Lateral border of scapula - a new bone-grafting site for alveolar ridge reconstruction prior to implant placement

15674 ORAL COMMUNICATION CLINICAL INNOVATIONS

Background

A lot of patients with severe alveolar bone atrophy need reconstruction before implant placement. For smaller-sized defects, bone blocks from intraoral sites are used. For total alveolar defects, grafts from extraoral sites are preferred. Iliac crest is frequently chosen, bone blocks of which consist mostly of cancellous bone. Grafts from lateral border of scapula may be used as an alternative donor site. Predominance of cortical bone in it leads to more stable results, as less resorption occurs.

Aim/Hypothesis

To develop and put into the clinical practice a new surgical technique of lateral border of scapula bone grafting and evaluate it's efficiency for alveolar bone reconstruction in patients with severe alveolar bone atrophy according to clinical, radiological and histological data.

Material and Methods

21 partially or fully edentulous patients received treatment for alveolar ridge resorption with bone autograft from lateral border of scapula prior to two-stage dental implant placement. Patients age and gender, localization, type and causation of the defect, size and characteristics of bone graft, postoperative complication were recorded. Radiological analysis performed by comparison of preoperative CBCT and CBCT six months after osteoplasty. Horizontal and vertical alveolar bone dimensions were measured at the position of 2, 4 and 6 teeth according to defect localization. Then arithmetic average and bone acquisition counted for every patient. We provided a histological analysis of intact bone samples taken from alveolar ridge of mandible, lateral border of scapula, iliac crest and calvarium to compare the bone structures of those anatomical sites. The following parameters were investigated- area of trabecula; intertrabecular space, vascularization and the total number of cells.

Results

21 patients (17 females, 4 males) with an average age of 45 ± 3 years had a reconstruction of alveolar bone with lateral border scapula graft. An average length of dental defect was 14 ± 2 teeth. According to complexity of osteoplasty, average time of surgery was 240.53 ± 18.05 min (range – 240.53 ± 18.05 min), grafting stage took 70.26 ± 5.69 minutes. Graft dimensions also depended on the extend of defect. Mean length of graft was 6.39 ± 0.61 cm, mean height was 2.31 ± 0.17 cm, mean width was 1.58 ± 0.13 cm. Bone graft intake from lateral border of scapula could be considered as minimally invasive procedure as a full range of donor arm movement has restored within 14 days since surgery in 100% cases. 5 months after reconstruction all patients were successfully placed averagely 7 implants. According to CBCT comparison, an average vertical bone gain in maxilla was 7.03 ± 0.32 mm, in horizontal – 4.31 ± 0.13 mm. In mandible an average vertical bone gain was 5.87 ± 0.47 mm, in horizontal −3.55 ± 0.14 mm.

Conclusion and clinical implication

Free bone graft from lateral border of scapula is an effective method for 3-dimentional reconstruction of alveolar ridge defects in patients with severe bone atrophy prior to implant placement. Bone graft volume is sufficient and donor site morbidity is low. Bone structure of lateral border of scapula is morphologically similar to ramus of mandible and calvarium. Therefore, the use of lateral border of scapula as an alternative extraoral donor site for alveolar reconstruction is beneficial.