Leonore C Dijkgraaf

The structure, biochemistry, and metabolism of osteoarthritic cartilage: A review of the literature

PURPOSE To understand the possible significance of the presence of proteases, cytokines, growth factors, and arachidonic acid metabolites in the osteoarthritic temporomandibular joint (TMJ), the pathogenesis of TMJ osteoarthritis (OA) is discussed, based on knowledge of structure, biochemistry and metabolism of osteoarthritic cartilage in general, and a classification of TMJ OA is presented.

Epidemiology and natural progression of articular temporomandibular disorders

The reported prevalence of temporomandibular disorders (TMDs) differs from study to study, probably because of methodologic errors and lack of standardized definitions of TMDs and their characteristics. Classification of TMDs should be in accordance with classification of synovial joint disorders as generally used by rheumatologists and orthopedic surgeons, in which articular disorders are distinguished from nonarticular disorders. Articular temporomandibular disorders appear to be self-limiting in a very high percentage of cases. Because of this nonprogressive nature, the outcome of nonsurgical management will be highly successful.

NORMAL CARTILAGE STRUCTURE, BIOCHEMISTRY, AND METABOLISM - A REVIEW OF THE LITERATURE

PURPOSE To understand the possible significance of the presence of proteases, cytokines, growth factors, and arachidonic acid metabolites in the osteoarthritic temporomandibular joint (TMJ), a review of the normal physiologic processes and participating factors in the normal TMJ is established, based on knowledge of structure, biochemistry and metabolism of normal cartilage in general.

Synovial inflammation in arthroscopically obtained biopsy specimens from the temporomandibular joint : A review of the literature and a proposed histologic grading system

Data indicate that the synovial lining of the temporomandibular joint (TMJ) in some respects differs from other joints. The normal variation in morphology of the synovial lining of the TMJ is quite great, whereas the variation in pattern of pathologic changes appears to be relatively small (ie, synovial inflammation is not of the severity as that in other joints). In the current review, a system for histologic grading of synovial inflammation is proposed. The system is based on semiquantitative evaluation of the following set of parameters: 1) synovial lining cell layers; 2) vascularity (number or size of vascular profiles); and 3) Inflammatory cell infiltrate (commonly lymphocytes).

Synovial membrane involvement in osteoarthritic temporomandibular joints : A light microscopic study

OBJECTIVE To study the light microscopic characteristics of the synovial membrane of osteoarthritic temporomandibular joints to evaluate synovial membrane involvement in the osteoarthritic process. STUDY DESIGN Synovial membrane biopsies were obtained during unilateral arthroscopy in 40 patients. Thirty-one temporomandibular joints were diagnosed with osteoarthritis. Osteoarthritis subgroups were defined on the basis of the presence of symptoms related to disk displacement and perforation. The control group consisted of nine temporomandibular joints that were not involved by osteoarthritis. During light microscopic examination of the synovial membranes, several light microscopic variables were recorded. Differences between groups and between subgroups were tested with chi 2 or Fishers exact tests with Mann-Whitney U tests and with Students t tests. RESULTS In the osteoarthritis group, the number of synovial intima cell layers was significantly higher, and fibrous intima matrix and fibrous subintima were found significantly more frequently than in the control group. Moreover, in the osteoarthritis group, intima cell hypertrophy in combination with a closely packed cell composition was found significantly more often in the first year of clinical signs and symptoms, whereas intima hyperplasia, fibrous intima matrix, dense surface material, and subintima elastic fibers were found significantly more frequently in the first 2 years of clinical signs and symptoms. CONCLUSIONS The findings in this study suggest that osteoarthritis of the temporomandibular joint may initially result in synovial intima hyperplasia and cell hypertrophy, and subsequently in deposition of fibrous material in the intima matrix. Eventually, fibrosis of the subintimal tissue may occur in combination with degeneration and subsequent normalization of the synovial intima cell layer. Overall, fibrosis was the most characteristic feature of synovial membranes of osteoarthritic temporomandibular joints. In conclusion, the involvement of the synovial membrane in osteoarthritis of the temporomandibular joint is characterized by an early proliferative phase and a late fibrous phase. It appears that the intense and prolonged fibrous phase may not be a normal appropriate response to an initial insult but rather an aberrant counterproductive response.

Structure of the normal synovial membrane of the temporomandibular joint : A review of the literature

PURPOSE The structure of the normal synovial membrane of the temporomandibular joint (TMJ) is discussed, based on knowledge of synovial membrane in synovial joints in general.

Calcium pyrophosphate dihydrate crystal deposition disease: a review of the literature and a light and electron microscopic study of a case of the temporomandibular joint with numerous intracellular crystals in the chondrocytes

The pathogenesis of calcium pyrophosphate dihydrate (CPPD) crystal deposition disease of synovial joints is still unclear, although overproduction of extracellular pyrophosphate (PPi) is thought to play a key role. We studied the light and electron microscopic appearances of a case of CPPD crystal deposition disease of the temporomandibular joint (TMJ) in search of new clues for its pathogenesis. Light microscopic examination of CPPD-containing material from the joint space revealed cartilaginous nodules with various degrees of crystallization. Transmission electron microscopic examination revealed numerous extra- as well as intracellular crystals and crystal shaped spaces in the chondrocytes. Other striking ultrastructural features of the chondrocytes included the presence of many mitochondria, frequently containing crystalline material, and the presence of highly dilated rough endoplasmic reticulum and large glycogen islands. The presence of intramitochondrial crystals may hypothetically imply a derangement in mitochondrial adenosine triphosphate or PPi metabolism. The finding of intracellular CPPD crystals in chondrocytes points to the existence of an intracellular pathway of CPPD crystal formation in CPPD crystal deposition disease of the TMJ and possibly in CPPD crystal deposition disease in general.

Arthroscopic findings in osteoarthritic temporomandibular joints

PURPOSE This article reports on the results of a study of the arthroscopic findings in the joint surfaces of osteoarthritic temporomandibular joints (TMJs). PATIENTS AND METHODS Arthroscopy was performed in the upper joint compartment of 40 TMJs in 40 patients. Thirty-one TMJs that were diagnosed with osteoarthritis (OA) constituted the OA group. On the basis of the presence of symptoms related to disc displacement and perforation, OA subgroups were defined. Nine TMJs that were not involved with OA constituted the control group. During the examination, various arthroscopic variables were recorded. Differences between groups and between subgroups were tested statistically. RESULTS In the OA group, several arthroscopic variables were found significantly more frequently than in the control group. These included retrodiscal tissue redundancy, adhesions, and heightened attachment to the posterior wall of the glenoid fossa; articular disc displacement and limited mobility; and cartilage degeneration in the articular eminence. Moreover, in the OA group, disc displacement was found significantly more frequently in the period after 6 months than during the first 6 months of clinical signs and symptoms. Anterodiscal hypervascularity was found significantly more frequently during the first year than after the first year, as well as more during the first 2 years than after the first 2 years of clinical signs and symptoms, whereas a lowered attachment on the anterior slope of the articular eminence was found significantly more often after 2 years than during the first 2 years of clinical signs and symptoms. CONCLUSIONS The findings in this study suggest that OA of the TMJ may initially result in synovial tissue hypervascularity, creeping synovitis, and redundancy, and subsequently in adhesion formation and a reduction of the posterior and anterior recess. Because of cartilage fibrillation on the articular eminence, and the subsequently reduced surface smoothness, the articular disc may become displaced. Eventually, disc mobility is limited, and adhesions and a reduced posterior and anterior recess prevail.

Three-dimensional visualization of the temporomandibular joint: A computerized multisectional autopsy study of disc position and configuration

To demonstrate disc position and disc configuration of the temporomandibular joint, three-dimensional multisectional computer reconstructions were made of 20 autopsy specimens (11 female, 9 male; mean age, 40.4 years). The presence of a distinct occlusion was the only criterion for selection. Normal disc position was found in 13 joints, partial anterior disc position was found in 5 joints, and complete anterior disc position was seen in 2 joints. Fifteen joints had biconcave disc configuration and 5 joints had deformed discs. Considering the high incidence of disc position deviating from the normal superior position, it is suggested that in some cases a so-called abnormal disc position can be regarded as within the limits of anatomic and physiological variability.

Function, biochemistry, and metabolism of the normal synovial membrane of the temporomandibular joint: A review of the literature

In the temporomandibular joint (TMJ), the function and biochemical and metabolic features of the normal synovial membrane have not yet been determined, but most likely are similar to those of normal synovial membrane of joints in other parts of the body, and therefore will be discussed based on knowledge of the synovial membrane in other joints.