William Custodio

Proteome and Peptidome of Human Acquired Enamel Pellicle on Deciduous Teeth

Understanding the composition and structure of the acquired enamel pellicle (AEP) has been a major goal in oral biology. Our lab has conducted studies on the composition of AEP formed on permanent enamel. The exhaustive exploration has provided a comprehensive identification of more than 100 proteins from AEP formed on permanent enamel. The AEP formed on deciduous enamel has not been subjected to the same biochemical characterization scrutiny as that of permanent enamel, despite the fact that deciduous enamel is structurally different from permanent enamel. We hypothesized that the AEP proteome and peptidome formed on deciduous enamel may also be composed of unique proteins, some of which may not be common with AEP of permanent enamel explored previously. Pellicle material was collected from 10 children (aged 18–54 months) and subjected to mass spectrometry analysis. A total of 76 pellicle proteins were identified from the deciduous pellicle proteome. In addition, 38 natural occurring AEP peptides were identified from 10 proteins, suggesting that primary AEP proteome/peptidome presents a unique proteome composition. This is the first study to provide a comprehensive investigation of in vivo AEP formed on deciduous enamel.

Correlation of mastication and masticatory movements and effect of chewing side preference.

The aims of this study were to correlate masticatory performance with mandibular movements during mastication, and to evaluate masticatory performance and mandibular movements of subjects with different types of mastication. Seventy-eight healthy dentate subjects were selected and divided into 2 groups: bilateral and unilateral chewers. This classification was set by using kinesiography during mastication of an artificial material. Unilateral mastication was defined as the majority of the cycles took place at one specific side. The same tracings used to define type of mastication were used to evaluate mandibular movements by means of its parameters. Masticatory performance was analyzed by comminution of the artificial material and a sieving method. Statistical analysis was performed by Spearmans correlation method, and Mann-Whitney and Students t-test, when appropriate, at 5% significance level. No correlation was found between masticatory performance and parameters of mandibular movement during mastication. Bilateral chewers presented significantly better (p<0.05) masticatory performance than unilateral ones, however no differences in parameters of mandibular movement were found between groups. Within the limits of this study, it may be concluded that parameters of jaw movements during mastication are not related to masticatory performance, and that the presence of a preferred chewing side worsens mastication.

Masticatory features, EMG activity and muscle effort of subjects with different facial patterns

It has been suggested that craniofacial morphology plays an important role in masticatory function, however, there are controversies and unsolved questions that still require elucidation. The aims of this study were to evaluate masticatory performance, mandibular movement, electromyographic (EMG) activity and muscle effort of masseter and anterior temporal muscles during mastication. Seventy-eight dentate subjects were selected and divided into three groups according to vertical facial pattern: brachyfacial, mesofacial and dolichofacial. Silicon-based material was used for chewing tests. Masticatory performance was determined by a 10-sieve method, and masticatory movements during mastication were assessed using a 3D mandibular tracking device. Electromyographic activities of masseter and anterior temporal muscles were evaluated during mastication, and muscle effort was calculated by the percentage of activity required for mastication based on maximum muscle effort. Data were analysed using anova and anova on-ranks tests. Dolichofacial subjects presented significantly poorer masticatory performance (6·64±2·04; 4·33±0·70 and 3·67±0·63), slower rate of chewing (1·34±0·27, 1·18±0·22 and 1·21±0·20 cycles per second) and larger posterior displacement during mastication (6·22±2·18; 5·18±1·87 and 5·13±1·89) than meso- and brachyfacial individuals, respectively. No statistical difference was detected among groups for the other masticatory movement parameters. There was no difference in absolute EMG amplitudes of masseter and anterior temporal muscles during mastication among groups, but the relative effort of both muscles was higher in dolichofacial, followed by meso- and brachyfacial subjects (masseter: 39·34± 2·25; 36·87±4·05 and 33·33±4·15; anterior temporal: 38·12±1·61; 38·20±8·01 and 35·75±2·48). It was concluded that the vertical facial pattern influences masticatory performance, mandibular movement during mastication and the effort masticatory muscles required for chewing.

Occlusal force, electromyographic activity of masticatory muscles and mandibular flexure of subjects with different facial types

Objective The aim of this study was to evaluate whether vertical facial patterns influence maximal occlusal force (MOF), masticatory muscle electromyographic (EMG) activity, and medial mandibular flexure (MMF). Material and Methods Seventy-eight dentate subjects were divided into 3 groups by Rickettss analysis: brachyfacial, mesofacial and dolychofacial. Maximum occlusal force in the molar region was bilaterally measured with a force transducer. The electromyographic activities of the masseter and anterior temporal muscles were recorded during maximal voluntary clenching. Medial mandibular flexure was calculated by subtracting the intermolar distance of maximum opening or protrusion from the distance in the rest position. The data were analyzed using ANOVA followed by Tukeys HSD test. The significance level was set at 5%. Results Data on maximum occlusal force showed that shorter faces had higher occlusal forces (P<0.0001). Brachyfacial subjects presented higher levels of masseter electromyographic activity and medial mandibular flexure, followed by the mesofacial and dolychofacial groups. Additionally, dolychofacial subjects showed significantly lower electromyographic temporalis activities (P<0.05). Conclusion Within the limitations of the study, it may be concluded that maximum occlusal force, masticatory muscle activity and medial mandibular flexure were influenced by the vertical facial pattern.

Chewing side, bite force symmetry, and occlusal contact area of subjects with different facial vertical patterns

Craniofacial dimensions influence oral functions; however, it is not known whether they are associated with function asymmetry. The objective of this study was to evaluate chewing side preference and lateral asymmetry of occlusal contact area and bite force of individuals with different craniofacial patterns. Seventy-eight dentate subjects were divided into 3 groups according to the VERT index as follows: (1) mesofacial, (2) brachyfacial and (3) dolichofacial. Chewing side preference was evaluated using jaw tracking equipment, occlusal contact area was measured by silicon registration of posterior teeth, and bite force was measured unilaterally on molar regions using 2.25 mm-thick sensors. Statistical analysis was performed using ANOVA on Ranks, Students t-test, and Mann-Whitney tests at a 5% significance level. Mesofacial, brachyfacial, and dolichofacial subjects presented more occlusal contact area on the left side. Only dolichofacial subjects showed lateral asymmetry for bite force, presenting higher force on the left side. No statistically significant differences were found for chewing side preference among all groups. Within the limitations of this study, it can be concluded that craniofacial dimensions play a role in asymmetry of bite force. ClinicalTrials.gov ID: NCT01286363.

Salivary proteins as predictors and controls for oral health

We will provide a translational view of using the recent technological advances in dental research for predicting, monitoring, and preventing the development of oral diseases by investigating the diagnostic and therapeutic role of salivary proteins. New analytical state-of-the-art technologies such as mass spectrometry and atomic force microscopy have revolutionized the field of oral biology. These novel technologies open avenues for a comprehensive characterization of the salivary proteins followed by the evaluation of the physiological functions which could make possible in a near future the development of a new series of synthetic protein for therapeutic propose able to prevent global oral diseases such as periodontal disease and dental caries, the two most prevalent oral diseases in the World.

Mastication, EMG Activity and Occlusal Contact Area in Subjects with Different Facial Types

Abstract Dentofacial morphology may affect orofacial functions, therefore the aim of the current study was to evaluate the influence of craniofacial morphology on masticatory function, occlusal contact area (OCA), and masticatory muscles activity. Seventy-eight (78) subjects were divided into three groups according to vertical facial pattern: 1. mesofacial; 2. brachyfacial; and 3. dolichofacial. Artificial material and the sieving method were used to access masticatory efficiency (ME). OCA was determined by registration of posterior teeth. Electromyographic (EMG) activity of the masseter and anterior temporal (AT) muscles was accessed bilaterally at rest and at maximal vertical clenching (MVC). ME (%) was significantly higher in brachyfacial and lower in dolichofacial subjects. Brachyfacials presented the highest OCA (mm2) followed by meso and dolichofacial subjects. The EMG of the masseter and AT at rest and at MVC showed that dolichofacial subjects presented the lowest activity values, while brachyfacial subjects presented significantly higher measurements. Craniofacial morphology affected masticatory function, OCA, and EMG activity of the masticatory muscles.