Cone-beam computed tomography study of mandibular morphology and tooth compensation in asymmetrical patients.

INTRODUCTION: This study evaluated mandibular morphology and transverse dental compensation between symmetrical and asymmetrical subjects, allocated according to sagittal skeletal patterns. In addition, the hypothesis that mandibular morphology and dental compensations differed between symmetrical/asymmetrical groups and also among the different types of sagittal skeletal patterns was tested. METHODS: Cone-beam computed tomography images of 96 patients were included in this study and were divided into 2 groups according to the degree of menton deviation: a symmetrical group with deviation up to 2.0 mm (n = 48; mean age, 15 ± 6 years), and an asymmetrical group with deviation from 3.5 mm (n = 48; mean age, 16 ± 8 years). The 2 groups were divided in accordance with the ANB angle: Class I, II, and III. Skeletal and dental measurements were performed. Intergroup and intragroup analyses were carried out, using a 2-way analysis of variance to assess the interaction of factors: symmetry and sagittal skeletal pattern; and the Student t test for differences between deviated (Dv) and nondeviated (NDv) sides. RESULTS: Symmetrical/asymmetrical groups and Class I, II, and III groups were similar in relation to demographic aspects (P = 0.412 and P = 0.357 for sex and age, respectively). Asymmetrical patients had higher values for body length and mandibular ramus and condyle height on the NDv side (P = 0.011, P = 0.024, and P = 0.001, respectively). When comparing the different skeletal patterns, patients with a Class III relationship demonstrated higher values for mandibular ramus height. Intergroup analysis showed no differences in dental parameters. In the comparison between the sides, the asymmetrical group showed a significant difference in canine inclination (P = 0.008), mandibular ramus height (P = 0.004), condyle height (P = 0.010) and gonion to midsagittal plane distance (P = 0.018). CONCLUSIONS: Asymmetrical subjects showed higher values for canine inclination and mandibular body, ramus and condylar height on the NDv side. The hypothesis was partially confirmed that mandibular morphology and dental compensations are different between symmetrical/asymmetrical groups and among different sagittal skeletal patterns.

Are temporomandibular disorders associated with facial asymmetry? A systematic review and meta-analysis.

OBJECTIVE: To assess scientific evidence of the association between temporomandibular joint (TMJ) disorders and facial asymmetry (FA). METHODS: A systematic review was performed in accordance with the PRISMA checklist. A search strategy was developed in electronic databases including MEDLINE, Scopus, Web of Science, Virtual Health Library and Cochrane Library until January 2020. Eligibility criteria included observational studies that investigated the occurrence of FA among patients with and without signs and symptoms of TMJ disorders. Risk of bias of individual studies was analysed after study selection and data collection processes according to Fowkes and Fulton guidelines. Four meta-analyses (MA) were performed to evaluate the association between TMJ disorders and linear/angular menton deviation, subgrouping the studies into unilateral and bilateral cases. The evidence was certainty-tested using the GRADE approach. RESULTS: The search retrieved 2371 studies, 31 of which were eligible for full-text reading. Seven cross-sectional clinical studies met the eligibility criteria and were included in the qualitative synthesis, comprising a total of 621 subjects (345 with TMJ disease and 276 in control group), four of which were classified as being methodologically sound. Five studies were eligible for quantitative synthesis. Linear and angular menton deviation was greater in individuals with unilateral TMJ disorders than controls (MD = 2.41 [0.33, 4.50] P = .02; I2  = 86% and MD = 2.68 [0.99, 4.38] P = .002; I2  = 0%, respectively). CONCLUSIONS: Despite the low certainty in evidence, the present study indicated that unilateral TMJ disorders are associated with FA. However, longitudinal studies with greater certainty of evidence should be conducted to achieve a stronger estimate of this association.

Impaction of mandibular canine associated with a dentigerous cyst: a 2. 5 - year follow-up report

Introduction: Dentigerous cyst is an odontogenic cyst lesion surrounding the crown of an unerupted or impacted tooth in the jaw. Objective: The aim of this case report is to describe the treatment planning and follow-up of a dentigerous cyst associated with the impaction of the permanent mandibular right canine tooth in an 11-year-old female. Case report: Radiographic assessment revealed a radiolucent unilocular round-shaped lesion localized in the mandibular symphysis. Enucleation was performed and the affected tooth was removed under general anesthesia. The patient is under follow-up due to orthodontic treatment. The affected area healed without complications. Conclusion: Two and a half years after the enucleation, the cyst had totally disappeared, and no recurrences were observed. Bone remodeling and neoformation were noticed.

Introdução: O cisto dentígero é uma lesão odontogênica ao redor da coroa de um dente não irrompido ou impactado na mandíbula. Objetivo: O objetivo deste relato de caso é descrever o plano do tratamento e o acompanhamento de um cisto dentígero associado à impactação do canino permanente inferior direito em uma criança do gênero feminino de 11 anos de idade. Relato do caso: A avaliação radiográfica revelou lesão unilocular radiolúcida de forma arredondada, localizada na sínfise mandibular. A enucleação foi realizada e o dente afetado foi removido sob anestesia geral. A paciente encontra-se em acompanhamento devido o tratamento ortodôntico. A área afetada curou sem complicações. Conclusão: Dois anos e meio após a enucleação, o cisto desapareceu totalmente e não houve recidivas. Remodelação óssea e neoformação foram observadas.