No abstract

Objectives: Sawhney type IV temporomandibular joint (TMJ) total ankylosis is a challenging situation in which fusion of the mandibular condyle to the glenoid fossa, to the skull base generally occurs. The current well documented concept is using TMJ prosthesis following gap arthroplasty to re-establish the function. Methods: Between 2009 and 2016, simultaneously, bilateral TMJ gap arthroplasty and Zimmer-Biomet Microfixation stock TMJ Replacement System performed for 30 joints in 15 patients. The demographic data, number of previous TMJ operations, complications and maximum interincisal opening (MIO), were evaluated via nonparametric Mann-Whitney U test and Spearman's rho correlation analysis (P < 0.05). Findings: The follow-up was 12-91 months. There were 5 female and 10 male patients. Mean values were; 39.4 (standard deviation [SD], 17.5) for age; 3 (SD, 1.8) for previous operations; 3.6 (SD, 2) mm for preoperative MIO; 34.6 (SD, 6.1) mm for immediate postoperative MIO and 31.5 (SD, 6) mm for postoperative late MIO. The occlusion was unchanged in 12 patients out of 15. In one patient occlusion worsened with less stable functional contact. MIO relevantly improved in all cases (P < 0.05). The neuropraxia occurred on temporal branch of facial nerve. In one patient paraesthesia of the lower lip on one side observed. Conclusions: In the era of custom-made TMJ replacement systems, the stock total TMJ replacement system is still a good option. Although it is cheaper and ready to be used immediately, it still needs to have a topographically prepared receiving site and elongation of operation time.

Background: In orthognathic surgery, traditionally, we know that the stability wire need to be prepared in at least 4 weeks before surgery, so does passive state of stability wire when the impression for surgical splint taken (generally, 1-2 weeks before surgery). Otherwise, recently, two-jaw surgery with minimal orthodontics or before the orthodontics is preferred. Even, two-jaw surgery without orthodontics is reported. Objectives: We do a study about the clinical needs of the surgical wire for 4 weeks before the surgery and how it affects the postoperative stability. Methods: We compared the surgical wire for 4 weeks before the surgery with other groups, which were cases with rectangular wire, nickel titanium and none (does not proceed orthodontics). We studied about 174 patients who underwent two-jaw surgery for correction of class III malocclusion at the Department of Oral and Maxillofacial Surgery, Pusan National Univ. Dental Hospital between November 2013 and July 2015. We compared two cephalograms between postoperative and 6-12 months after surgery about FH-palatal, FH-occlusal, FMA, SNA, SNB and so on in the lateral cephalograms. Findings: Any groups do not have significant difference than other groups. Conclusion: Four weeks period for stability does not offer a better result, we could drop the stability period which increase the treatment period and needless surgical wire-making course.