Digital imaging evaluation of the scapula for prediction of endosteal implant placement in reconstruction of oromandibular defects with scapular free flaps

Objective: Dental implant placement in scapular free flaps is challenging. This study examines the scapula with computed tomography to identify ideal locations for predictable implant placement during preoperative planning. Methods: Sixty-eight adult patient chest CT scans (34 men, 34 women) captured for various medical indications, were analyzed for age, height, weight, and scapula length. The lateral border of the scapula was divided into six equal segments; the midpoints of each segment (labeled proximally to distally as 1M–6M) were analyzed in cross-section as potential recipient sites for 3.5 × 8 mm implants. Also, we present a case of a 77-year-old male with ameloblastoma of the mandible who underwent patient specific planning and received a scapular free flap with dental implant placement. Results: There was greater bone availability in males with a mean depth of 8.3 ± 2.8 versus 5.1 ± 3.3 mm in females (p <.01). The proximal portion (1M) of the scapula in males and females had depths of 11.3 ± 1.5 and 9.5 ± 2.3 mm, respectively. Males had depths of 8.4 ± 3.0 in M3, 9.7 ± 1.7 in M4, and 8.9 ± 1.2 mm in M6. Depth of bone available for patients with heights ≥165 cm versus <165 cm had means of 10.4 ± 1.3 and 8.0 ± 1.6 mm (p <.01), respectively; but showed no significant differences between BMI (BMI <25 vs. ≥25) and bone availability (6.8 ± 1.7 vs. 6.8 ± 1.6, p =.07), or age (<55 years vs. ≥55 years) and bone availability (9.8 ± 1.6 vs. 9.8 ± 1.6, p =.11). In our case, the patient received 6 cm length of scapular bone with four 4.1 × 14 mm endosteal implants, which upon osseointegration was able to receive a fixed dental prosthesis. Three years after the initial surgery, the patient has had no difficulty with his prosthesis. Conclusion: In females the most proximal portion of the scapula will predictably accommodate a dental implant, while males have multiple sites including the proximal, middle, and distal portions.