Oncological Outcome of Node-Positive Oral Squamous Cell Carcinomas Treated With Selective and Comprehensive Neck Dissection.

Selective neck dissection (SND) is the treatment of choice in patients with oral squamous cell carcinomas (OSCCs) and clinically node-negative necks (cN0). The treatment of patients with positive-staged necks (cN+) includes SND as well as comprehensive neck dissection (CND). The clear benefit of one or the other remains under debate. We aim to address this lack of clarity by analysing patients with OSCC staged with clinically node-positive necks, treated with either CND or SND using a level-by-level approach. This retrospective study included patients diagnosed with OSCC with clinically (cN+) and pathologically (pN+) positive cervical lymph nodes (LNs) with clear neck level categorization during the years 2010-2019. In total, 74 patients were analysed. Cox regression analysis found no significance for the type of ND being an independent risk factor, neither for overall survival (OS) nor for disease-free survival (DFS). Regional recurrence of CND cases (5.77%) was comparable to SND cases (9.09%). For OS, extracapsular spread (ECS) and male sex were identified as independent risk factors with poorer outcome. pT-stage and ECS were found to be independent risk factors for DFS. The results of this study suggest that both CND and SND may be viable treatment options for certain patients with OSCC pN+.

Volumetric evaluation of osteotomy gap following mandibular bilateral sagittal split osteotomy using a novel semi-automated approach: a pilot study.

OBJECTIVES: To establish an analysis pipeline for the volumetric evaluation of the osteotomy site after bilateral sagittal split osteotomy (BSSO). PATIENTS AND METHODS: Cone-beam computed tomography (CBCT) was performed before, directly after BSSO, and 6-12 months after surgery. Image segmentations of each osteotomy gap data set were performed manually by four physicians and were compared to a semi-automatic segmentation approach. RESULTS: Five patients with a total of ten osteotomy gaps were included. The mean interclass correlation coefficient (ICC) of individual patients was 0.782 and the standard deviation 0.080 when using the manual segmentation approach. However, the mean ICC of the evaluation of anatomical sites and time points separately was 0.214, suggesting a large range of deviation within the manual segmentation of each rater. The standard deviation was 0.355, further highlighting the extent of the variation. In contrast, the semi-automatic approach had a mean ICC of 0.491 and a standard deviation of 0.365, which suggests a relatively higher agreement among the operators compared to the manual segmentation approach. Furthermore, the volume of the osteotomy gap in the semi-automatic approach showed the same tendency in every site as the manual segmentation approach, but with less deviation. CONCLUSION: The semi-automatic approach developed in the present study proved to be valid as a standardised method with high repeatability. Such image analysis methods could help to quantify the progression of bone healing after BSSO and beyond, eventually facilitating the earlier identification of patients with retarded healing.

Quantifying bone healing after mandibular displacement in orthognathic surgery.

Impaired bony healing following bilateral sagittal split osteotomy (BSSO) is a major unmet medical need for affected patients, and rare occurrences can hinder the identification of underlying risk factors. We hypothesised that osseous union following BSSO can be quantified using volumetric analysis, and we aimed to identify the risk factors for impaired bone healing. The percentage change in bony volume was measured in orthognathic patients following BSSO using two consecutive postoperative cone-beam computed tomography scans. Patients' characteristics and treatment parameters were documented, and correlation and regression analyses of these variables performed. Thirty-six patients (23 men and 13 women) with a mean (SD) age of 33.28 (11.86) years were included. The gap site (lingual versus buccal) (p < 0.01) had a significant impact on the change in volume. Age (p = 0.06) showed a trend towards significance. Initial width of the osteotomy gap, sex, and indication for surgery did not influence osseous healing. Increased age at surgery and the side of the buccal osteotomy are independent risk factors for impaired osseous healing following BSSO.

Diagnostic pitfalls in pediatric orbital entrapment fractures.

Prompt diagnosis and management of orbital entrapment fractures in the pediatric patient have been advocated. This retrospective study analyzed a cohort of orbital entrapment fractures in pediatric patients with regard to diagnostic pitfalls, treatment and outcomes in a Level I trauma center in Germany. Based on medical records and radiological imaging, patients under the age of 18 years who presented with orbital fractures during 2009-2021 were analyzed. Overall, 125 patients presented with orbital fractures, of whom 29 patients (23.2%) had orbital entrapment fractures. The majority of patients presented with monocle hematoma (n = 23), diplopia (n = 20), and/or restricted extraocular eye movement (n = 14). While all patients with orbital entrapment fractures underwent three-dimensional imaging, 10 radiological reports (34.5%) did not include findings on orbital entrapment fractures. All patients underwent surgical exploration in less than 24 h. In 12 patients, clinical symptoms such as diplopia and restricted ocular elevation were documented upon postoperative evaluation before discharge. Considering the significant proportion of orbital entrapment fractures that are not noted on radiological imaging, prompt clinical examination should be initiated in pediatric patients at risk for orbital fractures. Urgent surgical intervention should be recommended in entrapment fractures.

The risk of osteomyelitis after mandibular fracture is doubled in men versus women: analysis of 300,000 patients.

Postoperative complications following mandibular fracture treatment vary from local wound infections to severe conditions including osteomyelitis and impaired fracture healing. Several risk factors have been associated with the development healing disorders, including fracture localisation, treatment modality and substance abuse. However, limited research on the sex-specific influence of these complications exists. A total of about 300,000 female and male patients with mandibular fractures were examined in two cohorts. After matching for confounders (age, nicotine and alcohol dependence, malnutrition, overweight, anaemia, diabetes, osteoporosis and vitamin D deficiency), two cohorts were compared with propensity-score-matched patients according to outcomes (osteomyelitis, pseudoarthrosis and disruption of the wound) within 1 year after fracture. There were significant differences between female and male patients regarding the occurrence of osteomyelitis (odds ratio [OR] [95% confidence interval]: 0.621 [0.563; 0.686]) and disruption of the wound (OR [95% confidence interval]: 0.703 [0.632; 0.782]). Surprisingly, matching for the expected confounders did not change the results substantially. Sex plays a dominant role in determining the risk stratification for postoperative osteomyelitis and disruption of the wound, after accounting for other potential confounding factors. Additional research is needed to understand the underlying mechanisms and to develop sex-specific strategies to prevent these complications.

Impact of the adjacent bone on pseudarthrosis in mandibular reconstruction with fibula free flaps.

BACKGROUND: Mechanical and morphological factors have both been described to influence the rate of pseudarthrosis in mandibular reconstruction. By minimizing mechanical confounders, the present study aims to evaluate the impact of bone origin at the intersegmental gap on osseous union. METHODS: Patients were screened retrospectively for undergoing multi-segment fibula free flap reconstruction of the mandible including the anterior part of the mandible and osteosynthesis using patient-specific 3D-printed titanium reconstruction plates. Percentage changes in bone volume and width at the bone interface between the fibula/fibula and fibula/mandible at the anterior intersegmental gaps within the same patient were determined using cone-beam computed tomography (CBCT). Additionally, representative samples of the intersegmental zones were assessed histologically and using micro-computed tomography (µCT). RESULTS: The bone interface (p = 0.223) did not significantly impact the change in bone volume at the intersegmental gap. Radiotherapy (p < 0.001), time between CBCT scans (p = 0.006) and wound healing disorders (p = 0.005) were independent risk factors for osseous non-union. Preliminary analysis of the microstructure of the intersegmental bone did not indicate morphological differences between fibula-fibula and fibula-mandible intersegmental bones. CONCLUSIONS: The bone interface at the intersegmental gap in mandibular reconstruction did not influence long-term bone healing significantly. Mechanical and clinical properties seem to be more relevant for surgical success.

Pediatric Maxillofacial Trauma: Insights into Diagnosis and Treatment of Mandibular Fractures in Pediatric Patients.

Aim: To assess the diagnostic and therapeutic approaches in pediatric mandibular fractures with regards to fracture pattern and localization. Patients and methods: This retrospective study included patients under the age of 17 years that presented to the Department of Oral and Maxillofacial Surgery at Charité-Universitätsmedizin Berlin with mandibular fractures over an 11-year long period (2010-2020). Medical records were analyzed for age, gender, injury mechanism, clinical presentation, imaging modalities, fracture pattern, and fracture management. Statistical analyses included descriptive statistics, normality testing, and Mann-Whitney U tests. Results: A total of 91 pediatric patients (23 females and 68 males) presented with mandibular fractures. The majority of mandibular fractures occurred in patients aged 13-16 years (67.0%, n = 61). The main causes were activities of daily life (34.1%), followed by assault (25.3%). Malocclusion and pain upon mandibular joint compression were documented in 72.5% and 51.7% of patients, respectively. The most frequently applied radiological diagnostic tool was a panoramic X-ray (49.5%). The main fracture patterns were single (42.9%) and double fractures (48.4%). An age-adapted surgical approach using open reduction and internal fixation (ORIF) was the most frequent management (61.5%). A conservative approach was favored in cases of condylar head fractures. Resorbable plates were used in eight cases of ORIF (8.8%). Conclusion: Treatment regimens should be carefully selected based on the unique anatomy of the pediatric patient with regards to centers of growth and dentition phase, to restore stomatognathic function and to maintain adequate skeletal growth and eruption of teeth. Clinical significance: This study illustrates the challenges of mandibular fracture management in the pediatric patient. How to cite this article: Hofmann E, Koerdt S, Heiland M, et al. Pediatric Maxillofacial Trauma: Insights into Diagnosis and Treatment of Mandibular Fractures in Pediatric Patients. Int J Clin Pediatr Dent 2023;16(3):499-509.

Treatment options for critical size defects - Comparison of different materials in a calvaria split model in sheep.

Bone defects of the craniofacial skeleton are often associated with aesthetic and functional impairment as well as loss of protection to intra- and extracranial structures. Solid titanium plates and individually adapted bone cements have been the materials of choice, but may lead to foreign-body reactions and insufficient osseointegration. In contrast, porous scaffolds are thought to exhibit osteoconductive properties to support bone ingrowth. Here, we analyse in critical size defects of the calvaria in sheep whether different bone replacement materials may overcome those remaining challenges. In a critical size defect model, bilateral 20 × 20 × 5-mm craniectomies were performed on either side of the sagittal sinus in 24 adult female blackheaded sheep. Bony defects were randomised to one of five different bone replacement materials (BRMs): titanium scaffold, biodegradable poly(d,l-lactic acid) calcium carbonate scaffold (PDLLA/CC), polyethylene 1 (0.71 mm mean pore size) or 2 (0.515 mm mean pore size) scaffolds and polymethyl methacrylate (PMMA)-based bone cement block. Empty controls (n = 3) served as references. To evaluate bone growth over time, three different fluorochromes were administered at different time points. At 3, 6 and 12 months after surgery, animals were sacrificed and the BRMs and surrounding bone analysed by micro-CT and histomorphometry. The empty control group verified that the calvaria defect in this study was a reliable critical size defect model. Bone formation in vivo was detectable in all BRMs after 12 months by micro-CT and histomorphometric analysis, except for the non-porous PMMA group. A maximum of bone formation was detected in the 12-months group for titanium and PDLLA/CC. Bone formation in PDLLA/CC starts to increase rapidly between 6 and 12 months, as the BRM resorbs over time. Contact between bone and BRM influenced bone formation inside the BRM. Empty controls exhibited bone formation solely at the periphery. Overall, porous BRMs offered bone integration to different extent over 12 months in the tested calvaria defect model. Titanium and PDLLA/CC scaffolds showed remarkable osseointegration properties by micro-CT and histomorphometric analysis. PDLLA/CC scaffolds degraded over time without major residues. Pore size influenced bone ingrowth in polyethylene, emphasising the importance of porous scaffold structure.

Direct Interaction of Avian Cryptochrome 4 with a Cone Specific G-Protein.

BACKGROUND: Night-migratory birds sense the Earth's magnetic field by an unknown molecular mechanism. Theoretical and experimental evidence support the hypothesis that the light-induced formation of a radical-pair in European robin cryptochrome 4a (ErCry4a) is the primary signaling step in the retina of the bird. In the present work, we investigated a possible route of cryptochrome signaling involving the α-subunit of the cone-secific heterotrimeric G protein from European robin. METHODS: Protein-protein interaction studies include surface plasmon resonance, pulldown affinity binding and Förster resonance energy transfer. RESULTS: Surface plasmon resonance studies showed direct interaction, revealing high to moderate affinity for binding of non-myristoylated and myristoylated G protein to ErCry4a, respectively. Pulldown affinity experiments confirmed this complex formation in solution. We validated these in vitro data by monitoring the interaction between ErCry4a and G protein in a transiently transfected neuroretinal cell line using Förster resonance energy transfer. CONCLUSIONS: Our results suggest that ErCry4a and the G protein also interact in living cells and might constitute the first biochemical signaling step in radical-pair-based magnetoreception.