Tanner-Whitehouse 2 method applied to the prediction of mandibular growth potentiality

根据Tanner-Whitehouse 2方法（TW 2），日本儿童的技能成熟比英国儿童提前。因此，在评价日本人下颌骨生长与骨骼成熟的相关性时，应以日本儿童标准化骨龄作为一般的成熟度指标。以下颌骨最终长度为标准变量，标准化骨龄为预测变量，进行多元回归分析，评价下颌骨生长潜力。结果表明，青春期前预测的下颌骨长度与成年期实际长度的差值均在3 mm以内，骨密度是预测下颌骨潜能的有效参数之一，而标准下颌骨生长曲线评价下颌骨的生长具有直观性，可以预测任何生长阶段的下颌骨长度。结果表明，标准化TW 2法能较好地评价下颌骨的生长发育状况，应用多元回归或标准生长曲线预测下颌骨的生长发育，对下颌骨的长期预测有一定的临床意义。在此之后，标准化的TW 2方法将成为正畸学领域骨骼成熟和颅面生长时间的标准评估方法。

Skeletal maturation of Japanese children are advanced when compared with English children that based on Tanner-Whitehouse 2 method(TW2). Therefore, when the correlation between mandibular growth and skeletal maturation in Japabese are evaluated, bone age standardized by Japanese children should be used as general maturity indicator. RUS method is most desirable among three kinds of TW2 methods.To evaluate mandibular growth potentiality, multiple regression analyzes are performed by using final mandibular length as criterion variables and standardized bone age as one of the predictor variables. The difference of the values between final mandibular length predicted in prepubertal stage and actual length at adult stage were under 3 mm. Besides bone age, bone mineral density may be one of the available parameters to predict mandibular potentiality.On the other hand, growth evaluation by using of standard growth curve of the mandible was intuitively comprehensible, and prediction of the mandiblar length at any growth stage was possible. Also, this method may be possible on patients with growth disorders.These results suggested that standardized TW2 method are better assessment of skeletal maturation and mandibular growth potentiality, and growth prediction of the mandible by using of multiple regression or standard growth curve were clinically useful for long-term prediction of the mandible. After this, standardized TW2 method will be standard assessment for skeletal maturation and craniofacial growth timing in field of Orthodontics.