Down syndrome: orofacial pain, masticatory muscle hypotonia, and sleep disorders.

The aim of the present study was to investigate orofacial pain in individuals with Down syndrome (DS) and determine possible associations with masticatory muscle hypotonia (MMH), maximum mouth opening (MMO), and sleep disorders. Twenty-three individuals with DS underwent a standardized clinical examination using Axis I of the Diagnostic Criteria for Temporomandibular Disorders, for the diagnosis of pain in the masseter and temporal muscles and temporomandibular joint (TMJ). MMH was investigated using electromyography of the temporal and masseter muscles and the measurement of maximum bite force (MBF). MMO was measured using an analog caliper. Sleep disorders (obstructive sleep apnea [OSA], snoring index [SI], and sleep bruxism index [SBI]) were investigated using type II polysomnography. Statistical analysis was performed. Nonsignificant differences were found in muscle and TMJ pain between the sexes. However, myalgia and referred myofascial pain in the left masseter muscle were more frequent in males (69%) than females (40%). Electrical activity of the temporal (left: p = .002; right: p = .004) and masseter (left: p = .008) muscles was significantly lower in males than in females. MBF range was lower in males than females, indicating the highest MMH among males. OSA, SI, and SBI were identified in both sexes, but with no statistically significant differences. We concluded that myalgia and referred myofascial pain were found in some individuals with DS, especially in males. Arthralgia was found mainly in females. Temporal and masseter myalgia may have exerted an influence on the severity of MMH in males, particularly on the left side.

The effect of Global Postural Reeducation on body weight distribution in sitting posture and on musculoskeletal pain. A pilot study.

OBJECTIVE: To quantify body weight distribution (BWD) in seated posture with an office chair instrumented with load cells and to evaluate the effects of ergonomic advice and Global Postural Reeducation (GPR) on seated BWD and on musculoskeletal pain. METHODS: Nineteen healthy females were randomly assigned: nine to the experimental group and 10 to the control group. Control group (CG) received only ergonomic verbal advice (EVA) regarding BWD in a seated position. Experimental group (EG) also received EVA and furthermore attended eight GPR sessions. Difference in the effects of the different therapeutic approaches was investigated using the non-parametric Wilcoxon-Mann-Whitney test. RESULTS: After treatments, there was no significant difference between the two groups as regards seated BWD. EG improved musculoskeletal pain significantly more than CG (p<0.005). Instead, musculoskeletal pain frequency decreased (p<0.005) only in EG (after EVA and GPR sessions), in neck, cervical, thoracic, lumbar, shoulders and wrists areas. CONCLUSIONS: Despite both interventions did not induce any significant improvement on seated BWD, adding GPR to EVA was related to a better reduction on musculoskeletal pain in young health females.

Analysis of masseter and temporal muscles during surgical extraction of impacted third molars.

With the aim of contributing to the discussion on stomatognathic system dysfunction after surgical procedures, this study compared the electromyographic activity of the superficial masseter and temporal masticatory muscles before, during, and after impacted mandibular third molar extractions. Muscular activity was recorded presurgery, transsurgery, immediately postoperatively, and on postoperative days 7, 15, and 30. Twenty patients requiring extraction of impacted mandibular third molars were selected and evaluated. In 20 patients who underwent mandibular third molar extractions, electromyography showed no alterations in muscle tone, and no statistically significant differences were observed in the left and right temporal and masseter muscles at any of the experimental periods at either mandibular rest or isometric contraction position. However, the degree of mouth opening increased 11.76% from pretreatment to 30 days after surgery. These results may reflect the shorter, careful extraction procedure performed by the surgeon.

Effect of a hyperbolide mastication apparatus for the treatment of severe sleep bruxism in a child with cerebral palsy: long-term follow-up.

PURPOSE: Sleep bruxism is common among the various oromotor alterations found in individuals with cerebral palsy (CP). Few studies have investigated the use of the mastication device denominated "hyperbola" (HB) and none was found describing the use of such a device for the treatment of bruxism in children with CP. The aim of the present study was to evaluate the effect of the HB on electromyographic (EMG) activity in the jaw-closing muscles and the reduction in sleep bruxism in a child with CP using surface EMG analysis before and after nine months of treatment. METHODS: A seven-year-old boy with severe spastic CP and sleep bruxism was enrolled in this study. The HB was chosen as the treatment option for sleep bruxism in this case because the child did not accept an occlusal splint. The HB has a hyperbolic shape and is made of soft, non-toxic, odorless, tasteless silicone. There are five different sizes of HB manufactured based on the diversity of tooth sizes. This device produces proprioceptive excitation in the dentoalveolar nerve, spindles and Golgi tendon organs. HB has been employed for the treatment of temporomandibular disorder, abnormal oro-dental development, abnormal occlusion, xerostomy, halitosis and bruxism. HB therapy was performed for 5 min six times a day over a nine-week period. Surface EMG of the mandible at rest and during maximum contraction was performed on the masseter and temporalis muscles bilaterally to evaluate electromyographic activity before and after nine months of HB usage. RESULTS: HB usage led to a visible tendency toward the reorganization of mastication dynamics, achieving a marked balance in electromyographic activity of the jaw-closing muscles and improving the child's quality of life. CONCLUSION: Based on the findings of the present study, this noninvasive therapy may be useful for individuals with cerebral palsy due to its positive effects and low cost, which allows its use in the public health realm. Further clinical studies with a larger sample size are needed to validate these results and allow the development of a new treatment protocol for patients with spastic cerebral palsy.