Journal of Stomatology Oral and Maxillofacial Surgery最新文献

Purpose

The study aims to analyse the effects of condylar rotation on the biomechanical environment of the TMJ after bilateral sagittal split ramus osteotomy (BSSRO) through the finite element method (FEM).

Methods

Thirteen patients with mandibular prognathism and twenty-three normal subjects were recruited. The three-dimensional (3D) models were reconstructed. 13 representative morphological parameters were measured for comparison. A patient was selected to perform virtual BSSRO surgery by rotating the condyles in MIMICS. The preoperative and postoperative 3D models of the patient were subsequently imported into ABAQUS for finite element analysis. The preoperative and postoperative stresses and joint spaces in the TMJs were investigated.

Results

The maxillofacial morphologies of the patients with mandibular protrusion was significantly different from those of the asymptomatic subjects (P<.05). Stresses in the postoperative group were lower than those in the preoperative group. The rotation of the condyle could cause the variations in stress levels and joint spaces within the TMJs. Inward and upward rotation of the condyle was associated with higher stress in the TMJ, whereas the lowest stress was observed when the condyle remained stationary following surgical intervention.

Significance

Lateral, medial and superior joint spaces were more related to the stresses in the TMJs. The condyle should be kept in place as much as possible to avoid disrupting the balance of the TMJ in patients with mandibular protrusion.

Aim

The study was conducted to evaluate soft tissue profile changes using autogenous fat augmentation or onlay PEEK versus sliding genioplasty for correction of deficient chin in patients with retruded chin.

Material and methods

Thirty-three patients with deficient chins were included in the study. The patients were distributed into 3 groups: the fat augmentation group as intervention I, the PEEK augmentation group as intervention II, and the osseous genioplasty group as control group. Preoperative and postoperative CBCT were performed for all patients. With the aid of MIMICS,3-MATIC, and PROPLAN software, diagnosis, virtual planning, and evaluation were performed. The Face-Q questionnaire was used to assess patient satisfaction.

Results

There was a statistically significant difference regarding soft tissue relapse in the fat group after 6 months when compared to the control group (mean difference= 0.770), while there was no statistically significant difference regarding soft tissue relapse between PEEK and control group (mean difference= -0.060). Intragroup comparison has shown no statistically significant difference regarding soft tissue relapse within all groups between follow-up periods (P = 0.1389 for the fat group, P = 0.8739 for the peek group, and P = 0.8410 for the control group). All patients showed a statistically significant increase in scores of satisfaction with the chin between follow-up periods (P = 0.0165, P = 0.0150, and P = 0.0293) respectively.

Conclusions

Fat augmentation can be a good intervention choice in mild-moderate deficient cases. PEEK PSI has a stable surgical outcome.

Objective

The objective of this study was to conduct a comparative analysis of the components of the temporomandibular joint in individuals with unilateral, bilateral cleft lip and palate (CLP), and in healthy individuals, utilizing cone beam computed tomography (CBCT) images.

Method and material

The present study employed a cross-sectional design and recruited participants aged 18 to 30 years. The participants were categorized into three groups: a control group consisting of 36 individuals without any cleft, a group of 35 patients with unilateral cleft lip and palate (UCLP), and a group of 15 patients with bilateral cleft lip and palate (BCLP). The analysis of CBCT images encompassed the examination of condylar height and angulation, glenoid fossa height and width, articular eminence inclination, as well as joint spaces across all three groups. The Kruskal-Wallis and Mann-Whitney tests were employed to ascertain the significant differences among the three groups.

Results

The UCLP and BCLP groups demonstrated a statistically significant reduction in condylar height and articular eminence inclination in comparison to the control group. Furthermore, a significant difference in the width of the glenoid fossa was seen between the group with clefts and the control group.

Conclusion

The CBCT images showed significant differences in several aspects of the temporomandibular joint, including condylar height, articular eminence inclination, and glenoid fossa width, in individuals with cleft palate. These abnormalities can contribute to the development of temporomandibular joint diseases. Therefore, recognizing these distinctions can help prevent further deterioration and progression of temporomandibular disorders (TMD) in CLP patients.

Objective

In cases where the brands of implants are not known, treatment options can be significantly limited in potential complications arising from implant procedures. This research aims to explore the application of deep learning techniques for the classification of dental implant systems using panoramic radiographs. The primary objective is to assess the superiority of the proposed model in achieving accurate and efficient dental implant classification.

Material and Methods

A comprehensive analysis was conducted using a diverse set of 25 convolutional neural network (CNN) models, including popular architectures such as VGG16, ResNet-50, EfficientNet, and ConvNeXt. The dataset of 1258 panoramic radiographs from patients who underwent implant treatment at faculty of dentistry was utilized for training and evaluation. Six different dental implant systems were employed as prototypes for the classification task. The precision, recall, F1 score, and support scores for each class have included in the classification accuracy report to ensure accurate and reliable results from the model.

Results

The experimental results demonstrate that the proposed model consistently outperformed the other evaluated CNN architectures in terms of accuracy, precision, recall, and F1-score. With an impressive accuracy of 95.74 % and high precision and recall rates, the ConvNeXt model showcased its superiority in accurately classifying dental implant systems. Notably, the model's performance was achieved with a relatively smaller number of parameters, indicating its efficiency and speed during inference.

Conclusion

The findings highlight the effectiveness of deep learning techniques, particularly the proposed model, in accurately classifying dental implant systems from panoramic radiographs.

Purpose

To compare the effectiveness of anodized and sandblasted large-grit acid-etched surface modification implants in clinical applications.

Methods

This systematic review has been registered at PROSPERO (CRD42023423656). A systematic search was performed using seven databases. The meta-analysis was performed using the RevMan 5.4 program and Stata 17.0 software. An analysis of the risk of bias in the included studies was conducted using the Cochrane Handbook for Systematic Reviews of Interventions and the Newcastle-Ottawa scale.

Results

A comprehensive analysis of 16 studies, which collectively encompassed a total of 2768 implants, was finished. Following a five years follow-up, the meta-analysis showed that the cumulative survival rate of implants was lower in the anodized group compared to the sandblasted large-grit acid-etched group (RR, 3.47; 95 % confidence interval [CI], 1.23 to 9.81; P = 0.02). Furthermore, the anodized group and the sandblasted large-grit acid-etched group had similar marginal bone loss over the one to three years follow-up period. However, it was observed that the marginal bone loss increased at the five years follow-up period in the anodized group in comparison to the sandblasted large-grit acid-etched group (SMD, 2.98; 95 % CI, 0.91 to 5.06; P = 0.005). In terms of biological complications, plaque index, bleeding on probing, and probing pocket depth, we found no statistically significant differences between the anodized and sandblasted large-grit acid-etched group.

Conclusions

The sandblasted large-grit acid-etched group exhibited higher implants cumulative survival rate and less marginal bone loss compared to the anodized group. Moreover, both groups demonstrated similar incidences of biological complications, plaque index, bleeding on probing, and probing pocket depth, suggesting overall equivalence in these aspects.

In this study, we aimed to provide guidance for selecting bone grafting materials in cases of alveolar clefts. Twenty-nine patients with unilateral complete alveolar clefts were categorized into three groups based on the bone grafting material used: Group A (iliac bone block grafts), Group B (iliac cancellous bone grafts), and Group C (chin bone block grafts). Cone-beam computed tomography (CBCT) data were analyzed using Mimics 19.0 software. Results showed that Group A had the highest bone formation rate, with significant differences observed between Groups A and B, as well as between Groups B and C. Group A and Group C had the highest proportion of Type I in volume assessment, while Group B had the highest proportion of Type III, Significant differences were observed in the distribution of volume assessment scores among the three groups. Bone height measurement results indicated that buccal-side measurement points had a higher proportion of Type I bone height than palatal-side measurement points. Bone width measurement results showed that Type I bone width was highest in Group C, while Type IV bone width was highest in Group B. Significant differences were observed in the distribution of implanted bone width among the three groups. Total grafting scores indicated that Types A and D were predominant in Groups A and C, while Group B had the highest proportion of Type D. Significant differences were observed in the distribution of total grafting scores among the three groups. The comprehensive evaluation method provides accurate assessment of alveolar cleft bone grafting outcomes and is applicable in clinical settings. Based on the results, we consider both iliac bone blocks and chin bone blocks as suitable materials for alveolar cleft bone grafting. Grafting material selection should consider preoperative gap volume measured using CBCT, required bone quantity, donor site complications, and overall clinical needs.

Purpose

This retrospective study aimed to evaluate sequential changes in soft tissue thickness after bilateral sagittal split ramus osteotomy (BSSRO) in skeletal class III patients with facial asymmetry and to explore their correlation with surgical movements for optimal postoperative facial symmetry and esthetic outcomes.

Material and Methods

This study included 37 patients with class III malocclusion and > 4 mm Menton (Me) deviation who underwent BSSRO. Posteroanterior cephalograms were captured at preoperative (T0), 6 weeks (T1), 6 months (T2), and 1 year (T3) postoperative intervals to analyze changes in Me deviation, fronto-ramal inclination (FRI), and soft tissue thickness. Statistical analysis was conducted to assess the changes in soft tissue thickness over time and the effects of surgical correction.

Results

Significant improvements in facial asymmetry were noted after surgery, with reductions in Me deviation and FRI on both the deviated side (DS) and non-deviated side (NDS). An increase in soft tissue thickness was observed on both the DS and NDS after surgery, with the NDS showing a continued increase between 6 months and 1 year, indicating an ongoing compensation for symmetry restoration. The study also identified a positive correlation between the surgical movement of the FRI and the increase in soft tissue width on the NDS after 6 months.

Conclusion

This study established that soft tissue thickness continues to adapt and change up to 1 year after BSSRO, underscoring the need for a long-term evaluative approach in orthognathic surgery for patients with facial asymmetry.

Objectives

Botulinum toxin is used in human in repeatedly masticatory muscles injections. A single BTX injection in animal induces mandibular bone loss with a muscle enthesis hypertrophic metaplasia. Our aim was to evaluate mandibular bone changes after unilateral repeated injections of BTX in adult rats.

Study design

Mature male rats were randomized into 3 groups: one, two or three injections. Each rat received injections in right masseter and temporalis muscles. The left side was the control side. Microcomputed tomography was used to perform 2D and 3D analyses.

Results

Bone loss was evidenced on the right sides of alveolar and condylar bone. Alveolar bone volume increased in both control left side and injected right side whereas condylar bone volume remained constant in all groups, for both sides. Enthesis bone hypertrophic metaplasias were evidenced on the BTX injected sides without any modification with the number of injections.

Conclusion

BTX repeated injections in masticatory muscles lead to major mandibular condylar and alveolar bone loss that does not worsen. They lead to the occurrence of an enthesis bone proliferation that is not dependent on the number of injections. These results are an argument for the safety of BTX injections in masticatory muscles in human.