IntroductionPatients with juvenile idiopathic arthritis (JIA) and involvement of the temporomandibular joint (TMJ) often experience abnormal facial growth. Three-dimensional (3D) assessment of dentofacial growth deviation has become more common with advancement and commercialization of imaging technologies. However, no standardized guidelines exist for interpretation of 3D imaging in patients with JIA. The aim of this study was to propose and validate morphometric measures for the 3D radiographic assessment of dentofacial growth deviation in patients with JIA to enhance: 1) Description of dentofacial growth deviation; 2) Treatment planning; 3) Longitudinal follow-up.MethodsThe study was conducted in a standardized sequential-phased approach involving: 1) Preliminary decision-making; 2) Item generation; 3) Test of content-validity; 4) Test of reliability; 5) Test of construct validity; 6) Establishment of final recommendations.ResultsTwenty-one morphometric measures were evaluated. Based on results of reliability and validity-testing including subjects with JIA (n = 70) and non-JIA controls (n = 19), seven measures received a “high recommendation” score. Those measures were associated with posterior mandibular height, occlusal cant, mandibular asymmetry, mandibular inclination, and anterior/posterior lower face height. Nine other measures were “moderately recommended” and five received a “somewhat recommendation” score.ConclusionSeven morphometric measures were considered very useful in the 3D assessment of growth deviation in patients with TMJ disease associated with JIA. These variables can be used to standardize the description of dentofacial deformities and to plan corrective interventions.