Mandibular buccal shelf and infrazygomatic crest thicknesses in patients with different vertical facial heights.

INTRODUCTION: The purpose of this study was to use cone-beam computed tomography (CBCT) to determine bone thickness in the mandibular buccal shelf (MBS) and the infrazygomatic crest (IC) in individuals with different vertical facial heights for ultimate placement of miniscrews. METHODS: The sample consisted of 100 individuals aged at least 16 years, of whom 58 were women, and 42 were men. The mean age was 19.18 years (± 5.5 standard deviation). The patients' facial height was determined by the gonial angle. Cross-sectional slices of the MBS and IC were obtained with CBCT to evaluate bone thickness for the insertion of miniscrews in these extra-alveolar sites. Spearman's nonparametric test was used to correlate the gonial angle with MBS and IC thickness. The level of significance was 5%. RESULTS: The gonial angle ranged from 102.4° to 143.2°. Bone thickness in the MBS increased posteriorly, whereas bone thickness in the IC decreased posteriorly. There was an inversely proportional correlation between the gonial angle and the MBS. There was no correlation between the IC and the gonial angle. CONCLUSIONS: Short-faced individuals had higher bone thickness values in the MBS than long-faced ones. There was no correlation between the patients' vertical face height and the bone width in the IC. The best site to install miniscrews in the MBS is buccal to the second molar distal root, whereas in the IC, it is buccal to the first molar mesiobuccal root. CBCT may be necessary to install extra-alveolar miniscrews correctly, especially in the IC.

Efficacy of viscosupplementation with hyaluronic acid in temporomandibular disorders: A systematic review.

OBJECTIVE: To perform a systematic review of the viscosupplementation effectiveness with hyaluronic acid (HA) in the articular Temporomandibular Dysfunctions (TMDs) clinical management. METHOD: Electronic searches were performed in the following databases: MEDLINE (via PubMed), Scopus, Web of Science, Cochrane Library, EMBASE, LILACS, BBO, SIGLE (System for Information on Grey Literature in Europe), ClinicalTrials.gov, and the Brazilian Clinical Trials Registry (ReBec). Only randomized clinical trials that evaluated the intra-articular administration of HA or its derivatives in osteoarthritis and/or anterior displacement of the temporomandibular joint (TMJ) disc were included. The primary outcomes evaluated were patients' self-report of pain and/or discomfort in the TMJ. Each study was assessed for the risk of bias, using the Cochrane collaboration's risk of bias tool. RESULTS: A total of 640 studies were obtained in the electronic search. After the application of the eligibility criteria, manual search, and duplicate removal, 21 articles were included. Five articles classified their volunteers with internal derangements of the TMJ, in 4 articles the treatment was directed to participants with disc displacement with reduction and the other articles evaluated HA therapy in osteoarthritis. The protocols presented heterogeneity, varying in the form of application, associated or not with arthrocentesis, number of applications, molecular weight, dose and concentration. Nine studies presented high risk of bias. CONCLUSION: Due to the heterogeneity and methodological inconsistencies of the studies evaluated, it was not possible to establish the efficacy of HA in articular TMDs.