano@mail.cc.tohoku.ac.jp