Yoon Yu Jung, Kang Ju-Young, Kim Kyung-Ho, Cha Jung-Yul, Ahn Hyung Joon, Choi Yoon Jeong
Department of Orthodontics, Institute of Craniofacial Deformity, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea.
Department of Orofacial Pain and Oral Medicine, Yonsei University College of Dentistry, Seoul, Korea.
Clin Oral Investig. 2023 Sep;27(9):5367-5376. doi: 10.1007/s00784-023-05156-2. Epub 2023 Jul 19.
Masticatory function, including masticatory muscle activity and occlusal function, can be affected by craniofacial morphology. This study aimed to investigate the relationship between craniofacial morphology and masticatory function in participants who had completed orthodontic treatment at least two years before and had stable occlusion.
Fourty-two healthy participants were prospectively enrolled and divided into three vertical cephalometric groups according to the mandibular plane angle. Masticatory muscle activity (MMA) in the masseter and anterior temporalis muscles was assessed using surface electromyography. The occlusal contact area (OCA) and occlusal force (OF), defined as occlusal function in this study, were evaluated using occlusal pressure mapping system. Masticatory muscle efficiency (MME) was calculated by dividing MMA by OF. The craniofacial morphology was analyzed using a lateral cephalogram. The masticatory function was compared using one-way analysis of variance. Pearson correlations were used to assess relationships between craniofacial morphology and masticatory function.
The hypodivergent group had the lowest MMAand the highest MME in the masseter (167.32 ± 74.92 µV and 0.14 ± 0.06 µV/N, respectively) and anterior temporalis muscles (0.18 ± 0.08 µV/N, p < 0.05). MMA in the masseter showed a positive relationship with mandibular plane angle (r = 0.358), whereas OCA (r = -0.422) and OF (r = -0.383) demonstrated a negative relationship (p < 0.05). The anterior temporalis muscle activity negatively correlated with ramus height (r = -0.364, p < 0.05).
Vertical craniofacial morphology was related to masticatory function. Hypodivergent individuals may have low MMA and high occlusal function, resulting in good masticatory muscle efficiency.
Hypodivergent individuals require careful consideration in orthodontic diagnosis and prosthetic treatment planning.
咀嚼功能，包括咀嚼肌活动和咬合功能，会受到颅面形态的影响。本研究旨在调查至少在两年前完成正畸治疗且咬合稳定的参与者的颅面形态与咀嚼功能之间的关系。
前瞻性招募42名健康参与者，并根据下颌平面角将其分为三个垂直头影测量组。使用表面肌电图评估咬肌和颞肌前部的咀嚼肌活动（MMA）。使用咬合压力映射系统评估咬合接触面积（OCA）和咬合力（OF），在本研究中定义为咬合功能。咀嚼肌效率（MME）通过将MMA除以OF来计算。使用侧位头影测量片分析颅面形态。使用单因素方差分析比较咀嚼功能。采用Pearson相关性分析评估颅面形态与咀嚼功能之间的关系。
低角型组咬肌的MMA最低，MME最高（分别为167.32±74.92μV和0.14±0.06μV/N），颞肌前部也是如此（0.18±0.08μV/N，p<0.05）。咬肌的MMA与下颌平面角呈正相关（r=0.358），而OCA（r=-0.422）和OF（r=-0.383）呈负相关（p<0.05）。颞肌前部活动与升支高度呈负相关（r=-0.364，p<0.05）。
垂直颅面形态与咀嚼功能相关。低角型个体可能具有较低的MMA和较高的咬合功能，从而导致良好的咀嚼肌效率。
在正畸诊断和修复治疗计划中，低角型个体需要仔细考虑。
