Changes in temporomandibular joint disc position and form following Herbst and fixed orthodontic treatment

Objective: To determine the changes in the position and form of the temporomandibular joint articular disc in adolescents with Class II division 1 malocclusion and mandibular retrognathism treated with the Herbst appliance (phase I) and fixed orthodontic appliance (phase II).Materials and Methods: Thirty-two consecutive adolescents went through phase I of treatment and 23 completed phase II. the temporomandibular joints were evaluated qualitatively by means of magnetic resonance images at the beginning of treatment (T1), during phase I (T2), at the end of phase I (T3), and at the end of phase II (T4).Results: Significant changes in disc position were not observed with the mouth closed between T1 X T3 (P = .317), T3 X T4 (P = .287), or T1 X T4 (P = .261). At T2, on average, the disc was positioned regressively. With the mouth open, no difference was observed between T1 X T3 (P = .223) or T1 X T4 (P = .082). We did observe a significant difference between T3 X T4 (P < .05). Significant changes in the disc form were found with the mouth closed between T1 X T2 (P < .001) and T2 X T3 (P < .001).Conclusions: At the end of the two-phase treatment, in general terms, the position and form of the initial articular discs were maintained; however, in some temporomandibular joints some seemingly adverse effects were observed at T4. (Angle Orthod. 2010;80:843-852.)Univ Santa Cecilia, Dept Orthodont, BR-11055330 São Paulo, BrazilUniv São Paulo, Dept Orthodont, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Diagnost Imaging, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Otorhinolaryngol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Diagnost Imaging, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Otorhinolaryngol, São Paulo, BrazilWeb of Scienc

Evaluation of the condyle and disk position of temporomandibular joints by means of magnetic resonance in adolescents presenting with mandibular retrognatism treated with the Herbst appliance

O objetivo deste estudo prospectivo foi avaliar a posicao do condilo e disco das articulacoes temporomandibulares (ATMs), por meio de ressonancia magnetica (FIM), F em adolescentes portadores de maloclusao de Classe li, divisao 15' de Angle, associada a retrognatismo mandibular, tratados durante 12 meses com o aparelho ortopedico de Herbst. A amostra constou de 20 adolescentes brasileiros (40 ATMs), leucodermas, de ambos os sexos (sete do genero masculino e 13 do feminino), em fase de crescimento, com idade media de 12 anos e oito meses, desvio padrao de um ano e um mes e ausencia de deslocamento do disco articular. As imagens de RM foram adquiridas em tres tempos do tratamento: T1 - ao inicio, T2 -no periodo de oito semanas ate 10 semanas da colocacao do aparelho, e T3 - apos 12 meses, no final do periodo de avaliacao. Foi realizada uma avaliacao qualitativa da posicao do condilo na fossa mandibular, com boca fechada (BF), maxima intercuspidacao habitual (MIH) e da mobilidade condilar com boca aberta (BA). A posicao do disco articular foi avaliada de forma qualitativa e quantitativa com BF, MIH e BA. Na avaliacao qualitativa da posicao do condilo, foi observado que 33 (82,5 por cento) condilos de 40 ATMs estavam concentricos (BF) e retroposicionados (MIH) antes do inicio do tratamento (T1), ficaram anteriorizados (BF e MIH) no tempo intermediario (T2), retornando a posicao original (BF e MIH) no final do periodo de avaliacao (T3). Em sete (17,5 por cento) articulacoes o comportamento foi diferente, porem nao caracterizando uma condicao patologica. A avaliacao qualitativa da mobilidade condilar realizada com BA mostrou que 34 (85 por cento) condilos nao tiveram alteracoes nos tres tempos do tratamento, sendo que destes, 26 (65 por cento) condilos apresentaram mobilidade normal (T1, T2 e T3), seis (15 por cento) condilos hipermobilidade (T1, T2 e T3), e dois (5 por cento) condilos hipomobilidade (T1, T2 e T3). Em 15 por cento das articulacoes ocorreram alteracoes, sendo que em duas (5 por cento) articulacoes os condilos estavam com mobilidade normal (T1) e ficaram com hipomobilidade (T2 e T3); em duas (5 por cento) articulacoes os condilos estavam com mobilidade normal (T1 e T2) e ficaram com hipermobilidade (T3), e em duas (5 por cento) articulacoes, os condilos estavama(au)BV UNIFESP: Teses e dissertaçõe

Changes in temporomandibular joint disc position and form following Herbst and fixed orthodontic treatment

Objective: To determine the changes in the position and form of the temporomandibular joint articular disc in adolescents with Class II division 1 malocclusion and mandibular retrognathism treated with the Herbst appliance (phase I) and fixed orthodontic appliance (phase II). Materials and Methods: Thirty-two consecutive adolescents went through phase I of treatment and 23 completed phase II. The temporomandibular joints were evaluated qualitatively by means of magnetic resonance images at the beginning of treatment (T1), during phase I (T2), at the end of phase I (T3), and at the end of phase II (T4). Results: Significant changes in disc position were not observed with the mouth closed between T1 X T3 (P = .317), T3 X T4 (P = .287), or T1 X T4 (P = .261). At T2, on average, the disc was positioned regressively. With the mouth open, no difference was observed between T1 X T3 (P = .223) or T1 X T4 (P = .082). We did observe a significant difference between T3 X T4 (P < .05). Significant changes in the disc form were found with the mouth closed between T1 X T2 (P < .001) and T2 X T3 (P < .001). Conclusions: At the end of the two-phase treatment, in general terms, the position and form of the initial articular discs were maintained; however, in some temporomandibular joints some seemingly adverse effects were observed at T4. (Angle Orthod. 2010;80:843-852.

Temporomandibular joint evaluation with magnetic resonance imaging in children with functional unilateral posterior crossbite, treated with rapid maxillary expansion

Introduction: the purpose of this prospective study was to evaluate qualitatively articular disc position and configuration of the temporomandibular joint (TMJ) with magnetic resonance imaging (MRI) in children with functional unilateral posterior crossbite (FUPXB) treated with Haas-type orthopedic appliances. Methods: the sample included 30 Brazilian children (60 TMJs) of both sexes (8 boys, 22 girls), aged 6.8 to 14.2 years (mean, 10.5 years; SD, 2.1 years). the MRIs were acquired in closed-mouth (CM), maximum-intercuspal (MI), and open-mouth (OM) positions in 3 stages of treatment: initial (T1), at the beginning of treatment; intermediate (T2), immediately after the removal of the expander, and final (T3), 9 months later, at the end of the observation period. Results: No changes were found in articular disc positions of 96.6% of the TMJs in the CM and MI positions, and in 95% in the OM position at T1, T2, and T3. for the articular disc configuration, no changes were observed in 96.66% of the TMJs in the CM and MI positions, and in all TMJs in the OM position, at T1, T2, and T3. Conclusions: On average, this treatment method did not change articular disc positions and configurations. (Am J Orthod Dentofacial Orthop 2009;136:207-17)Univ São Paulo, Paulista Sch Med, Dept Diagnost Imaging, São Paulo, BrazilUniv Santa Cecilia, Dept Orthodont, Santos, BrazilUniversidade Federal de São Paulo, Paulista Sch Med, Dept Imaging Diagnost, São Paulo, BrazilUniversidade Federal de São Paulo, Paulista Sch Med, Dept Imaging Diagnost, São Paulo, BrazilWeb of Scienc