Objective: To investigate long term the average changes in craniofacial morphology in a group of Norwegian juvenile idiopathic arthritis (JIA) patients with mixed diagnosis from 6 to 35 years of age. A matched group of healthy individuals was included as controls.
Material and methods: Craniofacial development in 38 females and 16 males with JIA was followed on lateral cephalograms from childhood for 23-31 years. The patients were compared with the healthy individuals at the ages of 6, 9, 12, and 35 years.
Results: At 6 and 9 years of age, the average craniofacial morphology in the JIA patients was similar to that of the control subjects. At 12 years of age, significant craniofacial morphological differences between the JIA and the control subjects appeared. These included a steeper mandibular plane angle and a more retrognathic position of the mandible. The length of the mandible (ar-gn), the height of the ramus (ar-tgo), and the length of the corpus (tgo-gn) were significantly smaller in the JIA patients. The average growth direction of the chin was more downward in the JIA patients. A smaller posterior facial height and a higher ratio between the anterior and posterior facial heights were also observed. The differences in craniofacial morphology between the patients and the control group were more pronounced at 35 years of age than at earlier ages.
Conclusion: The typical craniofacial morphological pattern in JIA patients was established between 9 and 12 years of age. From the age of 12 until the age of 35, this morphological pattern remained relatively stable, in contrast to the pattern in the healthy control subjects.