Comparative evaluation of the early effects of the low-level laser therapy versus intra-articular steroids on temporomandibular joint acute osteoarthritis in rats: A histochemical, molecular and imaging evaluation

Abstract

Background. Osteoarthritis (OA) is a serious degenerative joint disease. It is one of the main causes of disability in the world. Current treatment modalities have numerous side effects. Subsequently, health experts are looking for alternative therapies. Objectives. The aim of the study was to evaluate the early effects of low-level laser therapy (LLLT) vs intra-articular (IA) corticosteroids (CS) on acute temporomandibular joint osteoarthritis (TMJOA). Material and methods. Sixty rats were divided into 3 groups: group 1-untreated OA; group 2-OA treated with CS; and group 3-OA treated with LLL. Half of the animals in each group were sacrificed at 1 and 4 weeks post treatment. The temporomandibular joint was dissected and evaluated histochemically, using quantitative real-time polymerase chain reaction (qRT-PCR), and radiographically. Results. Histochemically, Safranin-O staining revealed an obvious reduction in proteoglycans in the untreated osteoarthritic group. However, both of the treated groups showed a moderate increase in glycosaminoglycan (GAG) staining. As for the qRT-PCR results, caspase-3 showed the highest mean value in the untreated OA group, followed by the CS group, while the lowest mean value was recorded in the LLL group. Radiographically, the condyle showed erosion, flattening, osteophyte formation, and sclerosis in the untreated group, but there was great improvement in both of the treated groups. Conclusions. Both laser and cortisone showed reparative and formative effects, as evidenced by the increases in the proteoglycan content. However, LLL was superior in its anti-apoptotic effects. Cone beam computed tomography (CBCT) is a valuable tool in assessing osseous abnormalities.

Osteoarthritis of the Temporomandibular Joint: A Narrative Overview

“…TMJ total prosthesis is schematically shown in Figure 4. Finally, He et al reported the potential of the use of low-intensity pulsed ultrasound for the early protection of cartilage [42], and AbuBakr et al reported the potential effectiveness of low-level laser therapy [5], which is used to relieve pain in various musculoskeletal disorders [69]. This therapy is known for its stimulatory effects on tissue metabolism and its ability to modulate the inflammatory process after injury.…”

“…Most studies included in this literature review used animal models [5,6,8,11,13,36,38,[40][41][42][43][44][45][46][47][48][49][50][51][52][53][54]57]. The most commonly investigated animals were mice and rats [5,8,11,13,36,38,[41][42][43][44][45][46][47][48][49][51][52][53][54]57]. One study was performed on rabbits [6].…”

“…Osteoarthritis (OA) is a common chronic degenerative joint disease characterized by synovitis, cartilage destruction, and subchondral bone remodeling [ 1 , 2 , 3 , 4 ]. It occurs progressively and can lead to disability [ 5 ]. It can be either monoarticular or polyarticular [ 6 ].…”

“…The temporomandibular joint (TMJ) is occasionally affected by chronic pathologies such as chondromatosis or OA [ 5 , 8 , 9 ]. OA can result in cortical bone erosion, flattening of joint compartments, osteophyte formation, subchondral sclerosis, and subcortical cyst formation [ 2 , 5 , 10 ].…”

Glucocorticoid Effects on Proteoglycans and Glycosaminoglycans

“…Moreover, DXM pretreatment or post-treatment of bovine explants inhibits GAG loss and increases PG synthesis in cartilage explants exposed to TNFα, preventing cartilage degradation [ 36 ]. GCs also restored the decreased content of total GAGs in rats temporomandibular joints in an in vivo model of acute temporomandibular joint osteoarthritis [ 37 ]. A similar result was shown for rat knee joints, where DXM administration at a dose of 1 mg/kg immediately prior to TNFα injection prevented TNFα-induced degradation of CSPG aggrecan and the release of aggrecanase-generated aggrecan fragments from the articular cartilage into the synovial fluid [ 38 ].…”