Yamaguchi Manami, Kim Yong-Il, Park Heetae, Yamaguchi Tetsutaro
Department of Orthodontics, School of Dentistry, Kanagawa Dental University, Yokosuka 238-8580, Japan.
Department of Orthodontics, School of Dentistry, Pusan National University, Yangsan 50612, Republic of Korea.
Diagnostics (Basel). 2024 Dec 21;14(24):2879. doi: 10.3390/diagnostics14242879.
BACKGROUND/OBJECTIVES: Methods for predicting final mandibular length have been studied for many years. We aimed to estimate the final mandibular length at the end of the growth period by analyzing changes in cervical vertebral morphology using longitudinal lateral cephalograms.
Longitudinal lateral cephalograms of elementary school students aged 6-15 who did not undergo orthodontic treatment, collected between 1965 and 1973, were used. For this analysis, 370 images from 44 female individuals were selected, and cervical vertebral morphology was assessed using the semi-landmark method. Generalized Procrustes analysis and principal component analysis were performed, and changes in maxillofacial skeletal and cervical vertebral morphology were analyzed using a linear mixed model with repeated measures. A predictive formula for estimating final mandibular length was developed based on morphological changes in the fourth cervical vertebra.
The difference between the predicted and actual final mandibular lengths using the semi-landmark method was 0.17 ± 0.08 mm. The marginal R value of the prediction formula was 0.957, and the conditional R was 0.990, demonstrating very high accuracy. The annual increase in mandibular length remained consistent each year but slowed after 14 years of age. Geometric morphometric analysis revealed significant morphological changes in the fourth cervical vertebra at 14 years of age, coinciding with a deceleration in mandibular growth.
A highly accurate formula was developed to predict final mandibular length based on morphological changes in the fourth cervical vertebra. Cervical vertebral morphology may provide valuable information related to mandibular growth during adolescence.
背景/目的：预测下颌骨最终长度的方法已研究多年。我们旨在通过分析纵向头颅侧位片上颈椎形态的变化，来估计生长发育期结束时的下颌骨最终长度。
使用1965年至1973年间收集的6至15岁未接受正畸治疗的小学生的纵向头颅侧位片。本次分析选取了44名女性个体的370张图像，采用半地标法评估颈椎形态。进行了广义Procrustes分析和主成分分析，并使用重复测量的线性混合模型分析颌面骨骼和颈椎形态的变化。基于第四颈椎的形态变化，开发了一个估计下颌骨最终长度的预测公式。
使用半地标法预测的下颌骨最终长度与实际最终长度之间的差异为0.17±0.08毫米。预测公式的边际R值为0.957，条件R为0.990，显示出非常高的准确性。下颌骨长度的年增长量每年保持一致，但在14岁后放缓。几何形态计量学分析显示，14岁时第四颈椎有明显的形态变化，这与下颌骨生长减速相吻合。
基于第四颈椎的形态变化，开发了一个高度准确的公式来预测下颌骨最终长度。颈椎形态可能为青春期下颌骨生长提供有价值的信息。
