3D printed pre-operative surgical planning model in cat

Introduction/purpose 3D models own patient-specific anatomy could be a powerful referral for surgical planning, enabling a more prepared surgical theatre. The aim of the study was to report a case of 3D pre-operative surgical planning model in a cat with temporomandibular joint (TMJ) ankylosis. Methods A three-years old castrated male domestic shorthair cat with a diagnosis of right TMJ ankylosis was submitted for a computed tomographic (CT) scan of the head to build a 3D model for pre-operative planning. A 16-slice multidetector CT scanner was used (Slice Thickness 0.75mm; Kw 130; mAs 45; Pitch 0.8). A segmentation was performed through 3DSlicer, and an STL file of skull and mandibular bone was generated. Mesh models were elaborated in order to be feasible for slicing and printing. The skull and the mandible were printed on their own through a double extrusion 3D Printer, with Poly-Lactic Acid. Results CT revealed a rounded right condylar process, with irregular and reduced TMJ space. Right condylectomy through piezoelectric surgery was performed. 3D model was used prior the surgery to easy identify the ideal angulation for condylectomy and during the surgery to verify the proper extent of the osteotomy. At 6-months follow-up the range of mouth opening is close to normal. Discussion/conclusion This is the first reported 3D printed pre-operative surgical planning model for condylectomy in a cat with TMJ ankylosis. The pre-operative surgical simulation through 3D printed model enabled to appreciate the uncommon bone anatomy and to facilitate surgery.