Fraga Marcelo Reis, Vitral Robert Willer Farinazzo, Mazzieiro Enio Tonani
Orthodontontic Department, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
Pediatr Dent. 2012 May-Jun;34(3):216-9.
This study determined the relationship between tooth-size reduction, agenesis and the occurrence of palatally displaced canines (PDCs). Emphasis was given to the association between anomalous and/or absent maxillary lateral incisors and PDCs.
Pretreatment records of 66 consecutively treated orthodontic patients with PDCs and 66 controls were evaluated. Maximum mesiodistal (M-D) crown diameters were recorded for all teeth, except the second and third molars. Tooth agenesis was evaluated by radiographs. The level of significance was P<.05.
The occurrence of agenesis in the PDC sample was approximately 26%. Congenital absence of the lateral incisors was noted in 2 male subjects (3%). The occurrence of small lateral incisors was approximately 39%.
Female subjects with palatally displaced canines showed significant overall reductions of the maximum mesiodistal widths for all teeth, except the mandibular first molars. Female PDC subjects with 1 or more congenitally absent teeth showed significant reductions in M-D diameters of the maxillary left lateral incisors, mandibular second premolars, and first molars in relation to the female PDC subjects with no absent teeth. The association between tooth agenesis and PDCs was not observed. There also was no significant association between adjacent anomalous and/or absent maxillary lateral incisors and PDCs.
本研究确定牙齿大小减小、牙齿缺失与腭侧移位尖牙（PDC）发生之间的关系。重点关注上颌侧切牙异常和/或缺失与PDC之间的关联。
对66例连续接受治疗的PDC正畸患者和66例对照的治疗前记录进行评估。记录除第二和第三磨牙外所有牙齿的最大近远中（M-D）冠径。通过X线片评估牙齿缺失情况。显著性水平为P<0.05。
PDC样本中牙齿缺失的发生率约为26%。2名男性受试者（3%）存在先天性侧切牙缺失。小侧切牙的发生率约为39%。
患有腭侧移位尖牙的女性受试者除下颌第一磨牙外，所有牙齿的最大近远中宽度均有显著总体减小。与无牙齿缺失的女性PDC受试者相比，有1颗或更多颗先天性缺失牙齿的女性PDC受试者上颌左侧侧切牙、下颌第二前磨牙和第一磨牙的M-D直径显著减小。未观察到牙齿缺失与PDC之间的关联。相邻上颌侧切牙异常和/或缺失与PDC之间也无显著关联。
