The Nippon Dental University Niigata Hospital, Niigata, Japan.
Angle Orthod. 2010 Nov;80(6):1002-9. doi: 10.2319/020210-69.1.
To explore the association of maxillary first molar agenesis with other dental anomalies in Japanese orthodontic patients.
A total of 32 subjects with one or two congenitally missing maxillary first molars (group M) were selected and divided into group 1M (12 subjects with one maxillary first molar missing) and group 2M (20 subjects with two maxillary first molars missing). As controls, 32 sex-matched subjects without agenesis of maxillary first molars were collected (group C). Panoramic and periapical radiographs, cephalograms, study models, intraoral photographs, and anamnestic data were used to identify anomalies of permanent teeth. Chi-square, Fisher's exact, Kruskal-Wallis, and Steel-Dwass tests were used to make statistical comparisons.
The prevalence rates of tooth agenesis other than the maxillary first molars and advanced tooth agenesis, with third molars excluded, were significantly higher in group 2M than in group C. The absence of second premolars was most common. The prevalence rate of third molar agenesis was significantly higher in groups 1M and 2M than in group C. The occurrence of symmetrical agenesis of the mandibular third molars was particularly notable in group 2M as compared to group 1M, in which maxillary third molar agenesis was predominant. There was no significant association between maxillary first molar agenesis and other dental anomalies, except for agenesis of teeth other than maxillary first molars.
Agenesis of maxillary first molars is associated with a higher prevalence of other permanent tooth agenesis and advanced tooth agenesis.
探讨上颌第一磨牙先天缺失与日本正畸患者其他牙齿异常的关系。
共选择 32 名上颌第一磨牙先天缺失 1 或 2 颗的患者（M 组），并将其分为 1M 组（12 名上颌第一磨牙缺失 1 颗）和 2M 组（20 名上颌第一磨牙缺失 2 颗）。另选 32 名性别匹配且无上颌第一磨牙缺失的患者作为对照组（C 组）。使用全景片和根尖片、头颅侧位片、模型、口内照片和病史资料来确定恒牙异常。采用卡方检验、Fisher 确切概率法、Kruskal-Wallis 检验和 Steel-Dwass 检验进行统计学比较。
2M 组除上颌第一磨牙以外的牙齿缺失和第三磨牙以外的恒牙缺失发生率明显高于 C 组。第二前磨牙缺失最为常见。1M 组和 2M 组第三磨牙缺失发生率明显高于 C 组。与 1M 组相比，2M 组下颌第三磨牙对称性缺失更为明显，而 1M 组上颌第三磨牙缺失更为常见。上颌第一磨牙缺失与除上颌第一磨牙以外的牙齿缺失以外的其他牙齿异常之间无显著相关性。
上颌第一磨牙缺失与其他恒牙缺失和恒牙缺失发生率增加有关。
