Relationships among Occlusal Force, Condylar Surface Area, and Facial Patterns

Abstract

169Mandibular growth that is infl uenced by co-activation of jaw muscles influences craniofacial morphology, 1,2) and is closely related to the amount and direction of condylar growth.3) The primary factor determining the magnitude and direction of the temporomandibular joint (TMJ) load is the interaction of muscle forces.4) The magnitude and distribution of functional stress within the TMJ is important for the development of the TMJ. 5)However, excessive loads, 5, 6) loads with a long duration 5,7) and loads at high frequency 5,8) Abstract:The interactions between orofacial muscles and skeletal patterns are widely recognized as significant factors in craniofacial growth. Many studies have suggested that the vertical facial growth pattern correlates with occlusal forces and the activity of masticatory muscles. In particular, it has been suggested that occlusal forces produced by masticatory muscles are converted into physiological stress at the condyle in the form of functional strain. In such circumstances, the dimensions and morphology of the condyle ought to be affected. The aim of this study is to test the hypothesis that low-angle subjects with larger occlusal forces tend to have mandibular condyles with a larger surface area than high-angle subjects. Cone-beam computed tomographic scans were obtained from 14 Japanese adult subjects (17 to 33 years old, 7 high angle and 7 low angle) at 60 kV and 10 mA. Occlusal force was measured by pressure-indicating fi lms, and the surface area of the condyle was calculated from axial CT data. The correlation between occlusal conditions and the surface area of condyles was compared between the two facial groups. We found that the low-angle group had a signifi cantly larger surface area and volume of condyles than the high-angle group and that there was a positive correlation between occlusal forces and condylar surface area. Our fi ndings demonstrate that occlusal force is one of the important factors that affect the mechanical environment of the condyle.

In vivo measurement of three-dimensional load exerted on dental implants: a literature review

“…Unlike the static load to the implant during clenching, dynamic loads from various directions were also found to be exerted on the implant during chewing. The dynamic changes in the magnitude and direction of the load on the implant might be due to not only the food properties and texture [ 38 ] but also to the control mechanism and the configuration of the masticatory components [ 45 , 46 ]. Three factors affecting the load directional change during functions were suggested: the friction between the two contacting teeth, the contact sliding along the incline planes of the cusp, and the formation of new contacts and loss of existing contacts influenced by the periodontal ligament.…”

Relationship between the Mandibular Condyle Position and the Bite Force in the People with Normal Temporomandibular Joint

“…Te occlusal force is one of the important factors that can infuence the growth and development of maxillofacial structures [12,13] and the morphology of mandibular condyle [13,14]. Te occlusal stability is infuenced by the muscular function, as well [15].…”