Al-Masri Maram M N, Ajaj Mowaffak A, Hajeer Mohammad Y, Al-Eed Muataz S
Department of Orthodontics, University of Damascus Dental School, Damascus, Syrian Arab Republic.
Associate Professor, Department of Orthodontics, University of Damascus Dental School, Damascus, Syrian Arab Republic, Phone: 00963113141343, e-mail:
J Contemp Dent Pract. 2015 Aug 1;16(8):630-7. doi: 10.5005/jp-journals-10024-1733.
To evaluate the bone thickness and density in the lower incisors' region in orthodontically untreated adults, and to examine any possible relationship between thickness and density in different skeletal patterns using cone-beam computed tomography (CBCT).
The CBCT records of 48 patients were obtained from the archive of orthodontic department comprising three groups of malocclusion (class I, II and III) with 16 patients in each group. Using OnDemand 3D software, sagittal sections were made for each lower incisor. Thicknesses and densities were measured at three levels of the root (cervical, middle and apical regions) from the labial and lingual sides. Accuracy and reliability tests were undertaken to assess the intraobserver reliability and to detect systematic error. Pearson correlation coefficients were calculated and one-way analysis of variance (ANOVA) was employed to detect significant differences among the three groups of skeletal malocclusion.
Apical buccal thickness (ABT) in the four incisors was higher in class II and I patients than in class III patients (p < 0.05). There were significant differences between buccal and lingual surfaces at the apical and middle regions only in class II and III patients. Statistical differences were found between class I and II patients for the cervical buccal density (CBD) and between class II and III patients for apical buccal density (ABD). Relationship between bone thickness and density values ranged from strong at the cervical regions to weak at the apical regions.
Sagittal skeletal patterns affect apical bone thickness and density at buccal surfaces of the four lower incisors' roots. Alveolar bone thickness and density increased from the cervical to the apical regions.
使用锥形束计算机断层扫描（CBCT）评估未经正畸治疗的成年人下切牙区域的骨厚度和密度，并研究不同骨骼型中厚度与密度之间的可能关系。
从正畸科存档中获取48例患者的CBCT记录，包括三组错（牙合）畸形（I类、II类和III类），每组16例患者。使用OnDemand 3D软件，为每个下切牙制作矢状面切片。从唇侧和舌侧在牙根的三个水平（颈部、中部和根尖部）测量厚度和密度。进行准确性和可靠性测试以评估观察者内可靠性并检测系统误差。计算Pearson相关系数，并采用单因素方差分析（ANOVA）检测三组骨骼错（牙合）畸形之间的显著差异。
II类和I类患者四颗切牙的根尖颊侧厚度（ABT）高于III类患者（p < 0.05）。仅在II类和III类患者中，根尖和中部区域的颊侧和舌侧表面存在显著差异。I类和II类患者之间的颈部颊侧密度（CBD）以及II类和III类患者之间的根尖颊侧密度（ABD）存在统计学差异。骨厚度和密度值之间的关系从颈部区域的强相关到根尖区域的弱相关。
矢状骨骼型影响四颗下切牙根颊侧表面的根尖骨厚度和密度。牙槽骨厚度和密度从颈部到根尖区域增加。
