Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil.
J Appl Oral Sci. 2011 Aug;19(4):343-9. doi: 10.1590/s1678-77572011005000008. Epub 2011 Jun 3.
The aim of this study was to evaluate whether vertical facial patterns influence maximal occlusal force (MOF), masticatory muscle electromyographic (EMG) activity, and medial mandibular flexure (MMF).
Seventy-eight dentate subjects were divided into 3 groups by Ricketts's analysis: brachyfacial, mesofacial and dolychofacial. Maximum occlusal force in the molar region was bilaterally measured with a force transducer. The electromyographic activities of the masseter and anterior temporal muscles were recorded during maximal voluntary clenching. Medial mandibular flexure was calculated by subtracting the intermolar distance of maximum opening or protrusion from the distance in the rest position. The data were analyzed using ANOVA followed by Tukey's HSD test. The significance level was set at 5%.
Data on maximum occlusal force showed that shorter faces had higher occlusal forces (P<0.0001). Brachyfacial subjects presented higher levels of masseter electromyographic activity and medial mandibular flexure, followed by the mesofacial and dolychofacial groups. Additionally, dolychofacial subjects showed significantly lower electromyographic temporalis activities (P<0.05).
Within the limitations of the study, it may be concluded that maximum occlusal force, masticatory muscle activity and medial mandibular flexure were influenced by the vertical facial pattern.
本研究旨在评估面型的垂直向特征是否会影响最大牙合力（MOF）、咀嚼肌肌电图（EMG）活动和下颌中切迹深度。
78 名有牙患者根据 Ricketts 的分析法分为 3 组：短面型、均面型和长面型。使用力传感器双侧测量磨牙区最大牙合力。最大自主闭口时记录咀嚼肌（咬肌和颞肌前束）的肌电活动。通过减去最大开口或前伸位的颌间距离与休息位时的距离，计算下颌中切迹深度。采用方差分析（ANOVA）后进行 Tukey's HSD 检验对数据进行分析。检验水准为 5%。
最大牙合力数据显示，面下 1/3 较短的患者具有更高的牙合力（P<0.0001）。短面型患者的咬肌肌电活动和下颌中切迹深度最高，其次是均面型和长面型。此外，长面型患者的颞肌前束肌电活动明显较低（P<0.05）。
在本研究的限制范围内，可以得出结论，最大牙合力、咀嚼肌活动和下颌中切迹深度受面型垂直向特征的影响。
