Jain Shikha, Shetty K Sadashiva, Prakash Anaveri T, Agrawal Mamta, Jain Shweta
Aust Orthod J. 2014 May;30(1):39-44.
Eruption disturbances, tooth size and specific malocclusions are known to be genetically influenced. The clinical association between these traits may indicate common genetic controls.
A cross-sectional clinical study was designed to test the null hypothesis that the maximum mesiodistal crown diameter (MMD) of maxillary and mandibular central and lateral incisors and the prevalence of various classes of incisor relationships (Class I, II/1, II/2 and III) do not differ between the subjects with and without permanent mandibular canine(s) impaction.
Dental models of 43 subjects diagnosed with mandibular canine(s) impaction (Impaction Group - IG) were compared with those of 86 subjects of a control reference sample (Control Group - CG). Independent t-test and chi-square tests were used to determine the association between mandibular canine(s) impaction and the MMD of the incisors and the incisor relationship, respectively. The likelihood of various incisor relationships between the IG and CG were evaluated according to odds ratios.
A fourfold increase (p < 0.0001) in the overall frequency of Class II/2 incisor relationship was observed in the IG when compared to controls.
The null hypothesis was rejected. Subjects with mandibular canine(s) impaction appeared to be characterised with wider incisors and a remarkably high rate of Class II/2 malocclusion. This information assists the understanding of genetically controlled dental anomalies, which are likely to coexist with mandibular canine(s) impaction.
萌出紊乱、牙齿大小和特定错牙合畸形已知受遗传影响。这些特征之间的临床关联可能表明存在共同的遗传控制。
设计一项横断面临床研究，以检验零假设，即有和没有恒牙下颌尖牙阻生的受试者之间，上颌和下颌中切牙及侧切牙的最大近远中牙冠直径（MMD）以及各类切牙关系（I类、II/1类、II/2类和III类）的患病率没有差异。
将43名被诊断为下颌尖牙阻生的受试者（阻生组 - IG）的牙模与86名对照参考样本受试者（对照组 - CG）的牙模进行比较。分别使用独立t检验和卡方检验来确定下颌尖牙阻生与切牙的MMD以及切牙关系之间的关联。根据优势比评估IG和CG之间各种切牙关系的可能性。
与对照组相比，IG中II/2类切牙关系的总体频率增加了四倍（p < 0.0001）。
零假设被拒绝。有下颌尖牙阻生的受试者似乎具有更宽的切牙和显著高的II/2类错牙合率。这些信息有助于理解可能与下颌尖牙阻生共存的遗传控制的牙齿异常。
