Background

The aim of this cross-sectional study was to compare the dimensions of mandibular symphysis (MS) between gender and the different sagittal and vertical skeletal relationships.

Material and Methods

Pre-treatment records of orthodontic patients were divided according to gender, sagittal (Class I, II and III) and vertical (decreased, average and increased mandibular plane [MP] angle) skeletal relationships. Measurements of MS parameters were performed on lateral cephalograms using IMAGEJ software. Comparisons between MS parameters and gender and the different skeletal relationships was performed using multifactorial and one-way ANOVA, and independent sample t-tests.

Results

A total of 104 records (25 males and 79 females) fulfilled the inclusion criteria. Males had significantly greater MS surface area, dentoalveolar length, skeletal symphysis length, total symphysis length, vertical symphysis dimension and symphysis convexity (p < 0.05). Skeletal Class II patients had significantly greater dentoalveolar and skeletal symphysis lengths while Class III had greater chin length, vertical symphysis dimension and symphysis convexity (p < 0.05). Patients with decreased vertical dimension had greater skeletal symphysis length (p = 0.026) and those with an average vertical relationship had greater chin length (p < 0.001).

Conclusions

The morphology of the mandibular symphysis is affected by gender, sagittal and vertical skeletal patterns. Males had increased mandibular symphysis surface area and linear dimensions. Class II patients had greater dentoalveolar length. Chin length was greater in patients with an average MP angle.

中文翻译：

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不同矢状和垂直骨骼关系中的下颌联合尺寸

背景

这项横断面研究的目的是比较性别与不同矢状和垂直骨骼关系之间的下颌联合 (MS) 的维度。

材料与方法

正畸患者的治疗前记录根据性别、矢状（I、II和III类）和垂直（下颌平面[MP]角减小、平均和增大）骨骼关系进行划分。使用 IMAGEJ 软件对侧位头影图进行 MS 参数的测量。使用多因素和单向 ANOVA 以及独立样本 t 检验进行 MS 参数和性别以及不同骨骼关系之间的比较。

结果

共有 104 条记录（25 条男性和 79 条女性）符合纳入标准。男性的 MS 表面积、牙槽骨长度、骨骼联合长度、联合总长度、垂直联合尺寸和联合凸度显着增加（p  < 0.05）。骨骼 II 类患者的牙槽骨和骨骼联合长度显着增加，而 III 类患者下巴长度、垂直联合尺寸和联合凸度更大（p  < 0.05）。垂直尺寸减小的患者骨骼联合长度更长（p = 0.026），平均垂直关系的患者下巴长度更长（p < 0.001）。

结论

下颌联合的形态受性别、矢状和垂直骨骼模式的影响。男性的下颌联合表面积和线性尺寸增加。II 类患者的牙槽长度更大。平均 MP 角的患者下巴长度更大。