ABSTRACT
Objectives: This study aimed to create a three-dimensional histological reconstruction through the AI-assisted classification of tissues and the alignment of serial sections. The secondary aim was to evaluate if the novel technique for histological reconstruction accurately replicated the trabecular microarchitecture of bone. This was performed by conducting micromorphometric measurements on the reconstruction and comparing the results obtained with those of microCT reconstructions. Methods: A bone biopsy sample was harvested upon re-entry following sinus floor augmentation. Following microCT scanning and histological processing, a modified version of the U-Net architecture was trained to categorize tissues on the sections. Detector-free local feature matching with transformers was used to create the histological reconstruction. The micromorphometric parameters were calculated using Bruker's CTAn software (version 1.18.8.0, Bruker, Kontich, Belgium) for both histological and microCT datasets. Results: Correlation coefficients calculated between the micromorphometric parameters measured on the microCT and histological reconstruction suggest a strong linear relationship between the two with p-values of 0.777, 0.717, 0.705, 0.666, and 0.687 for BV/TV, BS/TV, Tb.Pf Tb.Th, and Tb.Sp, respectively. Bland-Altman and mountain plots suggest good agreement between BV/TV measurements on the two reconstruction methods. Conclusions: This novel method for three-dimensional histological reconstruction provides researchers with a tool that enables the assessment of accurate trabecular microarchitecture and histological information simultaneously.
ABSTRACT
OBJECTIVES: This case series aimed to assess the feasibility of a custom-made decompression appliance fabricated using a digital workflow to decompress odontogenic cysts. Additionally, the treated cysts were assessed for volumetric changes. METHODS: A three-dimensional (3D) reconstruction software (CoDiagnostiX version 10.4) was used to obtain the master cast STL (Standard Tessellation Language) file by placing a customized virtual implant to create a recess for the tube of the decompression device. The decompression appliance was planned using Dental Wings Open Software (DWOS). Following rapid prototyping, the tube of the appliance was perforated using round burs. In cases where the appliances were designed to replace teeth, denture teeth were added using the conventional workflow. The appliances were delivered on the day of the cystostomy. Following decompression, cyst enucleation was performed. Cyst volume was assessed by manual segmentation of pre- and post-operative cone-beam computed tomography (CBCT) reconstructions using slice-by-slice boundary drawing with a scissors tool in the 3DSlicer 4.10.2 software. Percentage of volume reduction was calculated as follows: volume reduction/pre-operative volume × 100. RESULTS: Six odontogenic cysts in six patients (5 male, 1 female; age 40 years, range: 15-49 years) with a pre- and post-operative cyst volume of 5597 ± 3983 mm3 and 2330 ± 1860 mm3 respectively (p < 0.05) were treated. Percentage of volume reduction was 58.84 ± 13.22 % following a 6-month-long decompression period. CONCLUSIONS: The digital workflow described in this case series enables the delivery of decompression appliances at the time of cystostomy, thus effectively reducing the volume of odontogenic cysts. The resulting bone formation established a safe zone around the anatomical landmarks; therefore, during enucleation surgery, complications to these landmarks can be avoided.
Subject(s)
Odontogenic Cysts , Humans , Male , Female , Adult , Workflow , Odontogenic Cysts/diagnostic imaging , Odontogenic Cysts/surgery , Cone-Beam Computed Tomography , Software , DecompressionABSTRACT
OBJECTIVES: This in vitro study aimed to compare the accuracy of implant placement in model surgeries carried out by implementation of three different methods. METHODS: An in vitro study was conducted on 3D printed study models randomly assigned to three study groups. In Group 1, model surgeries were assisted by augmented reality (AR)based dynamic navigation (Innooral System, Innoimplant Ltd, Budapest, Hungary). In Group 2, implants were placed with a free-hand method, and in Group 3, static Computer Assisted Implant Surgery (CAIS) was used (coDiagnostiX software, version 10.4 Dental Wings, Montreal, CA, USA). A total of 48 dental implants (Callus Pro, Callus Implant Solutions GmbH, Hamburg, Germany) were placed (16 implants in four models per study group). The primary outcome variables were angular deviation, coronal, and apical global deviation. These were calculated for all implants based on preoperative registration of the surgical plan and postoperative cone beam computed tomography (CBCT) reconstruction. RESULTS: The accuracy of implant placement using AR-based dynamic navigation showed no significant difference compared to static CAIS (angular deviation, 4.09 ± 2.79° and 3.21 ± 1.52°; coronal deviation, 1.27 ± 0.40 mm and 1.31 ± 0.42 mm; and apical global deviation 1.34 ± 0.41 mm and 1.38 ± 0.41 mm). Global deviation results were significantly lower with AR-based dynamic navigation than with the free-hand approach (coronal and apical global deviation of 1.93 ± 0.79 mm and 2.28 ± 0.74 mm, respectively). CONCLUSIONS: Implant positioning accuracy of AR-based dynamic navigation was comparable to that of static CAIS and superior to that obtained by the free-hand approach. CLINICAL SIGNIFICANCE: Implementing Augmented Reality based dynamic Computer Assisted Implant Surgery (CAIS) in model surgeries may allow to obtain an implant positioning accuracy comparable to that provided by static CAIS, and superior to that obtained through the free-hand approach. Further clinical studies are necessary to determine the feasibility of AR-based dynamic navigation.
Subject(s)
Augmented Reality , Dental Implants , Computer-Aided Design , Computers , Cone-Beam Computed Tomography , Dental Implantation, Endosseous , Humans , Imaging, Three-DimensionalABSTRACT
The aim of our randomized clinical study was to analyze the influence of surgical experience and bone density on the accuracy of static computer-assisted implant surgery (CAIS) in edentulous jaws using a mucosa-supported surgical template with a half-guided implant placement protocol. Altogether, 40 dental implants were placed in the edentulous jaws of 13 patients (novice surgeons: 18 implants, 6 patients (4 male), age 71 ± 10.1 years; experienced surgeons: 22 implants, 7 patients (4 male), age 69.2 ± 4.55 years). Angular deviation, coronal and apical global deviation and grey level measurements were calculated for all implants by a blinded investigator using coDiagnostiX software. 3DSlicer software was applied to calculate the bone volume fraction (BV/TV) for each site of implant placement. There were no statistically significant differences between the two study groups in either of the primary outcome variables. There was a statistically significant negative correlation between angular deviation and both grey level measurements (R-value: -0.331, p < 0.05) and BV/TV (R-value: -0.377, p < 0.05). The results of the study suggest that surgical experience did not influence the accuracy of implant placement. The higher the bone density at the sites of implant placement, the higher the accuracy of static CAIS.
ABSTRACT
BACKGROUND: Alveolar atrophy following tooth loss is a common limitation of rehabilitation with dental implant born prostheses. Ridge splitting is a well-documented surgical method to restore the width of the alveolar ridge prior to implant placement. The aim of this case series is to present a novel approach to ridge expansion using only autogenous bone blocks. Methods: Patients with Kennedy Class I. and II. mandibles with insufficient bone width were included in this study. Ridge splitting was carried out with the use of a piezoelectric surgery device by preparing osteotomies and after mobilization of the buccal cortical by placing an autologous bone block harvested from the retromolar region as a spacer between the buccal and lingual cortical plates. Block-grafts were stabilized by osteosynthesis screws. Implant placement was carried out after a 3-month healing period. A total of 13 implants were placed in seven augmented sites of six patients. RESULTS: Upon re-entry, all sites healed uneventfully. Mean ridge width gain was 2.86 mm, range: 2.0-5.0 mm. CONCLUSIONS: Clinical results of our study show that the modified ridge splitting technique is a safe and predictable method to restore width of the alveolar ridge prior to implant placement.
