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

Mandibular condyles/condylar cartilages can be considered as major growth sites of the mandible. Condylar affection by arthritis may therefore have an impact on craniofacial growth and development and joint function. In JIA patients with TMJ involvement, up to 70% show some form of craniofacial growth disturbance, which may be due to an adverse inflammatory effect on the condylar cartilages, reducing their normal growth potential and/or real destruction of the condyles. Craniofacial morphology in JIA patients has been classically described as “bird-face” outlook with micrognathic/retrognathic mandible with posterior rotation in relation to the cranial base, large lower anterior facial height, and anterior open bite in patients with insufficient dento-alveolar compensational growth. Impaired masticatory function is known to have an impact on the mandibular growth in normal circumstances. Therefore, it is plausible that impaired masticatory function further worsens growth capacity of the mandibular condyle in JIA. Variability in craniofacial morphology in JIA patients with TMJ affection depends on the severity of arthritis, onset age, and individual genetic variability influencing growth and responsiveness to treatment. Thanks to early diagnosis and proper medication, the prevalence of “bird-face” appearance of JIA patients is decreasing.