Three-dimensional finite element analysis of temporomandibular joints in patients with jaw deformity during unilateral molar clenching before and after orthognathic surgery

摘要

Jawdeformities not only negatively affecta patient'sappearance,chewing,and other oralfunctions butalso causeself-abasementand other psychological disorders. Moreover, they can causetemporomandibular disorder (TMD). Mandibular prognathismis the mostcommon maxillofacial deformity, which accounts forabout 43%ofallmaxillofacial deformities. [1] Facialasymmetry isanothercommon jawdeformitywith an incidenceranging from8.7%to 23.3%. [2] Combined orthognathicsurgeries have been often performed for thesejawdeformities. Sagittalsplit ramus osteotomy (SSRO) isacommon surgery for mandibular treatment; however, there has been aconcern about itseffect on temporomandibular joint (TMJ). [3–5] Le Fort I osteotomy isatreatmentmethod for maxillary deformities, [6,7] whichwas first described by Obwegeser in 1969. [8] The method has been popular owing to estheticconsiderations [9] ; however, itcan causesomeissues, such as relapse, fracture, poor stability,and cranial nerveinjuries.