Simone Cecilio Hallak Regalo

Age and gender influence on maximal bite force and masticatory muscles thickness

The present study aimed investigate the age and gender influence on maximal molar bite force and at outlining the criteria for normal masticatory muscle development in a sample of 177 Brazilian Caucasian dentate individuals aged 7-80 years divided into five age groups: I (7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years), and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided in respect to gender (20 M/20 F). Bite force was recorded with a mouth-adapted 1000N dynamometer and the highest out of three records was regarded as the maximal bite force. The data were submitted to multivariate statistical analysis (SPSS 17.0 p<0.05). Effects of group and gender were found, but no interactions between them. The ANOVA showed significant differences between groups bilaterally. Bonferronis test showed that group I had significantly lower bite force means at both sides as compared to all groups, except group V. No differences were found between the left and right sides. In all the groups, gender was found to be a significant factor associated with maximal bite force. A global comparison including all the subjects and measures showed that the means of men were approximately 30% higher than those of women. Within-group comparisons yielded similar results in all groups. Muscle thickness was measured with a SonoSite Titan ultrasound tool using a high-resolution real-time 56mm/10MHz linear-array transducer. Three ultrasound images were obtained from the bilateral masseter and temporal muscles at rest and at maximal voluntary contraction. The means of the three measures in each clinical condition were analyzed with multivariate statistical analysis (SPSS 17.0 p<0.05). A gradual increase in thickness of the masseter and temporal muscles was found both at rest and maximal voluntary contraction for groups I to IV, whereas a decrease in muscle thickness was observed in group V. Multivariate analysis showed that in both conditions there was an effect of group and gender. The study of the development of the stomatognathic system in relation to age and gender can provide useful data for the identification of normal and impaired functioning patterns. The results of this study indicate that age and gender are associated with structural and functional alterations in the muscles of the stomatognathic system.

Use of the Fonseca's questionnaire to assess the prevalence and severity of temporomandibular disorders in brazilian dental undergraduates

This study to assessed the prevalence of signs and symptoms of temporomandibular disorders (TMD) by means of the frequency distribution of data for 218 dentistry students from a Brazilian public university using the Fonsecas questionnaire. The group consisted of 96 men and 122 women, with an average age of 20 years. Of the students, 53.21% showed some level of TMD: 35.78% mild TMD 11.93% moderate and 5.5% severe. Women were the most affected group, with 63.11% showing some level of TMD, against 40.62% of men. When considering only severe TMD, women are approximately 9 times more affected than men. Students with any level of TMD showed marked characteristics: 76.72% considered themselves tense people; 71.55% reported to clench or grind their teeth; 65.52% reported clicking of the temporomandibular joint; 64.66% reported frequent headache and 61.21% neck pain. In conclusion, clinical signs and symptoms of TMD can occur in young population and this information is of great importance for the early diagnosis of the dysfunction.

Ageing and surface EMG activity patterns of masticatory muscles

The purpose of this study was to evaluate the influence of age on the electromyographic activity of masticatory muscles. All volunteers were Brazilian, fully dentate (except for Group I - mixed dentition), Caucasian, aged 7-80, and divided into five groups: I (7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years) and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided with respect to gender (20 M/20 F). Surface electromyographic records of masticatory muscles were obtained at rest and during maximal voluntary contraction, right and left laterality, maximal jaw protrusion and maximal clenching in the intercuspal position. Statistically significant differences (P < 0.05) were found in all clinical conditions among the different age groups. Considerably different patterns of muscle activation were found across ages, with greater electromyographic activity in children and youth, and decreasing from adults to aged people.

Changes in Masticatory Performance and Quality of Life in Individuals With Chronic Periodontitis

BACKGROUND This study evaluates the effect of periodontitis on masticatory performance and quality of life index. METHODS Patients (n = 24; 23 to 76 years of age) with periodontal conditions ranging from healthy to generalized disease categorized by the alveolar bone height-to-tooth length (AB/T) ratio were separated into the following two groups: control (AB/T >50%) and test (AB/T <50%). The masticatory performance was evaluated through continuous mastication of a special device called a biocapsule. The Brazilian Oral Health Impact Profile (OHIP-14Br) questionnaire was used to assess the oral health-related quality of life. The Student t test was applied for independent samples (P <0.05) to evaluate the masticatory performance, and the Mann-Whitney U test was used to determine quality of life (P <0.05). RESULTS There was a statistically significant difference in masticatory efficiency between groups (P = 0.006). Statistically significant differences were also observed in the following parameters: 1) physical pain (P = 0.003); 2) psychologic discomfort (P = 0.008); 3) physical disability (P = 0.033); and 4) OHIP-14Br total score (P = 0.001). The control group achieved the best indicators. Both the masticatory performance and quality of life indicators showed significant correlation with the alveolar bone height. CONCLUSION The loss of periodontal supporting structures has negative effects on the masticatory performance and quality of life.

Emg analysis after laser acupuncture in patients with temporomandibular dysfunction (TMD). Implications for practice

The aim of this study was to analyze the effect of low level laser applied to acupuncture points of patients diagnosed with temporomandibular dysfunction (TMD). Ten patients aged between 20 and 50 years were clinically examined with regard to pain and dysfunction of the masticatory system. They received laser applications (GaAlAs diode laser, 780 nm wavelength; 70 mW power output, 35 j/cm(2)) in acupuncture specific points (Ig4, C3, E6, E7) once a week, for ten sessions. The range of jaw movement was registered after each session and visual analogue scale (VAS) was applied. Results were analyzed (SPSS-15.0-Chicago) during the comparison, before and after treatment. Statistical tests showed significant improvements (p < 0.01) in painful symptoms and electromyographic activities of masseter muscles in maximal habitual occlusion after laser applications but no significant improvements (p = 0.05) in measurements of mandibular movements. The laser therapy in specific acupuncture points promoted improvement of symptoms and it may be used as complementary therapy for TMD.

Evaluation of rhBMP-2 and Natural Latex as Potential Osteogenic Proteins in Critical Size Defects by Histomorphometric Methods

This in vivo study evaluated the osteogenic potential of two proteins, recombinant human bone morphogenetic protein‐2 (rhBMP‐2) and a protein extracted from natural latex (Hevea brasiliensis, P‐1), and compared their effects on bone defects when combined with a carrier or a collagen gelatin. Eighty‐four (84) Wistar rats were divided into two groups, with and without the use of collagen gelatin, and each of these were divided into six treatment groups of seven animals each. The treatment groups were: (1) 5 μg of pure rhBMP‐2; (2) 5 μg of rhBMP‐2/monoolein gel; (3) pure monoolein gel; (4) 5 μg of pure P‐1; (5) 5 μg of P‐1/monoolein gel; (6) critical bone defect control. The animals were anesthetized and a 6 mm diameter critical bone defect was made in the left posterior region of the parietal bone. Animals were submitted to intracardiac perfusion after 4 weeks and the calvaria tissue was removed for histomorphometric analysis. In this experimental study, it was concluded that rhBMP‐2 allowed greater new bone formation than P‐1 protein and this process was more effective when the bone defect was covered with collagen gelatin (P < 0.05). Anat Rec, 2010.

Evaluation of mandibular range of motion in Brazilian children and its correlation to age, height, weight, and gender

This study aimed to measure the active mandibular range of motion (ROM) (mouth opening: MO; right and left lateral movements: RL and LL; protrusion: P) in Brazilian children of both genders and of various ages, weights, and heights, and to establish correlations among such variables. Study subjects (n = 303) were healthy boys and girls, with ages ranging between 6 and 14 years, who were regular students of a public school in the state of São Paulo. Analysis of variance and intra-class correlation coefficients were considered significant for p < 0.05. Weak significant correlations were observed between mandibular ROM and age, height, and weight. No statistically significant differences (p > 0.05) were observed regarding mandibular ROM between gender groups. Mean mandibular ROM values showed significant increases (p < 0.05) in relation to age, height, and weight, except for RL (p > 0.05), in the studied age range. Significantly smaller (p < 0.05) mean mandibular ROM values were observed for the intervals of 6 and 7 years of age, 1.15-1.35 m, and 17.30-26.50 kg, in relation to the other ranges. Nonetheless, no differences were observed among mean mandibular ROM values in the ranges 8 to 12-14 years, 1.36-1.75 m, and 47-85 kg. Thus, it is suggested that weight, height, and age variables be considered when obtaining mandibular ROM values, particularly in children aged 6 to 7 years, measuring 1.15-1.35 m, and weighing between 17.3-46.5 kg.

Electromyographic evaluation in children having rapid maxillary expansion

INTRODUCTION The aim of this study was to analyze the electromyographic activity of the masseter and temporalis muscles of children having rapid maxillary expansion (RME) with a bonded rapid maxillary expansion appliance. METHODS The sample consisted of 27 children (mean age, 8.6 years) with posterior crossbite who required RME treatment. Electromyographic activity of the masseter and temporalis muscles was analyzed before treatment and after the appliance was removed. The mean interval between the 2 analyses was 5 months. Muscular activity was electromyographically analyzed in rest position, and with maximum voluntary dental clenching and chewing. Differences in the 2 measurements were evaluated by using paired t tests. RESULTS AND CONCLUSIONS Electromyographic analysis showed that activity of the masseter and temporalis muscles increased significantly after the expansion appliance was removed during rest, dental clenching, and habitual chewing.

Biomaterials Applied to the Bone Healing Process

Una innovacion reciente en medicina es la utilizacion de biomatenales en la reparacion de defectos oseos. Este trabajo tiene como objetivo presentar una actualizacion de los usos y aplicaciones de biomateriales y de sus diversos constituyentes mas empleados en la reparacion de los huesos

Morphodigital Study of the Mandibular Trabecular Bone in Panoramic Radiographs

El objetivo de este estudio fue correlacionar las caracteristicas morfodigitales del trabeculado oseo mandibular para de esta manera, verificar indicios de senales de osteoporosis, utilizando para esto, radiografias panoramicas de pacientes de ambos sexos. Los resultados del estudio mostraron diferencias entre los grupos masculino y femenino, en la cuantificacion de hueso trabecular mandibular (p 0,05). El grupo masculino presento un padron oseo trabecular mas compleo y fuerte que el grupo femenino. Este hallazgo puede ser un importante indicador en cuanto a los riesgos de osteoporosis, por ejemplo, siendo posible afirmar que los huesos de los individuos del grupo masculino estan menos sujetos a riesgo de fractura por osteoporosis