ALVEOLAR DISTRACTION OSTEOGENESIS FOR BONE AUGMENTATION OF SEVERELY ATROPHIC RIDGES IN 10 CONSECUTIVE CASES: A HISTOLOGIC AND HISTOMORPHOMETRIC STUDY

Background: This study analyzed bone healing in surgically osteodistracted maxillary and mandibular ridges histologically and histomorphometrically at two different times to determine the best time to insert dental implants. Methods: Ten consecutive patients with severe maxillary (two patients) or mandibular (eight patients) atrophy underwent surgical osteodistraction with an extraosseous distractor. Seven days after the surgery, the distractor was activated at a rate of 1 mm/day until achieving the planned bone lengthening. The distractor was removed after a consolidation period of 70 days. Bone biopsies were obtained at implant insertion: 70 days after the end of distraction on the day of distractor removal in six patients (group A) or 180 days afterwards in four patients (group B). The biopsies were evaluated histologically and histomorphometrically to measure the osteocyte lacunar area (OLA). Results: The histologic and histomorphometrical analysis of the distracted bone 70 days after the end of distraction showed well-organized lamellar bone. At 180 days, the bone was more compact and mature; the mineralization of the matrix was greater; and an increased, but small, amount of marrow space was evident (35% versus 45%). The mean OLA was 80.11 ± 27.59 μm2 in group A and 70.4 ± 33.58 μm2 in group B. The difference between the two biopsy groups was not significant (P = 0.315). Conclusion: The results of this study showed that there was definitely similar bone formation in the distracted area for both healing periods, and placing implants clinically worked in both of these time periods in the limited number of cases observed.