Orientador: Vanessa Monteiro Pedro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-03T23:41:36Z (GMT). No. of bitstreams: 1 Semeghini_TatianaAdamov_D.pdf: 2521486 bytes, checksum: 66bbbe5501501dd84c2354d69d48a0a4 (MD5) Previous issue date: 2004 / Resumo: Embora a co-ativação da musculatura cervical durante a movimentação da mandíbula tenha sido estudada na literatura, esta situação ainda é pouco descrita quando comparados voluntários clinicamente normais e portadores de disfunções musculares. O objetivo deste trabalho foi estudar eletromiograficamente a co-ativação bilateral do músculo esternocleidomastoideo em relação aos Mm. Da mastigação em voluntários clinicamente normais e em portadores de bruxismo. Para a coleta do sinal mioelétrico foi utilizado um eletromiógrafo (*Lynx Eletronics) formado por um módulo condicionador de sinais de 12 bits de resolução, filtro tipo Butterworth (10,6 - 509 Hz) com ganho de 100 vezes, e placa conversora A/D, colocado dentro de uma Gaiola Eletrostática de Faraday. O registro mioelétrico foi realizado pelo software Aqdados, com apresentação simultânea dos canais usados e freqüência de amostragem de 1000 Hz, instalado em um computador 486 DX padrão. O sinal foi captado por eletrodos ativos diferenciais simples, formados por duas barras retangulares de prata paralelas, espaçadas por 10mm. e fixas entre si. A impedância de entrada dos eletrodos foi de 10G¿OMEGA¿, CCMR de 130 dB e 2pF, com ganho de 100 vezes. Foram também utilizados no estudo: eletrodo de referência; esparadrapos impermeáveis; Parafilme M (American National Can TM); metrônomo (Picollo - Winter), régua milimetrada. O sinal eletromiográfico foi coletado em três situações: a) isotonia dos músculos da mastigação; b) CIVM dos músculos da mastigação; c) CIVM do M. ECM. Os dados foram avaliados estatisticamente pelos testes ANOVA - Medidas Repetidas e Teste T para dados não pareados, de acordo com a situação estudada. Os resultados evidenciaram a presença da co-ativação do M. ECM em ambos grupos estudados e a análise dos valores médios de RMS bruto dos Mm. da mastigação revelou diferenças estatisticamente significativas entre os entre os grupos estudados nas variáveis músculos, lados e situações, validando os critérios de inclusão da amostra adotados nesta pesquisa. Em voluntários clinicamente normais, a ativação do M. ECM foi significativamente menor durante a isotonia que na isometria dos Mm. da mastigação, enquanto que em portadores de bruxismo, estas diferenças não foram verificadas. Na CIVM dos Mm. da mastigação, evidenciou-se uma diminuição das porcentagens bilaterais de co-ativação do M. ECM em relação à porção anterior do M. temporal, além da diminuição da ativação do músculo masseter e um aumento da ativação do músculo temporal em portadores de bruxismo, quando. comparados aos voluntários clinicamente normais. Comparando os valores de ativação do M. ECM nos movimentos mandibulares à sua CIVM, verificou-se uma diminuição de ativação muscular do lado direito em voluntários portadores de bruxismo. Os resultados desta pesquisa, sob suas condições experimentais realizadas, permitiram concluir que houve co-ativação do M. esternocleidomastoideo durante a movimentação mandibular e que esta parece sofrer influência das alterações dos músculos da mastigação em voluntários portadores de bruxismo, embora seja perceptível a necessidade de realização de mais estudos sobre o tema / Abstract: Although cervical muscles co-activation during jaw movements has been studied, this verification is stilllittle described in literature when are compared healthy subjects and patients with muscular dysfunction. The aim of this study was to verify by surface electromyography the bilateral co-activation of the sternocleidomastoid (SCM) muscle regarding to chewing muscles in healthy and bruxism volunteers. To record myoelectric signs, has been used a 16 channel signal conditioner with 12 bits dynamic band resolution (*Lynx Eletronics), Butterworth-type band pass filter (10,6-509 Hz) with gain of 100 times, and A/D converter board, placed inside of an Electrostatic Cage of Faraday. The myoelectric signs were displayed through by Aqdados Software installed in an Ibm-pc 486 DX2, that have showed simultaneous presentation of the used channels, each one with frequency of sampling of 1000 Hz. The signal was caught by simple active electrodes, formed by two rectangular and parallel silver bars, spaced for 10 mm. and fixed between it. The electrodes impedance of input was of 10G, 130 dB of CMRR and 2pF, with 100 times of gain. The materiaIs also used in this study were: reference electrode; adhesive tapes; Parafilm-M (American National Can¿POT. TM¿),metronome (Picollo-Winter) and milimetric ruler. The myoelectric signal was collected in three positions: a) chewing movements; b) clenching movements; c) isometric contraction of SCM muscles. The data has been evaluated statistically by ANOVA-repeated measures and impaired T tests, on accordance with the studied situation. The results have evidenced the presence of SCM coactivation in both groups and the analysis of RMS average values by chewing muscles have showed significant statistical differences between groups referring muscles, sides and situations analyzed, witch may be valid the criteria of sample inclusion adopted on this research. In healthy volunteers, the SCM co-activation was significantly fewer during chewing that in clenching, while that in bruxism subjects, these differences have not been verified. During clenching, a reduction of SCM co-activation referred as temporalis anterior muscle was proven, beyond the reduction of masseter muscle with an increase of temporalis anterior muscle activation has been observed in bruxism subjects. Comparing the values of SCM activation on jaw movements with its maximal isometric contractions, has been verified a significant reduction of muscular activity in right side on bruxism subjects. The results of this research, under those experimental conditions, have allowed concluding that the sternocleidomastoid coactivation during the jaw movements was verified in humans and that this seems to suffer influences from muscular alterations caused by bruxism. Thus, it is perceivable the necessity of accomplishment of more studies about this subject / Doutorado / Anatomia / Doutor em Biologia Buco-Dental

M.Tech. / OBJECTIVE: An association between cervicogenic headache, cervical joint dysfunction and the presence of myofascial trigger points in the sternocleidomastoid muscle exists. This study is aimed at determining the most effective Chiropractic treatment protocol in the management of cervicogenic headache by comparing the objective and subjective measurements gained in delivering Chiropractic spinal manipulative therapy to the upper cervical spine, myofascial dry needling therapy to myofascial trigger points in the sternocleidomastoid muscle and/or a combination of both therapies. DESIGN: Forty-eight participants suffering from cervicogenic headache were allocated into one of three groups of equal male to female ratio. Each patient was examined and cleared for participation in a clinical trial in which Diversified Chiropractic techniques and/or myofascial dry needling therapy were delivered. Group 1 received Chiropractic spinal manipulative therapy to the upper cervical spine. Group 2 received myofascial dry needling therapy to myofascial trigger points in the sternocleidomastoid muscle. Group 3 received a combination of the mentioned therapies. DURATION AND MEASUREMENTS: Participants were consulted seven times in a four week period. They were treated twice per week for three weeks and a final, follow-up assessment was performed at the start of the fourth week. Subjective and objective measurements were taken and recorded on the first, fourth and seventh consultations. Subjective measurements were taken via the Vernon-Mior Neck Pain and Disability Questionnaire, Triple Visual Analogue Scale and the Headache Disability Index. Objective measurements included cervical spine ranges of motion which were measured using the Cervical Range of Motion Instrument (CROM). The data was statistically analysed using the Shapiro-Wilk, Kruskal-Wallis, Mann-Whitney, Friedman and Wilcoxon Signed Ranks tests. RESULTS: Clinically and statistically significant improvements in all three groups were noted over the course of the study, with regards to perception of pain, disability and cervical spine range of motion. Statistically significant changes in ranges of motion were demonstrated in Group 1 for flexion, extension, lateral flexion (right and left) and right rotation; in Group 2 for right lateral flexion and left rotation and in Group 3 for all cervical ranges of motion. The comparison between the groups (intergroup analysis) showed no statistically significant changes except for right lateral flexion at the first consultation (pre-treatment). CONCLUSION: The results show that Chiropractic spinal manipulative therapy and dry needling are both effective treatment protocols in decreasing pain and dysfunction and increasing cervical range of motion in patients suffering from cervicogenic headache. This was demonstrated clinically, and to a lesser degree, statistically. The results carry a possible suggestion that although the different treatment options are effective individually, no treatment option proves to be statistically superior.

Book Summary: This book comprehensively covers the assessment and treatment of balance system impairments. Designed to be used in graduate programs in audiology, and by practicing audiologists, it is also appropriate for those in the fields of physical therapy, otolaryngology, and neurology. Assessment chapters address ocular motility testing, positional/positioning testing, caloric testing, rotational testing, computerized dynamic posturography, and vestibular evoked potentials. Treatment chapters cover non-medical, medical, and surgical treatment of dizziness and vertigo, vestibular rehabilitation and assessment of and intervention for falls risk. Additionally, the book provides background information on the vestibular and ocular motor systems, sample cases, and a final chapter, "Putting It All Together."

Doença de Parkinson é classificada como uma doença crônica degenerativa e progressiva, prevalecendo em indivíduos de 50 a 70 anos de idade, sendo mais comum no gênero masculino. Apresenta como principais sinais e sintomas o tremor ao repouso, bradicinesia, rigidez muscular e instabilidade postural, comprometendo a cadeia musculoesquelética. Esta pesquisa avaliou a eficiência dos ciclos mastigatórios por meio do envoltório linear do sinal eletromiográfico do músculo masseter, temporal e esternocleidomastoideo em indivíduos com doença de Parkinson. Foram selecionados 24 participantes na faixa etária entre 50 e 70 anos que foram distribuídos em dois grupos: com Doença de Parkinson (média ± DP 66,16 ± 3,37 anos, n=12) e sem Doença de Parkinson (média ± DP 65,83 ± 3,01 anos, n=12). O eletromiógrafo MyoSystem-I P84 foi utilizado para avaliar a eficiência dos ciclos mastigatórios na mastigação habitual e não habitual. Os dados foram tabulados e submetidos à análise estatística (teste t de student, p <= 0.05). Os resultados demonstraram que o grupo com a Doença de Parkinson apresentou aumento da atividade eletromiográfica durante os ciclos mastigatórios na mastigação não habitual com Parafilm M® sendo significativo para o músculo temporal direito (p = 0,01). Para a mastigação habitual de alimentos consistentes e macios houve uma maior ativação dos músculos mastigatórios e cervical para o grupo com a doença quando comparado ao grupo controle, sendo significativo para a mastigação habitual com amendoins o músculo temporal direito (p = 0,02), temporal esquerdo (p = 0,03), masseter direito (p = 0,01) e músculo esternocleidomastoideo direito (p = 0,001) e para a mastigação habitual com uvas passas o músculo temporal direito (p = 0,001), temporal esquerdo (p = 0,001), masseter direito (p = 0,001), masseter esquerdo (p = 0,03), esternocleidomastoideo direito (p = 0,001). Baseados nos resultados deste estudo pode-se concluir que em indivíduos com a Doença de Parkinson demonstrou menor eficiência na mastigação não habitual e habitual com alimentos consistentes e alimentos macios quando comparado ao grupo controle. / Parkinson\'s disease is classified as a chronic degenerative and progressive disease, prevalent in individuals from 50 to 70 years of age, being more common in the male gender. It presents as main signs and symptoms the tremor at rest, bradykinesia, muscular rigidity and postural instability, compromising the musculoskeletal chain. This research evaluated the efficiency of masticatory cycles by means of the linear envelope of the electromyographic signal of the masseter, temporal and sternocleidomastoid muscle in individuals with Parkinson\'s disease. Twenty-four participants in the age group between 50 and 70 years old were divided into two groups: Parkinson\'s disease (mean ± SD 66.16 ± 3.37 years, n = 12) and without Parkinson\'s disease (mean ± SD 65.83 ± 3.01 years, n=12). The MyoSystem-I P84 electromyograph was used to evaluate the masticatory cycling efficiency in habitual and non-habitual mastication. Data were tabulated and submitted to statistical analysis (student t test, p <= 0.05). The results showed that the group with Parkinson\'s Disease showed an increase in electromyographic activity during the masticatory cycles during non-habitual mastication with Parafilm M® being significant for the right temporal muscle (p = 0.01). For the usual mastication of consistent and soft foods, there was a greater activation of the masticatory and cervical muscles for the group with the disease when compared to the control group, being significant for the usual chewing with peanuts the right temporal muscle (p = 0.02), (p = 0.01) and right sternocleidomastoid muscle (p = 0.001) and for the habitual mastication with raisins the right temporal (p = 0.001), left temporal = 0.001), right masseter (p = 0.001), left masseter (p = 0.03), right sternocleidomastoid (p = 0.001). Based on the results of this study, it can be concluded that in individuals with Parkinson\'s disease, the efficiency of chewing is unusual and usual with consistent foods and soft foods when compared to the control group.

Vestibular evoked myogenic potentials (VEMP) are short latency electromyograms (EMG) evoked by high-level acoustic stimuli and recorded from surface electrodes over the tonically contracted sternocleidomastoid (SCM) muscle and are presumed to originate in the saccule. The present experiments examined the effects of click and tone-burst level and stimulus frequency on the latency, amplitude, and threshold of the VEMP in subjects with normal hearing sensitivity and no history of vestibular disease. VEMPs were recorded in all subjects using 100 dB nHL click stimuli. Most subjects had VEMPs present at 500, 750, and 1000 Hz, and few subjects had VEMPs present at 2000 Hz. The response amplitude of the VEMP increased with click and tone-burst level, whereas VEMP latency was not influenced by the stimulus level. The largest tone-burst-evoked VEMPs and lowest thresholds were obtained at 500 and 750 Hz. VEMP latency was independent of stimulus frequency when tone-burst duration was held constant.

Vestibular-evoked myogenic potentials (VEMPs) are proposed as a reliable test to supplement the current vestibular test battery by providing diagnostic information about saccular and/or inferior vestibular nerve function. VEMPs are short-latency electromyograms (EMGs) evoked by high-level acoustic stimuli and recorded from surface electrodes over the tonically contracted sternocleidomastoid muscle. VEMP amplitude is influenced by the EMG level, which must be controlled. This study examined the ability of subjects to achieve the EMG target levels over a range of target levels typically used during VEMP recordings. In addition, the influence of target EMG level on the latency and amplitude of the click- and tone-evoked VEMP was examined. The VEMP amplitude increased as a function of EMG target level, and the latency remained constant. EMG target levels ranging from 30 microV to 50 microV are suggested for clinical application of the VEMP.

Doença de Parkinson é um distúrbio neurológico, crônico e progressivo que promove alterações motoras com acometimento funcional da musculatura estriada esquelética. Este estudo avaliou a força de mordida molar, atividade eletromiográfica e espessura dos músculos temporal, masseter e esternocleidomastoideo de indivíduos com e sem a doença de Parkinson. Participaram 24 indivíduos, faixa etária entre 50 e 70 anos, distribuídos em dois grupos: com a doença de Parkinson, seguindo os estágios I e III de incapacidade da escala de Hoehn e Yahr, média ± DP 66,16 ± 3,37; n = 12 (GP) e sem a doença, média ± DP 65,83 ± 3,01; n = 12 (GC). Foi utilizado o dinamômetro digital Kratos na análise da força de mordida molar máxima direita e esquerda. O eletromiógrafo MyoSystem BR1 foi usado para captação do sinal eletromiográfico nas condições posturais da mandíbula em repouso, lateralidade direita e esquerda, protrusão, apertamento dental em contração voluntária máxima com e sem Parafilm M®. A imagem da espessura muscular foi mensurada por meio do ultrassom Sono Site Titan nas condições de repouso e apertamento dental em contração voluntária máxima. Os dados obtidos foram tabulados e submetidos à análise estatística (SPSS 21.0, teste t de student; p &le;0,05). A atividade eletromiográfica e espessura muscular revelaram diferenças significantes em quase todos os músculos durante as condições posturais mandibulares entre GP e GC (p&le;0,01 e p&le;0,05). Essas diferenças também foram observadas na força de mordida molar máxima direita e esquerda (p&le;0,01). O GP apresentou maior atividade EMG, maior espessura dos músculos temporais, menor espessura dos músculos masseteres e esternocleidomastoideos e menor força de mordida molar máxima. O entendimento de que a doença de Parkinson está associada com a função prejudicada do sistema estomatognático é extremamente importante para os profissionais da área da saúde na tomada de decisões relacionadas ao tratamento funcional reabilitador. / Parkinson\'s disease is a neurological, chronic and progressive disorder that promotes motor alterations with functional impairment of the skeletal striated musculature. This study evaluated the molar bite strength, electromyographic activity, and thickness of the temporal, masseter and sternocleidomastoid muscles of individuals with and without Parkinson\'s disease. Twenty-four individuals, aged between 50 and 70 years old, were divided into two groups: with Parkinson\'s disease, following stages I and III of Hoehn and Yahr disability, mean ± SD 66.16 ± 3.37; n = 12 (GP) and without the disease, mean ± SD 65.83 ± 3.01; n = 12 (GC). The Kratos digital dynamometer was used to analyze the maxillary right and left molar bite force. The MyoSystem BR1 electromyograph was used to capture the electromyographic signal at postural conditions of the resting mandible, right and left laterality, protrusion, maximum voluntary contraction, with and without Parafilm M®. The image of muscular thickness was measured by means of the Sono Site Titan ultrasound in the conditions of rest and dental tightening in maximum voluntary contraction. Data were tabulated and submitted to statistical analysis (SPSS 21.0, student t-test; p&le;0.05). The electromyographic activity and muscle thickness revealed significant differences in almost all muscles during mandibular postural conditions between PG and CG (p&le;0.01 and p&le;0.05). These differences were also observed in the right and left maximal molar bite force (p&le;0.01). The PG presented higher EMG activity, a greater thickness of the temporal muscles, lower thickness of the masseter and sternocleidomastoid muscles, and a lower maxillary bite force. The understanding that Parkinson\'s disease is associated with the impaired function of the stomatognathic system is extremely important for health professionals in making decisions related to functional rehabilitative treatment.

Doença de Parkinson é classificada como uma doença crônica degenerativa e progressiva, prevalecendo em indivíduos de 50 a 70 anos de idade, sendo mais comum no gênero masculino. Apresenta como principais sinais e sintomas o tremor ao repouso, bradicinesia, rigidez muscular e instabilidade postural, comprometendo a cadeia musculoesquelética. Esta pesquisa avaliou a eficiência dos ciclos mastigatórios por meio do envoltório linear do sinal eletromiográfico do músculo masseter, temporal e esternocleidomastoideo em indivíduos com doença de Parkinson. Foram selecionados 24 participantes na faixa etária entre 50 e 70 anos que foram distribuídos em dois grupos: com Doença de Parkinson (média ± DP 66,16 ± 3,37 anos, n=12) e sem Doença de Parkinson (média ± DP 65,83 ± 3,01 anos, n=12). O eletromiógrafo MyoSystem-I P84 foi utilizado para avaliar a eficiência dos ciclos mastigatórios na mastigação habitual e não habitual. Os dados foram tabulados e submetidos à análise estatística (teste t de student, p <= 0.05). Os resultados demonstraram que o grupo com a Doença de Parkinson apresentou aumento da atividade eletromiográfica durante os ciclos mastigatórios na mastigação não habitual com Parafilm M® sendo significativo para o músculo temporal direito (p = 0,01). Para a mastigação habitual de alimentos consistentes e macios houve uma maior ativação dos músculos mastigatórios e cervical para o grupo com a doença quando comparado ao grupo controle, sendo significativo para a mastigação habitual com amendoins o músculo temporal direito (p = 0,02), temporal esquerdo (p = 0,03), masseter direito (p = 0,01) e músculo esternocleidomastoideo direito (p = 0,001) e para a mastigação habitual com uvas passas o músculo temporal direito (p = 0,001), temporal esquerdo (p = 0,001), masseter direito (p = 0,001), masseter esquerdo (p = 0,03), esternocleidomastoideo direito (p = 0,001). Baseados nos resultados deste estudo pode-se concluir que em indivíduos com a Doença de Parkinson demonstrou menor eficiência na mastigação não habitual e habitual com alimentos consistentes e alimentos macios quando comparado ao grupo controle. / Parkinson\'s disease is classified as a chronic degenerative and progressive disease, prevalent in individuals from 50 to 70 years of age, being more common in the male gender. It presents as main signs and symptoms the tremor at rest, bradykinesia, muscular rigidity and postural instability, compromising the musculoskeletal chain. This research evaluated the efficiency of masticatory cycles by means of the linear envelope of the electromyographic signal of the masseter, temporal and sternocleidomastoid muscle in individuals with Parkinson\'s disease. Twenty-four participants in the age group between 50 and 70 years old were divided into two groups: Parkinson\'s disease (mean ± SD 66.16 ± 3.37 years, n = 12) and without Parkinson\'s disease (mean ± SD 65.83 ± 3.01 years, n=12). The MyoSystem-I P84 electromyograph was used to evaluate the masticatory cycling efficiency in habitual and non-habitual mastication. Data were tabulated and submitted to statistical analysis (student t test, p <= 0.05). The results showed that the group with Parkinson\'s Disease showed an increase in electromyographic activity during the masticatory cycles during non-habitual mastication with Parafilm M® being significant for the right temporal muscle (p = 0.01). For the usual mastication of consistent and soft foods, there was a greater activation of the masticatory and cervical muscles for the group with the disease when compared to the control group, being significant for the usual chewing with peanuts the right temporal muscle (p = 0.02), (p = 0.01) and right sternocleidomastoid muscle (p = 0.001) and for the habitual mastication with raisins the right temporal (p = 0.001), left temporal = 0.001), right masseter (p = 0.001), left masseter (p = 0.03), right sternocleidomastoid (p = 0.001). Based on the results of this study, it can be concluded that in individuals with Parkinson\'s disease, the efficiency of chewing is unusual and usual with consistent foods and soft foods when compared to the control group.

Doença de Parkinson é um distúrbio neurológico, crônico e progressivo que promove alterações motoras com acometimento funcional da musculatura estriada esquelética. Este estudo avaliou a força de mordida molar, atividade eletromiográfica e espessura dos músculos temporal, masseter e esternocleidomastoideo de indivíduos com e sem a doença de Parkinson. Participaram 24 indivíduos, faixa etária entre 50 e 70 anos, distribuídos em dois grupos: com a doença de Parkinson, seguindo os estágios I e III de incapacidade da escala de Hoehn e Yahr, média ± DP 66,16 ± 3,37; n = 12 (GP) e sem a doença, média ± DP 65,83 ± 3,01; n = 12 (GC). Foi utilizado o dinamômetro digital Kratos na análise da força de mordida molar máxima direita e esquerda. O eletromiógrafo MyoSystem BR1 foi usado para captação do sinal eletromiográfico nas condições posturais da mandíbula em repouso, lateralidade direita e esquerda, protrusão, apertamento dental em contração voluntária máxima com e sem Parafilm M®. A imagem da espessura muscular foi mensurada por meio do ultrassom Sono Site Titan nas condições de repouso e apertamento dental em contração voluntária máxima. Os dados obtidos foram tabulados e submetidos à análise estatística (SPSS 21.0, teste t de student; p &le;0,05). A atividade eletromiográfica e espessura muscular revelaram diferenças significantes em quase todos os músculos durante as condições posturais mandibulares entre GP e GC (p&le;0,01 e p&le;0,05). Essas diferenças também foram observadas na força de mordida molar máxima direita e esquerda (p&le;0,01). O GP apresentou maior atividade EMG, maior espessura dos músculos temporais, menor espessura dos músculos masseteres e esternocleidomastoideos e menor força de mordida molar máxima. O entendimento de que a doença de Parkinson está associada com a função prejudicada do sistema estomatognático é extremamente importante para os profissionais da área da saúde na tomada de decisões relacionadas ao tratamento funcional reabilitador. / Parkinson\'s disease is a neurological, chronic and progressive disorder that promotes motor alterations with functional impairment of the skeletal striated musculature. This study evaluated the molar bite strength, electromyographic activity, and thickness of the temporal, masseter and sternocleidomastoid muscles of individuals with and without Parkinson\'s disease. Twenty-four individuals, aged between 50 and 70 years old, were divided into two groups: with Parkinson\'s disease, following stages I and III of Hoehn and Yahr disability, mean ± SD 66.16 ± 3.37; n = 12 (GP) and without the disease, mean ± SD 65.83 ± 3.01; n = 12 (GC). The Kratos digital dynamometer was used to analyze the maxillary right and left molar bite force. The MyoSystem BR1 electromyograph was used to capture the electromyographic signal at postural conditions of the resting mandible, right and left laterality, protrusion, maximum voluntary contraction, with and without Parafilm M®. The image of muscular thickness was measured by means of the Sono Site Titan ultrasound in the conditions of rest and dental tightening in maximum voluntary contraction. Data were tabulated and submitted to statistical analysis (SPSS 21.0, student t-test; p&le;0.05). The electromyographic activity and muscle thickness revealed significant differences in almost all muscles during mandibular postural conditions between PG and CG (p&le;0.01 and p&le;0.05). These differences were also observed in the right and left maximal molar bite force (p&le;0.01). The PG presented higher EMG activity, a greater thickness of the temporal muscles, lower thickness of the masseter and sternocleidomastoid muscles, and a lower maxillary bite force. The understanding that Parkinson\'s disease is associated with the impaired function of the stomatognathic system is extremely important for health professionals in making decisions related to functional rehabilitative treatment.

Vestibular evoked myogenic potentials (VEMPs) are short-latency electromyograms evoked by high-level acoustic stimuli recorded from surface electrodes over the tonically contracted sternocleidomastoid (SCM) muscle. These responses are presumed to originate in the saccule. The purpose of this preliminary report is to provide an overview of our initial experience with the VEMP by describing the responses obtained in five subjects. Click-evoked VEMPs were present at short latencies in two normal-hearing subjects, one patient with profound congenital sensorineural hearing loss, and one patient with a severe sensorineural hearing loss due to Meniere's disease. Additionally, VEMPs were absent in a patient with profound sensorineural hearing loss following removal of a cerebellopontine angle tumor. The amplitude of the VEMP was influenced by the amount of background activity of the SCM muscle, stimulus level, and stimulus frequency. Tone-burst evoked responses showed an inverse relationship between stimulus frequency and response latency. VEMPs may prove to be a reliable technique in the clinical assessment of vestibular function.