Superioralization of the Inferior Alveolar Nerve and Roofing for Extreme Atrophic Posterior Mandibular Ridges with Dental Implants

Inferior alveolar nerve repositioning surgical techniques and outcomes - a systematic review

Inferior alveolar nerve (IAN) lateralization (IANL) or transposition (IANT) are both techniques allowing for dental implant placement in posterior atrophic mandibles. The aim of this study was to systematically review the implant survival rate and the complications associated with IAN reposition techniques with simultaneous implant placement in atrophic posterior mandibles. This systematic review was conducted following PRISMA guidelines (Preferred Reporting Items for Systematic review and Meta-Analysis). The review was designed to answer the following PICO question: Is IAN repositioning (I) a safe and efficient technique (O) to treat patient looking for fixed dental rehabilitation of an atrophic posterior mandible (P). Thirty-three articles were reviewed, including a total of 899 patients, and approximately 950 IAN repositioning procedures. Dental implant survival rate ranged between 86.95% and 100% with a mean dental survival rate of 90.16%. Among the 269 patients who underwent IANT, there were 93% immediate neurosensory disturbance, and 15% persistent neurosensory disturbance. Among the 350 patients who underwent IANL, there were 93% immediate neurosensory disturbance, and 6% persistent neurosensory disturbance. IANT and IANL are reliable techniques allowing safe dental implant placement in atrophic posterior mandible with high patient satisfaction. IANL seems to cause less persistent neurosensory disturbances compared to IANT. The level of evidence is poor due to the high number of bias present in the included studies. IAN neurosensory disturbance assessment should be better homogenized in order to increase comparability.

Survival Rates of Dental Implants in Autogenous and Allogeneic Bone Blocks: A Systematic Review

Background and Objectives: Preliminary studies emphasize the similar performance of autogenous bone blocks (AUBBs) and allogeneic bone blocks (ALBBs) in pre-implant surgery; however, most of these studies include limited subjects or hold a low level of evidence. The purpose of this review is to test the hypothesis of indifferent implant survival rates (ISRs) in AUBB and ALBB and determine the impact of various material-, surgery- and patient-related confounders and predictors. Materials and Methods: The national library of medicine (MEDLINE), Excerpta Medica database (EMBASE) and Cochrane Central Register of Controlled Trials (CENTRAL) were screened for studies reporting the ISRs of implants placed in AUBB and ALBB with ≥10 participants followed for ≥12 months from January 1995 to November 2021. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias was assessed via several scoring tools, dependent on the study design. Means of sub-entities were presented as violin plots. Results: An electronic data search resulted in the identification of 9233 articles, of which 100 were included in the quantitative analysis. No significant difference (p = 0.54) was found between the ISR of AUBB (96.23 ± 5.27%; range: 75% to 100%; 2195 subjects, 6861 implants) and that of ALBB (97.66 ± 2.68%; range: 90.1% to 100%; 1202 subjects, 3434 implants). The ISR in AUBB was increased in blocks from intraoral as compared to extraoral donor sites (p = 0.0003), partially edentulous as compared to totally edentulous (p = 0.0002), as well as in patients younger than 45 as compared to those older (p = 0.044), cortical as compared to cortico-cancellous blocks (p = 0.005) and in delayed implantations within three months as compared to immediate implantations (p = 0.018). The ISR of ALBB was significantly increased in processed as compared to fresh-frozen ALBB (p = 0.004), but also in horizontal as compared to vertical augmentations (p = 0.009). Conclusions: The present findings widely emphasize the feasibility of achieving similar ISRs with AUBB and ALBB applied for pre-implant bone grafting. ISRs were negatively affected in sub-entities linked to more extensive augmentation procedures such as bone donor site and dentition status. The inclusion and pooling of literature with a low level of evidence, the absence of randomized controlled clinical trials (RCTs) comparing AUBB and ALBB and the limited count of comparative studies with short follow-ups increases the risk of bias and complicates data interpretation. Consequently, further long-term comparative studies are needed.

Simultaneous implant placement with autogenous onlay bone grafts: a systematic review and meta-analysis

Several authors have suggested that implants can be placed simultaneously with onlay bone grafts without affecting outcomes. Therefore, the purpose of this study was to answer the following clinical questions: (1) What are the outcomes of implants placed simultaneously with autogenous onlay bone grafts? And (2) is there a difference in outcomes between simultaneous vs delayed placement of implants with autogenous onlay bone grafts? Databases of PubMed, Embase, and Google Scholar were searched up to 15 November 2020. Data on implant survival was extracted from all the included studies (single arm and comparative) to calculate point estimates with 95% confidence intervals (CI) and pooled using the DerSimonian–Laird meta-analysis model. We also compared implant survival rates between the simultaneous and delayed placement of implants with data from comparative studies. Nineteen studies were included. Five of them compared simultaneous and delayed placement of implants. Dividing the studies based on follow-up duration, the pooled survival of implant placed simultaneously with onlay grafts after <2.5 years of follow-up was 93.1% (95% CI 82.6 to 97.4%) and after 2.5–5 years was 86% (95% CI 78.6 to 91.1%). Implant survival was found to be 85.8% (95% CI 79.6 to 90.3%) with iliac crest grafts and 95.7% (95% CI 83.9 to 93.0%) with intra-oral grafts. Our results indicated no statistically significant difference in implant survival between simultaneous and delayed placement (OR 0.43, 95% 0.07, 2.49, I²=59.04%). Data on implant success and bone loss were limited. Data indicates that implants placed simultaneously with autogenous onlay grafts have a survival rate of 93.1% and 86% after a follow-up of <2.5 years and 2.5–5years respectively. A limited number of studies indicate no significant difference in implant survival between the simultaneous and delayed placement of implants with onlay bone grafts. There is a need for randomized controlled trials comparing simultaneous and delayed implant placement to provide robust evidence.