Abstract
Purpose: This study aimed to determine the reasons for the extraction of permanent teeth in the Kami-Ina Area, Nagano Prefecture, Japan.
Methods: Dentists belonging to the Kami-Ina Dental Association were asked to fill in a questionnaire when they extracted one or more permanent teeth during the 41-day period between June 27, 2016 and August 6, 2016. Items in the questionnaire on tooth extraction included gender, age, location of extracted tooth, main reasons for extraction structures in the oral cavity (attrition, wedge shaped defect (WSD), palatal torus and mandibular torus), oral hygiene condition, snacking habit, preference for sweets, dental check-up and pulp vitality. Logistic regression was used to compare the frequency distributions. Data analyses were performed using SPSS version 22 (IBM).
Results: Information on 1,010 extracted teeth from 804 patients was obtained; 549 teeth were removed from males, 457 teeth from females and 4 teeth from unknown gender. The largest number of teeth extracted was in patients aged over 75 years. A total of 265 teeth were extracted due to periodontal disease, 239 teeth due to third molar problems, 208 teeth due to apical periodontitis, 201 teeth due to fracture, and 84 teeth due to caries. The results of logistic regression analysis showed that tooth loss due to caries and periodontal disease had significantly lower odds for persons with good hygiene and that tooth loss due to caries and apical periodontitis had significantly lower odds for persons receiving regular dental check-ups. There was a significant association between structures in the oral cavity (attrition and WSD) and tooth loss due to fracture.
Conclusions: In this study, periodontal disease was the most frequent cause of tooth extraction, followed in order by third molar problems, apical periodontitis, tooth fracture, and caries. The results suggest that:
1. The risk of tooth extraction due to caries and periodontal disease is low when the periodontal condition is good.
2. The risk of tooth extraction due to caries and apical periodontitis is low with regular dental check-ups.
3. The risk of tooth extraction due to fracture increases with attrition and WSD.
