Biological reconstruction of the temporomandibular joint by chondro-osseous graft: clinical and experimental study

Abstract

This study includes 35 children treated by reconstruction of the temporomandibular joint (TMJ) by chondro-osseous graft harvested from iliac crest for management of 2 diseases; the first one was ankylosis of the TMJ. There were 25 cases of 9 girls and 16 boys, and there were 10 cases of hypoplasia of the TMJ of first-arch dysplasia syndrome or hemifacial microsomia, of which 4 were females and 6 were males. Their ages ranged between 4 and 13 years (mean, 8.5 years); follow-up of the patients ranged from 3 to 5 years. All patients showed good result and without recurrence of ankylosis or restriction of mouth opening, and growth of the face was acceptable and without using osteotomies for correction of jaw relationship or distraction techniques.Experimental studies on rabbits were performed to prove the condyle as growth center and after excision of the head of condyle and disk in newly growing rabbits of 3 months of age; after 3 months of follow-up, we observed severe deformity of the rabbits' mandible, and the mandible deviated to the affected side on the first experiment. In the second experiment, reconstruction of the TMJ and condyle of the rabbits by chondro-osseous graft harvested from iliac crest of the same rabbit was carried out in 8 animals to assess the viability and value of chondro-osseous graft to replace the TMJ. After 3 months, all animals were killed. Postmortem studies were done to assess the healing process of the graft or any resorption of the graft. Histological studies of the graft showed 4 layers: the first articular layer was thick because of functional demand of masticatory process for hard food of rabbits; the second layer was the granular mesenchymal stem cells layer, very active and multiple layers that represent the proliferative layer; the third layer showed conversion of cartilage cells to osteoid cells, and the fourth layer was the osteoid layer. On follow-up of clinical cases, the graft was continued for functional demand of growth, repair, and remodeling of the condyle.