Altered MAstication Contribute to TMJ PAin

Study Overview
=================
Brief Summary
-----------------
The cause of temporomandibular joint disorders remains unknown. It is considered multifactorial and includes physical (peripheral) and psychosocial (central) factors. It has been showed an association: a steeper condylar path, flatter lateral anterior guidance, and habitual chewing on the symptomatic side. This finding argues the possibility of causation of some of these characteristics. This double blind longitudinal study aims to assess if the presence of one habitual chewing side could contribute to temporomandibular joint disorders over time. Method. Young adults with no signs or symptoms of TMD will be assessed. Participants with one chewing side (observed and interview); with steeper condylar path and lower lateral guidance angles will be considered consistent one side chewers, and this side will be considered more susceptible to suffer TMD. Mouth opening, hemispheric dominance and hemimandibular retrognathia will be considered as secondary pre-specified outcomes. Four years later, both TMJs of each participant presenting signs and/or symptoms will be evaluated according to DC/TMD.

Official Title
-----------------
One Habitual Chewing Side May Contribute to Chronic Temporomandibular Joint Disorder Pain

Conditions
-----------------
Temporomandibular Joint Disorders, Mastication Disorder

Intervention / Treatment
-----------------
* Other: Diagnostic


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: healthies full dentates normal occlusion One habitual chewing side Exclusion Criteria: Severe malocclusion, dental decay, severe periodontal disease. Pains from other origins or Orthodontics are not criteria for exclusion

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Diagnostic|OBSERVATIONAL, DIAGNOSTIC PROCEDURES. Young adults with no signs or symptoms of TMD will be assessed. The chewing function, condylar path angles and lateral guidance angles will be recorded. Maximum comfortable and unassisted jaw opening, hemispheric dominance and hemimandibular retrognathia will be considered as secondary pre-specified outcomes. Three-Four years later, both TMJs of each participant presenting signs and/or symptoms will be evaluated according to DC/TMD. Same recordings as baseline will be carried out.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presence or not of symptoms of temporomandibular joint disorders according to DC/TMD | Pain-intensity (0-10 VAS scale, Von Korf) | At 3 years follow-up | 
| Change of maximal unassited jaw opening | Maximum unassisted jaw opening or interincisal distance (from edge to edge) measured by a Boley gauge. Up 38 in females and up 40 mm in males are considered limited. | Baseline and 3 years follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of condylar paths angles inclination | Alteration of parasagittal plane Axiography of condyle motion in respect Frankfort horizontal plane | Baseline and 3-4-years follow-up (end of the study) | 
| Alteration of lateral dental guidance angles | Angle between Frankfort plane and lateral dental anterior guidance | Baseline and 4-years follow-up (end of the study) | 
| Change of maximal comfortable jaw opening | Maximum jaw opening or interincisal distance (from edge to edge) measured by a Boley gauge. Up 38 in females and up 40 mm in males are considered limited. | Baseline and 4-years follow-up (end of the study) | 
| Change of the habitual chewing side | Determining the habitual chewing side by direct observation using chewing gum, First cicle, and subsequent cicles (7 or over of 10 cicles), interview (used one habitual chewing side?: 1, no, alternate; 2, yes, right; 3, yes, left; 4, I don't know) and kinesiography. | Baseline and 3-4-years follow-up (end of the study) | 
| Change of lateral deviation during maximal unassisted jaw opening | Kiesiography K7 | Baseline, 3 years follow-up | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
occlusion, pain