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摘要
The purpose of this study was to investigate the outcome of early interceptive treatment of primary anterior crossbites with posterior occlusal acrylic resin blocks in combination with a 2 x 4 appliance, and to examine the differences in craniofacial morphology between the stable and relapse groups. Lateral cephalograms of 46 subjects (17 males and 29 females; average mean age 4 years 2 months +/- 5 months) with a primary anterior crossbite were obtained before (T0) and immediately after (T1) treatment and at a 6 year follow-up (T2). The patients were assigned to either a stable (n = 35; 13 males and 22 females) or a relapse (n = 11; 4 males and 7 females) group according to the amount of overjet when the permanent incisors had erupted. The differences in craniofacial morphology between the groups were compared using a two-tailed t-test. @@@ The results revealed that the relapse subjects had a more forward position of the mandible relative to the cranial base and maxilla, a longer mandible and an increased gonial angle at T0. At T1, both groups had a positive overjet, but the treatment changes were different. Between T1 and T2, the maxillary length (A'-Ptm') increased less in the relapse group, the angle between the posterior border of the mandibular ramus and SN plane (Ram-SN) decreased and gonial angle increased and vice versa in the stable group. @@@ When posterior bite raising and 2 x 4 appliance therapy are used to correct primary anterior crossbites, all patients showed an immediate positive treatment response, whereas approximately one-quarter of subjects relapsed into a reverse overjet when the permanent incisors had erupted, mainly because of a more severe Class III craniofacial morphology at T1 and unfavourable growth during T1-T2.
- 出版日期2011-10
- 单位深圳市儿童医院
