In patients with different degrees of suture oscification, mini-screw assisted rapid palatal expansion; investigation of its effects on the face, skull base and the temporomandibular joint region with 3d finite element analysis

Objective: In this study, mini-screw assisted rapid palatal expansion (MARPE) performed in patients with different degrees sutural ossification; It is aimed to investigate the amount stress and displacement in the face, skull base and temporomandibular joint region by finite element analysis. Materials and Methods: MARPE applied models with different sutural ossification degrees. Models; Type A model with incomplete ossification all sutures, Type B model with partially complete ossification all sutures, Type C model with complete ossification all sutures, Type D model with partially complete ossification midpalatal suture and complete ossification all other sutures. Force 100 Newtons applied to maxilla in transversal direction and resulting stress and displacement evaluated. Algor Fempro (ALGOR, Inc. 150 Beta Drive Pittsburgh, PA 15238-2932 USA) software used for analysis. Results: Highest stresses in models observed midpalatal suture, after periphery mini screws. Type B and Type D groups, when the peripheral sutures maxilla are examined, it is seen that Type D receives more stress. Other hand, when Type C and Type D groups examined, there is no great difference between resulting stresses. Greatest stress in foramen ovale seen Type C and Type D groups. Greatest stresses in SOS seen Type A and Type B groups. When midpalatal suture examined transversal axis, more opening observed in posterior than anterior. When results obtained from condyle examined, it seen that condyle moved upward and forward and mandibula showed anterior rotation. Conclusions: MARPE can be used for patients with high angle and maxillary constriction. There is no harm in using MARPE in different developmental stages. As the degree of ossification increased, the stresses at the skull base found to increase, but these stresses observed to be at negligible level. Key words: mini-screw, rapid maxillary expansion, suture ossification, finite element analysis