Body Weight Loss After Orthognathic Surgery: Comparison Between Postoperative Intermaxillary Fixation with Metal Wire and Elastic Traction, Factors Related to Body Weight Loss.

INTRODUCTION: The aim of this study was to compare body weight loss between postoperative intermaxillary fixation with metal wire and elastic traction and to investigate factors related to body weight loss after orthognathic surgery. MATERIALS AND METHODS: Subjects were 59 patients with dentofacial deformity, comprising 31 patients treated with intermaxillary fixation (IMF) and 28 patients treated with elastic traction without IMF (ELT) just after surgery. Body weight loss was measured at 1 week (T1) and 2 weeks (T2) after surgery. Body weight loss was compared between IMF and ELT, and factors related to body weight loss were statistically analyzed. RESULTS: Body weight loss ratio was significantly increased in IMF (2.6%) rather than in ELT (1.4%) at T1, but only tended to be increased in both groups at T2, showing no statistical difference. Body weight loss ratio was significantly increased at T2 compared to T1 in both groups. Body weight loss was significantly greater at T2 than at T1. CONCLUSION: Both IMF and ELT cause body weight loss after orthognathic surgery, but IMF causes body weight loss earlier than ELT and increased early body weight loss increases continuous body weight loss after orthognathic surgery.

Relations between anterior disc displacement and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle.

In this study we investigated the relation between anterior disc displacement (ADD) and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle. Thirty female patients (60 joints) with both conditions were evaluated. Magnetic resonance imaging of the temporomandibular joint (TMJ) was used to diagnose both ADD and changes to the mandibular condyle (erosion, osteophyte, and deformity). The relations among ADD, changes to the mandibular condyle, and maxillomandibular morphology were examined statistically. Changes to the mandibular condyle had a higher score than sym anterior open bite, the deviated side in asymmetric anterior open bite, and the non-deviated side. The score for disc displacement on the non-deviated side was lower than both the sym side and the deviated side. Unilateral changes to the mandibular condyle and unilateral disc displacement were not apparent in sym anterior open bite, but a unilateral non-displaced disc was seen only on the asymmetric side. Mandibular condylar changes were significantly more common on the deviated, than on the non-deviated, side. The SNB angle was significantly smaller, and the ANB, GZN, and SN-mandibular plane angles were significantly larger in sym anterior open bite. Overjet, ANB angle, GZN angle, and SN-MP angle were significantly larger, and the SNB angle was significantly smaller, in the presence of ADD without reduction and mandibular condylar deformity. We conclude that the prevalence of ADD without reduction and changes to the mandibular condyle were related to mandibular asymmetry and mandibular morphology in anterior open bite. This retrospective study suggests that ADD without reduction and mandibular condylar bone changes may be related to the progression of skeletal class II open bite and mandibular asymmetry in cases of skeletal open bite.

Incidence of anterior disc displacement without reduction of the temporomandibular joint in patients with dentofacial deformity.

The aim of this study was to investigate the incidence of anterior disc displacement without reduction (ADDwoR) of the temporomandibular joint (TMJ) in patients with dentofacial deformity. Eighty-eight female patients (176 joints) with skeletal class III malocclusion and 33 female patients (66 joints) with skeletal class II malocclusion, with or without anterior open bite and asymmetry, were evaluated. Magnetic resonance imaging (MRI) of the TMJ was used to diagnose ADDwoR. A statistical analysis was performed to examine the relationship between ADDwoR and skeletal structure. ADDwoR was present in 37 of the 66 joints (56.1%) in class II compared to 34 of the 176 joints (19.3%) in class III (P<0.05). In class III, ADDwoR was significantly more common in joints with mandibular asymmetry (24/74; 32.4%) than in joints with open bite (9/62; 14.5%) and joints with open bite and without mandibular asymmetry (1/38; 2.6%). In class II, ADDwoR was significantly less common in joints with mandibular asymmetry and without open bite (1/8; 12.5%). ADDwoR was only observed on the deviated side in both class III and class II with mandibular asymmetry. The prevalence of ADDwoR differed according to the dentofacial morphology.