236例不同骨性畸形磨牙颊舌向角度关系的研究

Study on buccolingual inclination of molars in 236 patients with different skeletal malocclusions

目的评估不同骨性畸形患者磨牙的颊舌向角度关系,旨在为预置矫治器的选择、治疗计划的制定及并发症的预防提供理论依据及临床参考。方法选取2016—2017年南京医科大学附属口腔医院正畸科就诊的236例患者(男88例,女148例)的锥形束CT资料进行测量分析,评估第一磨牙的颊舌向角度在不同矢状向及垂直向骨性畸形中有无差异。结果矢状向骨性畸形中,骨性Ⅲ类患者的上颌第一磨牙颊舌向角度较骨性Ⅰ类、Ⅱ类患者的更大,骨性Ⅱ类患者的下颌第一磨牙颊舌向角度较骨性Ⅰ类、Ⅲ类患者的更大,差异有统计学意义。不同垂直骨面型患者的角度差异也较大,高角患者的上颌第一磨牙颊舌向角度较均角、低角患者的更大,但下颌第一磨牙的颊舌向角度较其他两组更小,差异显著。ANB角度的大小与上颌磨牙的颊倾度呈负相关,而与下颌磨牙的颊倾度呈正相关。结论随着矢状向骨性畸形的差异增大,骨性Ⅱ类患者上颌磨牙有舌侧倾斜的趋势,下颌磨牙有颊侧倾斜的趋势,骨性Ⅲ类患者相反,这一定程度上代偿了骨骼畸形的横向不调。在治疗不同骨性错牙合时,应考虑这些因素以避免临床并发症的发生。

Objective To examine the buccolingual inclination of first molars in patients with different skeletal malocclusions to provide theoretical and clinical reference for how to select preadjusted appliances,make treatment plan and prevent complications in different cases.Methods CBCT data of 236 patients(88 males,148 females)treated at Department of Orthodontics in the Affiliated Stomatological Hospital of Nanjing Medical University from 2016 to 2017,were analyzed to evaluate the discrepancy of buccolingual inclination of first molars with respect to different sagittal and vertical classifications.Results The study showed that the maxillary first molars were more buccally inclined in skeletal ClassⅢsubjects than ClassⅠorⅡsubjects,while the mandibular ones were more buccally inclined in skeletal ClassⅡsubjects than ClassⅠorⅢsubjects.Differences were statistically significant.Large differences in angle were found among different growth patterns,which showed the most buccal inclination in the maxilla and the most lingual inclination in the mandible for subjects in the high angle group.ANB angle was negatively correlated with buccolingual inclination of maxillary molars but positively correlated with buccolingual inclination of mandibular molars.Conclusion With the increase of sagittal skeletal deformity,the tendency of lingual inclination of maxillary molars and buccal inclination of mandibular molars in skeletal ClassⅡpatients increases while the tendency in skeletal ClassⅢpatients is the opposite.The inclinations compensate for the transverse skeletal discrepancy.These should be taken into consideration to avoid clinical complications when treating different skeletal malocclusions.