Alloplastic total temporomandibular joint replacement using stock prosthesis: a one-year follow-up report of two cases
A 50-year-old female patient who had no specific medical history visited the hospital with facial asymmetry (chin deviation to the right side), limitation of mouth opening, and jaw pain that had persisted for two years. The clinical examination showed limitation of mouth opening (approximately 20 mm) along with TMJ pain on the left side and deviation of chin top to the right side. The radiography and computed tomography showed signs of considerable osseous proliferation extended to the cranial base and multiple radiopaque lesions suspected as phlebolith.() The initial diagnosis was osteochondroma on the left condyle. She underwent condylectomy, and her chin top--which deviated to the right side--was also reduced to the midsagittal plane. Active physical therapy was conducted, and clinical favorable mouth opening (approximately 32 mm) was finally achieved in four months.() Two years after surgery, however, she complained of limitation of mouth opening and discomfort of mastication. The X-ray revealed trauma from occlusion (TFO) in the maxillary molar area on the ipsilateral side as well as progressive osteoarthritis on the previous resection area. Total TMJ replacement using stock prosthesis on the ipsilateral joint was finally planned.\nStock TMJ prosthesis consists of fossa and condylar components, each of which requiring preauricular and retromandibular approaches. After condylectomy was performed to secure spaces for prosthesis via the preauricular approach, retromandibular incision was conducted. Bone trimming of uneven surface on articular eminence was followed by the installation of fossa component, and subsequent positioning of the condylar component was accomplished. After the optimal occlusion of the patient was maintained, fixation of the mandibular component was done with titanium screw.() Since the TMJ replacement, the patient had not suffered from remarkable postoperative complications including ipsilateral facial nerve weakness, paresthesia, pain, and dysfunction. She began light mouth opening exercise two weeks after the surgery and subsequently performed active exercise. Finally, she was able to maintain approximately 30 mm mouth opening, favorable mastication capability, and alleviation of TMJ pain since two months postoperative.()