Importance of Bone Markers and Radiological Status on Clinical Signs of Temporomandibular Joint Disorders

This chapter describes the diagnostics of temporomandibular joint disorders (TMDs) with the main focus on the radiographic changes and the role of different bone markers as procollagen type I N-terminal propeptide (P1NP), C-telopeptide crosslaps of type I col‐ lagen (CTX-1) as well as vitamin D (25(OH)D) in the pathogenesis of TMDs. From our population-based study, 47% subjects had TMJ problems where pain is commonly ac‐ companied by stiffness, sounds and functional limitations, resulting in a decreased quali‐ ty of life, and thus exert a significant negative impact on activities of daily living (ADL). Assessment of individual pain level is important in the evaluation of TMD. Radiographic examination is commonly used for assessment of TMJ problems. Orthopantomograph (OPTG) is the most routine method for assessment of bone structural changes as erosions, flattening and osteophytes of the condyle and temporal part of TMJ. It is found that sub‐ jects with increased levels of P1NP, CTX-1 have less TMJ pain/discomfort. Increased lev‐ els of CTX-1 would probably cause an immediate increase of P1NP which is known as a sensitive marker of bone formation. TMJ radiographic changes seem to be related to the low level of 25(OH)D level. Hence, the aim of this chapter is to critically review the evidence of possible association between TMJ pain and bone radiographic changes with main focus on the role of differ‐ ent bone markers and vitamin D.