Mucedero M, Franchi L, Ricchiuti M R, Cozza P
Department of Orthodontics, University of Rome "Tor Vergata", Rome, Italy.
Department of Surgery and Translational Medicine, Orthodontics, University of Florence, Florence, Italy.
Eur J Paediatr Dent. 2015 Mar;16(1):45-50.
To evaluate the association between the mesially displaced maxillary first premolar (MDP) and the early displacement of the adjacent permanent canine (EDC) before their eruption.
A sample of 1247 subjects in the intermediate mixed dentition stage was assessed for the presence of MDP and EDC. All subjects were divided into two groups: MDP group and noMDP group. For each subject two angular measurements (premolar-occlusal plane η and л premolar-midline angles) were analysed on panoramic radiographs. The chi-square test with Yates correction was performed to compare the prevalence rate of EDC in MDP (MDP-EDC) and noMDP groups. The statistical comparisons for the values of η and л angles between MDP vs noMDP, MDP vs MDP-EDC, and noMDP vs MDP-EDC groups were performed by means of ANOVA with Bonferroni correction.
The prevalence rate of EDC in the MDP group was significantly greater than in the noMDP group (66% vs. 12.1%). MDP-EDC group showed a significantly larger л angle than in the MDP group resulting in an increased mesial inclination of displaced premolars.
MDP can be considered a dental anomaly associated to maxillary canine displacement.
评估上颌第一前磨牙近中移位(MDP)与相邻恒牙尖牙萌出前早期移位(EDC)之间的关联。
对1247名处于混合牙列中期的受试者样本进行MDP和EDC情况评估。所有受试者分为两组:MDP组和非MDP组。在全景X光片上对每位受试者进行两个角度测量(前磨牙-咬合平面η角和前磨牙-中线角)。采用校正Yates检验比较MDP组(MDP-EDC)和非MDP组中EDC的患病率。通过方差分析及Bonferroni校正对MDP组与非MDP组、MDP组与MDP-EDC组、非MDP组与MDP-EDC组之间的η角和角值进行统计学比较。
MDP组中EDC的患病率显著高于非MDP组(66%对12.1%)。MDP-EDC组的角显著大于MDP组,导致移位前磨牙的近中倾斜度增加。
MDP可被视为与上颌尖牙移位相关的牙齿异常。