Application of Augmented Reality to Maxillary Resections: A Three-Dimensional Approach to Maxillofacial Oncologic Surgery

In the relevant global context, although virtual reality, augmented reality, and mixed reality have been emerging methodologies for several years, only now have technological and scientific advances made them suitable for revolutionizing clinical care and medical settings through the provision of advanced features and improved healthcare services. Over the past fifteen years, tools and applications using augmented reality (AR) have been designed and tested in the context of various surgical and medical disciplines, including maxillofacial surgery. The purpose of this paper is to show how a marker-less AR guidance system using the Microsoft^® HoloLens 2 can be applied in mandible and maxillary demolition surgery to guide maxillary osteotomies. We describe three mandibular and maxillary oncologic resections performed during 2021 using AR support. In these three patients, we applied a marker-less tracking method based on recognition of the patient's facial profile. The surgeon, using HoloLens 2 smart glasses, could see the virtual surgical planning superimposed on the patient's anatomy. We showed that performing osteotomies under AR guidance is feasible and viable, as demonstrated by comparison with osteotomies performed using CAD-CAM cutting guides. This technology has advantages and disadvantages. However, further research is needed to improve the stability and robustness of the marker-less tracking method applied to patient face recognition.

Point-of-Care Virtual Surgical Planning and 3D Printing in Oral and Cranio-Maxillofacial Surgery: A Narrative Review

This paper provides an overview on the use of virtual surgical planning (VSP) and point-of-care 3D printing (POC 3DP) in oral and cranio-maxillofacial (CMF) surgery based on a literature review. The authors searched PubMed, Web of Science, and Embase to find papers published between January 2015 and February 2022 in English, which describe human applications of POC 3DP in CMF surgery, resulting in 63 articles being included. The main review findings were as follows: most used clinical applications were anatomical models and cutting guides; production took place in-house or as "in-house-outsourced" workflows; the surgeon alone was involved in POC 3DP in 36 papers; the use of free versus paid planning software was balanced (50.72% vs. 49.27%); average planning time was 4.44 h; overall operating time decreased and outcomes were favorable, though evidence-based studies were limited; and finally, the heterogenous cost reports made a comprehensive financial analysis difficult. Overall, the development of in-house 3D printed devices supports CMF surgery, and encouraging results indicate that the technology has matured considerably.

Effect of COVID-19 Italian Lockdown on Maxillofacial Trauma Related to Domestic Violence: A Retrospective Cohort Study

Background: This retrospective study aims to identify the potential reasons for the increase in maxillofacial trauma from domestic violence in the first COVID-19 lockdown and propose some strategies that could be effective in fighting it during any future pandemic events. Materials and Methods: The study was conducted on patients with maxillofacial trauma who arrived at the Maxillofacial Unit of the Magna Graecia University of Catanzaro from 9 March to 3 May 2020, who were compared with those registered in the same period in 2019. Inclusion criteria were: patients of both sexes and admission diagnosed with maxillofacial trauma with or without bone fracture. Exclusion criteria were: patients less than 7 years of age, maxillofacial trauma that occurred outside the established period, and patients unconscious or with unclear clinical history. Patients were divided into two groups according to the mechanism of injury (MOI): “domestic” and “non-domestic” trauma. Both descriptive and regressive statistical analysis was conducted using a Student’s t-test with a significance level set at p < 0.05. Results: The total number of maxillofacial fractures in 2020 was similar to 2019 (31 pcs in 2020 vs. 38 pcs in 2019). Before the lockdown, most of the trauma occurred in non-domestic settings (25% in 2020 vs. 76.67% in 2019), especially in road accidents (4.17% in 2020 vs. 20% in 2019). During the lockdown, most of the trauma occurred in a domestic setting (75% in 2020 vs. 23.33% in 2019), especially interpersonal violence (31.58% in 2020 vs. 14.28% in 2019). There were 7 cases of interpersonal violence recorded in 2020 (1 male and 6 female), compared to only one case (female) recorded in 2019, with a statistically significant p-Value (0.0475). Conclusions: The first COVID-19 lockdown has provided the opportunity to study the aetiology of domestic trauma due to interpersonal violence attributable to economic and social problems, all of which were aggravated by the impediment to requesting help due to the difficulty of contacting the services and the general slowdown in the ways out of violence. The analysis conducted and compared with data in the literature suggests the adoption of a proactive (and non-reactive) approach to combat domestic violence during pandemic events.

A Comparative Study on Sedation Efficacy Between General and Regional Anesthesia with Dexmedetomidine in Patients Under Maxillofacial Surgery

BACKGROUND AND OBJECTIVE

Securing the airway in the surgery of maxillofacial disorders and traumas is fundamental during the operation. The present study aims to investigate the beneficial sedative effects of dexmedetomidine (DEX) in patients who underwent maxillofacial surgery with regional anesthesia compared to general anesthesia.

METHODS

Fifty patients, aged 20-45 years old were randomly divided into two groups of regional anesthesia (RA) and general anesthesia (GA) (each n=25). The group RA received regional block with sedation (DEX: 1 μg/kg infused over 10 min followed by the maintenance dose of 0.5 μg/kg/h) and the group GA underwent general anesthesia (DEX: 0.1 μg/kg/min over 10 min followed by 0.4-0.7 μg/kg/h). Postoperative pain scores, anesthesia outcomes, hemodynamic parameters, the time of the post-anesthesia care unit (PACU) discharge and intra and postoperative complications were comparatively assessed in both groups.

RESULTS

The baseline characteristics of the patients (age, gender, BMI, and ASA physical status) showed no differences between the two groups (P>0.05). Although the duration of surgery and recovery time showed no differences between the groups, the duration of anesthesia and extubation time was remarkably lower in the RA group than in the GA group (P<0.01). Administration of nerve blocks demonstrated less pain and longer sleep time in the postoperative phase as compared to the GA group. Heart rate and mean arterial blood pressure were significantly less in the RA group at the end of the loading dose of DEX and incision time (P<0.05). SpO2, respiration rate and Ramsay sedation scale did not exhibit any significant differences between the two groups at all-time points (P>0.05). No significant differences were observed with regard to the adverse events between the two groups (P>0.05).

CONCLUSIONS

Although our findings revealed that both methods are suitable and safe methods for maxillofacial surgery, the outcomes of anesthesia with regional block and sedation include less pain in the postoperative phase, shorter extubation time and earlier discharge from the PACU demonstrated that this method is more reliable for maxillofacial surgery. Further controlled studies are needed to compare the effectiveness and safety profiles of two RA and GA techniques and also to compare DEX with other anesthetic agents to achieve optimum outcomes in maxillofacial surgeries.

Malar and maxillary fractures among pediatric patients and the risk factors for mortality

BACKGROUND/AIMS

No studies have characterized the morbidity and mortality of maxillary & malar fractures on a national scale. The aim of this study was to examine the risk factors for mortality in pediatric patients who had sustained maxillary and malar fractures by using a national pediatric hospital inpatient care database.

MATERIALS AND METHODS

This retrospective cohort study was conducted using the Kids' Inpatient Database (KID). The primary predictor variable was the cause of injury. The primary outcome variable was mortality rate. Additional predictor variables included age, gender, race, income, payer information, year and place of injury, number of facial fractures, concomitant facial fractures, other fractures of the body, and intracranial/internal organ injury. Univariate and multivariate regression models were performed to assess risk factors for mortality. Statistical significance was set to a p-value <.05.

RESULTS

A total of 5859 patients met the inclusion criteria. The most common age group was 13-17 years of age (n = 3816, 65.1%). Motor vehicle accidents were the most common mechanism of injury (n = 2172, 37.1%). The presence of cranial vault (OR = 2.81, p = .017), skull base (OR = 2.72, p < .001), and vertebral column fractures (OR = 2.13, p = .016), as well as sub-arachnoid hemorrhage (OR = 4.75, p = .005), traumatic pneumothorax/hemothorax (OR = 2.16, p = .015), and heart/lung injury (OR = 3.37, p < .001) were each independently associated with increased odds of mortality.

CONCLUSIONS

Patients in their late teens most commonly sustained malar and maxillary fractures, likely due to general trends in craniomaxillofacial development. The presence of other fractures located in close proximity to the mid-face increased the risk of mortality among pediatric patients with malar and maxillary fractures. This may be explained by the anatomical approximation of the mid-face to vital neurovascular structures of the head, which, when damaged, may prove fatal.

Where Is the Artificial Intelligence Applied in Dentistry? Systematic Review and Literature Analysis

This literature research had two main objectives. The first objective was to quantify how frequently artificial intelligence (AI) was utilized in dental literature from 2011 until 2021. The second objective was to distinguish the focus of such publications; in particular, dental field and topic. The main inclusion criterium was an original article or review in English focused on dental utilization of AI. All other types of publications or non-dental or non-AI-focused were excluded. The information sources were Web of Science, PubMed, Scopus, and Google Scholar, queried on 19 April 2022. The search string was “artificial intelligence” AND (dental OR dentistry OR tooth OR teeth OR dentofacial OR maxillofacial OR orofacial OR orthodontics OR endodontics OR periodontics OR prosthodontics). Following the removal of duplicates, all remaining publications were returned by searches and were screened by three independent operators to minimize the risk of bias. The analysis of 2011–2021 publications identified 4413 records, from which 1497 were finally selected and calculated according to the year of publication. The results confirmed a historically unprecedented boom in AI dental publications, with an average increase of 21.6% per year over the last decade and a 34.9% increase per year over the last 5 years. In the achievement of the second objective, qualitative assessment of dental AI publications since 2021 identified 1717 records, with 497 papers finally selected. The results of this assessment indicated the relative proportions of focal topics, as follows: radiology 26.36%, orthodontics 18.31%, general scope 17.10%, restorative 12.09%, surgery 11.87% and education 5.63%. The review confirms that the current use of artificial intelligence in dentistry is concentrated mainly around the evaluation of digital diagnostic methods, especially radiology; however, its implementation is expected to gradually penetrate all parts of the profession.

Osteoconductive Silk Fibroin Binders for Bone Repair in Alveolar Cleft Palate: Fabrication, Structure, Properties, and In Vitro Testing

Osteoconductive silk fibroin (SF) binders were fabricated for the bone repair of an alveolar cleft defect. Binders were prefigureared by mixing different ratios of a mixture of random coils and SF aggregation with SF fibrils: 100:0 (SFB100), 75:25 (SFB75), 50:50 (SFB50), 25:75 (SFB25), and 0:100 (SFB0). The gelation, molecular organization, structures, topography, and morphology of the binders were characterized and observed. Their physical, mechanical, and biological properties were tested. The SF binders showed gelation via self-assembly of SF aggregation and fibrillation. SFB75, SFB50, and SFB25 had molecular formation via the amide groups and showed more structural stability than SFB100. The morphology of SFB0 demonstrated the largest pore size. SFB0 showed a lowest hydrophilicity. SFB100 showed the highest SF release. SFB25 had the highest maximum load. SFB50 exhibited the lowest elongation at break. Binders with SF fibrils showed more cell viability and higher cell proliferation, ALP activity, calcium deposition, and protein synthesis than without SF fibrils. Finally, the results were deduced: SFB25 demonstrated suitable performance that is promising for the bone repair of an alveolar cleft defect.

Nasotracheal intubation performance with the mcgrath videolaryngoscope versus macintosh laryngoscope in oral and maxillofacial surgery- An observational study

Background and Aim

Nasotracheal intubation is the main route to secure the airway in oral and maxillofacial surgery patients. This study was aimed to compare the intubation times and glottis visualization of McGrath video laryngoscope with the Macintosh laryngoscope for routine nasotracheal intubation.

Materials and Methods

Records of seventy-one ASA (American Society of Anesthesiologists) I-II patients were evaluated and allocated into two groups (McGrath video laryngoscope (VL) and Macintosh groups). Intubation times, modified intubation difficulty scale (MIDS) scores, and hemodynamic parameters (heart rate and mean arterial pressure) were compared after the anesthesia induction and the intubation.

Results

Mean intubation time in the McGrath group (24.9 ± 5.9 seconds) was significantly lower than that of the Macintosh group (28 ± 6.2 seconds; P = 0.037). Magill forceps were needed less in the McGrath group compared to the Macintosh group (13.89% vs. 42.86%; P = 0.009). Total MIDS scores were similar (P = 0.778). There was no significant difference in the hemodynamic parameters between the groups.

Conclusion

The McGrath VL significantly reduced the intubation time and the use of Magill forceps compared with Macintosh direct laryngoscope and can be utilised effectively for routine nasotracheal intubation.

Diabetes Mellitus and Oral Cancer: A Retrospective Study from Austria

AIM

This study aimed to analyse the possible linkage between diabetes mellitus (DM) and oral cancer among Austrians.

PATIENTS AND METHODS

We performed a retrospective DM and/or impaired fasting glucose (IFG) screening in 573 patients who underwent maxillofacial surgery under general anaesthesia between January 1, 2018 and December 31, 2019.

RESULTS

Of the total patients, 26.5% (n=152) had cancer diagnosis, whereas the remaining 73.5% (n=421) formed the control group. The prevalence of glucose metabolism disorder (GMD) was significantly (p<0.00001) more common among cancer patients (59.9% vs. 36.5%). Squamous cell carcinoma and sublingual tumours represented the most common tumour type (93.4%) and location (35.5%), respectively. Smoking was significantly (p=0.00093) more common within the cancer group.

CONCLUSION

Our data suggest an association between GMD and oral cancer.

Early weight gain in infants with Robin sequence after mandibular distraction

This retrospective cohort study was performed to assess weight gain in infants with Robin sequence (RS) treated by mandibular distraction osteogenesis (MDO). The primary outcome variable was average daily weight gain for the following time periods: (1) birth to MDO (T1), (2) MDO to distractor removal (T2), (3) distractor removal to 6 months later (T3), and (4) 6 months to 12 months following distractor removal (T4). Published growth curves were used for comparison. Differences were assessed using the Wilcoxon matched-pairs signed rank test. Twenty-two infants were included in the study. During T1, the infants had 9.47 ± 12.61 g/day less weight gain than expected (P = 0.001). However, for T2, T3, and T4, the infants demonstrated 3.48 ± 6.17 g/day (P = 0.028), 2.19 ± 4.47 g/day (P = 0.030), and 1.83 ± 3.25 g/day (P = 0.028) more weight gain than expected. Feeding tube use resulted in improved weight gain during T1 (P < 0.001), but was associated with poorer weight gain in T3 (P = 0.003) and T4 (P = 0.001). In conclusion, infants with RS treated by MDO demonstrated poorer weight gain relative to their peers between birth and the MDO operation. However, from the MDO procedure to 12 months post-distractor removal, infants who had MDO showed faster weight gain than their age-matched peers.

[The Maxillofacial Surgery department of the Central Research Institute of Dentistry and Maxillofacial Surgery - past, present, and future perspectives]

The article presents the history of foundation and development of the Maxillofacial Surgery department of the Central Research Institute of Dentistry and Maxillofacial Surgery, as well as main current scientific and clinical achievements.

[On the occasion of 100 years of foundation of Maxillofacial Surgery Clinic of the Central Research Institute of Dentistry and Maxillofacial Surgery]

The paper presents the history of the maxillofacial surgery in the walls of Maxillofacial Surgery Clinic of the Medical and Prosthetic Institute and later in the Central Research Institute of Dentistry and Maxillofacial Surgery.

Immunohistochemical Analysis of the Beclin-1 Expression Predicts the Progression of Oral Squamous Cell Carcinoma

Background: Autophagy is a cellular process responsible for maintaining homeostasis; a dysregulation of this process is involved in the development and progression of neoplasms. Beclin-1 is one of the major proteins linked to autophagy. However, the data regarding the association between the role of Beclin-1 and the progression of Oral Squamous Cell Carcinoma (OSCC) are rather low. For this reason, the objective of this study is to evaluate, through immunohistochemical techniques, the prognostic role of the expression of Beclin-1 autophagy marker in patients with OSCC. Methods: This is a single-centre retrospective study that includes patients with OSCC admitted to the Maxillofacial Unit of “Magna Graecia” University between January 2019 and September 2020. All the samples obtained from surgery were treated with anti Beclin-1 antibodies and subjected to immunohistochemical methods. Results: A total of 26 samples were analysed and the following variables were evaluated for each: percentage of positive Beclin-1 expression by tumour cells, signal strength of tumour cells, and total score. The variables considered were first normalised according to the D’Agostino and Pearson test, then analysed using the Pearson linear correlation coefficient: a statistically significant correlation was found between the parameters infiltration-intensity (p = 0.0088), infiltration-percent (p = 0.0123), intensity-total score (p = 0.0060). Conclusions: The immunohistochemical evaluation of Beclin-1 revealed a statistically significant correlation between the intensity of the molecule’s expression and a greater degree of infiltration of the neoplasm. Beclin-1 can, therefore, be considered a valid prognostic index of disease.

Detecting Binocular Diplopia in Orbital Floor Blowout Fractures: Superiority of the Orthoptic Approach

Background and Objectives: In patients with orbital floor blowout fracture (OFBF), accurate diagnosis of ocular motility disorder is important for decisions about conservative or surgical therapy. However, the accuracy of the traditional test for detecting binocular diplopia/ocular motility disorder using a moving pencil or finger (hereinafter, “finger test”) has been generally accepted as correct and has not been subject to scrutiny so far. Hence, its accuracy relative to full orthoptic examination is unknown. Materials and Methods: In this paper, the results of the “finger test” were compared with those derived from a complex examination by orthoptic tests (considered “true” value in patients with OFBF). Results: “Finger test” detected ocular motility disorder in 23% of patients while the full orthoptic examination proved much more efficient, detecting ocular motility disorder in 65% of patients. Lancaster screen test and test with color filters were the most important tests in the battery of the orthoptic tests, capable of identifying 97.7% and 95.3% of patients with ocular motility disorder, respectively. Still, none of the tests were able to correctly detect all patients with ocular motility disorder in itself. Conclusions: As the presence of ocular motility disorder/binocular diplopia is an important indication criterion for the surgical solution of the orbital floor blowout fracture, we conclude that a complex orthoptic evaluation should be always performed in these patients.

A Health Technology Assessment in Maxillofacial Cancer Surgery by Using the Six Sigma Methodology

Squamous cell carcinoma represents the most common cancer affecting the oral cavity. At the University of Naples "Federico II", two different antibiotic protocols were used in patients undergoing oral mucosa cancer surgery from 2006 to 2018. From 2011, there was a shift; the combination of Cefazolin plus Clindamycin as a postoperative prophylactic protocol was chosen. In this paper, a health technology assessment (HTA) is performed by using the Six Sigma and DMAIC (Define, Measure, Analyse, Improve, Control) cycle in order to compare the performance of the antibiotic protocols according to the length of hospital stay (LOS). The data (13 variables) of two groups were collected and analysed; overall, 136 patients were involved. The American Society of Anaesthesiologist score, use of lymphadenectomy or tracheotomy and the presence of infections influenced LOS significantly (p-value < 0.05) in both groups. Then, the groups were compared: the overall difference between LOS of the groups was not statistically significant, but some insights were provided by comparing the LOS of the groups according to each variable. In conclusion, in light of the insights provided by this study regarding the comparison of two antibiotic protocols, the utilization of DMAIC cycle and Six Sigma tools to perform HTA studies could be considered in future research.

Common postoperative complications after general anesthesia in oral and maxillofacial surgery

Aim and Objectives:

Anesthesia is Greek word meaning loss of sensation, and involves painful invasive procedure to be performed with little distress and no pain to the patient. Postoperative anesthetic complications are very common and duration of surgery is frequently cited as major risk factor for postoperative complications. The recognition and treatment of these complications are important when providing good quality care. The purpose of this study was to evaluate mild, moderate, and severe postoperative complications in patients undergoing maxillofacial surgery under general anesthesia and also determine the safety of general anesthesia in healthy and patients with comorbidities.

Subjects and Methods:

This prospective study was conducted in the oral and maxillofacial surgery department. Two hundred and twenty patients who were operated under general anesthesia were taken in study. All relevant past medical and dental records were noted and were supported by preformulated questionnaire and was filled preoperatively and after surgery to 12 weeks.

Results:

Mild-to-moderate and severe complications were noted. Females showed more complications than males. Most common complications were sore throat, dysphagia, nausea, vomiting, pain, swelling in normal patients, and in patients with comorbidities delayed wound healing, hypertension, and infection were also seen.

Conclusion:

The use of General Anesthesia is considered safe but it has few risks associated with it and past medical conditions should be evaluated preoperatively.

Variant Innervation of the Medial Pterygoid Muscle from the Lingual Nerve

During a routine dissection of the infratemporal fossa and lateral face, a branch of the left lingual nerve was observed entering the medial pterygoid muscle. Normally, the nerve to the medial pterygoid is a direct branch from the mandibular nerve, with no communications with the lingual nerve. There are many reports involving variations of the mandibular nerve; however, few reports describe lingual nerve variations involving the medial pterygoid muscle. Reconstructive surgeries for cosmesis and trauma, tumor excision, and impacted third molar removal may all damage the lingual nerve and might, as seen in the present case, affect the medial pterygoid muscle. Given the presumed rarity of this variation, we discuss the possible embryological origins as well as the surgical conflicts that may arise with this type of variation.

Histopathology of the temporomandibular joint disc: Findings in 30 samples from joints with degenerative disease

Aim

The aim of this study is to show the anatomical and histological features of the displaced temporomandibular joint (TMJ) disc in joints with degenerative disease.

Methods

This study was performed on a total of 30 TMJ discs extracted from 22 patients, who underwent surgical discectomy after failure of conservative non‐surgical treatment regimens to control pain and/or limited range of motion. All joints had imaging signs of an anteriorized disc position and degenerative joint disease. Samples of the extracted discs were stored in formalin, cut into 3 micron‐thick sections imbedded in paraffin and processed with hematoxylin‐eosin.

Result

All the samples present irreversible morphologic and histological alterations. The macroscopical evaluation showed that 14 discs were worn and fragmented in several parts, and one disc was perforated. Morphological alterations with deformation and degenerative signs were shown in all discs, which were all severely worn and compromised. Histologically, various alterations were found, such as pre‐fibrous sclerosis with myxoid degeneration and collagen deposits (N = 25), an increase in fibro‐hyaline and fibrous tissues, with loss of elasticity (N = 25), scattered calcifications (N = 15), and synovial inflammation with microvascular proliferation and increased cellularity, presence of lymphocytes, histiocytes and plasma cells (N = 18). After the intervention, all patients reported decreased pain levels and showed improved function at 6 months.

Conclusion

These observations suggest that degenerative joint disease is accompanied by a anteriorized discs featuring abnormal macroscopical and histological changes. From a clinical viewpoint, this may suggest that, when treatment escalation leads to consider TMJ surgery, total discectomy is the most reasonable approach.

Lasers in Maxillofacial Surgery - Review of Literature

The availability of different wavelengths of lasers has created a surgical panacea in the last decade and laser technology has become the standard of care for many oral and maxillofacial surgical procedures. In this article, based on literature search, we have reviewed the usage of laser in maxillofacial surgery based on the current evidence available on laser-assisted maxillofacial surgery, in PubMed database.

Protocol and Evaluation of 3D-Planned Microsurgical and Dental Implant Reconstruction of Maxillary Cleft Critical Size Defects in Adolescents and Young Adults

Functional and esthetic final reconstruction of the cleft maxilla is still challenging. Current reconstructive and augmentation techniques do not provide sufficient bone and soft tissue support for the predictable rehabilitation with dental implants due to presence of maxillary bone critical size defects and soft tissue deficiency, scaring and poor vascularity. In this article the protocol for the use of 3D virtual surgical planning and microvascular tissue transfers for the reconstruction and rehabilitation of cleft maxilla is presented. Twenty-five patients (8 male/17 female) aged 14–41 years old with cleft-associated critical size defects were treated by 3D-virtual planned microvascular tissue transfers taken either from fibula, iliac crest, radial forearm, or medial femoral condyle. Follow-up lasted 1–5 years. No significant bone resorption (p > 0.005) nor volume loss of the graft was observed (p = 0.645). Patients received final permanent prosthetic reconstruction of the anterior maxilla based on 2–5 dental implants, depending on the defect severity. This is the first study presenting the use of virtual planning in the final restoration of the cleft maxilla with microvascular tissue transfers and dental implants. Presented protocol provide highly functional and aesthetic results.

To map or not to map the cN0 neck: Impact of sentinel lymph node biopsy in canine head and neck tumours

Tumour stage is a prognostic indicator for canine malignant head and neck tumours (MHNT). However, consensus is lacking on nodal staging in the absence of clinically apparent nodal disease (cN0 neck). This prospective observational study aims to determine the diagnostic accuracy of radiopharmaceutical and blue dye for sentinel lymph node biopsy (SLNB), to assess the correspondence between sentinel lymph node (SLN) and clinically expected regional lymph node (RLN) and the impact on staging of the procedure in dogs with MHNT and cN0 neck. Twenty-three dogs with MHNT and cN0 neck underwent tumour excision and SLNB guided by preoperative lymphoscintigraphy and intraoperative gamma-probe and blue dye. Diagnostic performances and detection rate were calculated. Correspondence between SLN and RLN, number of nodes excised, histopathological status of the SLN and complications related to the procedure were recorded. The mapping technique identified at least one SLN in 19/23 dogs, with a detection rate of 83%. The SLN did not correspond to the RLN in 52% of dogs. Multiple nodes were removed in 61% of dogs. At histopathology, eight (42%) dogs had SLN+, of which four differed from the RLN. Only minor self-limiting complications occurred in five (22%) dogs. Radiopharmaceutical and blue dye guidance is accurate (sensitivity 88.9%; specificity 100%) for SLNB in dogs with MHNT and cN0 and allowed the extirpation of unpredictable and/or multiple SLN with minimal morbidity. Incorporation of SLNB in the management of MHNT is desirable to correctly stage the cN0 neck, owing the unpredictability of the lymphatic drainage.

Technique to manage intraoperative cuff leak from damaged endotracheal tube pilot balloon

We report a technique that was utilized to manage an intraoperative airway complication occurring during orthognathic surgery wherein the endotracheal tube pilot balloon was inadvertently damaged during the procedure. Readily available operating room materials were used to safely and rapidly repair the damaged endotracheal tube pilot balloon. This allowed the perioperative team to avoid emergent endotracheal tube exchange and potential airway complications.

25-Gauge Catheter as a Surrogate to Anterior Chamber Maintainer in Trabeculectomy

A flat anterior chamber (AC) is a distinctive feature in status post vitrectomy eyes during trabeculectomy. The use of AC maintainers is useful to help prevent this peroperative situation. We herein describe the surgical technique using a 25-gauge intravenous catheter as a surrogate to conventional AC maintainers. A potential advantage of this approach is the low cost in the current economic environment with limited health restraints.

Endoscopic-Assisted Oropharyngectomy for Early Oropharyngeal Cancer in Trismus Patients

Objective: Management of the early-stage oropharyngeal carcinoma in trismus patients underlying with multiple head and neck cancer history is a clinical challenge because minimal invasive surgery such as transoral robotic surgery or transoral laser microsurgery is contraindicated, while open surgery or concurrent chemoradiation (CCRT) wound cause long-term adverse effect. Therefore, we developed a novel endoscopic surgical approach for these patients. Methods: Four patients were enrolled for endoscopic-assisted oropharyngectomy. The oropharyngeal tumor was resected with an adequate margin via a one-surgeon bimanual approach with the aid of a high-resolution videoendoscopic system, scope holder, and designed surgical instruments. The postoperative surgical margin status, trismus status, perioperative complication, average hospital stay, and follow-up period were recorded. Results: The endoscopic-assisted oropharyngectomy was successfully applied in all 4 patients with en bloc tumor excision and adequate free margin status. The mean hospital stay was 6.5 days, and all patients could tolerate oral diet within 2 weeks. There was no perioperative complication noted. No tumor recurrence was identified in patients followed up 2 years after surgery. Conclusion: Endoscopic-assisted oropharyngectomy for patients with trismus and multiple head and neck cancer history is a safe, minimal invasive, and effective treatment choice other than open surgery or CCRT. It provides a safe option for patients with limited mouth opening.

Why do some extraction sites develop medication-related osteonecrosis of the jaw and others do not? A within-patient study assessing radiographic predictors

PURPOSE

To compare radiographic predictors of medication-related osteonecrosis of the jaw in dental extraction sites.

MATERIALS AND METHODS

Forty-one oncological patients undergoing intravenous or subcutaneous antiresorptive treatment, with a history of dental extraction visualised by panoramic imaging, were included in this retrospective study. Age-, sex- and extracted tooth-matched healthy patients who had previously undergone panoramic imaging were selected as controls (n = 57). A total of 288 extraction sites were independently evaluated by two oral and maxillofacial radiologists, who assessed eight distinct radiographic features. The radiographic features of extraction sites were noted to allow comparison between and within subjects regarding healing and osteonecrosis development. The association between radiographic findings, underlying dental disease and medication-related osteonecrosis of the jaw was also tested. The level of significance was set at 5%.

RESULTS

Patients under antiresorptive treatment presented with widening of the periodontal ligament space, thickening of the lamina dura, sclerotic bone pattern, horizontal bone loss and periapical radiolucency with bone reaction (P ≤ 0.05). Development of medication-related osteonecrosis of the jaw was associated with altered bone pattern, angular bone loss, furcation involvement and unsatisfactory endodontic treatment (P ≤ 0.05). An association between medication-related osteonecrosis of the jaw and previous dental disease was also found, particularly for periapical lesions and endodontic-periodontal disease (P ≤ 0.05).

CONCLUSIONS

Radiographic predictors of further development of medication-related osteonecrosis of the jaw in extraction sites include heterogeneous bone pattern, angular bone loss and furcation involvement. Extraction sites with underlying bony changes related to endodontic and endodontic-periodontal disease are more prone to development of medication-related osteonecrosis of the jaw.

Complications of Poly-l-Lactic Acid and Polyglycolic Acid (PLLA/PGA) Osteosynthesis Systems for Maxillofacial Surgery: A Retrospective Clinical Investigation

Two second-generation PLLA/PGA bioresorbable osteosynthetic plate systems for oral and maxillofacial surgery are available in Japan. The two systems have different PLLA-PGA component ratios (RapidSorb^®, 85:15; Lactosorb^®, 82:18) and plate and screw shapes. We conducted a retrospective study to compare our clinical evaluation and examine the incidence of postoperative complications between the two plate systems. A retrospective survey was conducted in 148 patients (midfacial fracture/trauma (68.2%) and dentofacial deformity patients (31.8%); males (54.7%); median age, 37.5 years) treated using maxillofacial osteosynthetic plate systems. The complications included plate exposure (7.4%), infection, (2.7%), and plate breakage (0.7%). Multivariate logistic regression analysis showed a significant correlation between sex (female), plate system (Lactosorb^®), number of plates, and pyriform aperture and periorbital sites of plate placement (p < 0.05). Additionally, the propensity score-adjusted model showed a significant correlation between Lactosorb^® and postoperative complications (odds ratio 1.007 (95% confidence interval, 1.001–1.055), p < 0.01). However, the two plate systems showed a low incidence rate of complications, and the plate integration and survivability were similar using 2.0-mm or 1.5-mm resorbable plate regardless of the plate system. Our findings suggest that female sex and a greater number of plates are risk factors for postoperative complications, whereas pyriform aperture and periorbital plate placements reduce the risk.

Existence of a Neutral-Impact Maxillo-Mandibular Displacement on Upper Airways Morphology

Current scientific evidence on how orthognathic surgery affects the airways morphology remains contradictory. The aim of this study is to investigate the existence and extension of a neutral-impact interval of bony segments displacement on the upper airways morphology. Its upper boundary would behave as a skeletal displacement threshold differentiating minor and major jaw repositioning, with impact on the planning of the individual case. Pre- and post-operative cone beam computed tomographies (CBCTs) of 45 patients who underwent maxillo-mandibular advancement or maxillary advancement/mandibular setback were analysed by means of a semi-automated three-dimensional (3D) method; 3D models of skull and airways were produced, the latter divided into the three pharyngeal subregions. The correlation between skeletal displacement, stacked surface area and volume was investigated. The displacement threshold was identified by setting three ∆Area percentage variations. No significant difference in area and volume emerged from the comparison of the two surgical procedures with bone repositioning below the threshold (approximated to +5 mm). A threshold ranging from +4.8 to +7 mm was identified, varying in relation to the three ∆Area percentages considered. The ∆Area increased linearly above the threshold, while showing no consistency in the interval ranging from -5 mm to +5 mm.

3D and 4D printing in dentistry and maxillofacial surgery: Printing techniques, materials, and applications

3D and 4D printing are cutting-edge technologies for precise and expedited manufacturing of objects ranging from plastic to metal. Recent advances in 3D and 4D printing technologies in dentistry and maxillofacial surgery enable dentists to custom design and print surgical drill guides, temporary and permanent crowns and bridges, orthodontic appliances and orthotics, implants, mouthguards for drug delivery. In the present review, different 3D printing technologies available for use in dentistry are highlighted together with a critique on the materials available for printing. Recent reports of the application of these printed platformed are highlighted to enable readers appreciate the progress in 3D/4D printing in dentistry.

Custom-Made Zirconium Dioxide Implants for Craniofacial Bone Reconstruction

Reconstruction of the facial skeleton is challenging for surgeons because of difficulties in proper shape restoration and maintenance of the proper long-term effect. ZrO₂ implant application can be a solution with many advantages (e.g., osseointegration, stability, and radio-opaqueness) and lacks the disadvantages of other biomaterials (e.g., metalosis, radiotransparency, and no osseointegration) or autologous bone (e.g., morbidity, resorption, and low accuracy). We aimed to evaluate the possibility of using ZrO₂ implants as a new application of this material for craniofacial bone defect reconstruction. First, osteoblast (skeleton-related cell) cytotoxicity and genotoxicity were determined in vitro by comparing ZrO₂ implants and alumina particle air-abraded ZrO₂ implants to the following: 1. a titanium alloy (standard material); 2. ultrahigh-molecular-weight polyethylene (a modern material used in orbital surgery); 3. a negative control (minimally cytotoxic or genotoxic agent action); 4. a positive control (maximally cytotoxic or genotoxic agent action). Next, 14 custom in vivo clinical ZrO₂ implants were manufactured for post-traumatologic periorbital region reconstruction. The soft tissue position improvement in photogrammetry was recorded, and clinical follow-up was conducted at least 6 years postoperatively. All the investigated materials revealed no cytotoxicity. Alumina particle air-abraded ZrO2 implants showed genotoxicity compared to those without subjection to air abrasion ZrO₂, which were not genotoxic. The 6-month and 6- to 8-year clinical results were aesthetic and stable. Skeleton reconstructions using osseointegrated, radio-opaque, personalized implants comprising ZrO₂ material are the next option for craniofacial surgery.

Cooperation of the maxillofacial and plastic surgeon in reconstructive surgical procedures in gunshot injury - a case report

Lower and middle face defects resulting from gunshot wounds often cause severe functional and cosmetic deformities. The purpose of this case report is to refer to our experiences in the treatment of facial gunshot trauma associated with attempted suicide that resulted in a complex facial injury. The goal of the treatment of complex facial injuries is a proper reconstruction of the hard and soft tissue defects and sufficient rehabilitation of the relevant functions, such as speech, nutrition and appearance. A close cooperation of the maxillofacial and plastic surgeon is essential to achieve a satisfactory outcome.

Augmented reality in craniomaxillofacial surgery: added value and proposed recommendations through a systematic review of the literature

This systematic review provides an overview of augmented reality (AR) and its benefits in craniomaxillofacial surgery in an attempt to answer the question: Is AR beneficial for craniomaxillofacial surgery? This review includes a description of the studies conducted, the systems used and their technical characteristics. The search was performed in four databases: PubMed, Cochrane Library, Embase, and Web of Science. All journal articles published during the past 11 years related to AR, mixed reality, craniomaxillofacial, and surgery were considered in this study. From a total of 7067 articles identified using AR- and surgery-related keywords, 39 articles were finally selected. Based on these articles, a classification of study types, surgery types, devices used, metrics reported, and benefits were collected. The findings of this review indicate that AR could provide various benefits, addressing the challenges of conventional navigation systems, such as hand-eye coordination and depth perception. However, three main concerns were raised while performing this study: (1) it is complicated to aggregate the metrics reported in the articles, (2) it is difficult to obtain statistical value from the current studies, and (3) user evaluation studies are lacking. This article concludes with recommendations for future studies by addressing the latter points.

Third-generation modular mandible endoprosthesis in Macaca fascicularis

The aim of this study was to develop a third-generation modular mandible endoprosthesis that would experience less stress concentration at its stems compared to earlier generations, thereby minimizing micromotion and achieving long-term stability. In this three-piece modular design, different degrees of movement were incorporated between the endoprosthesis module interfaces. It was hypothesized that this unique feature would minimize stress concentration at the stems and hence promote osseointegration during the early phase of implantation. The endoprosthesis system was made of commercially pure grade 4 titanium, machined and surface-treated, then sterilized and implanted in segmental mandible defects of nine Macaca fascicularis. Clinical, radiological, histological, and histomorphometric evaluations were performed 4 months post-implantation. The endoprosthesis systems with a degree of movement incorporated, exhibited superior performance compared to the rigid system: 30.9-34.8 times higher percentage bone-implant contact (P< 0.0001) and 3.4-4.1 times higher percentage bone area (P<0.0001), with osseointegration noted at the posterior stems. However, fibrous tissue encapsulation was noted around the majority of the anterior stems in all groups. Although the degree of movement was favourable for improving bone healing and stability of the endoprosthesis system, more work needs to be done to investigate other strategies to further reduce loading on the endoprosthesis to achieve predictable osseointegration at the stems.

Risk Assessment of Surgical Interventions Performed on Non-Infected Patients During COVID-19 Pandemic

Background A number and a variety of surgical interventions were highly affected by the novel coronavirus disease (COVID-19) outbreak. Most of the elective operations were discontinued with the fear of exacerbating the disease in patients and spreading it among healthcare professionals. Objective The objective of this study was to report postoperative rates of COVID-19 in patients who underwent emergency and urgent surgery during the pandemic and to determine a safe algorithm in order to propose an ideal approach for surgeries. Patients and methods A total of 162 patients being operated upon emergency or urgent causes between March 11 and May 31 2020 were included in the study. Safety measures advised by the World Health Organization were applied. The patients' operative data and postoperative COVID-19 status were recorded and statistically evaluated. Results Surgical interventions were required for skin cancer, upper extremity trauma, soft tissue infections, maxillofacial trauma, lower extremity trauma and other causes. Local anesthesia was used for 127 patients (78.4%). General anesthesia was used for 28 patients (17,3%). Two of 162 patients contracted COVID-19 postoperatively on days 15 and 21, respectively. No statistical significance was found between surgery and anesthesia types regarding COVID-19 risk. Conclusion It appears that emergency and urgent surgeries can be performed safely. However, this relies upon adequate safety measures being taken with regards to screening for COVID-19 antigen positivity in patients preoperatively. Further evidence is required to determine the safety of elective surgeries.

The Wearable VOSTARS System for Augmented Reality-Guided Surgery: Preclinical Phantom Evaluation for High-Precision Maxillofacial Tasks

BACKGROUND

In the context of guided surgery, augmented reality (AR) represents a groundbreaking improvement. The Video and Optical See-Through Augmented Reality Surgical System (VOSTARS) is a new AR wearable head-mounted display (HMD), recently developed as an advanced navigation tool for maxillofacial and plastic surgery and other non-endoscopic surgeries. In this study, we report results of phantom tests with VOSTARS aimed to evaluate its feasibility and accuracy in performing maxillofacial surgical tasks.

METHODS

An early prototype of VOSTARS was used. Le Fort 1 osteotomy was selected as the experimental task to be performed under VOSTARS guidance. A dedicated set-up was prepared, including the design of a maxillofacial phantom, an ad hoc tracker anchored to the occlusal splint, and cutting templates for accuracy assessment. Both qualitative and quantitative assessments were carried out.

RESULTS

VOSTARS, used in combination with the designed maxilla tracker, showed excellent tracking robustness under operating room lighting. Accuracy tests showed that 100% of Le Fort 1 trajectories were traced with an accuracy of ±1.0 mm, and on average, 88% of the trajectory's length was within ±0.5 mm accuracy.

CONCLUSIONS

Our preliminary results suggest that the VOSTARS system can be a feasible and accurate solution for guiding maxillofacial surgical tasks, paving the way to its validation in clinical trials and for a wide spectrum of maxillofacial applications.

Adjuvant management of locally advanced oral squamous cell carcinoma - real-world challenges and opportunities

Patients with locally advanced oral squamous cell cancer (LAOSCC) are treated with adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) following surgical ablation. This depends on the pathological risk factors and aims to reduce the risk of local recurrence and improve survival. Delivery of these aggressive treatments is, however, challenging particularly following major surgery. To inform the adaptations necessary to deliver gold-standard therapy, we aimed to describe real-world delivery of multimodality treatment in LAOSCC, in a UK population with high levels of disease incidence and low socioeconomic status. Patients with LAOSCC (T1-4 N1-3/T3-4 N0) who were treated between October 2014 and October 2016 and had a minimum follow up of 24 months were included. They were identified using the Somerset Cancer Register and data were collected through retrospective case note review. Approval was obtained from the audit departments at the relevant NHS institutions, and data were analysed using IBM SPSS Statistics for Windows version 24 (IBM Corp). The analysis included 129 patients with 82% having an initial performance status (PS) of 0-1. The most frequent change in PS was a one point drop (46%). Twenty of the 93 eligible patients (22%) underwent adjuvant CRT. A total of 37 (40%) began adjuvant CRT/RT within 42 days, and 79 (85%) within 56 days. A delay in initiating adjuvant therapy was associated with higher rates of complications and a longer postoperative hospital stay. Concordance between imaging and pathological nodal staging was poor (cK 0.223). PS frequently declines after complex surgical procedures and long postoperative recovery periods, leading to difficulties providing adjuvant treatments within the national guidance of 42 days. Frequent deviation from planned adjuvant therapies highlights the need for improved treatment strategies.

In vivo osseointegration and erosion of nacre screws in an animal model

The use of resorbable devices for osteosynthesis has become a subject of interest. Nacre has been proposed as a resorbable and osteoconductive material favoring bone apposition without triggering an inflammatory reaction. We compared the in vivo osseointegration and erosion of nacre screws in an animal model with titanium screws. Implantation of similar nacre and titanium screws was performed in the femoral condyles of adult rats. Animals (n = 41) were randomized in four groups sacrificed at day one, 1, 6, and 12 months. Microcomputed tomography (microCT) allowed 3D morphometry of erosion of nacre. Osseointegration was measured as the volume of trabecular bone bone volume/tissue volume (BV/TV) in a standardized volume of interest around each screw. Undecalcified bone histology was also done. Gross examination revealed a similar clinical osseointegration for titanium and nacre screws. A progressive erosion of nacre screws, but no erosion of titanium screws, was observed in microCT. The volume of nacre screws progressively decreased over time whereas no modification occurred for titanium. For titanium screws, BV/TV remained stable throughout the study. For nacre screws, the BV/TV decrease was not statistically different. A significant difference was found between nacre and titanium screws at 6 months but not at 12 months. The screw heads, outside the bone shaft, were not eroded even after 12 months. Erosion of nacre occurred during the entire study period, only within the bone shaft in direct contact with bone marrow. Bone apposition was observed on nacre surfaces without signs of erosion. Nacre is a promising biomaterial in maxillofacial surgery.

Telemedicine in Oral and Maxillo-Facial Surgery: An Effective Alternative in Post COVID-19 Pandemic

The aim of this work was to demonstrate the advantages of using telemedicine (TM) in the management of the outpatients with maxillofacial surgical pathologies during the COVID-19 pandemic. The study was conducted at the MaxilloFacial Surgery Unit of “Magna Graecia” University of Catanzaro, on two different groups of patients: a group of follow-up patients (A₁: patients in oncological follow-up after surgical treatment performed before the COVID-19 pandemic; A₂: suffering from chronic lesions such as precancerous lesions), and a group B of patients with first urgent visits (B₁: patients with suspected oncological pathology; B₂: patients with suspected urgent disease such as medication-related osteonecrosis of the jaws (MRONJ), odontogenic abscesses, temporomandibular joint (TMJ) dislocation, etc.). Participation in the study required possession of a smartphone with Internet access, e-mail and the use of a messaging service (WhatsApp or Telegram) to send photos and messages; completion by the patient of a COVID-19 screening questionnaire; submission of a satisfaction questionnaire by the doctors and patients. A total of 90 patients were included in this study. A high percentage of satisfaction emerged from the analysis of the satisfaction questionnaires of both patients and doctors.TM thus represents an excellent opportunity to improve accessibility to oncological and non-management activities, reducing the risk of Covid-19 dissemination and should be promoted and implemented in the post-pandemic era.

The Premasseteric Branch of the Facial Artery: A Review and Translation of Adachi's Work

The premasseteric branch of the facial artery is a variable posterior branch that is closely associated with the anterior border of the masseter muscle. Since its first description, the premasseteric branch has been described using different terms such as the masseteric or posterior branch of the facial artery. While the artery’s anatomy is known, it is infrequently discussed in the literature. This manuscript reviews the artery’s origin, course, and importance during maxillofacial procedures, especially those involving manipulation of the masseter. We also provide a translation of Adachi’s 1928 German text describing the branch.

Evaluation of factors influencing accuracy of virtual surgical planning in orthognatic surgery

Three-dimensional virtual surgical planning has become routine practice in orthognatic and reconstructive surgery for the possibility to realize presurgical evaluation of intraoperative bones movements, the prediction of postoperative results and the high level of accuracy. Thanks to surface superimposition between 3D planned and 3D postoperative model of maxillo-facial skeleton, a medium discrepancy less than 1 mm was found in scientific literature, considering 15 different points of maxillofacial skeleton. In our study we decided to evaluate different factors that could invalidate that result in the same cohort of patients, such as sex, kind of dentofacial deformity, asymmetry, type of surgical approach and entity of maxillo-mandibular movements (more or less than 1 mm). We found out no significant differences among groups. We can state that virtual surgical planning and 3D surgical splints are a valid means of diagnosis, treatment and predictivity regardless factors that could influence post-operative results. In conclusion, virtual surgical planning and 3D surgical splints facilitated diagnosis, treatment planning and accuracy regardless of sex, dentofacial deformity class, surgery techniques, entity of advancement and asymmetry.

Computer-assisted surgery for replacement of the temporomandibular joint with customized prostheses: can we validate the results?

PURPOSE

Replacing the temporomandibular joint poses an important challenge to maxillofacial surgeons, and for certain disorders, it represents the treatment's gold standard. Computer-assisted surgery (comprising preoperative virtual planning, virtual intraoperative navigation and 3D printing) is a useful tool for this type of surgery. However, we do not know if and how much the final position of the prosthesis differs, in absolute values, from what was planned virtually in the preoperative phase. We propose a comparative result validation system for temporomandibular joint replacement METHODS: In the present study, we propose a comparative validation system using overlapping images, between the model obtained with preoperative virtual planning and the postoperative result.

RESULTS

The mean difference for all screws of the glenoid prosthesis was 2.08 mm (range, 1.20-3.03) and for all screws of the condylar prosthesis it was 2.33 mm (range, 1.16-3.56). Mean overall difference between both prostheses in all patients was 2.21 mm (range, 1.16-3.56).

CONCLUSIONS

The validation system proposed by overlapping pre- and postoperative images in temporomandibular joint replacement allowed us to establish differences in absolute values between the virtual preoperative model and the actual postoperative result expressed in millimeters.

Cardiopulmonary exercise testing and cardiopulmonary morbidity in patients undergoing major head and neck surgery

Cardiopulmonary exercise testing (CPET) is used as a risk stratification tool for patients undergoing major surgery. In this study, we investigated the role of CPET in predicting day five cardiopulmonary morbidity in patients undergoing head and neck surgery. This observational cohort study included 230 adults. We recorded preoperative CPET variables and day five postoperative cardiopulmonary morbidity. Full data from 187 patients were analysed; 43 patients either had incomplete data sets or declined surgery/CPET. One hundred and nineteen patients (63.6%) developed cardiopulmonary morbidity at day five. Increased preoperative heart rate and duration of surgery were independently associated with day five cardiopulmonary morbidity. Those with such morbidity also had lower peak V̇O₂ 11.4 (IQR 8.4-18.0) vs 16.0 (IQR 14.0-19.7) ml.kg^-1.min^-1, P<0.0001 and V̇O₂ at AT 10.6 (IQR 9.1-13.1) vs 11.5 (IQR 10.5-13.0) ml.kg^-1.min^-1, p=0.03. Logistic regression model containing peak V̇O₂ and duration of surgery demonstrated that increased peak V̇O2 was associated with a reduction in the likelihood of cardiopulmonary complications OR 0.92 (95%CI 0.87 to 0.96), p=0.001. The area under the receiver operating characteristic curve for this model was 0.75(95%CI 0.68 to 0.82), p<0.0001, 64% sensitivity, 81% specificity. CPET can help to predict day five cardiopulmonary morbidity in the patients undergoing head and neck surgery. A model containing peak V̇O₂ allowed identification of those with such complications.

Comparison between Erich arch bars and intermaxillary screws in maxillofacial fractures involving the dental occlusion: a meta-analysis

This systematic review aimed to compare the Erich arch bars (EABs) with intermaxillary fixation (IMF) screws in maxillofacial fractures involving dental occlusion on perioperative parameters. Four electronic databases were searched: MedLine (Pubmed), Web of Science, VHL, and Cochrane Library. Inclusion criteria comprised clinical trials comparing the two IMF methods, assessing at least one of the outcomes: occlusal stability, oral hygiene, quality of life, time to apply and remove IMF appliances, and complications. Risk of bias was evaluated through the Cochrane risk of bias tool. Fifteen papers were included in the qualitative analysis and 12 of those in the meta-analysis. Times for EABs application (mean difference (MD) 46.83; 95% confidence interval (CI): 30.63-63.02) and removal (MD 22.89; 95% CI 14.61-31.17) were longer compared with IMF screws. There is higher risk of glove perforation (risk ratio (RR) 3.81; 95% CI 2.41-6.04) and lower risk of iatrogenic injuries (RR 0.21; 95% CI 0.09-0.48) when placing EABs compared with IMF screws. No significant differences in plaque index were found (MD 1.07; 95% CI -0.17 to 2.31). The quality of this evidence ranged from very low to low and was mainly compromised by risk of bias assessment. Further studies are necessary to evaluate transurgical IMF stability and postoperative occlusal quality and quality of life when comparing EABs with IMF screws.

Donor-Site Morbidity after Fibula Transplantation in Head and Neck Tumor Patients: A Split-Leg Retrospective Study with Focus on Leg Stability and Quality of Life

The free fibula flap has been one of the most important microvascular grafts for orofacial reconstruction for more than 30 years. The complication rates at the donor-site reported in literature are considered to be low, but the published data vary greatly in some cases. In particular, restrictions in the stability and balance of the involved leg and their effects on the quality of life have been described very inconsistently to date. Therefore, this study mainly focuses on the stability and balance of the affected leg in a split-leg design. Between December 2014 and January 2018, out of 119 subjects who underwent mainly jaw ablative tumor surgery and reconstruction using a fibula flap, 68 subjects were examined for donor site morbidity. Besides reporting general types of complications, two specific test procedures were used. The Star Excursion Balance Test (SEBT) as a practical test for ankle function and the Foot and Ankle Disability Index (FADI) as a questionnaire in order to assess quality of life, depending on the lower leg function. SEBT revealed an average of 55.3 cm with the operated leg as the supporting leg, which corresponds to 95.5% of 57.9 cm achieved with the healthy leg as the supporting leg. An average FADI score of 89.4% was recorded. SEBT and FADI seem to be suitable methods of examination for subjects post fibular transplantation and pointed out minimal limitations of the involved legs in comparison to the unaffected legs. These limitations were clinically not relevant and they had minor influence on the subjects’ quality of life and their daily activities.

Systemic Effects of Photobiomodulation on the Morphology of the Thyroid and Sublingual Glands: A Study in Rabbits

Objective: To investigate whether photobiomodulation (PBM) applied in a clinical situation with the purpose of improving the healing process of implants placed in the rabbit mandible would cause any morphological change in the thyroid and sublingual glands as a systemic effect of laser irradiation. Methods: Thirty-two New Zealand rabbits were randomly divided into four groups of eight animals each, one control group (CI, nonirradiated animals) and three experimental groups (EI, EII, and EIII) that received PBM postoperatively with an aluminum/gallium/arsenide laser diode (Theralase^®) at a wavelength of 830 nm (infrared) and 50 mW output power applied to two irradiation fields per session, for a total of seven sessions. All rabbits underwent surgical extraction of the mandibular left incisor, followed by immediate placement of an osseointegrated implant in the fresh socket. The experimental groups EI, EII, and EIII received PBM at an energy density of 5, 2.5, and 10 J/cm², respectively, per irradiation field. Results: There was no histomorphometric change in any of the groups. Conclusions: PBM, based on the irradiation protocol used in this study, does not cause morphological changes in the thyroid and sublingual glands when used to stimulate peri-implant bone healing in the rabbit mandible.

Application of Finite Element Analysis in Oral and Maxillofacial Surgery-A Literature Review

In recent years in the field of biomechanics, the intensive development of various experimental methods has been observed. The implementation of virtual studies that for a long time have been successfully used in technical sciences also represents a new trend in dental engineering. Among these methods, finite element analysis (FEA) deserves special attention. FEA is a method used to analyze stresses and strains in complex mechanical systems. It enables the mathematical conversion and analysis of mechanical properties of a geometric object. Since the mechanical properties of the human skeleton cannot be examined in vivo, a discipline in which FEA has found particular application is oral and maxillofacial surgery. In this review we summarize the application of FEA in particular oral and maxillofacial fields such as traumatology, orthognathic surgery, reconstructive surgery and implantology presented in the current literature. Based on the available literature, we discuss the methodology and results of research where FEA has been used to understand the pathomechanism of fractures, identify optimal osteosynthesis methods, plan reconstructive operations and design intraosseous implants or osteosynthesis elements. As well as indicating the benefits of FEA in mechanical parameter analysis, we also point out the assumptions and simplifications that are commonly used. The understanding of FEA's opportunities and advantages as well as its limitations and main flaws is crucial to fully exploit its potential.

Does Le Fort I osteotomy have an influence on nasal cavity and septum deviation?

Aims

Le Fort I (LI) osteotomy has been used for the correction of dento-facial deformities of the midface. The aim of this study was to determine the effects of advancement and impaction of the maxilla with LI osteotomy on the nasal cavity and septum.

Patients and Methods

In this study, 40 adult patients, 23 females and 17 males (mean age 20.52 ± 4.4 years), who underwent single-piece LI advancement and impaction surgery combined with a bilateral sagittal split osteotomy (BSSO) were included. Posterior-anterior (PA) and lateral cephalometric radiographs taken before surgery (T0) and at least three months after surgery (T1) were evaluated. The superior and anterior movements of maxilla, changes of the nasal cavity, nasal septum and maxillo-mandibular parameter were measured on the cephalometric radiographs. Treatment changes were statistically analyzed using paired sample t-test, and Pearson correlation analysis was applied for the determination of the relationship between variables.

Results

There was no statistically significant change in the deviation parameters (P > 0,05). However, a statistically significant decrease was found for left and right nasal cavity heights after LI osteotomy (P < 0.05). Furthermore, no significant correlation was found between septal deviation angle and extent of maxillary movement (P > 0.05). Positive correlation was found between nasal cavity width and amount of maxillary impaction. (P < 0.05).

Conclusion

The influence of maxillary impaction with LI osteotomy on nasal septum deviation was not found significant but maxillary impaction with LI osteotomy significantly increased the nasal cavity width.

Impact of COVID-19 on maxillofacial surgery practice: a worldwide survey

The outbreak of coronavirus disease 2019 (COVID-19) is rapidly changing our habits. To date, April 12, 2020, the virus has reached 209 nations, affecting 1.8 million people and causing more than 110,000 deaths. Maxillofacial surgery represents an example of a specialty that has had to adapt to this outbreak, because of the subspecialties of oncology and traumatology. The aim of this study was to examine the effect of this outbreak on the specialty of maxillofacial surgery and how the current situation is being managed on a worldwide scale. To achieve this goal, the authors developed an anonymous questionnaire which was posted on the internet and also sent to maxillofacial surgeons around the globe using membership lists from various subspecialty associations. The questionnaire asked for information about the COVID-19 situation in the respondent's country and in their workplace, and what changes they were facing in their practices in light of the outbreak. The objective was not only to collect and analyse data, but also to highlight what the specialty is facing and how it is handling the situation, in the hope that this information will be useful as a reference in the future, not only for this specialty, but also for others, should COVID-19 or a similar global threat arise again.

Molecular basis of unilateral condylar hyperplasia?

Unilateral condylar hyperplasia (UCH) causes progressive asymmetry of the mandible. The aetiology of this growth disorder is unknown. A two-centre prospective study was established, and 10 consecutive adult UCH patients scheduled for high condylectomy were included. The resected condylar tissue was divided into two parts, one for regular histopathology and one for DNA extraction. A panel of eight selected overgrowth genes (AKT1, AKT3, MTOR, PIK3CA, PIK3R2, PTEN, TSC1, TSC2) were sequenced using next-generation sequencing, with coverage of a minimum 500 times in order to be able to detect low-grade mosaicisms. Subsequently, untargeted whole exome sequencing (WES) was performed to detect variants in other genes present in three or more patients. No mutation was detected in any of the overgrowth genes, and untargeted exome sequencing failed to detect any definitively causative variant in any other gene. Ten genes had a rare variant in three or more patients, but these cannot be designated as causative without additional functional studies. The hypothesis that the cause in at least some patients with UCH is a somatic mutation in a gene that controls cell growth could not be confirmed in this study.