Biochemical, histological and histochemical evaluation for laser irradiation therapy on temporomandibular joint of rat induced arthritis via complete Freund’s adjuvant.

Objective: the purpose of this study was to assess the therapeutic effects of low-level laser irradiation therapy (LLLT) after induction of the complete Freund adjuvant (CFA) osteoarthritis on rat temporomandibular joint (TMJ). Subject and Methods: 30 Sprague Dawley rats allocated into 3 groups, ten rats each kept in normal housing conditions. Group I; negative control group: rats having TMJ structure. Group II; osteoarthritis positive control group: rats were induced with arthritis with an intra-articular injection of CFA in the right TMJ. Group III; therapeutic group: rats served as evaluating group, received ten sessions of low-level laser therapy, 30 days after induction of arthritis by CFA injection. Rats of all groups were anesthetized, blood samples were withdrawn, and biochemically investigated for interleukin-10 (IL-10) and tumour necrosis factor alpha (TNF-α ) content. By the end of experimental period, all animals of the various groups were sacrificed and TMJ was dissected out and prepared for microtechnical procession for histological and histochemical investigations. Result: the histological, histochemical and biochemical studies showed that the LLLT had relieved the experimentally induced pathological features by the complete Freund’s adjuvant as evidenced by the relatively restored normal histological, biochemical and histochemical features comparable with those in the control animals. Conclusion: the temporomandibular joint can be effectively treated with low-level laser therapy osteoarthritis.