Abstract The etiology of temporomandibular disorders (TMD), which are considered as a heterogeneous group of psychophysiological disturbances, remains a controversial issue in clinical dentistry. This study aimed to evaluate whether the salivary alpha-amylase (sAA), cortisol levels, and anxiety symptoms differ between children with and without TMD. Initially, 316 young subjects were screened in public schools (nonreferred sample); 76 subjects aged 7–14 years were selected and comprised the TMD and control groups with 38 subjects each matched by sex, age, and the presence/absence of sleep bruxism. Four saliva samples were collected: upon waking, 30 min and 1 h after awakening (fasting), and at night (at 8 PM) on 2 alternate days to examine the diurnal profiles of cortisol and sAA. Anxiety symptoms were screened using the Multidimensional Anxiety Scale for Children (MASC-Brazilian version). Shapiro–Wilk test, Student’s t-test/Mann–Whitney U test, and correlation tests were used for data analysis. No significant differences were observed in the salivary cortisol area under the curve (AUCG mean ± SD = 90.22 ± 63.36 × 94.21 ± 63.13 µg/dL/min) and sAA AUCG (mean ± SD = 2544.52 ± 2142.00 × 2054.03 ± 1046.89 U/mL/min) between the TMD and control groups, respectively (p > 0.05); however, the clinical groups differed in social anxiety domain (t = 3.759; CI = 2.609, 8.496), separation/panic (t = 2.243; CI = 0.309, 5.217), physical symptoms (U = 433.500), and MASC total score (t = −3.527; CI = −23.062, −6.412), with a power of the test >80% and large effect size (d = 0.80), with no significant correlation between the MASC total score, cortisol, and sAA levels. Although children with TMD scored higher in anxiety symptoms, no difference was observed in the salivary stress biomarkers between children with and without TMD.

Objetivo avaliar o dimorfismo sexual e a relação entre as características morfológicas craniofaciais, dos arcos dentários e do músculo masseter na fase de dentição mista. Métodos 32 crianças, com idade entre 6-10 anos (14♀/18♂) com oclusão normal, compuseram a amostra. Características morfológicas craniofaciais, dos arcos dentários e espessura do masseter foram avaliadas por meio de radiografia cefalométrica posteroanterior, modelos em gesso e ultrassonografia, respectivamente. Os resultados foram analisados utilizando testes Shapiro-Wilk, Mann-Whitney/teste “t” e regressão linear múltipla para avaliar a relação entre a largura da face e idade, gênero, índice de massa corporal, espessura do masseter, distâncias intermolares e intercaninos (entre cúspides e pontos cervicais) e larguras nasal, maxilar, mandibular e intermolar. Resultados a espessura do masseter não diferiu significativamente entre os lados esquerdo e direito. A comparação entre os gêneros mostrou diferença significativa apenas na largura da face (maior em meninos). O modelo de regressão mostrou que a largura da face relacionou-se positivamente com o índice de massa corporal, espessura do masseter, distâncias intermolares (cúspides) e intercaninos (cervicais) inferiores e largura intermolar maxilar; e negativamente com a distância intermolares superiores (cúspides) e inferiores (cervicais) e intercaninos inferiores (cervicais). Ou seja, quando as demais variáveis foram adicionadas ao modelo, a variável explanatória gênero não alcançou valor significativo. Conclusão na amostra avaliada, a espessura do masseter e dimensões dos arcos dentários não diferiram entre gêneros; além disso, a largura da face mostrou relação significativa com o índice de massa corporal, espessura do masseter e dimensões dos arcos dentários, mas o gênero não contribuiu significativamente para sua variação.

Purpose to evaluate sexual dimorphism and the relationship between craniofacial characteristics, dental arch morphology and masseter muscle thickness in children in the mixed dentition stage. Methods the study sample comprised 32 children, aged 6-10 years (14♀/18♂) with normal occlusion. Craniofacial characteristics, dental morphology and masseter muscle thickness were evaluated by means of posteroanterior cephalometric radiographs, dental cast evaluation and ultrasound exam, respectively. The results were analyzed using Shapiro-Wilk test, Mann-Whitney/t-test and stepwise linear regression to assess the relation between face width and age, gender, body mass index, masseter thickness, distances between first molars and canines on dental casts (between cusps/cervical points), nasal, maxillary, mandibular and intermolar widths. Results masseter thickness showed no significant difference between the sides left/right. The comparison between genders showed significant difference only in face width, being larger in boys. The regression model showed that face width was positively related with body mass index, masseter thickness, mandibular first molar distances (cusps), mandibular canine distances (cervical points), and maxillary intermolar width; and negatively with maxillary (cusps) and mandibular molar distances (cervical points) and mandibular canine distances (cusps). That is, when the other studied variables were considered, the explanatory variable gender did not reach a significant value. Conclusion in the studied sample, the dimensions of the dental arches and masseter thickness did not differ between boys and girls; moreover, face width showed significant relationship with body mass index, masseter thickness, and dimensions of dental arches; but gender did not contribute significantly to face width variation.