Three-dimensional evaluation of secondary alveolar bone grafting in patients with unilateral cleft lip and palate: A 2-3 year post-operative follow-up.

OBJECTIVES: The present study aims to quantitatively assess secondary alveolar bone graft (SABG) resorption in unilateral cleft lip, alveolus and palate (UCLAP) patients in a 2-3 year longitudinal follow-up setting by using a validated 3D protocol. Furthermore, the potential relation of SABG resorption with maxillary canine position and a number of patient-related factors was investigated. METHODS: UCLAP patients who underwent SABG and had good quality CBCT images at the following timepoints were included in the study: pre-operative (T0), immediate (T1), 6 months (T2) and either 1-2 years (T3) or 2-3 years (T4) post-operative. The final bone grafted region was defined on the T1 scans and refined in the registered T0 scans. The bone graft after resorption was determined by applying threshold-based segmentation on the registered T2, T3 or T4 scans within the segmented bone graft volume. The position of the canines was determined at every timepoint at the cleft and non-cleft side. RESULTS: Forty-five UCLAP patients (mean age 9.0 ± 1.3 years) were included. In the first 6 months after SABG, 43.6% bone resorption was recorded. 2-3 years post-operative, 56% bone resorption was found if the maxillary canine was not yet erupted and 42.7% if it erupted through the graft. The vertical position of the canines was significantly higher on the cleft side at T3. CONCLUSIONS: The present study reports significant SABG resorption over time. However, no correlation was found between SABG resorption and canine position, nor between other patient-related factors.

Current Strategies for Treatment of Mandibular Fractures With Plate Osteosynthesis: A European Prospective Study.

PURPOSE: The training and preferences of surgeons influence the type of surgical treatment for mandibular fractures. This multicentre prospective study analyzed the current treatment strategies and outcomes for mandibular fractures with open reduction and internal fixation (ORIF). MATERIAL AND METHODS: This prospective study included patients aged ≥16 years who underwent ORIF for mandibular fractures in 12 European maxillofacial centers. Age, sex, pretrauma dental status, fracture cause, site and type, associated facial fractures, surgical approach, plate number and thickness (≤1.4 or ≥1.5 mm), duration of postoperative maxillomandibular fixation, occlusal and infective complications at 6 weeks and 3 months, and revision surgeries were recorded. RESULTS: Between May 1, 2021 and April 30, 2022, 425 patients (194 single, 182 double, and 49 triple mandibular fractures) underwent ORIF for 1 or more fractures. Rigid osteosynthesis was performed for 74% of fractures and was significantly associated with displaced ( P =0.01) and comminuted ( P =0.03) fractures and with the number of nonsurgically treated fracture sites ( P =0.002). The angle was the only site associated with nonrigid osteosynthesis ( P <0.001). Malocclusions (5.6%) and infective complications (5.4%) were not associated with osteosynthesis type. CONCLUSION: Rigid osteosynthesis was the most frequently performed treatment at all fracture sites, except the mandibular angle, and was significantly associated with displaced and comminuted fractures and the number of nonsurgically treated fracture sites. No significant differences were observed regarding postoperative malocclusion or infections among osteosynthesis types.

Open reduction and internal fixation of paediatric maxillozygomatic complex fractures: An 11-year multicentric retrospective study.

BACKGROUND/AIM: Paediatric maxillozygomatic complex (MZC) fractures are uncommon, and there is a scarcity of data regarding their surgical treatment. The aim of this study was to analyse choices and outcomes of open reduction and internal fixation (ORIF) for MZC fractures among 14 maxillofacial centers around the world. MATERIALS AND METHODS: This multicentric retrospective observational study included patients ≤16 years of age with quadripod MZC fractures treated with ORIF from January 2011 and December 2022. The following data were collected: age, gender, dentition stage (deciduous, mixed, and permanent), cause of injury, type of fracture, surgical approach, site of osteosynthesis (infraorbital rim, zygomaticomaxillary buttress, frontozygomatic, and zygomaticotemporal sutures), material (titanium or resorbable) and number of plates used, and outcome. The minimum follow-up was 6 months. Statistical analyses were performed with Fisher's exact test or chi-squared test, as appropriate. RESULTS: Sixty-four patients (mean age, 12.3 years) with quadripod MZC fractures were included. Seventy-two percent of patients received a single-point fixation. The zygomaticomaxillary buttress was the most common site for fixation, both in single-point and two-point fixation schemes, especially in combination with the frontozygomatic suture. Increasing age was associated with a higher rate of plate removal (p < .001). Postoperative complications included 5 (7.8%) cases of wound infections, 2 (3.1%) infraorbital paraesthesia, 1 (1.6%) ectropion. Residual facial asymmetry was found in 5 (7.8%) patients and was not associated with the type of fixation (p > .05). CONCLUSIONS: This study highlights the possibility of using ORIF, even with a single point of fixation, for the treatment of displaced quadripod MZC fractures in the paediatric population. The zygomaticomaxillary buttress was the preferred site of fixation and allowed for adequate stabilization with no external scars and a low risk of tooth damage. Future prospective studies with long-term follow-up are needed to establish definitive surgical protocols and clarify the surgical decision-making.

Recurrence Patterns of Odontogenic Keratocysts in Syndromic and Non-Syndromic Patients.

Purpose: Odontogenic keratocysts (OKCs) have high recurrence rates. We aimed to identify recurrence patterns in OKCs and the onset of second primary OKCs in non-syndromic and syndromic patients. Material and Methods: Patients with OKCs reporting to our department from 1998 to 2021 (23 years) were retrospectively evaluated using demographic, clinical (age, sex, location, and size), histopathological, radiographic, and treatment data. All patients were followed-up for > 3 years and evaluated for OKC recurrence. Patients with naevoid basal cell carcinoma syndrome (NBCCS) were evaluated separately. Results: We included 38 and 13 patients in the non-syndromic and syndromic OKC groups, respectively. The recurrence rates were 15.8 and 21.4% in the non-syndromic and syndromic groups, respectively; 8.9% of patients exhibited a second recurrence and 1.8% a third recurrence. No second primary OKCs were observed in the non-syndromic group; 76.9% of patients in the syndromic group developed at least one. Conclusion: We found a higher recurrence rate in patients with NBCCS compared with patients with non-syndromic OKCs (21.4 versus 15.8%). The probability of developing a second primary OKC in patients with NBCCS was higher compared with that in patients with non-syndromic OKCs (76.9 versus 0%). No statistically significant risk factors for OKC recurrence were identified.

The TSAR-osteotomy, a total subapical and ramus osteotomy: A technical note.

There are several treatment options to treat a class II dentofacial deformity with a pronounced chin. A total subapical osteotomy is one of these options. This type of osteotomy was refined to total subapical and ramus (TSAR) osteotomy. In this technical note, a detailed and schematic presentation of the TSAR osteotomy is presented step by step. The surgical approach to the TSAR osteotomy is divided into three parts. The first part consists of the horizontal osteotomy at the level of the ramus, the second part approaches the corticotomy to release and protect the mental nerve and the third part consists of connecting the horizontal ramus osteotomy and the local corticotomy around the mental nerve. In this third part, it is important that the inferior alveolar nerve (IAN) is actively sought and protected.

The Accuracy of Three-Dimensional Soft Tissue Simulation in Orthognathic Surgery-A Systematic Review.

Three-dimensional soft tissue simulation has become a popular tool in the process of virtual orthognathic surgery planning and patient-surgeon communication. To apply 3D soft tissue simulation software in routine clinical practice, both qualitative and quantitative validation of its accuracy are required. The objective of this study was to systematically review the literature on the accuracy of 3D soft tissue simulation in orthognathic surgery. The Web of Science, PubMed, Cochrane, and Embase databases were consulted for the literature search. The systematic review (SR) was conducted according to the PRISMA statement, and 40 articles fulfilled the inclusion and exclusion criteria. The Quadas-2 tool was used for the risk of bias assessment for selected studies. A mean error varying from 0.27 mm to 2.9 mm for 3D soft tissue simulations for the whole face was reported. In the studies evaluating 3D soft tissue simulation accuracy after a Le Fort I osteotomy only, the upper lip and paranasal regions were reported to have the largest error, while after an isolated bilateral sagittal split osteotomy, the largest error was reported for the lower lip and chin regions. In the studies evaluating simulation after bimaxillary osteotomy with or without genioplasty, the highest inaccuracy was reported at the level of the lips, predominantly the lower lip, chin, and, sometimes, the paranasal regions. Due to the variability in the study designs and analysis methods, a direct comparison was not possible. Therefore, based on the results of this SR, guidelines to systematize the workflow for evaluating the accuracy of 3D soft tissue simulations in orthognathic surgery in future studies are proposed.

Recommendations to minimize tooth root remodeling in patients undergoing maxillary osteotomies.

The purpose of this study was to report root remodeling/resorption percentages of maxillary teeth following the different maxillary osteotomies; i.e. one-piece, two-pieces, three-pieces Le Fort I, surgically assisted rapid palatal expansion (SARPE). The possibility of relationships between root remodeling and various patient- and/or treatment-related factors were further investigated. A total of 110 patients (1075 teeth) who underwent combined orthodontic and orthognathic surgery were studied retrospectively. The sample size was divided into: 30 patients in one-piece Le Fort I group, 30 patients in multi-pieces Le Fort I group, 20 patients in SARPE group and 30 patients in orthodontic group. Preoperative and 1 year postoperative cone beam computed tomography (CBCT) scans were obtained. A validated and automated method for evaluating root remodeling and resorption in three dimensions (3D) was applied. SARPE group showed the highest percentage of root remodeling. Spearman correlation coefficient revealed a positive relationship between maxillary advancement and root remodeling, with more advancement contributing to more root remodeling. On the other hand, the orthodontic group showed a negative correlation with age indicating increased root remodeling in younger patients. Based on the reported results of linear, volumetric and morphological changes of the root after 1 year, clinical recommendations were provided in the form of decision tree flowchart and tables. These recommendations can serve as a valuable resource for surgeons in estimating and managing root remodeling and resorption associated with different maxillary surgical techniques.

Virtual reconstruction of orbital defects using Gaussian process morphable models.

PURPOSE: The conventional method to reconstruct the bone level for orbital defects, which is based on mirroring and manual adaptation, is time-consuming and the accuracy highly depends on the expertise of the clinical engineer. The aim of this study is to propose and evaluate an automated reconstruction method utilizing a Gaussian process morphable model (GPMM). METHODS: Sixty-five Computed Tomography (CT) scans of healthy midfaces were used to create a GPMM that can model shape variations of the orbital region. Parameter optimization was performed by evaluating several quantitative metrics inspired on the shape modeling literature, e.g. generalization and specificity. The reconstruction error was estimated by reconstructing artificial defects created in orbits from fifteen CT scans that were not included in the GPMM. The developed algorithms utilize the existing framework of Gaussian process morphable models, as implemented in the Scalismo software. RESULTS: By evaluating the proposed quality metrics, adequate parameters are chosen for non-rigid registration and reconstruction. The resulting median reconstruction error using the GPMM was lower (0.35 ± 0.16 mm) compared to the mirroring method (0.52 ± 0.18 mm). In addition, the GPMM-based reconstruction is automated and can be applied to large bilateral defects with a median reconstruction error of 0.39 ± 0.11 mm. CONCLUSION: The GPMM-based reconstruction proves to be less time-consuming and more accurate than reconstruction by mirroring. Further validation through clinical studies on patients with orbital defects is warranted. Nevertheless, the results underscore the potential of GPMM-based reconstruction as a promising alternative for designing patient-specific implants.

OrthoCalc: The six degrees of freedom measurement workflow of rotational and displacement changes for maxilla positioning evaluation.

BACKGROUND: This study is undertaken to establish the accuracy and reliability of OrthoCalc, a 3D application designed for the evaluation of maxillary positioning. METHODS: We registered target virtual planned models, maxillary models from pre-operative and post-operative CT scans, and post-operative intra-oral scans to a common reference system, allowing for digital evaluation. To assess rotational changes, we introduced a novel measurement method based on virtual cuboid models. Displacement errors were calculated based on proposed registration matrices. We also compared OrthoCalc to established commercial medical software as a benchmark. RESULTS: Statistical significance calculated showed no significant differences between OrthoCalc and commercial software. the biggest error of 0.04 degree in rotation change was found in the yaw. A maximum displacement change of 0.75 mm was found in the X direction. CONCLUSIONS: Our study validates OrthoCalc as a precise and reliable tool for assessing maxillary position changes with six degrees of freedom in orthognathic surgery, endorsing its clinical utility.

Biocompatibility and osteogenic capacity of additively manufactured biodegradable porous WE43 scaffolds: An in vivo study in a canine model.

Magnesium is the most promising absorbable metallic implant material for bone regeneration and alloy WE43 is already FDA approved for cardiovascular applications. This study investigates the cyto- and biocompatibility of novel additively manufactured (AM) porous WE43 scaffolds as well as their osteogenic potential and degradation characteristics in an orthotopic canine bone defect model. The cytocompatibility was demonstrated using modified ISO 10993-conform extract-based indirect and direct assays, respectively. Additionally, degradation rates of WE43 scaffolds were quantified in vitro prior to absorption tests in vivo. Complete blood cell counts, blood biomarker analyses, blood trace element analyses as well as multi-organ histopathology demonstrated excellent biocompatibility of porous y WE43 scaffolds for bone defect repair. Micro-CT analyses further showed a relatively higher absorption rate during the initial four weeks upon implantation (i.e., 36 % ± 19 %) than between four and 12 weeks (41 % ± 14 %), respectively. Of note, the porous WE43 implants were surrounded by newly formed bony tissue as early as four weeks after implantation when unmineralized trabecular ingrowth was detected. After 12 weeks, a substantial amount of mineralized bone was detected inside and around the gradually disappearing implants. This first study on AM porous WE43 implants in canine bone defects demonstrates the potential of this alloy for in vivo applications in humans. Our data further underscore the need to control initial bulk absorption kinetics through surface modifications.

Policy of fourteen maxillofacial divisions towards titanium plates removal after internal fixation of paediatric maxillofacial fractures: A World Oral Maxillofacial Trauma (WORMAT) project.

INTRODUCTION: The aim of this 11-year retrospective multicentric study is to evaluate the policy of 14 maxillofacial surgery divisions in terms of titanium plate removal from paediatric patients who had undergone open reduction and internal fixation (ORIF) to treat maxillofacial fractures. MATERIAL AND METHODS: Patients ≤ 16 years undergoing surgical treatment for fractures of middle and lower third of the face between January 2011 and December 2022, with a minimum follow-up of 6 months, were included. Age (group A: ≤ 6 years, B: 7-12 years, C: 13-16 years), sex, fracture location and type, surgical approach, number, and location of positioned and removed plates, timing and indications for removal were recorded. RESULTS: 191/383 (50 %) patients (median age, 10 years; M:F ratio 2.1:1) underwent removal of 319/708 (45 %) plates. Maxillary dentoalveolar process (91 %), angle/ramus (63 %) and mandibular body (61 %) had a significantly higher removal rate than other fracture sites (p < 0.001). A significant decreasing trend in removal with increasing age was observed, from 83 % in Group A to 24 % in Group C (p < 0.001). On the total of positioned plates, 11 % were removed for symptomatic reasons (5 % infections, 6 % discomfort/pain) and 34 % for other reasons (28 % scheduled removal). DISCUSSION: This multicentric study showed that plate removal was not performed routinely in the paediatric population. The incidence and causes of symptomatic plates removal were consistent with the literature, while the plate removal rate from asymptomatic patients was lower. A correlation was found between increasing age and a reduction in the frequency of plate removal procedures.

Risk assessment of inferior alveolar nerve injury after wisdom tooth removal using 3D AI-driven models: A within-patient study.

OBJECTIVE: To compare a three-dimensional (3D) artificial intelligence (AI)- driven model with panoramic radiography (PANO) and cone-beam computed tomography (CBCT) in assessing the risk of inferior alveolar nerve (IAN) injury after mandibular wisdom tooth (M3M) removal through a within-patient controlled trial. METHODS: From a database of 6,010 patients undergoing M3M surgery, 25 patients met the inclusion criteria of bilateral M3M removal with postoperative unilateral IAN injury. In this within-patient controlled trial, preoperative PANO and CBCT images were available, while 3D-AI models of the mandibular canal and teeth were generated from the CBCT images using the Virtual Patient Creator AI platform (Relu BV, Leuven, Belgium). Five examiners, who were blinded to surgical outcomes, assessed the imaging modalities and assigned scores indicating the risk level of IAN injury (high, medium, or low risk). Sensitivity, specificity, and area under receiver operating curve (AUC) for IAN risk assessment were calculated for each imaging modality. RESULTS: For IAN injury risk assessment after M3M removal, sensitivity was 0.87 for 3D-AI, 0.89 for CBCT versus 0.73 for PANO. Furthermore, the AUC and specificity values were 0.63 and 0.39 for 3D-AI, 0.58 and 0.28 for CBCT, and 0.57 and 0.41 for PANO, respectively. There was no statistically significant difference (p>0.05) among the imaging modalities for any diagnostic parameters. CONCLUSION: This within-patient controlled trial study revealed that risk assessment for IAN injury after M3M removal was rather similar for 3D-AI, PANO, and CBCT, with a sensitivity for injury prediction reaching up to 0.87 for 3D-AI and 0.89 for CBCT. CLINICAL SIGNIFICANCE: This within-patient trial is pioneering in exploring the application of 3D AI-driven models for assessing IAN injury risk after M3M removal. The present results indicate that AI-powered 3D models based on CBCT might facilitate IAN risk assessment of M3M removal.