The role of functional orthodontic stress on implants in residual alveolar cleft

The most widely accepted protocol for alveolar cleft reconstruction is repair during the mixed dentition stage (age, 9 to 11 years), before eruption of the canine teeth. Alveolar bone grafting should not be considered as an isolated therapy but always as an integrated part of comprehensive orthodontic treatment.

The authors evaluate the results of transitional secondary osteoplasty, comparing the use of autogenous cancellous bone versus heterogenetic implants, in patients with unilateral complete clefts who did or did not undergo orthodontic treatment. From 1990 to 1994, 48 patients aged between 9 and 11 years with unilateral alveolar cleft underwent alveolar grafting by transitional secondary osteoplasty. In 30 patients (group A), autogenous cancellous bone was used, and in 18 patients (group B), a heterogenetic implant consisting of demineralized bone powder containing bone morphogenetic protein and hydroxylapatite was used.

Twenty-two patients in group A and 12 patients in group B underwent orthodontic treatment. After 10 to 12 years of follow-up, the clinical and radiographic examinations revealed that the best alveolar bone repair results were obtained using autologous bone graft in association with orthodontic treatment. Also, in the patients who underwent heterogenetic implantation, the orthodontic treatment clearly improved the quality of the osteoplasty.

The essential conditions for a successful osteoplasty include meticulous operative technique and orthodontic treatment. The latter plays an essential role at several stages of development in children with clefts. The "functional stress" on the autologous or heterogenetic implant exerts a decisive influence on the quality and volume of the osteoplasty, preventing progressive resorption.