青少年下颌后缩患者前导下颌治疗中髁突运动轨迹的特征

Characterization of condylar movements during mandibular advancement treatment in adolescents with mandibular retrognathism

目的研究青少年安氏Ⅱ类1分类下颌后缩患者使用无托槽隐形矫治技术前导下颌治疗中髁突运动轨迹的变化。方法本研究为双向性队列研究,纳入2022至2023年空军军医大学第三附属医院正畸科就诊的青少年安氏Ⅱ类1分类下颌后缩患者15例[30侧髁突,平均年龄(13.27±1.67)岁],使用无托槽隐形矫治技术导下颌向前治疗,分别在导下颌治疗前(T0)、导下颌治疗中(T1)[治疗时长(3.43±0.83)个月]和导下颌结束时(T2)[治疗时长(10.95±1.45)个月],采用下颌运动分析仪记录最大侧方运动、最大前伸运动和最大张口运动的髁突运动轨迹。比较治疗前、治疗中以及导下颌结束时的髁突运动轨迹特征,组间比较采用Friedman非参数检验,组内左右侧髁突运动比较采用Wilcoxon符号秩检验。结果下颌前伸运动中髁突位移量在治疗中明显减小,在导下颌结束时又增大[髁突前后位移量治疗前7.8(6.18,8.54)mm,治疗中5.8(4.52,7.04)mm,导下颌结束时7.83(6.49,8.66)mm,P<0.001;髁突空间位移量治疗前9.52(7.83,10.66)mm,治疗中7.99(6.02,9.53)mm,导下颌结束时9.71(8.65,11.36)mm,P=0.001]。在治疗前,下颌前伸运动中左右侧髁突位移量差异有统计学意义;而在治疗中和导下颌结束时,左右侧髁突位移量未见统计学差异。治疗前、治疗中和导下颌结束时,侧方运动和前伸运动中髁突运动标准差逐渐减小。结论青少年安氏Ⅱ类1分类下颌后缩患者在前导下颌治疗中,髁突运动范围发生先减小然后增大的适应性变化,左右侧髁突运动的差异减小,髁突运动标准差减小,下颌运动更趋于对称稳定。

ObjectiveTo study the changes in condylar trajectory during mandibular advancement treatment by clear aligners in adolescents with ClassⅡmandibular retrognathism.MethodsThis study was an ambispective cohort study,involving 15 adolescent patients(30 condyles,mean age 13.27±1.67 years)diagnosed with ClassⅡmandibular retrognathism.These patients attended the orthodontic department of the Third Affiliated Hospital of the Air Force Medical University from 2022 to 2023,and underwent mandibular advancement(MA)treatment using clear functional aligners.The jaw motion analyzer was used to record condylar motion trajectories during left and right lateral movements,protrusion movements,and opening movements,respectively,at stages of before the MA treatment(T0),during the MA treatment(T1)(3.43±0.83 months),and at the end of the MA treatment(T2)(10.95±1.45 months).The Friedman's nonparametric test for inter-group comparisons and the Wilcoxon signed-rank test for within-group comparisons of right-and left-side condylar movements were used to compare condylar movement trajectory features at three stages.ResultsDuring protrusive movement,the condylar range of motion decreased at T1 and then increased at T2 in comparison with T0[Pro-Co-X at T07.8(6.18,8.54)mm,T15.8(4.52,7.04)mm,T27.83(6.49,8.66)mm,P<0.001;Pro-Co-S at T09.52(7.83,10.66)mm,T17.99(6.02,9.53)mm,T29.71(8.65,11.36)mm,P=0.001].Before treatment(T0),there was a significant difference in the range of motion between the left and right condyles,but no significant difference between T1 and T2.The standard deviation of condylar movement in lateral movement and protrusive movement gradually decreased between T0,T1,and T2 treatments.ConclusionsAfter mandibular advancement treatment with clear functional aligner,the condylar range of motion presents adaptation by initial decrease followed by increase,the discrepancy between left and right condyle movement decreases,the standard deviation of condylar movement decreases,and condyle movement becomes more symmetrical and stable in adolescents with ClassⅡmandibular retrognathism.