Influence of preoperative anatomy and functional status on outcomes after total temporomandibular joint replacement with patient-specific endoprostheses: A retrospective cohort study.

BACKGROUND: Temporomandibular joint (TMJ) replacement may be indicated for various pathological conditions, and the type of condition can affect the surgical procedure and outcomes. The causes of limited range of motion after alloplastic TMJ replacement have not been extensively studied. OBJECTIVES: The present study aimed to evaluate the impact of preoperative jaw anatomy and functional status on the immediate and long-term outcomes of total TMJ replacement using a two-component patient-specific TMJ endoprosthesis. MATERIAL AND METHODS: This retrospective study included 31 patients who underwent total TMJ replacement surgery between 2016 and 2020. The main outcome variable was the maximal incisal opening (MIO) after treatment. Secondary outcome variables included MIO improvement and the presence and type of postoperative complications. The primary predictive variable was the preoperative initial MIO. Secondary predictive variables included sex, age, indications for TMJ replacement, preoperative occlusion, condition of the glenoid fossa and/or condyle, shortening of the mandibular ramus, sagittal mandible position, lateral chin deviation, shape of the coronoid process, and type of surgery. RESULTS: The mean preoperative MIO was 13.0 ±8.0 mm, while the mean MIO 1 month after surgery was 20.6 ±5.5 mm, which was not statistically significant. However, at a later follow-up, functional parameters showed a significant improvement (p = 0.003), with a mean MIO of 32.5 ±5.0 mm 3 years after surgery. Statistical analysis indicated that the initial mouth opening is the strongest predictor of long-term functional recovery after TMJ replacement. Postoperative complications occurred in 4 cases (12.9%) following patient-specific endoprosthesis (PSE) placement. CONCLUSIONS: The use of PSEs for TMJ replacement has enabled the restoration of anatomical relationships in complex clinical cases and an improvement in mouth opening. The preoperative MIO was the only factor that significantly influenced long-term functional outcomes.

Delayed reconstruction of the combat-related mandibular defects with non-vascularized iliac crest grafts: Defining the optimal conditions for a positive outcome in the retrospective study.

BACKGROUND: Reconstruction of mandibular defects caused by combat injuries is challenging for clinicians due to soft tissue defects and high complication risk. This study evaluated the outcomes of mandibular continuous defects reconstruction with non-vascularized iliac crest graft (NVICG) in patients with combat injuries. MATERIAL AND METHODS: Patients with continuous mandibular defects acquired by high-velocity agents, who received NVICG reconstruction with or without microvascular-free soft tissue or regional flaps, were included in the study. The outcome variable was graft loss due to postoperative complications or full (more than 90 %) resorption. The primary predictor variable was soft tissue defect in the recipient area. The secondary predictor variable was the length of the defect. Variables related to patients, defect site, surgery, and other complications were also evaluated. Statistical analysis was performed with the usage of independent sample t-test, Pearson's chi-squared and Fisher's exact tests with a significance level of P < 0.05 RESULTS: The study included 24 patients with 27 mandibular defects. Overall, the general success rate of reconstructions was 59.3 %. Soft tissue defects were significantly associated with graft failure and other complications (p < 0.05), which were mostly related to soft tissue defects. The graft success rate was only 14.3 % even in minor soft tissue defects. In turn, in reconstructions with sufficient soft tissue coverage, the graft survived in 75.0 % of the cases. In addition, patients with more delayed reconstruction had significantly fewer graft failures than those with earlier surgery (p < 0.05). No associations were found between defect size and complications. CONCLUSION: The sufficient soft tissue coverage is essential in the reconstruction of mandibular defects caused by combat injuries. Also, minor soft tissue defects should be covered with soft tissue flaps to avoid complications and graft loss in these specific injuries. Even large defects can be reconstructed with NIVICG if the soft tissue coverage is sufficient.

Clinical application of automated virtual orbital reconstruction for orbital fracture management with patient-specific implants: A prospective comparative study.

The aim of the study was to compare automated and manually conducted (slice-by-slice) virtual orbital wall reconstruction in terms of PSI design, manufacture, and clinical application for orbital fracture management. Patients with orbital wall fractures were evaluated for the potential for treatment with PSI, based on automated virtual wall reconstruction; these formed the main group. The surgical outcomes of these main-group patients' treatments were compared with those of the control group, which comprised patients randomly selected for this study, each of whom had the same orbital trauma patterns and were also managed with PSI. However, the control group patients were treated using 'slice-by-slice' virtual orbital reconstruction. Mean volume differences between the intact and reconstructed orbit were 0.65 ± 0.26 cm3 in the main group (n = 23) and 0.57 ± 0.23 cm3 in the control (n = 27; p = 0.837). In both groups, no cases of implant malposition or enophthalmos were detected after surgery. Orbital shape difference was similar for the main group and the control, at -3.3 ± 3.5% and 3.25 ± 2.5%, respectively (p = 0.929). Diplopia was diagnosed at the 3-month follow-up in 13.0% of the main group and in 11.1% of the control (p = 0.651). The average times spent on computer-aided design (CAD) procedures, including segmentation, virtual orbital reconstruction, and PSI design, were 36.7 ± 6.9 min in the main group and 72.9 ± 7.7 min in the control group (p < 0.001). Within the limitations of the study it seems that PSI based on automated virtual reconstruction is a relevant alternative treatment option for orbital fractures because of its clinical efficacy that is similar to PSI based on a 'slice-by-slice' CAD protocol.

Recurrent Ameloblastoma: Clinical Manifestation and Disease-Free Survival Rate.

Objectives: Ameloblastoma is a slow-growing epithelial odontogenic neoplasm of the jaws with a high recurrence rate. The main treatment strategies for this lesion are radical or conservative surgical approaches. The aim of the present study was to analyze clinical presentations, histological types, and treatment strategies of recurrent ameloblastoma and to define its disease-free survival (DFS) rate. Materials and Methods: Twenty-four cases of recurrent ameloblastomas, treated between January 2009 and July 2021, were enrolled in this study. Medical files from each patient, including gender, age, size of the lesion, localization, patient complaints, clinical manifestation, radiographic appearance, histological type, surgical management, and treatment results were reviewed and analyzed retrospectively. Result: Out of 69 operated primary ameloblastomas, the rate of recurrence was 35%. Out of 24 recurrent cases, 21 developed after conservative treatment and 3 after radical treatment. In most cases, recurrences were found in the mandible (n = 20). A unilocular pattern was predominant in radiographic examination (44%). Estimated 3-year DFS was 84.5 ± 4.8%, and the 5-year and 10-year DFS were 73.0 ± 6.3% and 43.9 ± 8.343.9 ± 8.3%, respectively. Conclusion: Results obtained in the present retrospective study proved the necessity of long-term follow-up after both conservative and radical treatment approaches. The DFS median in our study was 8 years (95% CI 6 years-10 years). For recurrent cases, radical resection with histologically free margins after exact MRI determination of the ameloblastoma border within the soft tissues should be considered as the method of choice to avoid secondary recurrence.

Application of Patient-Specific Implants as Alternative Approach to Zygoma Defect Management - A Retrospective Study.

INTRODUCTION: Zygoma defects are a challenging clinical problem and are frequently connected with the alteration of facial harmony, horizontal asymmetry of the face, and significant functional deficit. The application of patient-specific implants (PSIs) has the potential to improve the effectiveness of zygoma defect management. The aim of this study was to evaluate the anatomic, esthetic, and functional outcomes of PSI application for zygoma reconstruction. MATERIALS AND METHODS: A retrospective study was conducted on data from 11 patients with zygoma defects who underwent a reconstruction procedure in which a PSI was applied and was followed for >1 year after surgery with the evaluation of esthetic and functional outcomes. Precision of PSI position and anatomy reconstruction was estimated by superimposition of the models with automatic point-to-point measurement and determination of the existing deviations between models. RESULTS: The mean follow-up period in our study was 21.6 ± 6.2 months (range 14-39 months). No major complications occurred in the postoperative period: There were no clinical or computed tomography symptoms of maxillary sinusitis, implant-related infection, or implant exposure. The mean deviation between the planned and real positions of PSIs in our series was 0.72 ± 0.41 mm. The mean deviation between the reconstructed zygomatic complex and the mirrored intact side in our series was 1.45 ± 0.7 mm. The mean volume difference between the intact and damaged orbits was 1.7 ± 0.8 mm3. DISCUSSION: The results of the present study support the wider clinical application of PSIs in orbital and zygoma reconstructions, as it is an effective option to achieve precise reconstruction of the complex zygoma anatomy.

The epidemiology and management of ameloblastomas: A European multicenter study.

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence. A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05). Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.

Automatic evaluation of the orbital shape after application of conventional and patient-specific implants: Correlation of initial trauma patterns and outcome.

PURPOSE: To evaluate the precision of orbital shape reconstructions using either conventional plates (CPs) or patient-specific implants (PSIs) to treat different types of orbital fractures, and to evaluate their clinical outcomes. METHODS: A total of 92 orbital-reconstruction patients were included. Forty-seven patients, treated with PSIs, formed the main group. The remainder, treated with CPs, were the control group. All patients were examined pre- and postoperatively using computerized tomography (CT) and evaluated for enophthalmos and diplopia. Evaluation of differences in orbital shape between damaged and intact orbits after surgery was performed by commercial orbital analysis software. RESULTS: In the main group, mean orbital shape difference between damaged and intact orbits after surgery was 0.137 ± 0.8 cm3 (range -1.7-2.3 cm3). In the control group, the mean shape difference was 1.05 ± 1.9 cm3 (range -1.8-8.3 cm3), significantly higher (p = 0.007). Diplopia occurred in seven PSI patients three months after surgery (14.9%) and in thirteen CP patients (28.9%) (p = 0.181). Enophthalmos occurred in five PSI patients (10.6%) and in sixteen CP patients (35.6%) (p = 0.001). CONCLUSION: Precise orbital reconstruction prevents the development of enophthalmos after trauma in patients with orbital wall fractures. In patients with preserved infraorbital buttresses and posterior orbital ledges, there were no significant clinical differences between PSIs and CPs. For cases requiring cantilevered reconstruction, including those with zigomatic or maxillary fragment repositioning, preference should be given to the PSI procedure for both effectiveness and predictability.

Reliability of orbital volume measurements based on computed tomography segmentation: Validation of different algorithms in orbital trauma patients.

PURPOSE: To compare the most common methods of segmentation for evaluation of the bony orbit in orbital trauma patients. MATERIALS AND METHODS: Computed tomography scans (before and after treatment) from 15 patients with unilateral blowout fractures and who underwent orbital reconstructions were randomly selected for this study. Orbital volume measurements, volume difference measurements, prolapsed soft tissue volumes, and bony defect areas were made using manual, semi-automated, and automated segmentation methods. RESULTS: Volume difference values between intact and damaged orbits after surgery using the manual mode were 0.5 ± 0.3 cm3, 0.5 ± 0.4 cm3 applying semi-automated method, and 0.76 ± 0.5 cm3, determined by automated segmentation (р = 0.216); the mean volumes (MVs) for prolapsed tissues were 3.0 ± 1.9 cm3, 3.0 ± 2.3 cm3, and 2.8 ± 3.9 cm3 (p = 0.152); and orbital wall defect areas were 4.7 ± 2.8 cm2, 4.75 ± 3.1 cm2, and 4.9 ± 3.3 cm2 (p = 0.674), respectively. CONCLUSIONS: The analyzed segmentation methods had the same accuracy in evaluation of volume differences between two orbits of the same patient, defect areas, and prolapsed soft tissue volumes but not in absolute values of the orbital volume due to the existing diversity in determination of anterior closing. The automated method is recommended for common clinical cases, as it is less time-consuming with high precision and reproducibility.

Clinical efficacy of peek patient-specific implants in orbital reconstruction.

PURPOSE: To assess the clinical efficacy of custom made PEEK patient-specific implants in treatment of orbital wall defects. METHODS: Forty-five patients with unilateral post-traumatic orbital wall defects were enrolled in the study. They underwent subsequent reconstructive procedures using PEEK patient-specific implants (PSI) or pre-bent titanium plates. All the patients were examined with the standardized algorithm, including local status examination, vision assessment and computer tomography (CT) with measurements of the orbital volume. A comparative analysis of the treatment outcomes in two groups of patients (pre-bent plates/PSI) was performed. RESULTS: The study findings show an absence of any postoperative infection, inflamation or decreased visual acuity in either group. In PSI group, diplopia after surgery was absent in 82.1% of patients versus 70.6% of controls. The mean duration of surgery was 54.25 ± 16.8 min with PSI application and 82.9 ± 10.8 min with pre-bent plates. The mean difference between the intact and damaged orbital volume was 1.9 ± 1.4 cm3 in the control group versus 0.74 ± 0.6 cm3 in PSI group (р<0.05). CONCLUSION: PEEK PSI demonstrated higher clinical efficacy in comparison to pre-bent plates in orbital wall reconstruction especially in restoring the volume and shape of the damaged orbit.