Abstract: Transversal imbalance of the maxillary and mandibular is a common malocclusion in orthodontic treatment. Maxillary transverse deficiency is more common. Understanding the general pattern of the development of dental arch and basal bones′ width of maxillary and mandibula and mastering the treatment methods for its developmental abnormalities are important conditions for the correct implementation of treatment. This article provides a review on the general pattern of dental arch and basal bones′ transversal development of maxillary and mandibula，influencing factors and treatment methods of maxillary transverse deficiency，in order to provide reference for clinical diagnosis and treatment.

Key words: maxillary transversal deficiency, dental arch, basal bone, treatment, arch expansion

摘要： 上下颌横向不协调是正畸治疗中常见的错牙合畸形，其中，上颌横向发育不足较为常见。了解上下颌牙弓及基骨宽度发育的一般规律，并掌握其发育异常的治疗方法是正确实施治疗手段的重要条件。文章就上下颌基骨及牙弓横向发育的一般规律及上颌横向发育不足的影响因素和治疗方法做一综述，以期为临床诊疗提供参考。

关键词: 上颌横向发育不足, 牙弓, 基骨, 治疗, 扩弓