Evaluation of Horizontal Mandibular Ridge Augmentation Through Subperiosteal Tunneling by Using Bovine Sticky Bone (Radio-Histological Study)

The alveolar bone is a tooth-dependent tissue that extends from the basal bone of the maxilla and mandible to form and support the tooth sockets. Resorption of alveolar bone may be attributed to a variety of factors, such as tooth loss, trauma, periodontal disease, and pathologies. Tooth loss is often followed by a bone remodeling process leading to gradual horizontal and vertical bone ridge reduction.

The posterior mandible is the most challenging region for reconstruction and implant placement due to its critical neurovascular structures, thick cortical bone, and reduced vascular trabecular bone, requiring careful treatment planning for successful outcomes Multiple techniques such as osteoplasty, narrow implants, bone augmentation, ridge splitting, and distraction osteogenesis address deficient ridge width. However, conventional augmentation in the posterior mandible requires flap elevation and barrier membranes, increasing risks of complications such as pain, swelling, wound dehiscence, and membrane exposure.

To address these limitations, this study employed the subperiosteal tunneling technique for horizontal augmentation of posterior edentulous ridges. By creating a subperiosteal pouch without extensive flap elevation, this approach reduces tissue trauma, preserves periosteal integrity essential for bone regeneration, and eliminates the need for barrier membranes by harnessing the periosteum's regenerative potential.

Bovine sticky bone was utilized for its cohesive properties, enhanced stability, and regenerative potential. (31) This study evaluated the radiological and histological outcomes of horizontal mandibular ridge augmentation through subperiosteal tunneling using enriched bovine bone graft matrix (sticky bone). Conducted at the outpatient clinic of the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Tanta University.

Ten adult patients with mandibular horizontal alveolar ridge atrophy were included in the study. Their ages ranged from 34 to 42 years (mean ± SD: 38 ± 2.6). The gender distribution was 40% male and 60% female participants, reflecting women's predominance in dental treatment-seeking behavior.

At the 6-month follow-up, subperiosteal tunneling with sticky bone achieved a 90% success rate (9/10 patients). One 41-year-old female patient experienced failure (10%) due to an intraoperative tear during crestal tunneling, resulting in soft tissue compromise, infection, dehiscence, and total graft loss. The remaining patients demonstrated successful bone formation, rapid soft tissue healing with minimal morbidity, no dehiscence or graft exposure, and excellent long-term outcomes, confirming this technique's reliability as a membrane-free ridge augmentation alternative.

Clinical assessment of postoperative healing, using the Landry et al. healing index (161), demonstrated predictable progression from predominantly good healing at one week (60%) to universal excellent healing by one month, maintained through six months, which indicates a transient inflammatory response and a favorable biocompatibility and healing profile for the procedure.

Pain levels, assessed by the Visual Analog Scale (VAS), declined substantially throughout the treatment period. The mean VAS score was 3.70 ± 1.42 at one week, which significantly decreased to 1.30 ± 0.82 at two weeks. From the third week onward no pain was reported, with mean VAS scores consistently at 0 ± 0. Neurosensory function remained preserved throughout the follow-up period in all patients.

Radiographic assessment at six months demonstrated significant horizontal ridge augmentation with a mean width gain of 3.30 ± 0.97 mm. The calculated resorption rate of 17.58 ± 4.76% remained within biologically acceptable parameters for horizontal ridge augmentation procedures.

Histological examination of bone core specimens obtained during implant placement revealed Hematoxylin and Eosin (H\&E)-stained sections showing graft remnants well-integrated with mature lamellar bone, without evidence of inflammation or necrosis. Woven bone exhibited plump osteoblasts indicative of active bone formation, sparse osteoclasts with minimal resorption, and multiple reversal lines confirming ongoing remodeling. Osteoconduction was evident with graft particles surrounded by osteogenic cells and newly formed bone. Immunohistochemical analysis demonstrated strong osteocalcin expression within the bone matrix and moderate cytoplasmic staining in osteocytes of newly formed bone, confirming active mineralization and robust bone remodeling activity.