Maxillofacial Plastic and Reconstructive Surgery最新文献

Background: Relapses following orthognathic surgery have been reported to exceed 2% to 50%, depending on multiple factors. This study aimed to analyze the stability after orthognathic surgery in patients with mandibular ramus height asymmetry through 3D reconstruction using Cone-beam CT.

Methods: This retrospective cohort study investigated patients who underwent mandibular setback surgery using bilateral sagittal split ramus osteotomy. Three-dimensional CT scans were taken at three different time points. Evaluation of the postoperative stability involved measuring changes in the x, y, and z axes as well as roll and yaw rotations of the mandible at specific landmarks (B point, mental foramen) on 3D CT scans obtained immediately after surgery and 6-12 months postoperatively. They were categorized into four groups based on bilateral mandibular height asymmetry through Asymmetry index (AI). The one-way ANOVA was implemented to compare the intergroup differences and Tukey's post hoc test was employed. Additionally, the Pearson correlation coefficient was also calculated.

Results: A total of 24 patients were included in this study. The corresponding AI, representing the degree of asymmetry in both mandibles, were calculated as Group 1 was 1.25 ± 0.64%, Group 2 was 2.89 ± 0.47%, Group 3 was 5.03 ± 0.51%, and Group 4 was 9.40 ± 1.99%. The x-axis change in Group 4 was significantly larger at 1.71 mm compared to Group 1 at 0.64 mm. The mandibular roll, Group 4 showed a statistically significant increase at 1.33° compared to Group 1 at 0.35°. And there was a significant positive correlation observed between x-axis change and AI (p = 0.019), as well as between mandibular roll and AI (p = 0.025).

Conclusion: After orthognathic surgery, stability was influenced by numerous factors, with the findings of this study suggesting that the degree of ramus height asymmetry in the mandible can be considered one contributing factor.

Background: Tumor tissues comprise cancer cells and stromal cells, and their interactions form the cancer microenvironment. Therefore, treatments targeting cells other than cancer cells are also actively being developed, and among them, treatment targeting PD-1, an immune checkpoint molecule that is important in tumor immune evasion, has also been indicated for head and neck cancer. PD-L1, a ligand of PD-1, is expressed in both tumor cells and stromal cells, and the scoring system based on the combined positivity rates of both types of cells, the combined positive score (CPS), is used for predicting treatment effect. However, much is unknown regarding the expression of PD-L1. In this study, we histopathologically examined factors controlling the expression of PD-1/PD-L1. This study included 37 patients who underwent resection surgery for tongue squamous cell carcinoma in the Department of Oral and Maxillofacial Surgery at Tokyo Dental College Suidobashi Hospital. The expression levels of PD-L1, α-SMA, and p53 were assessed by immunohistochemical staining.

Results: Seven participants had CPS ≥ 20, twenty-four participants had 1 ≤ CPS < 20, and six participants had CPS < 1. The overall positivity rate of α-SMA, a marker for cancer-associated fibroblasts (CAFs), was 27% (10/37 participants), and the positivity rates of α-SMA for the three CPS groups were 85.7% (6/7 participants), 16.7% (4/24 participants), and 0% (0/6 participants), respectively. In addition, the overall positivity rate of p53 was 37.8% (14/37 participants), and the positivity rates of p53 for the three CPS groups were 71.4% (5/7 participants), 37.5% (9/24 participants), and 0% (0/6 participants), respectively.

Conclusions: The expression of PD-L1 demonstrated an association with α-SMA and p53 positivity. In addition, compared with the expression of p53, the expression of α-SMA demonstrated a higher association with PD-L1 expression in patients with a high CPS. The abovementioned findings suggest that the interactions between CAFs, cancer cells, and immunocompetent cells may regulate the expression of PD-L1.

Background: Despite the advancement of reconstructive surgical techniques, facial defect reconstruction has been always very challenging, aesthetic satisfaction has often been difficult to achieve due to the unique characteristics and complexity of the facial tissue. There have been various options regarding reconstruction and compensation of soft tissue loss all over the body rather than the face. Regardless of whether skin grafts, local flaps, and free flaps were used in the reconstruction process, each of them has its limitations. Beginning with skin grafts results could not always be satisfactory due to contracture, color, and lack of texture Additionally, local flaps have limitations due to mobility and the availability of overlapping skin and tissue, as well as the bulkiness of the pedicle which may need a second staged surgery and lately the difficulty of the free flaps and being a major surgery.

Results: Patients ages ranged between 23 and 77 years old, with a mean age of 58.33 ± 12.47. As regards the patients' sex, 63.3% of our patients were males and 36.7% were females. Co-morbidities were found in 60% of cases (DM 23.3%, HTN 20%, HCV 3.3%, cardiac 3.3%). Most flaps were facial artery perforator flaps 53.3%, then transverse facial artery 26.7%, superficial temporal artery 10%, angular artery 6.7%, and supra-trochlear artery 3.3%. Twenty-ix cases representing 86.7% of cases went uneventful, while complications showed in 4 cases representing 13.3% of cases, 1 case (3.3%) showed venous congestion that was relieved within 24 h after 2 suture releases, another case (3.3%) showed wound dehiscence that was improved after 2 days with regular dressings, the third patient (3.3%) had recurrence after 4 months that was treated by excision and grafting, while last patient (3.3%) had inadequate excision that was treated by radiotherapy. No bleeding or infection occurred. Also, we observed no correlation between flap length and complications. As regards the functional point of view, all patients showed no functional impairment at the donor site, and only one case showed functional impairment at the recipient site. As regards patient satisfaction, all 30 patients achieved positive satisfaction scores using the Likert scale, 18 cases were satisfied, and 12 cases were very satisfied.

Conclusion: The use of perforator-based flaps can provide a more effective and aesthetically pleasing solution for the reconstruction of small to moderate facial defects, provided that a reliable Perforator is accurately identified and executed by an experienced surgeon.

Introduction: Orthognathic surgery (OGS) is a highly sophisticated surgical technique that aims to repair a variety of skeletal and dental abnormalities, including misaligned jaws and teeth. It requires precise preoperative preparation and advanced surgical skills, which are typically learned through years of practical experience in operating rooms or laboratory-based surgical training facilities utilizing cadavers or models. The traditional physical hands-on method of surgical training is still used at OGS. However, this method requires a longer time of preparation. Currently, mixed reality (MR)-a combination of virtual reality and augmented reality technology-is an innovation of OGS. The present study aimed to present a comprehensive review of studies that assessed the advantages of utilizing mixed reality technology in OGS.

Methods: A modified Population, Intervention, Comparison, Outcome strategy was performed using a combination of electronic (PubMed, Cochrane, Embase) and manual searches between 2013 and 2023 exploring mixed reality (MR) technology in OGS in the last 10 years. The inclusion criteria were limited to the patient and study model focusing on the clinical application of MR and the associated field of OGS.

Result: The initial search indicated 1731 studies, of which 17 studies were included for analysis. The main results indicated that the use of MR technology in OGS led to high accuracy and time reduction as primary outcomes and cost-effectiveness and skill improvement as secondary outcomes. The review firmly concluded that MR technology exhibited a positive impact on students, trainees, and oromaxillofacial surgeons. However, due to the heterogeneity of the included studies, meta-analyses could not be performed. Collectively, these findings provide strong evidence for the advantages of MR technology in orthognathic surgery.

Conclusion: MR technology significantly improves OGS planning efficiency by providing pre-surgical information and serving as an intraoperative navigation tool, reducing surgical time without compromising outcomes. Virtual training using MR technology exerts a positive impact on knowledge and skill improvement for OGS. This innovative technology will revolutionize the healthcare system and enhance patient care.

Background: Many studies have been reported on tracheostomy to prevent upper airway obstruction after surgery. Among these, the scoring system proposed by Cameron et al. quantifies various factors that influence postoperative respiratory failure. This system provides a basis for surgeons to decide whether to perform an elective tracheostomy. In this study, the authors applied the Cameron scoring system retrospectively to patients undergoing severe oral cancer surgery to reevaluate the indications for elective tracheostomy and to investigate its clinical efficacy in airway management. In this study, a sample of 20 patients who underwent oral cancer surgery was selected and divided into two groups: 10 underwent tracheostomy and 10 did not. The Cameron scoring scores for each patient were extracted, to verify whether elective tracheostomy was performed in accordance with the threshold scores. Differences in scores and significant clinical impact factors between the two groups were analyzed and compared.

Result: The 10 patients who underwent tracheostomy had an average Cameron score of 6.4, all scoring above the recommended threshold of 5 for tracheostomy. For the 10 patients who did not undergo tracheostomy, the average score was 2.5, with 8 out of these 10 patients scoring below 5. Significant clinical impact factors observed included the location and size of the tumor, the performance of mandibulectomy and neck dissection, and the type of reconstruction surgery.

Conclusion: In planning surgery for oral cancer patients, it is essential to consider the use of elective tracheostomy based on preoperative assessment of the risk of postoperative airway obstruction using tools like the Cameron scoring system, and patients' condition. Research confirms that elective tracheostomy effectively enhances airway management in patients with severe oral cancer.

Background: Based on a three-dimensional (3D) orthognathic simulation, this technical report introduces a method for augmentation genioplasty using a proximal bone fragment of the mandible, which is typically discarded in intraoral vertical ramus osteotomy (IVRO).

Results: A 43-year-old female patient diagnosed with Class III malocclusion, presenting with a protruding mandible and long facial height, underwent surgical treatment. The surgical plan involved mandibular setback position using IVRO and augmentation genioplasty. The 3D orthognathic surgery including augmentation genioplasty simulation was performed. An excessively elongated proximal segment was sectioned following IVRO. The inferior part of the sectioned proximal bone fragment of the mandible was positioned to align with the requirements of advancement genioplasty. After ensuring that the placement of the fragment matched that of the simulated surgery, each bone fragment was fixed. At 1.5 years post-surgery, the grafted bone on the augmentation genioplasty was well maintained, with slight bone resorption.

Conclusions: Augmentation genioplasty using the proximal bone fragment of the mandible, which is typically discarded in IVRO, reduces the surgical complications associated with chin osteotomy. When a secondary genioplasty is required, genioplasty with osteotomy, movement of the cut bone fragments, partial bone-shaving osteotomy, and additional bone grafting are viable options.

Background: Orthodontic and surgical technical advances in recent years have resulted in treatment opportunities for a whole range of craniofacial skeletal disorders either in the adolescent or adult patient. In the growing child, these can include myofunctional orthodontic appliance therapy or distraction osteogenesis procedures, while in the adult, the mainstay approach revolves around orthognathic surgery. The literature agrees that for a change in craniofacial morphology to remain stable, the muscles acting upon the facial skeleton must be capable of adaptation in their structure and, therefore, their function. Failure of the muscles to adapt to the change in their length or orientation will place undesirable forces on the muscle attachments leading to potential instability of the skeleton. Adaptation can occur through various processes including those within the neuromuscular feedback mechanism, through changes within muscle structure or through altered muscle physiology, and through changes at the muscle/bone interface. It is now accepted that because there is no single method of assessing masticatory function, several measures should be taken, and whenever possible, simultaneously.

Methods: This investigation was designed to apply several, newly developed and more sophisticated methods of measuring muscle structure and function to a situation where adaptation of muscle is pivotal to the success of a therapeutic approach. Patients attending the combined orthodontic/orthognathic surgery clinic at the Clitrofa - Centro Médico, Dentário e Cirúrgico, in Trofa, Portugal, were screened. Ten patients scheduled for a bimaxillary osteotomy involving a combination of maxillary Le Fort I impaction procedure coupled with a sagittal split advancement of the mandible were selected to form the study group. The patients have MRI of the masseter muscle to evaluate the masseter muscle volume and fibre orientation changes. This exam was taken before surgery (T0), 6 to 12 months after surgery (T1), and 3 years after surgery (T2), by two independent observers, according to the protocol jointly developed between the Eastman Dental Institute - University of London and the MRI Centre - Department of Radiology at John Radcliffe Hospital - University of Oxford.

Results: Significant differences (p < 0.05) have been identified between Time 0 (pre-op) and Time 1 (6-12 months post-op) regarding the masseter area (mm²). The differences against Time 0 (pre-op) seem to disappear at Time 2 (3 years post-op).

Conclusions: MRI therefore seems to be a valid tool for measuring differences in the masseter muscle area and volume associated with high-severity occlusal deformities, although showing not to be as efficient in detecting the same differences in cases of low-severity occlusal deformities.

Background: The present systematic review intended to evaluate the current evidence on the modalities used for treating iatrogenic late paresthesia in the oral tissues innervated by the mandibular branch of the trigeminal nerve.

Main text: As a common side effect of dental procedures, paresthesia can exert a profound adverse effect on patients' quality of life. The inferior alveolar nerve (IAN) and lingual nerve (LN) have the highest chance of injury during several dental procedures, including mandibular orthognathic surgeries, implant placement, extraction of the third molar, anesthetic injections, flap elevation, and endodontic treatments. Moreover, several methods have been proposed for treating iatrogenic late paresthesia, including photobiomodulation (PBM), microsurgery, medication, and close observation until achieving spontaneous recovery of sensation. However, no gold standard treatment for iatrogenic paresthesia has been agreed upon up to now. The present study included a comprehensive search of the databases of PubMed, Embase, Scopus, and Web of Science up to December 04, 2023, resulting in a total of 3122 related studies. Then, the titles, abstracts, and full texts of the studies were evaluated. Ultimately, seven controlled randomized trials (RCTs) were included in the final analysis. Also, the risk of bias was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist. Among all fields, randomization, allocation concealment, and data analysis were found to have the highest chance of bias in the included studies.

Conclusions: In conclusion, PBM, vitamin B12, and corticosteroids could accelerate the recovery of late paresthesia. However, considering the low sample size of the included studies and the high risk of methodological bias, it is recommended to perform further RCTs with robust study designs following Good Clinical Practice (GCP) guidelines to achieve more reliable results.

Background: The management of internal derangement (ID) of the TMJ is challenging because of multiple etiologic factors and varying degrees of severity. The aim of this study was to evaluate the clinical outcomes of patients with unilateral ID treated with arthrocentesis and stabilization splint therapy during a 6-month period.

Methods: A total of 105 patients (87 females, 18 males) with unilateral ID were included in this study. Patients were divided into unilateral anterior disc displacement with reduction (ADDwR) and unilateral anterior disc displacement without reduction (ADDwoR). Patients with ADDwoR were subdivided according to the erosive bone changes. Objective parameters on mandibular movement and subjective parameters on pain were obtained and assessed. Their clinical outcomes before and after arthrocentesis and stabilization splint therapy were compared with the chi-square, Fisher's exact test, paired t-test, or Wilcoxon singed-rank test.

Results: All objective parameters of unilateral ID patients significantly increased at the 6-month follow-up. The differences in mean visual analog scale (VAS) pain scores were statistically significant in all subjective variables (p < 0.01). In joints with ADDwoR, preoperative maximal mouth opening, and maximal protrusive movement in both groups, with erosive and non-erosive changes were significantly increased after 6 months (p < 0.01). However, right and left maximal lateral movement increased after treatment in both groups but without significant differences. All VAS pain scores on jaw movement and palpation of associated muscles showed a significant decrease regardless of erosive changes.

Conclusions: The combination of arthrocentesis and subsequent stabilization splint therapy was shown to be highly effective in pain reduction and improvement of mandibular movements in both unilateral ADDwR and ADDwoR, as well as in cases with both erosive and non-erosive bony changes associated with unilateral ADDwoR.

Background: Focal and florid cemento-osseous dysplasia are benign fibro-osseous lesions affecting the quality and quantity of the jawbones. This study aimed to determine the viability of implant-based approaches in the affected patients.

Main text: Different scientific databases, including PubMed/MEDLINE, Scopus, Web of Science, Embase, the Cochrane Library, and Google Scholar, were searched until October 8, 2023, using a pre-determined search strategy. Two reviewers screened the retrieved reports and extracted the required information from the included studies. The eligibility criteria included English-language case reports/series or clinical trials. The JBI critical appraisal checklist for case reports was used to assess the methodological quality of the included studies. Three studies were deemed eligible to be included in this study out of the initial 202 records found. Five implants were placed in three patients, positioned in the proximity of the lesion area, without any additional treatment to remove the pathology. The mandibular posterior area was the affected site in all patients. Only one implant failed in one patient after 16 years, which was attributed to peri-implantitis and not the lesion. Other implants demonstrated successful maintenance over follow-up periods.

Conclusions: Although the number of the included records was relatively low to draw firm conclusions, it seems that implant-based treatments in patients with focal/florid cemento-osseous dysplasia could be viable, considering a conservative and well-planned approach.