McKinney J R, Harris E F
Department of Orthodontics, University of Tennessee, Memphis, TN 38163, USA.
Am J Orthod Dentofacial Orthop. 2001 Nov;120(5):530-41. doi: 10.1067/mod.2001.118784.
The nature of the planned orthodontic correction--primarily skeletal or dental--ought to be influenced by the age and the sex of the patient. Jaw growth should contribute more in younger adolescents and faster-growing boys, and the correction should be primarily dental in patients with little growth potential. Influences of age and sex were studied in 154 Class II Division 1 young people between 10 and 18 years of age at the start of treatment. Variations among 3 orthodontic techniques, Begg lightwire, standard edgewise, and straightwire, were also examined. The Johnston method of cephalometric analysis was used to partition changes into their skeletal and dental components. Analysis of covariance was used to identify changes because of patient age, patient sex, and treatment technique. Technique differences were localized to 2 areas: (1) less root torquing in the Begg group that left the maxillary incisors more upright than in the other groups and (2) more mesial molar crown tipping in the straightwire group because of using preangulated brackets. The patient's age had the greatest influences on (1) translation and mesial crown tipping of the molars (both changes were larger in younger patients) and (2) mandibular growth, which was greatest in younger patients and declined linearly with age. Forward movement of the maxillary molars was greatest in young patients, but this was exceeded at all ages by mesial translation of the lower molars, thus providing a net improvement in molar relationship. Linear growth was greater in males for all facial dimensions, but the sex difference of consequence was the large forward growth of the mandible that contributed significantly to the sagittal correction in boys but not in girls. One would not expect the effects of age and sex to be large because there is so much individual variation in the malocclusions and tempos of growth. Still, the present study shows that these factors produce readily measurable and systematic influences on the nature of the skeletodental correction.
计划进行的正畸矫治的性质——主要是骨骼性还是牙性——应该受到患者年龄和性别的影响。在年龄较小的青少年以及生长较快的男孩中，颌骨生长的作用更大，而对于生长潜力较小的患者，矫治应主要是牙性的。在治疗开始时，对154名年龄在10至18岁之间的安氏II类1分类青少年进行了年龄和性别的影响研究。还研究了三种正畸技术（Begg细丝弓技术、标准方丝弓技术和直丝弓技术）之间的差异。采用约翰斯顿头影测量分析法将变化分为骨骼和牙性成分。使用协方差分析来确定因患者年龄、患者性别和治疗技术导致的变化。技术差异集中在两个方面：（1）Begg组牙根转矩较小，使得上颌切牙比其他组更直立；（2）由于使用预成角度托槽，直丝弓组磨牙冠近中倾斜更多。患者年龄对以下方面影响最大：（1）磨牙的平移和近中冠倾斜（这两种变化在年轻患者中更大），以及（2）下颌生长，下颌生长在年轻患者中最大，并随年龄呈线性下降。上颌磨牙的向前移动在年轻患者中最大，但在所有年龄段，下颌磨牙的近中平移都超过了上颌磨牙，从而使磨牙关系得到净改善。所有面部维度中，男性的线性生长都更大，但具有重要意义的性别差异是下颌骨的大幅向前生长，这对男孩矢状向矫治有显著贡献，而对女孩则不然。由于错颌畸形和生长速度存在很大个体差异，人们不会预期年龄和性别的影响会很大。尽管如此，本研究表明这些因素对骨骼-牙性矫治的性质产生了易于测量且系统的影响。
