title: Assessment of magnetic resonance images of displacement of the disc of the temporomandibular joint in different types of condylar fracture.
abstract: To evaluate the displacement of the disc of the temporomandibular joint (TMJ) in different types of condylar fracture we studied 160 patients (222 joints) from May 2009-June 2014. All patients had computed tomographic scans (CT) and magnetic resonance images (MRI) taken preoperatively, and 24 patients (32 joints) had MRI postoperatively. CT scans were reviewed to categorise the types of condylar fracture (intracapsular, condylar neck, and subcondylar), and intracapsular condylar fractures were further classified into subtypes A, B, C, and M. MRI were then reviewed to record the position of the disc in each type of condylar fracture. The results were compared using the chi square test. There were 160 intracapsular condylar fractures, 40 fractures of the condylar neck, and 22 subcondylar fractures. Of the intracapsular condylar fractures, 75 were type A, 49 type B, 11 type C, and 25 type M. Discs were displaced in 153 intracapsular condylar fractures, 17 fractures of the condylar neck, and eight subcondylar fractures. Among the type A intracapsular condylar fractures, discs were displaced in 71/75, type B in 47/49, type C in 10/11, and in all 25 type M. The incidence of displaced discs between intracapsular condylar fractures on the one hand, and those of the condylar neck or subcondylar region on the other, was significant (p<0.001), but there were no differences among the various subtypes of intracapsular condylar fractures. Postoperative MRI showed successful results in 28/32 joints. Intracapsular condylar fractures were more likely to have displaced discs than the other types. But there were no differences among different subtypes of intracapsular condylar fractures.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Collage of Stomatology, Shanghai JiaoTong University School of Medicine, and Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.
authors.forename: JiSi
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Collage of Stomatology, Shanghai JiaoTong University School of Medicine, and Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. Electronic address: zhangshanyong@126.com.
authors.forename: ShanYong
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Collage of Stomatology, Shanghai JiaoTong University School of Medicine, and Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. Electronic address: yangchi63@hotmail.com.
authors.forename: Chi
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Collage of Stomatology, Shanghai JiaoTong University School of Medicine, and Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China; Department of Craniomaxillofacial and Plastic Surgery, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Abdelrehem
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Collage of Stomatology, Shanghai JiaoTong University School of Medicine, and Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.
authors.forename: DongMei
authors.initials: D
authors.lastname: He
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Collage of Stomatology, Shanghai JiaoTong University School of Medicine, and Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.
authors.forename: HanHsuan
authors.initials: H
authors.lastname: Chiu
mesh_terms: D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008335:Mandibular Condyle; D008337:Mandibular Fractures; D013704:Temporomandibular Joint; D013705:Temporomandibular Joint Disorders
keywords: Condylar fracture; MRI; disc displacement