Accurate dental implant fixture placement is critical for optimal restorative functional and esthetic outcomes. Computer-assisted implant surgery, including static computer-assisted implant surgery and dynamic computer-assisted implant surgery systems, improves accuracy compared to freehand techniques. Augmented reality (AR) offers further benefits by integrating preoperative planning with real-time intraoperative visualization, enhancing surgical results and providing valuable tools for training future implantologists. However, high costs and technological complexity have limited its widespread adoption. This technical note presents the first clinical application of a mobile-visualized AR navigation system. While the intraoperative interface operates on a smartphone, the system is built upon a comprehensive digital workflow involving cone-beam computed tomography imaging, intraoral scanning, photographic data, and bite registration for dynamic implant navigation in the anterior maxilla. Postoperative analysis showed maximum deviations of 2.0 mm in implant apex position and 9.15° in angulation from the planned trajectory. These results confirm accurate implant placement and support the feasibility of smartphone-based AR as a cost-effective, accessible solution for digital navigation in implantology. Further research with larger sample sizes is warranted to validate these preliminary findings.
5 January 2025 in Journal of Stomatology Oral and Maxillofacial Surgery
Precise volumetric measurement of newly formed bone after maxillary sinus floor augmentation (MSFA) can help clinicians in planning for dental implants. This study aimed to introduce a novel modular framework to facilitate volumetric calculations based on manually drawn segmentations of user-defined areas of interest on cone-beam computed tomography (CBCT) images MATERIAL & METHODS: Two interconnected networks for manual segmentation of a defined volume of interest and dental implant volume calculation, respectively, were used in parallel. The volume data of dental implant manufacturers were used for reference. The efficacy of this framework was demonstrated through practical applications for collecting CBCT data from patients after MSFA with the same quantity of two different bovine-derived bone substitutes: xenohybrid composite bone (Group I, n = 10) and hydroxyapatite (Group II, n = 10). The study was approved by the central Ethical Review Board of the federal state of Lower Austria (approval number: GS4-EK-4/451-2021). The volumes were measured immediately (T1) and 6 months (T2) after MSFA and before insertion of the dental implant. All measurements were analyzed for inter- and intravariability. P-values of >0.05 were obtained from the t-test analysis RESULTS: The manual delineation of Group II (n = 10) was easier than that of Group I (n = 10) due to the visual contrast of the CBCT scan. The mean volume was 861.65 ± 290.02 mm³ at T1 and 875.9 ± 288.96 mm³ at T2. This shows a moderate dispersion around the mean value, which indicates variability of the analyzed data DISCUSSION: The proposed network may be useful for the development of computer-based diagnostic systems for assessing the success of MSFA with bone replacement materials. The volumetric stability achieved with the two bone replacement materials were comparable.
Autologous tooth transplantation is the transplantation of an erupted, partially erupted, or unerupted tooth from one site to another in an individual. This is expected to maintain alveolar bone volume through physiological stimulation of the periodontal ligament (PDL). Tooth transplantation can be used for the closure of oroantral communication. As a simple, useful, and minimally invasive method, it should be considered a surgical option when a donor tooth is available in indicated cases. Herein, the authors report the case of a 20-year-old female patient whose left permanent maxillary first molar had to be extracted due to a longitudinal fracture and radicular cyst in the maxillary sinus floor. After the extraction, tooth 28 was exposed through an osteotomy and positioned in the gap. Nineteen years later, the autologous grafted tooth 28 could no longer be retained due to massive external resorption and was replaced by an implant. Human PDL stem cells can differentiate into bone-, fiber-, and cementum-forming cells and have the potential to build a PDL complex. Therefore, care must be taken to avoid damaging the PDL of the donor tooth during extraction. Autotransplanted teeth are expected to retain the alveolar bone volume. This case demonstrates the use of a transplanted tooth 28 for the treatment of a maxillary defect caused by the extraction of tooth 26 and removal of a radicular cyst. External resorption and regeneration of the bone of the maxillary sinus floor around the transplanted tooth occurred after 19 years.
12 December 2024 in Advances in Oral and Maxillofacial Surgery
Background: Maxillary sinus floor augmentation (MSFA) is commonly used to increase posterior maxillary bone volume prior to implant placement. Although generally successful, late complications can impact long-term outcomes. The purpose of the study was to estimate the incidence and timing of atypical late complications following (MSFA) using bovine xenohybrid bone grafts. The study also aimed to evaluate whether preoperative bone volume is associated with the risk of complications. Methods: This retrospective cohort study was conducted at the Center of Oral and Maxillofacial Surgery, Danube Private University, Krems-Stein, Austria, and included patients who underwent MSFA with bovine xenohybrid bone grafts and either simultaneous or staged implant placement between January 2020 and December 2023. Preoperative bone volume of the posterior maxilla measured via cone beam computed tomography (CBCT) in the planned implant insertion position. The primary endpoint was the time (days) from MSFA to the occurrence of a graft-related complication (defined as atypical if occurring more than 6 months after MSFA and not related to peri-implantitis) The covariates included subjects’ age, sex, the quantity of graft used for MSFA, timing of dental implant insertion (simultaneous vs. staged) and implant dimensions. Kaplan–Meier analysis and Cox proportional hazards regression were used to evaluate time-to-event data. Only one graft site per patient was analyzed. Results: Atypical complications occurred in 9 out of 47 patients (19.1%), with an average time to onset of 645 days. In a multivariable analysis, a lower preoperative bone volume was found to be an independent predictor of an increased risk of complications (hazard ratio [HR]: 0.972; 95% confidence interval [CI]: 0.925–1.021; p = 0.252). However, the quantity of graft used for MSFA was not found to be a predictor (p = 0.46). Conclusions: Within the limitations of a retrospective study, reduced native bone volume appears to increase the risk of atypical late complications following MSFA with bovine xenohybrid grafts. This makes closer clinical and radiologic follow-up of patients over a longer period very necessary.
Introduction: Digital panoramic radiographs (DPRs) are used in dental practice as the first diagnostic tool for the initial detection of head and neck regions soft-tissue calcifications. The aim of this study was to use a self-developed application (App) to evaluate the ability of dental students at different levels of training to examine known DPRs with different soft-tissue calcification. Methods: A total of known 100 DPRs with (n=50) and without (n=50) calcification were independently evaluated by four groups: preclinical, first clinical and last clinical dental students, and dentists with less than or equal to 1 year of professional experience in the same time (15 min) and examination conditions. Unity software was used to develop the examination App, which allowed to mark areas with calcifications on the DPRs. The data were statistically analyzed between the groups (significance level: P<0.05) for every location, and the detection rate was calculated as a percentage of detected calcifications. Results: Results revealed that the overall detection rate of calcifications in all groups was 29.17%. Dentists exhibited the highest detection rate (36.46%), followed by the last- (29.69%), first- (32.29%), and preclinical (15.10%) students. Conclusion: These findings suggest that clinical experience plays a role in the correct detection of soft-tissue calcifications in DPRs. However, deficiencies in radiological training during dental education may contribute to diagnostic errors. As these can become life-threatening risks, the results highlight the need for early training in the dental curriculum to improve diagnostic performance and minimize possible diagnostic errors.