Figure 1

Preparation of the temporomandibular joint negative mold (NM) for the guided self-generation procedure in a goat model.

(A) Based on cranial 3D CT, (B) the mandible was reconstructed and (C) printed in 3D. (D) A hydroxylapatite NM of the TMJ and mandibular ramus, 5 cm in length, was obtained. (E) After removal of a segment of the 3rd or 4th rib and costicartilage counting from caudally (#1) the regenerative unit was prepared from costal perichondrium and periosteum (#2). (F) Schematic illustration and (G) intraoperative view of the NM-guided tissue self-generation chamber including the previously prepared periosteum/perichondrium piece in combination with the NM. Finally, the self-generated tissue was used for autologous replacement in the temporomandibular joint (#3). (H) In the control group, the TMJ/mandibular ramus DBM scaffold was wrapped with the previously prepared periosteum/perichondrium. In both groups, the perichondrium covered the designated articular surface and the periosteum enclosed the osseous part. (I) An allogenic DBM scaffold of the same size served as positive control which was examined for (J) microstructure and porosity by scanning electron microscopy. (K) The study timeline consisted of 2 stages, construct self-generation and replacement, during which fluorescent labeling of osteogenesis, radiologic, histologic, and immunohistochemical analyses were performed. NM: negative mold; DBM: demineralized bone matrix; pc: perichondrium; po: periosteum; F: fluorescent labeling.