Skeletal and functional effects of treatment for unilateral posterior crossbite
Skeletal and functional effects of treatment for unilateral posterior crossbite
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DOI：
10.1016/s0889-5406(96)70178-6
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发表时间：
1996-02-01
影响因子：
3
通讯作者：
Yaffe, A
中科院分区：
文献类型：
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作者：
Brin, I;BenBassat, Y;Yaffe, A
单侧后牙合（UPXB）是一种常见的错牙合，经常表现为中线偏下，最终闭合时伴有II类细分关系，并且非常普遍的下颌运动反向序列（RS）模式。即使在消除了交叉咬合后，这些特征仍然存在。本研究的目的是详细检查治疗这类错牙合的形态学、骨骼和功能效果。实验组为24例混合牙列期UPXB患儿，采用可移动扩展板治疗；对照组为10例年龄相匹配的正常咬合患儿。纵向随访显示上颌弓稳定扩展至少1.5 mm，但只有50%的病例完全消除了交叉咬合。II类细分关系和下中线偏差的频繁持续性不是由于下颌功能性移位引起的，这是惊人的。预处理后前路（P-A）脑电图显示面部和上颌宽度减小。治疗后，上颌宽度的增长大于正常生长的预期。下颌运动反应的纵向评估显示，治疗后RS的患病率很高。综上所述，(1)UPXB组上颌和颧骨水平骨骼横向畸变的发生率高于预期；(2)可移动扩张器诱导上颌骨横向生长；(3)下颌运动的固有模式是UPXB的特征，并且不随正畸治疗而显着改变。
Unilateral posterior crossbite (UPXB) is a common malocclusion, frequently presenting a lower midline deviation, accompanied by Class II subdivision relationships in final closure and a very high prevalence of the reverse sequencing (RS) pattern of jaw movement. These features often persist even after the elimination of the crossbite. The purpose of the present study was to examine in detail the morphologic, skeletal, and functional effects of the treatment for this malocclusion category. The experimental group consisted of 24 children in the mixed dentition stage with UPXB who were treated with removable expansion plates and a control group of 10 age-matched children with normal occlusion. Longitudinal follow-up revealed a stable dental maxillary arch expansion of at least 1.5 mm but a complete elimination of crossbite in only 50% of the cases. The frequent persistence of Class II subdivision relations and lower midline deviation that were not due to functional mandibular shift was striking. The pretreatment posteroanterior (P-A) cephalograms indicated reduced facial and maxillary widths. After treatment, the achieved maxillary width increase was greater than expected with normal growth. Longitudinal assessment of the mandibular movement response revealed by the electrognathograph showed a high prevalence of RS, which was reduced after treatment. In conclusion, (1) a higher than expected prevalence of skeletal transverse aberrations at the maxillary and zygomatic levels were found in the UPXB group; (2) the removable expansion appliance induces transverse growth of the maxilla; and (3) an inherent pattern of jaw movement is characteristic to the UPXB and does not change significantly with orthodontic treatment.