Maria Peraire

Relationship between chewing side preference and handedness and lateral asymmetry of peripheral factors

OBJECTIVE To determine whether chewing side preference is related to handedness and lateral asymmetry of occlusal characteristics, muscular force and temporomandibular disorders (TMD) in a dentate population. DESIGN One hundred and seventeen dentate adults participated in this cross-sectional study. Static and dynamic occlusal characteristics were determined at the maximal intercuspal position and at the lateral excursions by scanning interocclusal records and analysing them using image software. Unilateral maximum bite force and finger-thumb grip force were measured by means of a gnathodynamometer. TMD were assessed according to the Research Diagnostic Criteria for TMD. Chewing side preference and masticatory laterality were determined by observing the jaws movement while each subject chewed silicone. Asymmetry or side difference of the variables was calculated. Correlation between side difference variables and masticatory laterality was studied using Spearman correlation coefficient. RESULTS Fifty-nine subjects chewed on the right, 15 on the left and 43 chewed on both sides. There was no relationship between preferred chewing side and handedness, lateral asymmetry of TMD or side difference in finger-thumb grip force. Significant and positive correlations were observed between masticatory laterality and side differences in bite force and side differences in occlusal contact area at intercuspal position (P<0.01). CONCLUSIONS Chewing side preference in a dentate population is related to lateral asymmetry of bite force and asymmetry of occlusal contact area at the intercuspal position but not to handedness.

Influence of static and dynamic occlusal characteristics and muscle force on masticatory performance in dentate adults

Masticatory performance is the outcome of a complex interplay of several factors. This study was carried out to determine the relationship between masticatory performance and several muscular-related and occlusion-related factors in a population with a full or near-full complement of natural teeth. One-hundred dentate young adults participated in this cross-sectional study. Maximum muscular force with jaw, hand, tongue, and cheek were measured by means of a gnatodynamometer. Occlusal contact area and number of teeth in contact were determined in the maximal intercuspal position and in a 1.5-mm right and left lateral excursion by means of interocclusal registrations that were scanned and analysed using image software. Masticatory performance was determined by sieving the Optosil particles resulting from 20 chewing cycles. Stepwise multiple linear regression analysis showed that the maximum bite force in the region of the first molar had the best correlation with masticatory performance and explained 36% of its variation. Static occlusion characteristics such as occlusal contact area, the lack of lateral crossbite and the number of anterior teeth in contact explained an additional 9% of the variation in masticatory performance. These findings suggest that variables related to dynamic occlusion or tongue or cheek force do not enhance the prediction of masticatory performance.

Risk factors for denture-related oral mucosal lesions in a geriatric population

STATEMENT OF PROBLEM Denture-related mucosal lesions have been broadly studied. However, no consensus has been reached regarding the risk factors associated with these lesions, and few studies have used multivariable analysis to determine the relative significance of different risks. PURPOSE The purpose of this study was to determine the relationship between systemic, local, and denture factors on the risk of denture-related oral mucosal lesions in an elderly population by using multivariable analysis. MATERIAL AND METHODS Eighty-four elderly denture wearers recruited from geriatric residences and day care centers participated in this cross-sectional study. All data were obtained by means of a questionnaire-interview, a physical examination, and complementary tests. Bivariate relationship and multiple logistic regression analyses were performed (α=.05). RESULTS Angular cheilitis (34%), traumatic ulcers (15%), and denture stomatitis (14%) were the 3 most common lesions, and the prevalence of at least 1 denture-related mucosal lesion was 54%. The presence of denture stomatitis was related to low saliva pH, never having smoked, and regular sugar consumption. Angular cheilitis was associated with age, complete edentulism, the presence of oral Candida, a lack of denture stability, and a reduced occlusal vertical dimension. The presence of traumatic ulcers was related to a resorbed residual alveolar ridge. The presence of at least 1 lesion was associated with poor masticatory efficiency, being resident in a care facility, oral Candida, and a lack of denture stability. CONCLUSIONS Several systemic, local, and denture-related characteristics are independent risk factors for denture-related mucosal lesions in an elderly population.

Study of mandibular movements during speech.

We recorded the mandibular movements produced during the reading of a text, in Spanish, using a kinesiograph in a random sample of 71 people aged 24 to 35. In each recording we measured nine variables and did a descriptive analysis of each variable. Our findings support that the mandibular movement during speech has some definite characteristics. The most important fact is that it could be a high percentage of occlusal contacts at incisal level during speech. This has to be taken into account when exploring an occlusal trauma of unknown etiology.

Relationship between jaw movement and masticatory performance in adults with natural dentition

Abstract Objective. This study determines the relationship between several characteristics of jaw movement and masticatory performance determined by multiple regression analysis and adjusted for occlusal contact area and bite force. Materials and methods. Forty-two young adults with natural dentition participated in this cross-sectional study. Occlusal contact area was determined at the maximum intercuspal position by scanning interocclusal records. Maximum unilateral force was measured by means of a gnathodynamometer. The height and amplitude of mastication, occlusal glide length, lateral guidance angle, anterior–posterior distance and cycle duration were recorded using the ARCUSdigma II system. Masticatory performance was determined by sieving the Optosil particles resulting from 20 chewing cycles. Results. Median particle size was negatively associated with height of mastication, maximum bite force, occlusal contact area and amplitude of mastication. Stepwise multiple linear regression analysis revealed that the height of mastication and dental guidance angle are the characteristics of jaw movement most closely related to masticatory performance. Conclusions. In adults with natural dentition, a large vertical height of mastication and a small dental guidance angle are the characteristics of jaw movement most closely associated with good masticatory performance, determined by multiple regression analysis and adjusted for occlusal contact area and bite force.

Is the side with the best masticatory performance selected for chewing

OBJECTIVE This study assessed the degree of relationship between masticatory laterality and lateral asymmetry of masticatory performance using silicon pieces enclosed in a latex bag. DESIGN Forty-two young adults with natural dentition participated in this cross-sectional, observational study. They performed four different masticatory assays, each consisting of five trials of chewing three pieces of silicon for 20 cycles. In one assay, they were asked to masticate unbagged silicon free-style, whilst in the three other assays they were asked to masticate bagged silicon free-style, unilaterally on the right-hand side and unilaterally on the left-hand side. The preferred chewing side was determined by calculating the asymmetry index for both the free-style assays. Masticatory performance was determined by sieving the silicon particles and the cycle duration was also recorded. Data were analysed using independent samples or paired t-test and linear regression. RESULTS Masticatory function using the bagged silicon was similar to that using the unbagged silicon. A significant and positive relationship was observed between the preferred chewing side expressed as the asymmetry index and the side with better masticatory performance. Alternate unilateral chewers demonstrated better masticatory performance than unilateral chewers. However, when free-style and unilateral chewing were compared for each subject, unilateral chewing was found to be as efficient as - or even more efficient than - free-style chewing. CONCLUSIONS There is a positive association between the preferred chewing side and the more efficient side. Alternate unilateral mastication per se does not promote better masticatory performance than consistently unilateral mastication.

Reliability of a visual analog scale for determining the preferred mastication side

STATEMENT OF PROBLEM Although the visual analog scale (VAS) is a simple tool for quantitatively measuring symptom perception, no studies have used the VAS to assess the degree of subjective masticatory laterality. PURPOSE The purpose of this study was to assess the reliability of the VAS for determining the preferred mastication side (PMS) and to compare it with other methods. MATERIAL AND METHODS A cross-sectional study was conducted in which 42 adults with natural dentition performed 2 masticatory sessions. Eight different methods were used to determine the PMS by combining different definitions, food tests, measurements, and number of cycles assessed. A test-retest was performed in 10 participants to evaluate the reliability of each method using the intraclass correlation coefficient. To assess the validity of the different methods, the Pearson correlations were performed (α=.05) between the 8 methods. RESULTS Self-assessment using the VAS had the highest reliability; it also had a positive and significant relationship with 6 of the 7 other methods. The method that showed the best validity used bagged silicone as the test food, determined the PMS by video recording, and assessed all masticatory cycles using the asymmetry index. Low reliability was found for methods using the location of gum bolus at standardized time intervals or electromyographic recordings. CONCLUSIONS The VAS provided a highly reliable means of assessing the degree of masticatory laterality perceived by the participant, with a positive and significant correlation with the majority of the other methods.

Peripheral, functional and postural asymmetries related to the preferred chewing side in adults with natural dentition.

The aim of this cross-sectional study was to determine the preferred chewing side and whether chewing side preference is related to peripheral, functional or postural lateral preferences. One hundred and forty-six adults with natural dentition performed three masticatory assays, each consisting of five trials of chewing three pieces of silicon placed into a latex bag for 20 cycles, either freestyle or unilaterally on the right- or left-hand side. Occlusal contact area in the intercuspal position, maximum bite force, masticatory performance and cycle duration were measured and the lateral asymmetry of these variables was calculated. Laterality tests were performed to determine handedness, footedness, earedness and eyedness as functional preferences, and hand-clasping, arm-folding and leg-crossing as postural lateral preferences. The preferred chewing side was determined using three different methods: assessment of the first chewing cycle for each trial, calculation of the asymmetry index from all cycles and application of a visual analogue scale. Bivariate relationship and multiple linear regression analyses were performed. Among unilateral chewers, 77% of them preferred the right side for chewing. The factors most closely related to the preferred chewing side were asymmetry of bite force, asymmetry of masticatory performance and earedness, which explained up to 16% of the variance. Although several functional or postural lateral preferences seem to be related to the preferred chewing side, peripheral factors such as asymmetry of bite force and of masticatory performance are the most closely related to the preferred chewing side in adults with natural dentition.

Influence of Matrix Type on Surface Roughness of Three Resins for Provisional Crowns and Fixed Partial Dentures

PURPOSE This study evaluated the effect of matrix type on the surface roughness of resins for provisional crowns and fixed partial dentures. MATERIALS AND METHODS Ninety specimens of two acrylic resins (Trim II, Tab2000) and one bis-acryl composite (Protemp II Garant) were fabricated using one of three matrices: irreversible hydrocolloid (Cavex CA37), poly(vinyl siloxane) (Aquasil) or vacuum-formed matrix (Bio-flow Hard). The sample size for each resin-matrix combination was 10. The vestibular face of one natural maxillary central incisor was used as a model to fabricate all the specimens, following the custom fabrication technique. The average roughness measurements, Ra (mum), were obtained using a profilometer, and the data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests. The results were contrasted against the surface roughness of the tooth using a one-sample t-test. RESULTS Aquasil and vacuum-formed matrix had a smoother surface than Cavex CA37 regardless of the resin tested (p < 0.05). Protemp II Garant had the smoothest surface regardless of the matrix used, with no significant differences when polymerized against the three different matrices. Trim II polymerized against Cavex CA37 had a rougher (p < 0.05) surface than Aquasil or vacuum-formed matrix. Tab2000 had the smoothest surface (p < 0.05) when polymerized against a vacuum-formed matrix. CONCLUSIONS There is no universal matrix that produces the smoothest surface: this depends on the compatibility between the resin and the matrix. Protemp II Garant polymerized against Cavex CA37 matrix yields a surface that is smooth enough not to require polishing unless this surface is adjusted.

Status of Removable Dentures and Relationship with Oral Candida‐Associated Factors in a Geriatric Population in Catalonia

PURPOSE Colonization by Candida is related to wearing a denture. How denture type, status, and maintenance play a role in determining Candida colonization remains unknown. This work evaluated removable denture status in an elderly population and explored the association between denture-related factors and oral Candida colonization as determined by systemic and local factors. MATERIALS AND METHODS Socio-demographic, general health, and behavioral data and oral factors were registered by means of a questionnaire. Oral, dental, and denture-related factors were assessed by clinical examination, and yeasts were isolated from oral and denture specimens. Multiple logistic regression analysis was used to explore the relative relevance of risk factors. RESULTS Overall, 52.4% of subjects used complete dentures in both lower and upper arches, and 90% of the prostheses were in good condition. Denture plaque index was high in most cases, and 75% of subjects had yeasts in their oral cavities. Oral Candida colonization was significantly associated with low saliva pH, sugar consumption, and the fault of a denture component; however, only sugar consumption was found to be an independent factor related with oral Candida colonization, showing an odds ratio of 3.04 in a multiple logistic regression model. CONCLUSIONS Elderly people in this study used a complete denture in good condition, with a median age of 15 years. Daily or weekly sugar consumption was found to be highly associated with oral colonization by Candida.