Timing of arthrocentesis in the management of temporomandibular disorders: an integrative review and meta-analysis.

The aim of this study was to assess the best timing to perform arthrocentesis in the management of temporomandibular disorders with regard to conservative treatment. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, reference list search, and manual search was performed. Relevant articles were selected after three search rounds for final review based on six predefined inclusion criteria, followed by a round of critical appraisal. Eleven publications, including eight randomized controlled trials and three prospective clinical studies, were included in the review. The studies were divided into three groups based on the timing of arthrocentesis: (1) arthrocentesis as the initial treatment; (2) early arthrocentesis; and (3) late arthrocentesis. Meta-analysis was carried out to compare the efficacy of improvement in mouth opening and pain reduction in the three groups. All three groups showed improvement in mouth opening and pain reduction, with forest plots suggesting that arthrocentesis performed within 3 months of conservative treatment might produce beneficial results. We conclude that there is a knowledge gap in the current literature regarding the preferable timing to perform arthrocentesis in the management of temporomandibular disorders, and more high-quality randomized controlled trials are required to shed light on this subject.

Is there a difference between the thicknesses of the rami in mandibular asymmetry?

The purpose of this retrospective study was to investigate whether the thicknesses of the two rami differ in patients with mandibular asymmetry. Preoperative cone beam computed tomography scans of 78 patients with mandibular asymmetry were assessed for ramus thickness, mandibular length, and mandibular shift. The results showed that the ramus was thinner on the longer side than on the shorter side in 85.9% of the patients. On average, the longer side of the mandible was 2.74mm longer (range 0.07-9.90mm, standard deviation 1.92mm) and 0.55mm thinner (range -0.61 to 2.02mm, standard deviation 0.59mm) than the shorter side (both P<0.001). This study indicates a trend in the discrepancy in ramus thickness between the longer and shorter side of about 8% of the mean thickness of the ramus. Regression analysis showed that for every 1-mm increase in the length of the mandible, the thickness of the superior aspect of the ramus was reduced by 0.041 mm (P=0.009) and the anterior aspect by 0.125 mm (P=0.001). Age and sex did not have a significant influence on the thickness of the mandible. It is concluded that the longer side of the mandible tends to be thinner at the ramus than the shorter side in patients with mandibular asymmetry. The implication of this finding could be important in relation to the sagittal split ramus osteotomy.

Surgical morbidities of sagittal split ramus osteotomy versus intraoral vertical ramus osteotomy for the correction of mandibular prognathism: a randomized clinical trial.

The sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) are two common orthognathic procedures for the treatment of mandibular prognathism. This randomized clinical trial compared the surgical morbidities between SSRO and IVRO for patients with mandibular prognathism over the first 2 years postoperative. Ninety-eight patients (40 male, 58 female) with a mean age of 24.4±3.5 years underwent bilateral SSRO (98 sides) or IVRO (98 sides) as part or all of their orthognathic surgery. IVRO presented less short-term and long-term surgical morbidity in general. The SSRO group had a greater incidence of inferior alveolar nerve deficit at all follow-up time points (P< 0.01). There was more TMJ pain at 6 weeks (P= 0.047) and 3 months (P= 0.001) postoperative in the SSRO group. The SSRO group also presented more minor complications, which were related to titanium plate exposure and infection. There were no major complications for either technique in this study. Despite the need for intermaxillary fixation, IVRO appears to be associated with less surgical morbidity than SSRO when performed as a mandibular setback procedure to treat mandibular prognathism.

Bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy: a long-term analysis.

A residual bone defect at the distal aspect of the adjacent second molar may occur after total removal of the lower third molar. Lower third molar coronectomy has been proved to be a safe alternative to total removal, but the extent of bone regeneration at the adjacent tooth after coronectomy is not well reported. The aim of this prospective study was to investigate the long-term bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy. Preoperative and postoperative cone beam computed tomography scans were measured to assess bone regeneration at the distobuccal (DB), mid-distal (MD), and distolingual (DL) aspects of the lower second molar. Forty-eight coronectomies in 37 patients (23 female) with a mean±standard deviation age of 29.1±7.2 years were assessed. The mean follow-up was 93.2±8.7 months. The mean bone level increase at DB, MD, and DL aspects was 3.2±1.6mm, 3.5±1.5mm, and 3.2±1.6mm, respectively; the bone levels were significantly higher than the preoperative measurements (P<0.001). Age and impaction patterns were not factors affecting bone regeneration. Based on this study, it appears that coronectomy of the lower third molar brings favourable bone regeneration at the distal aspect of the adjacent second molar.

Three-dimensional radiographic evaluation of root migration patterns 4-8.5 years after lower third molar coronectomy: a cone beam computed tomography study.

This prospective study in patients with a follow-up of 4-8.5years aimed to describe the long-term, three-dimensional changes of coronectomized lower third molar roots. Pre- and postoperative cone beam computed tomography (CBCT) scans were compared. The distance of root migration, the direction of root translation and rotation, and the amount of bone regeneration at the adjacent second molar and superficially to the third molar root were recorded. Age, gender, time elapsed following surgery, the status of the retained root including, impaction pattern and depth of impaction were tested to check if they were influencing factors for the above outcomes. A total of 57 coronectomized third molars from 44 patients were included. The distance of the mean root migration was 2.82mm, and they predominantly translated mesially (76.8%). Age negatively correlated with the distance of migration. Root remnants with a soft tissue coverage had less bone regenerated at the adjacent second molar (1.27mm vs. 2.95mm) in comparison to their impacted counterparts. Based on the present radiographic results and the absence of any pathological findings, coronectomy can be recommended for selected cases of third molar removal as a safe procedure with favourable long-term outcomes.