Mandibular Flexure in Patients

Study Overview
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Brief Summary
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The flexion of the mandible (MF) is a multifactorial phenomenon that occurs simultaneously with mandibular movements determining changes in the shape of the mandible. mandibular flexure (MF) may cause complications and failures in both conventional and implant-supported fixed dental prostheses (FDP) especially when a long-span prosthesis is planned to connect the anterior to the posterior region of the mandible. Previous studies reported increased biomechanical stress at the prosthetic and implant level, poor passivity of fit, impression distortion, pain during function, de-cementation of the prosthesis, porcelain chipping, prosthetic screw loosening and fracture, bone resorption and implant fracture. The aim of this study is to quantify the dimensional changes related to MF by means of a cone beam computed tomography (CBCT) between maximum opening (MO) and maximum intercuspation (OVD) positions. The null hypothesis was that there is no significant difference in terms of length and width of the mandible between maximum intercuspation and maximum opening positions.

Official Title
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Mandibular Flexure: An In-vivo Study in Dentate Patients.

Conditions
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Mandibular Flexure

Intervention / Treatment
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* Diagnostic Test: Mandibular flexure evaluation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Dentate patients, 18 years of age or older, Good health Need of implant treatment Exclusion Criteria: active periodontitis with tooth mobility neuromuscular disorders temporomandibular joint disorders parafunctional habits systemic condition preventing surgery history of oro-maxillofacial radiation therapy history of drug or alcohol abuse heavy smoking uncontrolled diabetes pregnancy lactation.

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Flexure<br>Dentate patients, 18 years of age or older, in good health and, in need of implant treatment | Diagnostic Test: Mandibular flexure evaluation<br>* A mandibular silicon impression was taken, and a vacuum molded thermoplastic stent with radiopaque fiducial markers (steel ball bearings) on the facial side of the canines and molars was fabricated for each patient. Two Cone Beam Computed Tomographs (CBCTs) were made per patient with their radiographic stent in the mouth at the OVD and MO positions at the University Advanced Digital Diagnostic Center. The CBCT examination was performed without any stitching procedure using a computed tomography (SCANORA 3DX; Dexis LLC) set up at 90 kV, 4 mA and a field of view (FOV) of 140 and 100 mm in height and width respectively, to decrease the radiation dose without affecting the quality of the examination.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mandibular Flexure in Occlusal Vertical Dimension (OVD) | A blind assessor made 4 four measurements per patient on an implant planning software (DTX Studio Implant software, Dexis LLC), evaluating the distance between the fiducial landmark at the contralateral canines and contralateral molars, and between ipsilateral canines and molars on both sides | 24 hours | 
| Mandibular Flexure in maximum opening (MO) | A blind assessor made 4 four measurements per patient on an implant planning software (DTX Studio Implant software, Dexis LLC), evaluating the distance between the fiducial landmark at the contralateral canines and contralateral molars, and between ipsilateral canines and molars on both sides | 24 hours |