This case report details the combined temporomandibular joint (TMJ), orthodontic and orthognathic treatment of an adult female with a subsequent anterior open bite caused by condylar resorption due to bilateral temporomandibular joint osteoarthritis (TMJOA). The total treatment course lasted three years and consisted of three key phases: Six months of stabilisation splint therapy to control TMJ symptoms and stabilise condylar remodelling; a surgery-first orthognathic procedure to address the underlying skeletal deformity; and 30 months of postoperative orthodontic treatment to refine occlusion. The patient's skeletal deformity including the Class II high-angle malocclusion associated with condylar resorption was corrected, and functional complaints related to the TMJ, and airway narrowing were resolved. Both occlusion stability and the facial profile achieved satisfactory results. This case is valuable for guiding the management of TMJOA with a skeletal Class II high-angle anterior open bite. It also emphasises the critical role of multidisciplinary collaboration in achieving optimal functional and aesthetic outcomes for complex TMJ-related dentoskeletal deformities.