evaluation of vertical height in anterior maxillary sandwich osteotomy: simultaneous versus delayed implant placement

Conditions: Alveolar Bone Resorption

Summary: vertical bone height has always presented challenge for the clinicians especially in the anterior aesthetic zone. therefore, this trial will attempt to compare whether better vertical bone height and implant placement technique can be achieved using simultaneous implant placement with the sandwich osteotomy, which is a time saving procedure performed in a single stage surgery; when compared to using fixation plates to support the segment followed by delayed implant placement.

fixation plates are usually used to support the segmentalized bone segment during vertical bone augmentation using sandwich osteotomy and inlay bone grafting; to minimize movement of the bone segment and allow for new bone formation. therefore, the aim of this study is to evaluate vertical bone height achieved at the anterior maxilla in vertical segmental sandwich osteotomy with simultaneous implant placement versus the same technique using fixation plates. description of sandwich osteotomy procedure to be done: * a full thickness pyramidal flap with buccal paracrestal incision and two vertical releasing incisions slightly divergent to each other will be made. then the mucoperiosteal flap will be reflected exposing the whole buccal cortical plate without reflection of the palatal mucosa. * the palatal mucosa will not be reflected to avoid disturbance of blood supply to the mobilized segment for proper healing. * with a tungsten carbide disc - 1 mm in thickness and 10 mm in diameter - the alveolar bone will be segmented using a horizontal cut 3 to 5 mm apical to the crest of the ridge, and two lateral vertically oblique cuts 1-2 mm away from adjacent teeth roots slightly converging toward the alveolar crest or almost parallel to each other; thus creating a trapezoid-shaped bone segment pedicled on the attached palatal tissues. * the horizontal and the two vertical cuts will then be revised using a set of graduated ridge splitting (fine chisels) osteotomes of sequential width and a light weight mallet to ensure that the surgical cuts are down to spongy bone. * the segment will then be mobilized crestally, pedicled on the non-reflected palatal tissue.

Eligibility criteria:
inclusion criteria: * age range from 20-55 years. no sex predilection. * patients free from any systemic conditions and bone metabolism diseases that might interfere with the surgical intervention, soft tissue or hard tissue healing. * edentulous anterior maxilla with vertically deficient alveolar ridge that is less than 10 mm measured from the crest of the alveolar ridge to the nasal floor. * normal vertical dimension with increased inter-arch space. * the minimum number of missing teeth in the anterior maxillary alveolar ridge is two adjacent anterior teeth. exclusion criteria: * • intra-bony lesions (e.g. cysts) or infections (e.g. abscess) that may retard the osteotomy healing. * previous grafting procedures in the edentulous area. * deficient horizontal dimensions of the alveolar ridge i.e. width is less than 5 mm.

Keywords: vertical bone augmentation inlay bone graft dental implants sandwich osteotomy