Linjawi Amal I, Afify Ahmed R, Baeshen Hosam A, Birkhed Dowen, Zawawi Khalid H
Orthodontic Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
Orthodontic Department, Faculty of Dentistry, Mansoura University. Egypt.
Saudi J Biol Sci. 2021 Jan;28(1):280-285. doi: 10.1016/j.sjbs.2020.09.062. Epub 2020 Oct 8.
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.
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.
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 ( < 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 ( < 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).
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.
本横断面研究的目的是比较不同性别以及矢状和垂直骨骼关系下下颌骨联合部（MS）的尺寸。
正畸患者的治疗前记录根据性别、矢状（I类、II类和III类）和垂直（下颌平面[MP]角减小、正常和增大）骨骼关系进行划分。使用IMAGEJ软件在头颅侧位片上测量MS参数。采用多因素和单因素方差分析以及独立样本t检验对MS参数与性别和不同骨骼关系进行比较。
共有104份记录（25名男性和79名女性）符合纳入标准。男性的MS表面积、牙槽骨长度、骨骼联合部长度、总联合部长度、垂直联合部尺寸和联合部凸度显著更大（P<0.05）。II类骨骼患者的牙槽骨和骨骼联合部长度显著更大，而III类患者的颏长度、垂直联合部尺寸和联合部凸度更大（P<0.05）。垂直尺寸减小的患者骨骼联合部长度更大（P = 0.026），垂直关系正常的患者颏长度更大（P<0.001）。
下颌骨联合部的形态受性别、矢状和垂直骨骼模式影响。男性下颌骨联合部表面积和线性尺寸增加。II类患者牙槽骨长度更大。MP角正常的患者颏长度更大。
