Fig. 3

Puricelli biconvex arthroplasty. A Partial removal of ankylosed tissue and preparation of the areas for reconstruction. 1 TMJ ankylosis. 2 Removal of ankylosed mass. 2a Perforation with spherical drill and ostectomy with chisel. 2b Ostectomies using piezosurgery. 2c Measurement of the gap using a surgical compass. 3 Sequential sculpting, with a milling cutter, of upper and lower (mandible stump) residual tissues in convex profiles. B Perforations of the sculpted remaining ankylosed area (upper and lower). 1 Perforations of the upper sculpted ankylosed mass (lateral view). 1a Lateral view. 2 Perforations of the lower sculpted ankylosed mass (mandible stump). 2a Lateral (lower) view. 2b Upper view. Mean perforation depth is 3 mm. C Reconstruction of the remaining upper and lower ankylosed areas with PMMA. 1 Reconstruction of the upper structure with PMMA with overlay of the ankylosed area. The perforations are filled by mechanical pressing, and sculpted with a spatula into a convex structure with about 6 mm width, occupying part of the 15-mm gap. The perforations are filled with plastic PMMA by mechanical pressing, with total overlay of the upper structure. 2 An elastic maxillomandibular immobilisation (EMMI) is performed, for the correct positioning of the mandible in relation to the maxilla. 2a With controlled oral lateral, and opening and closing movements, the best position for minimal contact after reconstruction of the mandible head is determined. 3 The mandible stump is filled with PMMA for reconstruction of a mandible head, sculpted using a spatula. The perforations are filled with plastic PMMA by mechanical pressing, with total overlay of the lower structure. 4 The EMMI is removed, and the minimal contact between the two structures results in successful restoration of joint function. The mandibular force vector now has an anteroposterior and inferosuperior direction in relation to the base of the skull