| 1. |
- Lewin, Susanne, et al.
(författare)
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Bone Volume Assessment Around Dental Implants After Open Maxillary Sinus Elevation Surgery : A Quantitative Approach to CBCT Images
- 2019
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Ingår i: International Journal of Oral & Maxillofacial Implants. - : QUINTESSENCE PUBLISHING CO INC. - 0882-2786 .- 1942-4434. ; 34:2, s. 489-498
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Cone beam computed tomography (CBCT) is an important imaging technique in maxillofacial evaluations. However, application-specific image analysis methods aimed at extracting quantitative information from these images need to be further developed. The aim of this study was to provide a robust and objective method that could assess radiologic changes around dental implants after sinus elevation surgery with simultaneous implant placement.Materials and Methods: The study was performed retrospectively on patients fulfilling the inclusion criteria. The included patients had been CBCT scanned preoperatively, at baseline (early after surgery), and 6 months postoperatively. In order to quantify the radiologic changes, an image analysis workflow was developed based on the postoperative baseline and 6-month scans. The workflow included metal artifact reduction, registration, and a standardized protocol for semiautomatic segmentation. Validation of different steps of the method was conducted by comparing scans from all time points. Comparison of constant volumes (eg, screws and bony parts not subjected to change) was used. Additionally, the Dice similarity coefficient (DSC) was used to measure the overlap of the segmentations.Results: The study included nine maxillary sinuses from six patients. The bone formation was quantified and visualized in 3D. In the validation, no significant differences were found for the constant volumes at the different scanning time points. The DSC showed accurate results with values > 0.92.Conclusion: The method presented in this study provides an objective and robust evaluation of bone formation around dental implants. The same methodologies can be applied in other studies of dental CBCT images, eg, for comparison of grafting materials or surgical strategies.
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| 2. |
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| 3. |
- Moafi, Roya, et al.
(författare)
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Haptic-Assisted Surgical Planning (HASP) in a Case of Bilateral Mandible Fracture
- 2022
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Ingår i: International Medical Case Reports Journal. - : Dove Medical Press Limited. - 1179-142X. ; 15, s. 707-712
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Tidskriftsartikel (refereegranskat)abstract
- Restoring normal skeletal anatomy in patients with complex trauma to the mandible can be difficult, the difficulty often increasing with an edentulous mandible. This study describes a case of a displaced edentulous bilateral mandibular fracture, which was preoperatively planned with the in-house haptic-assisted surgery planning system (HASP). A model of the virtually restored mandible was 3D-printed at the hospital and a reconstruction plate was outlined beforehand with the printed mandible as a template and served as a guide during surgery. This case suggests HASP as a valuable preoperative tool in the planning phase when dealing with maxillofacial trauma cases. With the application of virtual planning, the authors could analyze the desired outcome and were further supported in surgery by the guidance of the reconstruction plate outlined on the restored model of the mandible.
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| 4. |
- Riben, Christopher, et al.
(författare)
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Follow-Up of the Sinus Membrane Elevation Technique for Maxillary Sinus Implants without the Use of Graft Material
- 2016
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 18:5, s. 895-905
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is a limited amount of studies evaluating long-term results of the sinus membrane elevation technique for bone formation around implants in the maxillary sinus floor without the use of bone graft material.PURPOSE: To investigate the long-term results of this technique with regard to implant survival and bone gain in the maxillary sinus floor.MATERIALS AND METHODS: A retrospective study was conducted on patients who had undergone the surgical procedure from November 2001 to August 2008. Thirty-six patients with a total of 87 implants (ASTRA TECH Implant System™) in 53 sinuses were examined. After a submerged healing period of 6 months and at least 12 months of loading, the patients were examined clinically and radiologically. Implant stability was measured using resonance frequency analysis (RFA).RESULTS: The mean follow-up time was 4.6 years (range 1.5-7 years). Five implants were lost giving a survival rate of 94.3%.Subantral preoperative vertical bone levels were in the range of 1 to 10 mm. The average bone gain at the sinus floor was 6 mm. The 55 fixtures eligible for RFA displayed a mean implant stability quotient of 77 (range 56-85.5).CONCLUSION: The present study illustrates the long-term reliability of the technique.
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| 5. |
- Riben, Christopher, et al.
(författare)
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Quantification of Bone Height and Bone Volume Around Dental Implants After Open Maxillary Sinus Elevation Surgery Using CBCT.
- 2023
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Ingår i: International Journal of Oral & Maxillofacial Implants. - : Quintessence Publishing. - 0882-2786 .- 1942-4434. ; 38:4, s. 789-800
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To assess, using CBCT, the volume and height of bone formation after open maxillary sinus elevation without the use of grafts.Materials and Methods: The study was retrospective and included 24 patients with a total of 67 implants. CBCT examinations were conducted at baseline (0 to 43 days postsurgery) and after an average healing period of 6.2 months (range: 5.1 to 7.8 months). The image analysis included metal artifact reduction, registration, and a standardized protocol for segmenting the anatomical structures of the maxillary sinus, including calculating the 3D volumetric changes after bone formation. Conventional manual 2D measurement of vertical bone formation was executed for comparison. Clinical factors assumed to be relevant for bone formation were obtained from patient medical records.Results: One implant was lost before prosthetic loading, representing an early implant loss rate of 1.5%. Differences in intra- and interexaminer reproducibility were registered for the conventional 2D method (P < .05). The average vertical bone formation measured with the 2D method was 4.8 mm (4.6 to 5.0 mm), covering 60.2% of the implant height within the sinus. The average volumetric bone formation measured with the developed 3D image-analysis method was 801 mm3 in total and 195 mm3 in a restricted region around each implant. Bone formation was registered in 62% of the volume of the restricted region. A correlation regarding bone formation was found between the two methods (R2 = 0.705). Clinical factors such as age, smoking, general health, and postoperative complications did not correlate with the amount of bone formed.Conclusion: CBCT image analysis is a promising method for objective 3D evaluation of bone formation after sinus elevation. A correlation was seen between the manually measured bone height (2D) and the bone volume in a restricted region around each implant using the developed method (3D). Reducing visual interpretation minimizes errors related to examiner reliability. Clinical factors did not significantly affect the volumetric bone formation.
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| 6. |
- Riben, Christopher, et al.
(författare)
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The Maxillary Sinus Membrane Elevation Procedure : Augmentation of Bone around Dental Implants without Grafts - A Review of a Surgical Technique
- 2012
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Ingår i: International journal of dentistry. - : Hindawi Limited. - 1687-8736 .- 1687-8728. ; 2012, s. 105483-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundLong-term edentulism may in many cases result in resorption of the alveolar process. The sinus lift procedure aims to create increased bone volume in the maxillary sinus in order to enable installation of dental implants in the region. The method is over 30 years old, and initially autogenous bone grafts were used and later also different bone substitutes. Since 1997, a limited number of studies have explored the possibility of a graftless procedure where the void under the sinus membrane is filled with a blood clot that enables bone formation.AimTo describe the evolution of the sinus-lift technique and to review the literature related to the technique with a focus on long-term studies related to the graft-less technique.MethodsThe electronic database PubMed was searched, and a systematic review was conducted regarding relevant articles.ResultsA relatively few long-term studies using the described technique were found. However, the technique was described as reliable considering the outcome of the existing studies.ConclusionAll investigated studies show high implant survival rates for the graftless technique. The technique is considered to be cost-effective, less time-consuming, and related to lower morbidity since no bone harvesting is needed.
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