Effects of temporal muscle detachment and coronoidotomy on facial growth in young rats

This study analyzed the effects of unilateral detachment of the temporal muscle and coronoidotomy on facial growth in young rats. Thirty one-month-old Wistar rats were distributed into three groups: detachment, coronoidotomy and sham-operated. Under general anesthesia, unilateral detachment of the temporal muscle was performed for the detachment group, unilateral coronoidotomy was performed for the coronoidotomy group, and only surgical access was performed for the sham-operated group. The animals were sacrificed at three months of age. Their soft tissues were removed, and the mandible was disarticulated. Radiographic projections-axial views of the skulls and lateral views of hemimandibles-were taken. Cephalometric evaluations were performed, and the values obtained were submitted to statistical analyses. There was a significant homolateral difference in the length of the premaxilla, height of the mandibular ramus and body, and the length of the mandible in all three groups. However, comparisons among the groups revealed no significant differences between the detachment and coronoidotomy groups for most measurements. It was concluded that both experimental detachment of the temporal muscle and coronoidotomy during the growth period in rats induced asymmetry of the mandible and affected the premaxilla

Study of the inflammatory process induced by injection of carrageenan or formalin in the rat temporomandibular joint Estudo do processo inflamatório induzido pela injeção de carragenina ou de formalina na articulação temporomandibular de ratos

The aim of this study was to evaluate the effects of the injection of two phlogistic agents, carrageenan and formalin, in the rat TMJ, and the inflammatory process induced by these substances. In this study, a total of 45 adult rats were distributed in two experimental groups and a control group. The animals were sacrificed after three hours, 24 hours, three days, seven days, and 15 days after a single injection of each substance. Histological data initially demonstrated an inflammatory process represented by acute infiltration, which later became mixed, and finally chronic in both experimental groups. Hyperplasia of the synovial membrane was observed after three days, being intense at seven days, and present after 15 days only in the formalin group. Local saline injection in the control group caused no inflammatory reaction. It was concluded that a single local injection of carrageenan or formalin was enough to induce inflammatory reaction in the TMJ and periarticular soft tissues, and that the resulting processes were similar, but more persistent in the formalin group.<br>O objetivo deste trabalho foi avaliar os efeitos da injeção de dois agentes flogísticos, ou seja, carragenina ou formalina, na ATM do rato, e a evolução do quadro inflamatório provocado por essas substâncias. Foram utilizados 45 ratos, divididos em dois grupos experimentais e um grupo controle. Os animais foram sacrificados em lotes de três de cada grupo após três horas, 24 horas, três dias, sete dias e 15 dias da injeção. Histologicamente a reação inflamatória em ambos os grupos experimentais iniciou-se com infiltrado inflamatório agudo, tornando-se misto e depois crônico. Sinais de hiperplasia da membrana sinovial foram observados aos três dias, intensos aos sete dias, estando presentes aos 15 dias somente no grupo da formalina. A injeção de solução salina (grupo controle) não provocou reação inflamatória. No presente trabalho foi concluído que uma injeção local única na região da ATM de carragenina ou de formalina foi suficiente para induzir reação inflamatória na articulação e nos tecidos moles periarticulares. As reações inflamatórias resultantes da injeção desses agentes flogísticos foram semelhantes, mas o grupo da formalina mostrou infiltrado inflamatório mais persistente

Speech evaluation in children with temporomandibular disorders

OBJECTIVE: The aims of this study were to evaluate the influence of temporomandibular disorders (TMD) on speech in children, and to verify the influence of occlusal characteristics. MATERIAL AND METHODS: Speech and dental occlusal characteristics were assessed in 152 Brazilian children (78 boys and 74 girls), aged 8 to 12 (mean age 10.05 ± 1.39 years) with or without TMD signs and symptoms. The clinical signs were evaluated using the Research Diagnostic Criteria for TMD (RDC/TMD) (axis I) and the symptoms were evaluated using a questionnaire. The following groups were formed: Group TMD (n=40), TMD signs and symptoms (Group S and S, n=68), TMD signs or symptoms (Group S or S, n=33), and without signs and symptoms (Group N, n=11). Articulatory speech disorders were diagnosed during spontaneous speech and repetition of the words using the "Phonological Assessment of Child Speech" for the Portuguese language. It was also applied a list of 40 phonological balanced words, read by the speech pathologist and repeated by the children. Data were analyzed by descriptive statistics, Fisher's exact or Chi-square tests (&#945;=0.05). RESULTS: A slight prevalence of articulatory disturbances, such as substitutions, omissions and distortions of the sibilants /s/ and /z/, and no deviations in jaw lateral movements were observed. Reduction of vertical amplitude was found in 10 children, the prevalence being greater in TMD signs and symptoms children than in the normal children. The tongue protrusion in phonemes /t/, /d/, /n/, /l/ and frontal lips in phonemes /s/ and /z/ were the most prevalent visual alterations. There was a high percentage of dental occlusal alterations. CONCLUSIONS: There was no association between TMD and speech disorders. Occlusal alterations may be factors of influence, allowing distortions and frontal lisp in phonemes /s/ and /z/ and inadequate tongue position in phonemes /t/; /d/; /n/; /l/