Vertical ridge augmentation of atrophic posterior mandible using an inlay technique with a xenograft without miniscrews and miniplates: case series

Abstract

Background: Rehabilitation of partially or totally edentulous posterior mandible with implant-supported prosthesis has become a common practice in the last few decades, with reliable long-term results. The use of miniscrews and miniplates have been reported to increase the risk of fracture of the osteotomy segments. The purpose of this case series was to use an inlay technique, without the use of miniscrews and miniplates for stabilization of the transported bone fragments.

Materials and methods: Nine consecutive patients (six men and three women) aged between 26 and 51 years (mean 44 years) were enrolled in this study. A horizontal osteotomy was performed 2-3 mm above the mandibular canal, and two oblique cuts were made using a piezosurgery device. The final phase of the osteotomy was performed with chisels. The osteotomized segment was then raised in the coronal direction, sparing the lingual periosteum. Two miniblocks of xenograft without miniscrews and miniplates were inserted mesially and distally between the cranial osteotomized segment and the mandibular basal bone. The residual space was filled with particles of cortico-cancellous porcine bone. Four months after surgery, a panoramic X-ray was taken before implant insertion. A bone trephine with an internal diameter of 2 mm was used as the second dental drill to take a bone core biopsy during preparation of the #35 and #37 or #45 and #47 implant sites.

Results: The postoperative course was uneventful in seven of the nine patients. No dehiscence of the mucosa was observed at the marginal ridge of the mobilized fragment. Newly formed bone was present near the osteotomized segments, and was observed in the bottom half of the specimens and was identified by its higher affinity toward the staining. Newly formed bone was observed to be in close contact with the particles of biomaterials. No gaps or connective tissue were present at the bone-biomaterial interface. Histomorphometry demonstrated that 44±2.1% of the specimens was composed by newly formed bone, 18±0.8% by marrow spaces, and 33±2.4% by the residual grafted biomaterial.

Conclusion: The rigidity of the equine collagenated block allowed to eliminate the use of miniscrews and miniplates and simplified the technique. Moreover, the rigidity of the block allowed maintenance of the space.