高位J钩引起牙根吸收的临床观察

目的:评价标准方丝弓配合高位J钩对正畸治疗中牙根吸收的影响。方法:随机选择60例经过标准方丝弓技术治疗的安氏Ⅰ类或Ⅱ类Ⅰ分类伴上颌前突年轻女性患者,其中30例在内收前牙阶段应用高位J钩配合治疗。治疗前后拍摄全颌曲面断层片,分别测量2组治疗前后上颌4个切牙的牙根吸收等级,并经计算机进行χ2检验。结果:2组正畸治疗后均有明显的牙根吸收,治疗前后牙根吸收等级比较,2组均有显著性差异(P<0.01)。治疗后2组间牙根吸收等级比较,差异也呈显著性(P<0.01),标准方丝弓配合高位J钩组还出现了极重度吸收。结论:标准方丝弓配合高位J钩在正畸治疗中较单纯使用标准方丝弓技术更易产生严重的牙根吸收。

Effect of high pull J hook headgear on root resorption during orthodontic treatment

PURPOSE: The purpose of this study was to evaluate the effect of high pull J hook headgear(HPHG) on root resorption of maxillary incisors during orthodontic treatment. METHODS: Sixty female adolescent subjects who had finished orthodontic treatment were selected. They were either Class I or Class II division I cases treated with standard edgewise appliances. Half of the patients(30 cases) had an additional HPHG to assist upper anterior teeth retraction. They were matched to the other 30 cases with age and type of malocclusion. Panoramic radiographs taken before and after the orthodontic treatment were used to evaluate the degree of root resorption on upper incisors. Chi(2) test was used for statistical analysis. RESULTS: The incidence of root resorption on upper incisors was significantly increased after orthodontic treatment in both HPHG and non-HPHG groups (P<0.01). Compared to the non-HPHG group, more teeth in HPHG group showed moderate or severe root resorption (P<0.01). Some cases even encountered extremely severe root resorption. CONCLUSION: A combination of HPHG might lead to more severe root resorption on maxillary incisors during orthodontic treatment.