A single-stage computer-guided gap arthroplasty with simultaneous patient-specific total joint replacement with a novel flat fossa design: A case report

INTRODUCTION AND IMPORTANCE: The computer-guided approach for the patient-specific TMJ replacement is considered an ultimate reliable option in advanced cases. However, dislocation of the condylar head could happen with the concave fossa design. A flat design was described and used in this case. CASE PRESENTATION: A 15 years old male patient with mandibular asymmetry and class IV recurrent ankylosis of the right TMJ received a patient-specific artificial joint with computer-guided gap arthroplasty and orthognathic corrective mandibular surgery for the left side. The fossa component was made entirely flat, and the patient was followed up over the next year. CLINICAL DISCUSSION: Customized TMJ prosthetic solutions are reliable in advanced cases, especially when facial corrections are indicated; however, the commonly used concave design showed reported dislocations requiring some design modifications as proposed in the presented case. CONCLUSION: The flat fossa design of the artificial TMJ secures the same results as the anatomical fossa design without the incidence of dislocation.