Assessment of thickness and function of masticatory and cervical muscles in adults with and without temporomandibular disorders.

OBJECTIVE: The aim of this study was to evaluate the maximal bite force (MBF), electromyographic (EMG) activity and thickness of the masseter, anterior part of the temporalis and sternocleidomastoid (SCM) muscles in a group of young adults with and without temporomandibular disorders (TMDs). DESIGN: Nineteen individuals comprised the TMD group (6 males/13 females, aged 25.4±3.8 years), classified based on the Research Diagnostic Criteria for TMD (RDC/TMD), and 19 comprised the control group (6 males/13 females, aged 24.1±3.6 years). The MBF was determined with a transducer placed between the dental arches at the first molars level (N). The muscles were evaluated bilaterally at rest and during maximal voluntary clenching (MVC) by assessing EMG activity and performing ultrasonography (USG). The mean values of these measures for both sides of the mouth were used. The normality of the distributions was assessed by the Shapiro-Wilks test. Variables between groups and genders were compared using two-way factorial ANOVA test and correlated using the Spearman coefficient (α=0.05). Unpaired t test was used to compare variables between TMD subgroups. Logistic regression analysis was used to identify the variables associated with the presence of TMD. RESULTS: MBF, EMG and USG data were similar among clinical groups and among TMD subgroups. The thickness of masseter and SCM muscles in the relaxed and clenching states were significantly higher in males than females. On the other hand, the EMG of the temporalis muscle in the rest state was significantly higher in females than males. Additionally, the MBF was positively correlated with the USG characteristics of masseter and SCM muscles, as well as with the EMG activity of masseter and temporalis muscles in the TMD group. In this group, there was also a positive correlation between the thickness of the masseter muscle and its activity. On the other hand, the thickness of the SCM muscle was negatively correlated with its activity. A lower MBF was independently associated with the presence of TMD. CONCLUSIONS: Subjects with TMD exhibited similar values of MBF, thickness and electrical activity of masticatory and cervical muscles when compared with controls; positive correlations observed between these variables may suggest a muscular alteration in TMD patients and a co-activation of masticatory and cervical muscles during mandibular movement. This fact may also be confirmed by the negative association between bite forces and presence of TMD.

Assessment of orofacial dysfunctions, salivary cortisol levels and oral health related quality of life (ORHQoL) in young adults.

OBJECTIVE: To investigate the relationship of orofacial dysfunction and salivary cortisol levels with oral health quality of life (ORHQoL) in young adults. DESIGN: Thirty individuals of both genders (22.93±2.42 years) participated. The orofacial dysfunction was evaluated using the Nordic Orofacial Test-Screening (NOT-S) and the ORHQoL using the Oral Health Impact Profile (OHIP-49). Saliva samples were collected during three days, at waking up and 30 min after, obtaining the awakening cortisol response - ACR. The data were analysed by Mann-Whitney test, Spearman's correlation and multiple linear regression (α=0.05). The NOT-S scores and ACR (µg/dl) were dichotomized by the median (2.0 and 0.15, respectively). RESULTS: NOT-S and ACR showed similar values between genders (P>0.05). The individuals with NOT-S scores above the median presented values of "physical pain" domain significantly higher than the individuals with scores bellow or equal to the median. Significant correlations were found between the OHIP-49 domains "physical pain" and "physical disability" and NOT-S scores. In multiple linear regression, significant values were observed between NOT-S and OHIP-49 and the domains physical pain, physical disability, psychological disability, social disability and handicap, with determination coefficients ranging from 0.09 to 0.15. There was not association with the ACR. CONCLUSIONS: Individuals with orofacial dysfunction presented impairment in ORHQoL, but not enough to change salivary cortisol levels. Furthermore, gender did not have influence on ORHQoL in the studied sample.

Computerized biophotogrammetry evaluation of asymmetry facial in patients with temporomandibular disorders

Introdução: os protocolos de avaliação das assimetrias faciais em pacientes com disfunção temporomandibular são, em grande parte, realizados por meio da avaliação cefalométrica, que possibilita a visualização, mensuração e análise apenas do tecido duro. A análise facial pela biofotogrametria computadorizada tem sido utilizada como meio auxiliar diagnóstico, não expondo o indivíduo a radiação nociva, promovendo avaliação das estruturas craniofaciais, musculares e a disposição do tecido adiposo. Objetivo: avaliar a assimetria facial em pacientes com disfunção temporomandibular por meio da biofotogrametria computadorizada. Material e métodos: a amostra consistiu de 36 pacientes com disfunção temporomandibular (31 mulheres e 05 homens), e 11 indivíduos controles (06 mulheres e 05 homens). Para a seleção e classificação da amostra foi utilizado o Índice Clínico de Fonseca (1994), seguido do exame físico, odontológico e fisioterapêutico. Resultados: foram encontradas diferenças significativas (p=0,041) quando comparados o ângulo referente à boca, entre os lados direito e esquerdo, nos pacientes com disfunção temporomandibular. Conclusão: alterações na simetria facial podem estar presentes em pacientes com disfunção temporomandibular, e que a mesma se encontra localizada no terço inferior da face, principalmente na região da maxila, mandíbula e mento.

Introduction: the protocols of evaluation of the asymmetry facial in patients with temporomandibular disorders are, in general, realized by using cephalometric analysis, which provide the visualization, measurement and analysis of the hard tissue only. The facial analysis by computerized biophotogrammetry has been used as an auxiliary manner of diagnostic, not exposing the patient to harmful radiation, promoting the evaluation of craniofacial and muscular structures and fat layer disposition. Aim: evaluate the facial asymmetry in patients with temporomandibular disorders by computerized biophotogrammetry. Material and methods: the sample was 36 patients (31 women and 05 men) and 11 controls (06 women and 05 men) with temporomandibular disorders. For selection and classification of the sample, the Clinical Index of Fonseca (1994) was used, according to physical, dentistry and physiotherapic examination. Results: significant differences (p=0,041) were found between the mouth angle and the right and left sides in patients with temporomandibular disorders. Conclusion: alteration in facial symmetry can be observed in patients with temporomandibular disorders and it is located in lower portion of face, mainly in maxillary, mandibular and menton regions.

Alterações biomecânicas em pacientes portadores de Disfunção Temporomandibular antes e após o uso de dispositivos oclusais / Biomechanical alterations in patients with temporomandibular disorders before and after the use of occlusal splint

Introdução: alterações funcionais do complexo temporomandibular podem refletir em adaptações no sistema muscular do indivíduo, interferindo com a postura mandibular e conseqüentemente com a posição da cabeça e da cintura escapular, modificando a biomecânica corporal. Objetivo: avaliar as alterações posturais da cabeça e ombros, bem como o lado de contato prematuro e de preferência mastigatória, em pacientes com disfunção temporomandibular, antes e após o uso de placa oclusal. Materiais e Métodos: um exame clínico (intra e extra-oral) e físico foi realizado em 20 pacientes com a disfunção, antes, uma semana e um mês após o uso de um dispositivo oclusal. Resultados: os resultados demonstraram uma redução da sintomatologia dolorosa e alteração do lado de inclinação da cabeça. Conclusão: pode-se concluir que existe uma inter-relação entre a oclusão e a postura do indivíduo que pode sofrer alterações no seu funcionamento decorrente de modificações estomatognáticas.

Introduction: an altered function in temporomandibular complex can reflect in adaptations for the muscular device of the individual, intervening with the mandibular position and consequently with head and scapular waist posture, modifying the corporal biomechanics. Purpose: evaluated the postural alterations of skull and shoulders as well the contact premature side and masticatory preference side, in patients with Temporomandibular Disorder (TMD), before and after an occlusal splint insertion. Materials and Methods: Clinical (intra and extra-oral) and physical examinations were done in 20 patients with dysfunction, before, one week and one month after myorelaxant occlusal splint instalation. Results: the results showed reductions in pain symptoms and alteration of the side of head inclination. Conclusion: it can be concluded that exists an interrelation between occlusion and the postural position of the individual that can suffer alterations in its operation decurrently from stomatognathic modifications.

Avaliação topográfica do forame mandibular em peças anatômicas maceradas parcialmente dentadas e edêntulas / Mansibular foramen topographic evaluation on partly dentate and edentulous macerate anatomic pieces

O bloqueio do nervo alveolar inferior é uma das técnicas anestésicas que apresenta maior índice de falhas em odontologia, em razão da variação anatômica do forame mandibular (FM), que é de suma importância para o êxito da anestesia dos dentes inferiores, por ser utilizado como referência anatômica para deposição da solução anestésica. Este estudo se propõe a avaliar a localização topográfica do FM em cem mandíbulas humanas maceradas, de indivíduos total ou parcialmente edentados, utilizando paquímetro milimetrado e compasso de ponta seca. Observou-se que no sentido craniocaudal o FM encontrava-se no terço médio do ramo mandibular em 80,4 por cento e 89,1 por cento das mandíbulas parcialmente dentadas (md) em em 63 por cento e 74 por cento das mandíbulas edêntulas (mdd), no antímero direito (D) e no esquerdo (E), respectivamente. No sentido ântero-posterior (AP), 97,8 por cento (D/E) das md apresentavam o FM no terço médio do ramo mandibular e, nas mdd, em 96,3 por cento (D) e 92,6 por cento (E) o FM localizava-se nesta posição. Também nos entido AP, em 2,2 por cento (D) e 4,4 por cento (E) das md e em 11,1 por cento (D) e 9,2 por cento (E) das mdd o FM encontrava-se centralizado entre os bordos anterior e posterior do ramo ascendente da mandíbula. Pode-se conluir que não há exata correlação topográfica do FM em antímeros opostos para o mesmo indivíduo, tampouco entre indivíduos diferentes.