Genetic Polymorphisms and Their Association With Temporomandibular Disorders

Summary

Temporomandibular disorders (TMD) are the most common orofacial pain disorders of non-dental origin with the prevalence of 6.1-10.2%, and incidence of 3.9%. Observable pathology is mostly absent, and the etiology often remains unknown. Since some other painful conditions of unknown origin (eg. fibromyalgia), also imply genetic factors, the aim of the study is to investigate genetic predisposition in relation to the risk for TMD onset. This will be achieved through analysis of polymorphisms in the selected genes in TMD patients (DC/TMD) and matched control subjects. The possibility of involvement of specific polymorphisms in modulation of therapy response will also be investigated. The hypotheses: (I) the Single Nucleotide Polymorphism (SNPs) clustering will be dependent on presence or absence of TMD (comparison of patients with control subjects), and will possibly depend on source of pain, pain intensity, presence of bone changes, psychological features and previous orthodontic therapy, and (II) SNPs will influence the treatment response. Along with anamnestic and clinical examination and occlusal splint therapy, genomic DNA will be analyzed from the buccal swabs. Isolated DNA will be used for the determination of 19 polymorphisms of selected genes using Real-Time PCR method. The analysis of salivary oxidative stress markers and opiorphin will be also performed, as their relationship with TMD has been shown previously. This time, their concentration will be associated with polymorphisms in the promoters of genes responsible for their synthesis. The investigators expect to show that particular gene profile or group of SNPs represent a risk factor for TMD development. Innovative approach of the concept of determining the genetic predisposition for TMD has the potential for development of commercial genetic test with potential for risk estimation in relation to TMD onset. This could enable early interventions and active avoidance of environmental risk factors.

Conditions

• Temporomandibular Disorders
• Orofacial Pain

Interventions

DEVICE

stabilization splint

The device made of a hard acrylic on stone cast of the upper jaw in the centric relation position. It has a thickness of 1.5 mm at the level of the first molar.

PROCEDURE

physical therapy

Home-exercise program included exercises for passive and active stretching, joint mobilization, passive extension, and translational movements to the right, left, and forward.

DEVICE

placebo splint

The placebo splint was made of thin heat-treatable foil (0.5 mm). The foil was heated and printed over a plaster model of the upper jaw resulting in a very thin film over the occlusal surfaces of all teeth.

Sponsors & Collaborators

• Croatian Science Foundation

  lead OTHER_GOV

Principal Investigators

• Iva Z Alajbeg · School of Dental Medicine, University of Zagreb

Eligibility

Min Age

15 Years

Max Age

59 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2017-05-01

Primary Completion

2024-01-30

Completion

2025-01-30

Countries

• Croatia

Study Locations