Evaluation of the effectiveness of low level laser therapy on inflammation of temporomandibular joint in rabbit: A Tc-99m-HIG imaging study

Objectives Inflammatory joint disorders of temporomandibular joint (TMJ) are defined as a group of disorders in which internal and related structures of TMJ become inflamed. Tc-99m-HIG scintigraphy can be used to detect active joint inflammation. The aim of this study is to investigate the anti-inflammatory effects of Low Level Laser Therapy (LLLT) on aseptic inflammation of TMJ space using by Tc-99m-HIG scan.

Methods 12 male, New Zealand rabbits were included in the study. To evaluate recovery of inflammations, 6 randomly selected rabbits imaged before developing inflammation as normal group. Five percent formalin solution was locally injected to both right and left TMJ of all rabbits. Following the induction of inflammation, LLLT was performed 6 times for two weeks to left TMJs as treatment group. Right TMJs selected as control group. Scans were performed before and after each treatment with I.V administration of 3-5 mCi Tc-99m-HIG. Regions of Interests (ROI) were drawn on images for both sides of TMJ and background.

Results Scintigraphic values were compared with treatment/bkg, normal/bkg and control/bkg counts. For before and first week after treatment, statistically significant differences were observed for both treatment and control groups compared with normal group (p<0.05). No meaningful difference was found for both groups after second week. There was also no statistically significant difference between control and treatment groups.

Conclusions In this study, LLLT on TMJ inflammations was evaluated as ineffective and accuracy of Tc-99m-HIG scintigraphy on inflammation detection was pointed out.