Facial Patterns and Masticatory Symmetries

Study Overview
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Brief Summary
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The purpose of this study is to evaluate chewing side preference, and lateral asymmetry of occlusal contact area and bite force of individuals with different craniofacial patterns

Detailed Description
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Dolichofacial subjects presents poorer mechanical advantage, less efficiency in masticatory muscles during mastication and in generating bite force, smaller occlusal contact area and masticatory capacity when compared to brachyfacial individuals. Wide, bilateral chewing cycles were related to better masticatory performance, however, unilateral chewing was reported to be very common in population, and it has been associated to lateral asymmetry on bite force and occlusal contact area. It has been reported that dolichofacial subjects need greater muscular effort during mastication when compared to meso and brachyfacial subjects. This may cause functional overloading of weaker masticatory muscles, and may lead to functional asymmetries.

Official Title
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Preferred Chewing Side, Symmetry of Bite Force and Occlusal Contact Area of Subjects With Different Craniofacial Vertical Dimensions

Conditions
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Facies

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Full dentition, good general and oral health Exclusion Criteria: Facial deformities Severe malocclusion History of signs and symptoms of temporomandibular disorder History of parafunctions History of maxillofacial surgery or jaw injuries and orthodontic treatment concluded in the last 2 years

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 32 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Brachyfacial<br>Subjects with a horizontal facial growth pattern | |
| Mesofacial<br>Subjects with a balanced facial growth pattern | |
| Dolichofacial<br>Subjects with a vertical facial growth pattern | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Masticatory movements during mastication | A jaw tracking device was positioned on subjects face, who were asked to chew an artificial material in their habitual way. Tracings of jaw lateral movements during mastication were analyzed to classify in which side each chewing stroke was taken. If 80 percent or more chewing cycles were classified as left or right, the subjects were considered as unilateral chewer. | 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Bite force and occlusal contact area | A strain gauge was positioned on subject's first molar region unilaterally to measure the symmetry of bite force. The individual was asked to bite as hard as possible. The procedure was repeated to the other side, and the bite symmetry of sides was analyzed. To evaluate symmetry of occlusal contact area, a registration of posterior teeth was performed with the subjects in maximal intercuspal position. The registration was digitalized, discolored, color inverted and adjusted for size to evaluate thickness of registration material using a software. | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bite force, Dental occlusion, Face, Mastication, Morphology