Endo Saori, Sanpei Sugako, Ishida Rieko, Sanpei Shinya, Abe Ryota, Endo Toshiya
Orthodontic Dentistry, The Nippon Dental University Niigata Hospital, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.
Odontology. 2015 Jan;103(1):89-96. doi: 10.1007/s10266-013-0134-1. Epub 2013 Aug 29.
The purpose of this study was to investigate the patterns of third molar agenesis and incidence of agenesis of other permanent teeth in a Japanese orthodontic patient group. A total of 417 Japanese subjects (134 males and 283 females) with agenesis of one or more third molars were divided into four groups according to the agenesis pattern, and 874 other Japanese subjects (302 males and 572 females) without third molar agenesis were assigned to a control group. Panoramic radiographs and medical and dental records were used to examine for tooth agenesis. The Chi-square test and odds ratio were used to make statistical comparisons. The prevalence of third molar agenesis worked out at 32.3% with no statistically significant gender difference. A high prevalence rate of agenesis of third molars, unilateral or bilateral, could be considered characteristic of the Japanese orthodontic population. Significant increases in occurrence of oligodontia, and unilateral or bilateral agenesis of other teeth, including maxillary lateral incisors and maxillary and mandibular second premolars, were observed in all or almost all of the third molar agenesis groups, compared with the controls. A significantly increased prevalence rate of mandibular lateral incisor agenesis was observed in almost all of the third molar agenesis groups. The Japanese patients with third molar agenesis had a significantly increased occurrence of oligodontia, and unilateral or bilateral agenesis of maxillary and mandibular lateral incisors and second premolars, except for bilateral agenesis of mandibular lateral incisors.
本研究的目的是调查日本正畸患者群体中第三磨牙缺失的模式以及其他恒牙缺失的发生率。共有417名有一颗或多颗第三磨牙缺失的日本受试者（134名男性和283名女性）根据缺失模式分为四组，另外874名无第三磨牙缺失的日本受试者（302名男性和572名女性）被分配到对照组。使用全景X线片以及医疗和牙科记录来检查牙齿缺失情况。采用卡方检验和比值比进行统计学比较。第三磨牙缺失的患病率为32.3%，无统计学上的性别差异。第三磨牙单侧或双侧缺失的高患病率可被视为日本正畸人群的特征。与对照组相比，在所有或几乎所有第三磨牙缺失组中，观察到少牙畸形以及其他牙齿（包括上颌侧切牙和上颌及下颌第二前磨牙）单侧或双侧缺失的发生率显著增加。在几乎所有第三磨牙缺失组中，观察到下颌侧切牙缺失的患病率显著增加。有第三磨牙缺失的日本患者除下颌侧切牙双侧缺失外，少牙畸形以及上颌和下颌侧切牙及第二前磨牙单侧或双侧缺失的发生率显著增加。
