Relação entre disfunção temporomandibular, hipotonia dos músculos mastigatórios e distúrbios do sono em pacientes com síndrome de down / Relationship between temporomandibular disorders, hypotonia of masticatory muscles and sleep disorders in patients with Down syndrome

Investigar a presença de dor orofacial em pacientes com síndrome de Down (SD) e verificar sua influência na disfunção mastigatória (hipotonia muscular/frouxidão ligamentar) e nos distúrbios do sono nesses indivíduos. Vinte e três voluntários, jovens e adultos, de ambos os sexos, foram submetidos ao eixo I dos Critérios de Diagnóstico para Desordens Temporomandibulares (DC/TMD) para identificar a dor ou ausência de dor orofacial nos músculos masseter e temporal e na ATM (articulação temporomandibular). Na avaliação da função biomecânica, a hipotonia dos músculos mastigatórios (HPm) foi identificada a partir de eletromiografia de superfície (EMGs) dos músculos temporal (porção anterior) e masseter (porção superficial) em situação de contração voluntária máxima (CVM) e de força de mordida máxima (FMM), usando um transdutor de força e a frouxidão ligamentar identificada por meio da máxima abertura bucal (ABM) com auxílio de um paquímetro analógico. Os distúrbios do sono foram avaliados por exame de polissonografia tipo II (PSGII): apneia obstrutiva do sono (AOS), índice de ronco (IR) e índice de bruxismo do sono (IBS). Foram aplicados pré-testes estatísticos de Shapiro-Wilke de Bartlett, e para análise comparativa, os testes de Mann-Whitney e o teste T não-pareado para detectar diferenças entre os grupos comparados. Não houve diferenças significativas entre a dor muscular e na ATM entre os sexos; entretanto, a dor no músculo masseter esquerdo foi mais frequente em homens (69% dos pacientes) do que em mulheres (40% dos pacientes). As atividades elétricas dos músculos temporais direitos (p-valor 0,004) e esquerdos (p-valor 0,002) e no músculo masseter esquerdo (p-valor 0,008) foram estatisticamente menores nos homens que nas mulheres. Mulheres e homens apresentaram respectivamente: AOS grave (20% e 38,5%), IBS grave (40% e 54%), em variação de eventos/h, IBS (0 a 264 e 0 a 155) e o IR (4 a 45 e 6 a 53). A frouxidão ligamentar foi ligeiramente elevada em homens. Concluímos que a dor muscular mastigatória e artralgia foram encontradas. Provavelmente a dor influenciou no aumento da HPm pelo desuso dos músculos com dor, principalmente em ME dos homens. Não houve correlações entre a dor e os distúrbios do sono.

To investigate the presence of orofacial pain in patients with Down syndrome-DS and to verify its influence on the masticatory dysfunction (muscle hypotonia (MMH)/ligament hyperlaxity) and on the sleep disorders in these individuals. Twenty-three patients with DS were underwent a standardized clinical examination using the Diagnostic Criteria for Temporomandibular Disorders, axis I, to diagnose pain on masseter and temporal muscles and temporomandibular joint-TMJ. The MMH was proven by electromyographic records of the temporal and masseter muscles and by maximum bite force-MBF intensity using a force transducer, while the ligament hyperlaxity was identified through the maximum mouth opening-MMO, using an analog caliper. Sleep disorder (obstructive sleep apnea- OSA; snoring index-SI; and sleep bruxism index-SBI), were assessed through type II polysomnography home sleep test. Statistical analysis was done using Shapiro-Wilk and Bartlett statistical pre-tests, and for comparative analysis, the Mann-Whitney test and the unpaired t-test. Non-significant differences was verified between muscle and TMJ pains according to the sexes; however, the pain on the left masseter muscle was more frequent in men (69% of patients) than in women (40% of patients). The electrical activities of the temporal (left:p = 0.002; right:p= 0.004) and masseter (left:p= 0.008) muscles were statistically lower in men than in women. The MBF ranges were lower in men than in women. Women and men presented, respectively, severe OSA (20% and 38.5%), severe SBI (40% and 54%), and in events/h, SBI (0 to 264 and 0 to 155) and SI ( 4 to 45 and 6 to 53). Ligament hyperlaxity was slightly greater in men. We concluded that muscle and TMJ pains were found in some patients with DS, mainly in men. The pain on the temporal and masseter muscles may have influenced on the MMH severity in men, particularly in the left side. No correlation was found between the orofacial pain and sleep disorders.

Evaluation of the masticatory biomechanical function in Down syndrome and its Influence on sleep disorders, body adiposity and salivary parameters.

OBJECTIVE: To evaluate the phenotypic features of the masticatory biomechanics in atypical subjects with Down syndrome (DS). Its influence was analysed on sleep disorders, body adiposity and its risks, and some physicochemical properties of saliva. METHODS: Seventy subjects were enrolled to assess masticatory biomechanical function and divided into two groups: DS and control groups. Electrical activities of the masseter and temporal muscles (at rest and in maximum voluntary clench-MVC), maximum bite force-MBF and maximum mouth opening-MMO were investigated. Among the atypical subjects, just 24 participants underwent the anthropometry, the polysomnography II and the saliva testing (salivary flow rate-SFR, buffer capacity-BC and salivary cortisol levels, morning/SC-AM and night/SC-PM). RESULTS: MVC and MBF values showed high statistical significance in the control group (P < .001) than in the DS group of 35. MMO values were slightly increased in the DS group in relation to the control group. Overweight and obesity were found in both genders. Atypical women showed higher risk to develop cardiovascular-metabolic diseases than in atypical men. OSA severe was 20% for atypical women and 42.8% for atypical men, whereas snoring index was present in all genders. SFR was reduced in 100% of atypical subjects (hyposalivation in 10% women and 28.5% men). Furthermore, 100% BC, 66.6% SC-AM and 91.6% SC-PM showed normal patterns. CONCLUSION: Masseter and temporal muscle hypotonia was found in all atypical subjects with DS. This muscle dysfunction strongly was related to overweight/obesity, risks for development of cardiovascular/metabolic diseases, OSA severity, successive snoring episodes and salivary flow reduction in DS.