Mandibulofacial Adaptations in a Juvenile Animal Model of Temporomandibular Joint Arthritis

Abstract

Juvenile rheumatoid arthritis (JRA) is a chronic systemic disease of childhood that affects synovial joints including the temporomandibular joint (TMJ). Individuals with JRA of the TMJ frequently show aberrations in mandibulofacial development. Since the basis for these developmental perturbations is poorly understood, they remain a perplexing clinical problem to manage. To begin dissecting the mechanisms for altered craniofacial development in JRA of the TMJ, we characterized the gross morphologic adaptations in the facial skeleton in a juvenile animal model of TMJ arthritis. Arthritis was induced in ten 87-day-old male rabbits by intra-articular challenge with ovalbumin. Eight sham-challenged and 4 unchallenged rabbits were used as controls. Serial lateral head cephalograms, taken at 73 (T1), 87 (T2), 108 (T3), 129 (T4), and 150 (T5) days of age, were evaluated by linear measures of maxillary, mandibular, and posterior dental height dimensions. Differences in the absolute dimensions and relative percent incremental changes were compared by ANOVA and Fisher's test. The body weights, as well as the absolute measures and incremental changes in maxillary and posterior dental height dimensions, were not significantly different between the antigen-challenged and control groups. In contrast, absolute measures of posterior mandibular height, condylar neck height, and total mandibular length were significantly smaller (P < 0.05) in antigen-challenged rabbits than in both control groups at T5. Furthermore, the antigen-challenged rabbits demonstrated significantly smaller (P < 0.05) relative increases in all measures of mandibular length, and in total posterior mandibular and condylar neck heights. Cephalometric superimpositions on the cranial base and tantalum implants confirmed these quantitative observations. This investigation demonstrates mandibulofacial developmental aberrations in experimental JRA-like disease of the TMJ that are similar to those observed in humans with this disease.

Differences in masseter activity in patients with and without self-reported rheumatoid arthritis using surface electromyography: A cross-sectional study

“…Our sample represents adults between 20 to 60 years of age with non-severe rheumatoid arthritis or non-severe temporomandibular symptoms related to severe rheumatoid arthritis. We consider that the increase in RMS activity in patients with rheumatoid arthritis could be observed in patients with non-severe symptoms or as an onset of muscular disturbance, and muscular hyperactivity could be a first sign before a chronic muscular disturbance takes place [7,2,25,9]. Our results show a decreased rate of muscular activity with age and a decreased rate during the evaluated period in rheumatic patients.…”

“…We have non-cephalometric information of these patients and we were unable to evaluate the association of posterior mandibular height, condylar neck height, and total mandibular length that have been associated with the RMS mean described as mandibulofacial or masticatory muscular adaptations [27,25]. However, few studies [4,17,7] have used electromyographic evaluation and more research on this topic is needed in order to clarify or identify electromyographic activity patterns that could suggest the onset of muscular activity disturbance and at the same time present different patterns according to the severity of rheumatoid arthritis.…”

Craniofacial growth and dento-alveolar development in juvenile idiopathic arthritis patients

“…34 In a later cephalometric study, diminished dimensions of the mandible were found in arthritic animals. 35 These findings were confirmed by Stoustrup et al studying growing rabbits with induced TMJ arthritis using medical computed tomography (CT). 36 The images of the CT scans were superimposed, and the difference between normal and abnormal growth caused by TMJ arthritis was visualized (Fig.…”

Effect of methotrexate upon antigen‐induced arthritis of the rabbit temporomandibular joint

“…and Tominaga et al. to examine the antigen‐induced arthritis in the rabbit's temporomandibular joint .…”