Emphysema is caused by the invasion of air into the subcutaneous tissue and often occurs following the extraction of impacted mandibular third molars in the oral and maxillofacial region. In this study, we investigated the clinical characteristics of patients with subcutaneous emphysema that occurred during mandibular impacted wisdom tooth extraction. Twelve patients with emphysema that visited our department from July 2013 to June 2022 were included in the study. Analysis was conducted regarding the patients’sex, age, body mass index (BMI) and the disease's region, cause, detection, treatment, Winter and Pell-Gregory classification and spread into tissue spaces. There were six males and six females. The mean age was 27.5 (±9.6) years. The mean BMI was 19.5(±1.1) for males and 19.1（±1.4） for females. Six cases were associated with the mandibular right third molar, and six cases with the mandibular left third molar. The causes were high-speed air-driven handpieces in three cases and electric engine handpieces in nine cases (1:5 speed increasing contra-angle motor handpieces and straight motor handpieces). Emphysema was noticed by the surgeon in ten cases, and discovered via patient complaints in two cases. Emphysema occurred at the time of crown amputation in three cases, and it was detected after the tooth extraction was completed in nine cases. After the development of emphysema, all patients were treated with antimicrobial agents. The Winter and Pell-Gregory classifications were horizontal, and cases of ⅡA and ⅡB were common. Seven patients (58%) had mediastinal emphysema, and five patients (42%) had orbital emphysema. This study suggested that emphysema occurs regardless of gender, age and BMI. It was also found that emphysema spreads to a larger tissue space when an air-driven high-speed handpiece is used.
