Abstract

Aim: The pilot study aimed to evaluate the association between the presence of Temporomandibular Joint Ankylosis (TMJA) and the expression profile of the RANKL (nuclear kappa-B receptor activator factor/ligand) and OPG (osteoprotegerin) genes.

Methods: Jaw bone tissue samples not committed by ankylosis (jaw coronoid process jaw branch) and ankylotic block were collected from four children with TMJA during ankylosis surgical treatment composed the Test Group and Jaw bone tissue samples (jaw branch, jaw body) were collected from five adults with no history TMJA during jaw surgical treatment (trauma, extraction of mandibular third molar included and jaw dental implant installation) constituted the control group. The total RNA was isolated from osteoblasts using Trizol® reagent.The reverse transcription reaction of polymerase chain reaction (RT-PCR) was performed for the synthesis of complementary DNA (cDNA) from 300ng of RNA using the ImProm-II Reverse Transcription System™. Quantitative PCR evaluated OPG/RANKL mRNA expressions.

Results: RANKL gene expression showed reduced ‘levels in the test group compared to the control group (P=0.01). There was no significant difference between the levels of OPG gene expression (P=0.32) as well as the OPG/RANKL ratio (P=0.34) between the groups.

Conclusion: A change in the bone homeostasis from children with temporomandibular joint ankylosis favors the bone synthesis.

Keywords: Temporomandibular joint; Ankyllosis; Gene expression; RANK; OPG