骨性Ⅲ类患者正颌外科术前术后基骨及牙弓宽度变化的CBCT研究

CBCT study on changes of basal bone and dental arch width before and after orthognathic surgery in patients with skeletal classⅢmalocclusion

目的:探讨骨性Ⅲ类错牙合畸形患者正颌外科手术前后上下颌基骨及牙弓宽度的变化,为临床治疗提供经验参考和理论依据。方法:回顾分析2017年6月至2021年6月就诊于徐州市中心医院口腔科的骨性Ⅲ类错牙合畸形患者,其中行正畸-正颌外科联合治疗者32例,筛选出术前正畸配合上颌扩弓的26例患者,收集锥形束CT影像数据,建立三维影像,分别测量患者初诊时、正畸扩弓后及正颌手术后上、下颌基骨及牙弓宽度,采用配对样本t检验分析正畸扩弓后与正颌手术后基骨及牙弓宽度变化。结果:上颌扩弓后,基骨及牙弓宽度较初诊时增宽,差异有统计学意义(P<0.05);上颌手术后基骨及牙弓宽度小于术前正畸扩弓后约2~5 mm,差异有统计学意义(P<0.05);而下颌基骨及牙弓宽度在初诊、正颌手术前后则无明显缩窄,变化在1 mm以内,差异无统计学意义(P>0.05)。结论:骨性Ⅲ类错牙合畸形患者通常需进行术前上颌正畸扩弓,患者行正颌外科手术后上颌基骨及牙弓宽度较术前缩窄,术后正畸需配合继续扩弓;而下颌基骨及牙弓宽度无明显变化。

Objective: To evaluate the distinction of basal bone width and dental arch width before and after orthognathic surgery in patients with skeletal class Ⅲ malocclusion, and to provide empirical reference and theoretical basis for clinical treatment.Methods: A retrospective analysis was performed on patients with skeletal class Ⅲ malocclusion treated in the department of stomatology of Xuzhou Central Hospital from June 2017 to June 2021. Among them, 32 patients received orthodontic and orthognathic surgery, and 26 patients were screened out for preoperative orthodontic and maxillary arch expansion. CBCT image data were collected to establish three-dimensional images. The base bone discrepancies and dental arch widths of maxillomandibular were measured at initial diagnosis, after orthodontic arch expansion and after orthodontic surgery respectively. Paired samplesttest was used to analyze the variances of base bone widths and dental arch widths after orthodontic arch expansion and after orthodontic surgery.Results: After maxillary arch enlargement,the width of basal bone and dental arch was wider than that at initial diagnosis, with statistical significance(P<0.05). The widths of maxillary base bone and dental arch which patients were operated on were less 2~5 mm than themselves when the first time they were treated with arch expansion by orthodontic appliances, the difference was statistically significant(P<0.05), while the widths of mandibular base bone widths and dental arch was not significantly narrowed compared with preopration, and the change was within 1mm in width, and the difference was not statistically significant(P>0.05).Conclusions: Patients with skeletal class Ⅲ malformation usually require preoperative maxillary orthodontic arch expansion. After orthodontic arch expansion and orthodontic surgery, the maxillary base bone width and dental arch width of patients with skeletal class Ⅲ malocclusion were narrowed compared with that before the surgery.And further arch expansion was required after orthodontic surgery, while there was no significant change in mandible.