Peck S, Peck L, Kataja M
Department of Orthodontics and Dentofacial Orthopedics, Harvard School of Dental Medicine, Boston, Mass, USA.
Am J Orthod Dentofacial Orthop. 1996 Oct;110(4):441-3. doi: 10.1016/s0889-5406(96)70048-3.
Fifty-eight nonsyndromic North American white orthodontic patients with palatal displacement of one or both maxillary canine teeth were studied for associated tooth agenesis and peg-shaped maxillary lateral incisors. Agenesis of permanent teeth was identified by x-ray film analysis. Conical crown-size reduction (peg-shape anomaly) of the maxillary lateral incisor (l2) was determined by direct observation. Increases in absence of third molars and second premolars associated with the palatally displaced canine (PDC) anomaly were statistically very highly significant compared with normative data for tooth-agenesis prevalence. In contrast, the prevalence of l2 agenesis in the PDC sample showed no difference statistically compared with reference values. Reasons for this posterior site-specific suppression of tooth formation are not clear. The l2 peg-shape anomaly exceeded a 10-fold elevation in expression in the PDC sample, a very highly significant increase from normal prevalence. The findings are consistent with a hypothesis that the anomalies of tooth agenesis, tooth-size reduction, and PDC are biologic covariables in a complex of genetically related dental disturbances.
对58名北美非综合征性白人正畸患者进行了研究，这些患者存在一颗或两颗上颌尖牙腭侧移位的情况，研究其相关的牙齿缺失和上颌侧切牙呈钉状的情况。通过X线片分析确定恒牙缺失情况。通过直接观察确定上颌侧切牙（l2）的冠部呈锥形缩小（钉状异常）。与牙齿缺失患病率的标准数据相比，与腭侧移位尖牙（PDC）异常相关的第三磨牙和第二前磨牙缺失的增加在统计学上具有非常高度的显著性。相比之下，PDC样本中l2缺失的患病率与参考值相比在统计学上没有差异。牙齿形成这种后部特定部位抑制的原因尚不清楚。在PDC样本中，l2钉状异常的表达超过正常患病率10倍以上，是非常高度的显著增加。这些发现与以下假设一致：牙齿缺失、牙齿大小减小和PDC异常是一组遗传相关牙齿紊乱中的生物学协变量。
