Lateral Approach to the Maxillary Sinus and Mandibular Canal in Severely Atrophied Posterior Alveolar Bone.

PURPOSE: To present a technique to rehabilitate atrophied alveolar ridges in the posterior maxilla and mandible using bone lateral to the maxillary sinus and to the inferior alveolar nerve and to present a retrospective study of the technique. MATERIALS AND METHODS: Severe resorption of the posterior region of the maxilla and mandible was treated following a conservative approach. Patients who presented this bone crest condition that impeded the placement of implants and had an anatomy that allowed the inferior alveolar nerve or the maxillary sinus to be approached laterally were treated. The bone ridge thickness lateral to the maxillary sinus and the inferior alveolar nerve was measured by computed tomography, and implants with a wedge-shaped design were placed in the available bone. A retrospective review of clinical records of these patients, treated between 1998 and 2012 at the Clinest - Clinical Center of Research in Stomatology, was conducted. The studied variables were surgical and prosthetic complications, the implant survival rate, and the difference between the remaining bone ridge measurement in the ridge center and the implant length placed laterally. RESULTS: Fifty-six patients met the inclusion criteria. These patients received 208 implants according to the aforementioned technique. The mean implant length gain was 6.9 mm, varying from 0.5 to 12 mm. The cumulative survival rate was high for both maxillaries. For the implants placed beside the inferior alveolar nerve, none were lost at 2 years, two were lost at 5 years, and four were lost at 10 years. For the implants placed beside the maxillary sinus, only four implants were lost at 10 years. Nerve injuries and surgical/prosthetic complications occurred but were not significant. CONCLUSION: The use of available bone alongside the maxillary sinus and inferior alveolar nerve to place implants is a surgical possibility, and a predictable, safe approach, albeit delicate and experience-dependent.

Retrospective study of the survival and associated risk factors of wedge-shaped implants.

PURPOSE: To assess the long-term behavior of wedge-shaped implants and evaluate the influence of the associated risk factors on implant survival rates. MATERIALS AND METHODS: A retrospective review of clinical records of patients treated with wedge-shaped implants between 1992 and 2011 was conducted. Data on patient sex, age, smoking habits, and history of periodontitis; details of implant length, diameter, angle, and location; and data on surgical, reconstructive, and prosthetic procedures, and systemic disease were selected for analysis. RESULTS: A total of 1,169 implants placed in 154 patients (mean age 55.17 ± 11.33 years) were evaluated. Women received 637 implants, and men received 532 implants; 60.4% were placed in patients who were undergoing periodontal maintenance care, 17.9% in smokers, 17.7% in hypertensive patients, 5.7% in diabetic patients, and 4.4% in cardiac patients. The mean overall survival for implants was 194.26 ± 9.91 months. Seventy-three implants were lost: 3 before implant loading and 70 after loading. The cumulative survival rates at 5 and 10 years were 96.6% (confidence interval [CI]: 95.5% to 97.7%) and 91.8% (CI: 90.1% to 94.1%), respectively. Univariate analysis indicated tobacco smoking (P = .014) and implant location (P < .001) as significant risk factors for implant failure. The multivariate analysis showed tobacco smoking (P = .016), location (P = .001), and male sex (P = .038) as significant, and the latter factor was associated with previous periodontal disease. CONCLUSIONS: Overall survival of the wedge-shaped implant showed good long-term results. Male sex, tobacco smoking, and posterior maxillary location were associated with a greater risk of implant failure.