مرکز منطقه ای اطلاع رساني علوم و فناوري - An investigation of the biomechanical effects of vertical chin cup on mandibular condyle and ramus in those with and without anterior openbite: a finite element method

Abstract :

OBJECTIVE: To evaluate the biomechanical effects of vertical chin cup, an extraoral device especially used in patients with high-angle malocclusion, on temporomandibular joint (TMJ) in those with and without anterior open bite using finite element method. MATERIALS AND METHOD: Two different three-dimensional geometric models (Models I and II) were created for two subjects with or without anterior open bite (Models I and II, respectively) in order to determine the amount and distribution of the stresses created by vertical chin cup on the TMJ. ABAQUS software was used to calculate the amount and distribution of the stresses by forming mesh structure of the geometric models from digital images. RESULTS: There were differences in the amount and distribution of the stresses on the TMJ in Models I and II created by vertical chin cup with an orthopedic force of 5 N. Mandibular condylar region follows the highest amount of stress tension found in the teeth of Models I and II. The highest amount of stress detected in the mandibular condylar area in Models I and II were 5.64 and 1.38 MPa, respectively. There were differences in the localization of high stress zones found in the mandibular condyle of Models I and II. The stress at the mandibular condylar head of Model I was localized in the upper posterior region whereas it was localized in the upper front region in Model II. CONCLUSION: Clinicians should be aware of the possible pathological effects of standart orthopedic forces on TMJ in subjects with anterior open bite.