Chaushu Stella, Sharabi Shaltiel, Becker Adrian
Department of Orthodontics, Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel.
Am J Orthod Dentofacial Orthop. 2002 Apr;121(4):339-46. doi: 10.1067/mod.2002.121559.
An earlier study reported on the delayed dental age in about 50% of patients with palatally displaced canines (PDC), suggesting the possible existence of 2 different PDC phenotypes. The present study aimed to determine whether the PDC subgroup with late dental age displays different dental features from the PDC subgroup with normal dental age, supporting the above assumption. The 3 dental parameters examined were mesiodistal and buccolingual tooth sizes, the presence of anomalous maxillary lateral incisors, and other congenitally missing teeth. Fifty-eight subjects with PDC, 37 girls and 21 boys, were divided according to dental age and compared with age- and sex-matched controls. The results revealed marked sexual dimorphism. Delayed dental development was twice as prevalent among the PDC males. The existence of 2 distinct PDC subgroups was supported for males only. One subgroup was characterized by delayed dental development, smaller-than-average teeth, and a marked increase in the prevalence of anomalous lateral incisors. The second subgroup more closely resembled the controls, presenting a timely developed dentition, a moderate and nonsignificant increase of anomalous lateral incisors, and a reduction in the dimensions of only the central incisors and the first molars. In females, although the prevalence of anomalous lateral incisors was slightly increased in the late dental age subgroup, tooth sizes were remarkably similar, negating the existence of 2 distinct subpopulations. Studying the overall PDC group as a single entity produced confusing results because important differences were obscured when the 2 sexes and the 2 dental age subgroups (in males) were combined.
一项较早的研究报告称，约50%的腭向错位尖牙（PDC）患者存在牙齿发育延迟的情况，这表明可能存在两种不同的PDC表型。本研究旨在确定牙齿发育延迟的PDC亚组与牙齿发育正常的PDC亚组是否具有不同的牙齿特征，以支持上述假设。所检查的三个牙齿参数为近远中径和颊舌径牙齿大小、上颌侧切牙异常的存在情况以及其他先天性缺失牙。58名PDC受试者，37名女孩和21名男孩，根据牙齿年龄进行分组，并与年龄和性别匹配的对照组进行比较。结果显示出明显的性别差异。PDC男性中牙齿发育延迟的发生率是女性的两倍。仅在男性中支持存在两个不同的PDC亚组。一个亚组的特征是牙齿发育延迟、牙齿小于平均水平以及上颌侧切牙异常的发生率显著增加。第二个亚组与对照组更相似，表现为牙列发育正常、上颌侧切牙异常的发生率有适度但不显著的增加，并且仅中切牙和第一磨牙的尺寸减小。在女性中，尽管牙齿发育延迟亚组中上颌侧切牙异常的发生率略有增加，但牙齿大小非常相似，否定了存在两个不同亚群的观点。将整个PDC组作为一个整体进行研究产生了令人困惑的结果，因为当将两性和两个牙齿年龄亚组（男性）合并时，重要差异被掩盖了。
