Computer-assisted surgery for replacement of the temporomandibular joint with customized prostheses: can we validate the results?

PURPOSE: Replacing the temporomandibular joint poses an important challenge to maxillofacial surgeons, and for certain disorders, it represents the treatment's gold standard. Computer-assisted surgery (comprising preoperative virtual planning, virtual intraoperative navigation and 3D printing) is a useful tool for this type of surgery. However, we do not know if and how much the final position of the prosthesis differs, in absolute values, from what was planned virtually in the preoperative phase. We propose a comparative result validation system for temporomandibular joint replacement METHODS: In the present study, we propose a comparative validation system using overlapping images, between the model obtained with preoperative virtual planning and the postoperative result. RESULTS: The mean difference for all screws of the glenoid prosthesis was 2.08 mm (range, 1.20-3.03) and for all screws of the condylar prosthesis it was 2.33 mm (range, 1.16-3.56). Mean overall difference between both prostheses in all patients was 2.21 mm (range, 1.16-3.56). CONCLUSIONS: The validation system proposed by overlapping pre- and postoperative images in temporomandibular joint replacement allowed us to establish differences in absolute values between the virtual preoperative model and the actual postoperative result expressed in millimeters.

Reduction of bilateral dislocation of TMJ and Rendu Osler Weber syndrome: case report and physiopathological model.

Temporomandibular joint dislocation (TMJ) is an infrequent clinical situation, representing 3% of all the human body's dislocations. The etiological factors reported are associated to alterations typical of the joint or of the muscular-ligament apparatus, or to clinical conditions that may cause dislocation. We present the case of a 46-year-old patient with hereditary hemorrhagic telangiectasia with bilateral dislocation of the TMJ. There are several potential causes (antipsychotics, intubation, etc.) although the deposit of manganese in the basal ganglia that produce extrapyramidal symptoms could be the most consistent cause.