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Purpose: The present systematic review aimed to investigate the accuracy of zygomatic implant (ZI) placement using dynamic computer-aided surgery (d-CAIS), static computer-aided surgery (s-CAIS), and a free-hand approach in patients with severe atrophic edentulous maxilla and/or deficient maxilla. Methods: Electronic and manual literature searches until May 2023 were performed in the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases. Clinical trials and cadaver studies were selected. The primary outcome was planned/placed deviation. Secondary outcomes were to evaluate the survival of ZI and surgical complications. Random-effects meta-analyses were conducted and meta-regression was utilized to compare fiducial registration amounts for d-CAIS and the different designs of s-CAIS. Results: A total of 14 studies with 511 ZIs were included (Nobel Biocare: 274, Southern Implant: 42, SIN Implant: 16, non-mentioned: 179). The pooled mean ZI deviations from the d-CAIS group were 1.81 mm (95% CI: 1.34–2.29) at the entry point and 2.95 mm (95% CI: 1.66–4.24) at the apex point, and angular deviations were 3.49 degrees (95% CI: 2.04–4.93). The pooled mean ZI deviations from the s-CAIS group were 1.19 mm (95% CI: 0.83–1.54) at the entry point and 1.80 mm (95% CI: 1.10–2.50) at the apex point, and angular deviations were 2.15 degrees (95% CI: 1.43–2.88). The pooled mean ZI deviations from the free-hand group were 2.04 mm (95% CI: 1.69–2.39) at the entry point and 3.23 mm (95% CI: 2.34–4.12) at the apex point, and angular deviations were 4.92 degrees (95% CI: 3.86–5.98). There was strong evidence of differences in the average entry, apex, and angular deviation between the navigation, surgical guide, and free-hand groups (p < 0.01). A significant inverse correlation was observed between the number of fiducial screws and the planned/placed deviation regarding entry, apex, and angular measurements. Conclusion: Using d-CAIS and modified s-CAIS for ZI surgery has shown clinically acceptable outcomes regarding average entry, apex, and angular deviations. The maximal deviation values were predominantly observed in the conventional s-CAIS. Surgeons should be mindful of potential deviations and complications regardless of the decision making in different guide approaches. [ABSTRACT FROM AUTHOR]

This case report demonstrates the use of dynamic navigation guidance for bone reduction. Information about smile line position incorporated in a virtual plan and accurate transfer to the surgical field enhances the predictability of the treatment. A virtual wax-up was made, and implant positions along with bone reduction were planned accordingly. Residual teeth in the maxilla were extracted, and bone reduction and zygomatic implant placement were assisted by surgical navigation, while conventional implants were placed using the surgical template, followed by immediate loading. When surgical navigation is used for implant placement, navigated bone reduction can easily be incorporated in the workflow. The accuracy of bone reduction was evaluated together with the accuracy of two zygomatic implants assisted by a navigation system and four conventional implants assisted by a static template. The mean deviation between planned and performed bone reduction was 1.3 ± 0.39 mm (range: 0.8 to 1.7 mm). The accuracy of this procedure corresponds to the accuracy of guided implant placement and can be considered reliable after confirmation through clinical trials. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate primary stability of 3.7-mm diameter porous tantalum Trabecular Metal (TM) implant, and compare it to fully threaded implants, in the in vitro model of immediate implant placement in the anterior maxilla. A total of 60 implants were placed into bovine ribs using surgical guides. Implants were divided in 3 groups of 20 according to the design: TM, Tapered Screw-Vent (TSV), and NobelReplace. To simulate immediate placement in anterior maxilla, implants were placed under a sharp angle toward the ribs, not fully submerged. Placement angle of 20.7° was calculated after analysis of 148 virtually planned implants on cone beam computerized tomography scans of 40 patients. No statistically significant difference in implant stability quotient (ISQ) was found between TM (65.8 ± 2.6), TSV (64.7 ± 2.7), and NobelReplace (64.6 ± 2.7). TSV implants achieved higher insertion torque (37.0 ± 4.8 Ncm) than TM (32.9 ± 5.2 Ncm) and NobelReplace (23.2 ± 3.3 Ncm). TSV had the shortest insertion time of 13.5 ± 1.0 seconds, compared to 15.2 ± 1.2 seconds for TM, and 19.7 ± 1.7 seconds for NobelReplace. Pearson correlation analysis showed significantly correlated insertion torque and ISQ values for TM group (P =.011, r =.56), a nonsignificant correlation was found for TSV and NobelReplace. The results of the present study indicate that TM implant can achieve good primary implant stability in insertion torque and resonance frequency analysis. [ABSTRACT FROM AUTHOR]

Objectives: Genetic variants in the hedgehog signaling pathway and VDR gene are involved in inflammatory responses and neoplastic transformation. Current study investigated whether single-nucleotide polymorphisms in the hedgehog pathway genes PTCH1, GLI1, SMO, and VDR contribute to susceptibility to odontogenic cystic lesions, odontogenic keratocysts, or inflammatory radicular cysts. Material and methods: Current study examined polymorphisms of PTCH1 (rs357564) and PTCH1 insertion (IVS1-83), GLI1 (rs2228224, rs2228226), SMO (rs2228617), and VDR (rs2228570, rs731236, rs7975232). A case-control study was conducted on 41 keratocyst cases, 43 radicular cyst cases, and control group of 93 healthy individuals without cystic lesions, radiographically confirmed. Single-nucleotide polymorphisms were assessed by real-time and TaqMan SNP genotyping assays, while PTCH1 insertion 18 bp IVS1-83 polymorphism was determined by PCR. Results: The difference in genotype distribution between keratocyst cases and control group was observed for PTCH1 IVS1-83 and GLI1 rs2228224 polymorphism (p = 0.022, p = 0.030, respectively). Homozygous mutant GG genotype within GLI1 rs2228224 is associated with increased susceptibility for odontogenous keratocysts, with adjusted odds ratio of 4.098 (confidence interval of 1.482–11.328, p = 0.007). Conclusion: GLI1 rs2228224 and PTCH1 polymorphisms could predispose to odontogenic keratocysts. Clinical relevance: Variants in hedgehog signaling pathway genes, such as GLI1 and PTCH1, and vitamin D receptor gene, might be considered as molecular risk factors in odontogenic cystic lesions and potential targets for novel therapeutic approaches. [ABSTRACT FROM AUTHOR]