A modified pull-through approach with a pedicled bone flap for oral and oropharyngeal cancer resection: a feasibility study.

PURPOSE: Compromised swallowing, speaking, and local complications are the major disadvantages of established approaches to the posterior tongue and oropharynx. The mandibular split involves an esthetically unpleasant bipartition of the lower lip and is prone to bony non-union or sequestration. The conventional pull-through technique on the other hand lacks the secure reattachment of the lingually released soft tissues. METHODS: The feasibility of a new modified pull-through approach was tested on three anatomical specimens. CAD/CAM cutting guides were used to design a retentive bone flap to properly refixate the genioglossus and geniohyoid muscles after the procedure. The radiographic assessment and treatment planning was performed on 12 cadavers. The entire procedure was tested surgically via dissection in three of those cases. This procedure was then applied in a clinical case. RESULTS: Precise repositioning and dynamic compression of bony segments was possible reproducibly and without injury to adjacent structures. In all dissected cases, a median lingual foramen was found and in two cases vessels entering it could be dissected Radiologic anatomical landmarks were sufficient in all 12 cases to perform the clinical planning procedure. Clinically, the osteotomized segment demonstrated good blood supply and plateless repositioning was verified postoperatively via cone beam scan. CONCLUSION: The method presented is safe and easy to perform. Individual cutting guides improve the safety and accuracy of the procedure, potentially eliminating the need for osteosynthesis. We provide the anatomical and radiologic basis for clinical evaluation of this pedicled bone flap procedure and present the clinical application of this modified pull-through approach.

Prognostic value of lymph node involvement in oral squamous cell carcinoma.

OBJECTIVES: Different parameters have been identified in patients with oral squamous cell carcinomas (OSCC) that have a serious impact on survival, including residual tumour and extracapsular spread. Moreover, other factors, including the lymph node ratio (LNR) and lymph node yield (LNY), have been suggested as prognostic markers. MATERIAL AND METHODS: This retrospective study included patients diagnosed with OSCC and cervical lymph node metastases during the years 2010-2020. Patients' records were evaluated regarding lymph node status, final therapy regime, tumour recurrence, time to death, tumour association with death, disease-free survival (DSF), and overall survival (OS). RESULTS: In 242 patients with a mean age of 63.57 ± 11.24 years, treated either by selective neck dissection (SND; n = 70) or by modified radical neck dissection (MRND; n = 172), 5772 lymph nodes were detected. The LNR and LNY were identified as independent risk factors in OS and DFS. The optimal cut-off point for the LNY was ≥ 17 lymph nodes in the SND and ≥ 27 lymph nodes in the MRND group. The metastatic lymph node clearance (MLNC) was established as a score to relate the LNR and LNY to the extent of lymph node removal. Survival analysis showed statistically significant differences among score levels. CONCLUSIONS: As information about the extent of nodal dissection is excluded from LNR and LNY, we propose the use of a new scoring system comprising individual cut-off values for LNY and LNR with regard to the extent of neck dissection. CLINICAL RELEVANCE: MLNC might help to identify high-risk OSCC patients with metastatic lymph nodes.

Modified McLaughlin's Dynamic Muscle Support in the 21st Century? A Retrospective Study With a Prospective Follow-Up Analysis for Patients With Long Standing Facial Paralysis.

INTRODUCTION: Facial nerve paralysis can dramatically affect the life of a patient as it leads to significant alterations of the facial symmetry and functional limitations. Various methods exist including free neuromuscular flaps to reanimate patients suffering from uni- or even bilateral facial nerve paralysis. The more than 60-year-old technique described by McLaughlin continues to offer an alternative with distinct advantages for the individual patient. The present study aimed to evaluate clinical outcome and satisfaction of patients treated with a modified McLaughlin's Dynamic Muscle Support. MATERIALS AND METHODS: A total of 13 patients (mean age of 58.4 years) who received a modified McLaughlin's Dynamic Muscle Support due to uni- or bilateral long-standing facial paralysis were included. Medical records were reviewed retrospectively, and patients were contacted for additional follow-up. Patients who agreed to participate in the follow-up study were asked to answer a self-developed questionnaire. RESULTS: In all patients, a rehabilitation of facial symmetry with an improvement of the mimic expression could be achieved. Mean length of inpatient stay was 6.5 days and average duration of surgery was 121 minutes. No surgical site infection occurred. Mean follow-up was 23 months. Most of the patients were fully satisfied with the result and could experience functional and esthetic improvement.Patients who participated in the prospective follow-up study were very satisfied with the esthetic result and functional outcome. CONCLUSIONS: Even in times of advanced microsurgical techniques, McLaughlin's Dynamic Muscle Support appears to be a good alternative for the successful treatment of long-standing facial paralysis.

Reliability of NI-RADS criteria in the interpretation of contrast-enhanced magnetic resonance imaging considering the potential role of diffusion-weighted imaging.

OBJECTIVES: To assess inter- and intrareader agreement of the Neck Imaging Reporting and Data System (NI-RADS) used in contrast-enhanced magnetic resonance imaging (MRI) including analysis of diffusion-weighted imaging (DWI), which is currently not part of the NI-RADS criteria. METHODS: This retrospective study included anonymized surveillance contrast-enhanced MRI datasets of 104 patients treated for different head and neck cancers. Three radiologists experienced in head and neck imaging reported findings for the primary site and the neck using NI-RADS criteria in a first step and evaluated DWI sequences for the primary site in a second step. Thirty randomly selected imaging datasets were again presented to the readers. Kappa statistics and observed agreement (Ao) were calculated. RESULTS: Interreader agreement across all MRI datasets was moderate (κFleiss = 0.53) for NI-RADS categories assigned to the primary site, substantial for NI-RADS categories of the neck (κFleiss = 0.67), and almost perfect for DWI of the primary site (κFleiss = 0.83). Interreader agreement for the primary site was particularly low in cases of cancer recurrence (κFleiss = 0.35) and when categories 2a, 2b, and 3 were combined (κFleiss = 0.30). Intrareader agreement was considerably lower for NI-RADS categories of the primary site (range Ao = 53.3-70.0%) than for NI-RADS categories of the neck (range Ao = 83.3-90.0%) and DWI of the primary site (range Ao = 93.3-100.0%). CONCLUSION: Interreader agreement of NI-RADS for reporting contrast-enhanced MRI findings is acceptable for the neck but limited for the primary site. Here, DWI has the potential to serve as a reliable additional criterion. KEY POINTS: • NI-RADS was originally designed for contrast-enhanced computed tomography with or without positron emission tomography but can also be used for contrast-enhanced magnetic resonance imaging alone. • Overall interreader agreement was acceptable for NI-RADS categories assigned to the neck but should be improved for the primary site, where it was inferior to DWI; similar tendencies were found for intrareader agreement. • DWI is currently no criterion of NI-RADS, but has shown potential to improve its reliability, especially for categories 2a, 2b, and 3 of the primary site.

Retrospective Evaluation of NI-RADS for Detecting Postsurgical Recurrence of Oral Squamous Cell Carcinoma on Surveillance CT or MRI.

BACKGROUND. Imaging surveillance is important for the early diagnosis of recurrence after definitive treatment of oral squamous cell carcinoma (OSCC). The Neck Imaging Reporting and Data System (NI-RADS) includes a standardized template for surveillance imaging and categorizes probability of recurrence at the primary site and in the neck (cervical lymph nodes) by assigning categories of 1 (no evidence of recurrence), 2 (low suspicion, subdivided into 2a and 2b for the primary site), 3 (high suspicion), and 4 (definite recurrence). OBJECTIVE. The aim of this study was to determine the rate of locoregional and nodal OSCC recurrence stratified by NI-RADS category among patients undergoing surveillance CT or MRI. METHODS. This retrospective study included 158 patients enrolled in an institutional surveillance program after resection of OSCC with curative intent. A total of 503 contrast-enhanced CT or MRI examinations performed during surveillance were evaluated. Each examination was randomly assigned to one of four radiologists with expertise in head and neck imaging, who provided NI-RADS categories for the primary site and the neck (1006 assigned NI-RADS categories). NI-RADS performance in identifying recurrence was assessed by ROC curve analysis. All four readers evaluated 50 randomly assigned cases to determine interreader agreement by use of the Kendall W statistic. RESULTS. Cancer recurrence was confirmed in 7.6% (38/503) of cases for the primary site and in 6.2% (31/503) for the neck. For the primary site, recurrence rates were 1.0% in NI-RADS category 1, 7.1% in category 2a, 5.6% in category 2b, 66.7% in category 3, and 100.0% in category 4. For the neck, recurrence rates were 0.5% in category 1, 7.0% in category 2, 80.0% in category 3, and 100.0% in category 4. NI-RADS had AUC values of 0.934 for the primary site and 0.959 for the neck. Interreader agreement was 0.67 for the primary site and 0.81 for the neck. CONCLUSION. NI-RADS offers excellent discriminatory power in detection of OSCC recurrence, both for the primary site and the neck. CLINICAL IMPACT. Radiologists and maxillofacial surgeons should implement NI-RADS in surveillance regimens for postoperative OSCC to help detect recurrences in an effective and standardized manner using imaging.

One stage microvascular mandible reconstruction by using scapula chimeric flap combined with computer-aided-design and computer-aided-manufacturing plate including bilateral alloplastic TMJ prosthesis: A case report.

This report focuses a defect comprising the complete mandible due to osteonecrosis, including both condyles, that required bilateral temporomandibular joint (TMJ) reconstruction with complete mandibular corpus using a computer-aided-design and computer-aided-manufacturing(CAD-CAM) planning to harvest a scapula chimeric free flap combined with plate including bilateral alloplastic TMJ prosthesis. This procedure was realized in one and the same surgery. A 73 year-old-man developed an osteoradionecrosis of the total mandible including both condyles after radiation therapy for a squamous cell carcinoma of the tongue base(cT4aN2bM0G3). A CAD-CAM reconstruction was planned with a plate extended by bilateral individual TMJ prosthesis, individual fossa components and combined with a composite free flap originating from the subscapular vessel system including scapula(circumflex subscapular artery) for reconstruction of the mandibular corpus which was osteotomized in three segments with a resection guide, the parascapular skin paddle (descending branch of circumflex subscapular artery) for compensation of the soft tissue deficiency of the cervical skin and latissimus dorsi muscle(thoracodorsal artery) for the inner mucosal lining and intraoral reconstruction. The subscapular artery was anastomosed to the external carotid artery and two concomitant veins were sutured end-to-side to the internal jugular vein. The patient was discharged without feeding tube and tracheostomy. No complications have been observed after 6 months follow-up. The patient was able to tolerate soft diet and had comprehensible speech. Thus, a total mandibular reconstruction including both condyles using alloplastic and autoplastic reconstruction in one and the same stage is a valid option and may be considered in comparably severe cases.

Oxidative and Nitrosative Stress in Oral Squamous Cell Carcinoma.

INTRODUCTION: The incidence of oral squamous cell carcinoma (OSCC) shows a constant increase, while the long-term outcome remains poor over the last decades. Radical oxygen and nitrogen species (RONS) - initially released by carcinogens, such as alcohol and tobacco, and later maintained by the tumor microenvironment - appear to be strongly associated to chronic inflammation, tumor induction, progression, and metastatic spread. The aim of this study was to evaluate the role of oxidative and nitrosative stress in primary OSCC compared to healthy tissue specimens and to identify their impact on tumor carcinogenesis. MATERIALS AND METHODS: In this basic research study, tissue samples of 30 patients with primary OSCC were evaluated for the expression of pAKT, pERK, 3-NT, NOS1, NOS3, MAPK1, and IP-8 by immunohistochemistry and RT-PCR and compared to those of a healthy control group (n = 30). RESULTS: The results showed a significantly increased expression of pAKT (p < 0.001), pERK (p = 0.01), 3-NT (p = 0.039), NOS1 (p = 0.025), NOS3 (p = 0.046), and MAPK1 (p = 0.032) in OSCC tissue samples compared to healthy controls. CONCLUSION: The results of this study prove the tested stable degradation products to be suitable for the detection of RONS in OSCC. Moreover, the significantly increased expression underlines the role of RONS in carcinogenesis of OSCC, suggests specific mechanisms of detection, and anticipates supplementary research.

Analysis of outcome for elderly patients after microvascular flap surgery: a monocentric retrospective cohort study.

OBJECTIVES: Increasingly, aging societies pose a challenge, particularly in the most developed countries. This trend leads to an increasing group of old and very old patients presenting unique requirements and challenges. One of these challenges consists in reassessment and adaption of established treatment strategies for the elderly patients. There is an ongoing discussion taking place among cranio-maxillo-facial surgeons about the appropriate extent of reconstructive flap surgery for old patients. MATERIALS AND METHODS: This monocentric retrospective cohort study investigated 281 reconstructions with microvascular flaps by comparing the risk for a negative outcome, which was defined as revision, flap loss, and patient death, between three subgroups of elderly patients and younger patients. The three subgroups of elderly patients were defined as-1: young old (65-74 years), 2: old (75-84 years), and 3: oldest old (≥ 85 years). The group of the younger patients was defined by age between 50 and 64 years. Data were obtained within a defined period of 42 months. RESULTS: Significant correlations with a negative outcome were found for the variables stay on IMC/ICU, multiple flaps, and radiotherapy prior surgery. Our data showed no significant correlation between age and a higher risk for a negative outcome. CONCLUSION: Defect reconstruction with microvascular flaps in old patients is not related with a higher risk for a negative outcome. CLINICAL RELEVANCE: Independently of age, treatment with microvascular flaps is an option for all operable patients, with an indication for oncologic surgery. For optimal therapy planning, individual patient resources and preferences should be considered instead of chronologic age.

Improving results in rat fracture models: enhancing the efficacy of biomechanical testing by a modification of the experimental setup.

BACKGROUND: Animal fracture models, primarily performed in rats, are crucial to investigate normal and pathological bone healing. However, results of biomechanical testing representing a major outcome measure show high standard deviations often precluding statistical significance. Therefore, the aim of our study was a systematical examination of biomechanical characteristics of rat femurs during three-point bending. Furthermore, we tried to reduce variation of results by individually adapting the span of bearing and loading areas to the bone's length. METHODS: We examined 40 paired femurs of male Wistar-rats by DXA (BMD and BMC of the whole femur) and pQCT-scans at the levels of bearing and loading areas of the subsequent biomechanical three-point bending test. Individual adjustment of bearing and loading bars was done respecting the length of each specimen. Subgroups of light (< 400 g, n = 22) and heavy (> 400 g, n = 18) animals were formed and analysed separately. We furthermore compared the results of the individualised bending-setting to 20 femurs tested with a fix span of 15 mm. RESULTS: Femurs showed a length range of 34 to 46 mm. The failure loads ranged from 116 to 251 N (mean 175.4 ± 45.2 N; heavy animals mean 221 ± 18.9 N; light animals mean 138.1 ± 16.4 N) and stiffness ranged from 185 N/mm to 426 N/mm (mean 315.6 ± 63 N/mm; heavy animals mean 358.1 ± 34.64 N/mm; light animals mean 280.8 ± 59.85 N/mm). The correlation of densitometric techniques and failure loads was high (DXA R2 = 0.89 and pQCT R2 = 0.88). In comparison to femurs tested with a fix span, individual adaptation of biomechanical testing homogenized our data significantly. Most notably, the standard deviation of failure loads (221 ± 18.95 N individualized setting vs. 205.5 ± 30.36 N fixed) and stiffness (358.1 ± 34.64 N/mm individualized setting vs. 498.5 ± 104.8 N/mm fixed) was reduced by at least one third. CONCLUSIONS: Total variation observed in any trait reflects biological and methodological variation. Precision of the method hence affects the statistical power of the study. By simply adapting the setting of the biomechanical testing, interindividual variation could be reduced, which improves the precision of the method significantly.

Functional donor site morbidity longer than one year after fibula free flap: A prospective biomechanical analysis.

OBJECTIVES: The fibula free flap is the workhorse procedure for osseous reconstruction. The objective of this study was to investigate long-term functional outcomes of the harvesting site. PATIENTS AND METHODS: About 19 patients (10 male, 9 female, mean age 58.1 years) were available for the long-term analysis 13-51 months after surgery. Jumping mechanography and balance testing on a ground force reaction plate (Leonardo Mechanograph GFRP) were performed before and surgery. The Esslinger Fitness Index (EFI, maximum peak power in W/kg normalized for age and gender) was considered as primary endpoint. Secondary outcomes were maximum force, range of motion in the ankle joint, sensory limitations, the American Orthopedic Foot and Ankle Society Score (AOFAS-Score), and subjective perceptions. RESULTS: We found no significant difference between pre- and postoperative EFI (70.4% versus 66.0%, P = 0.07) and body sway (1.72 cm2 versus 2.60 cm2 , P = 0.093). The AOFAS-Score was reduced by 8.8 points (99.1 points versus 90.3 points, P < 0.001). Dorsal extenstion (31.6° versus 24.1°, P < 0.001) and flexion (32.3 versus 25.6° flexion, P = 0.011) were significantly reduced and 6 patients had chronic pain. CONCLUSIONS: Reduced peak power and balance ability seem to be reversible short-term effects after fibula harvesting. We recommend preoperative patient education and standardized protocols for physiotherapy.

A biomechanical, micro-computertomographic and histological analysis of the influence of diclofenac and prednisolone on fracture healing in vivo.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) have long been suspected of negatively affecting fracture healing, although numerous disputes still exist and little data are available regarding diclofenac. Glucocorticoids interfere in this process over a similar and even broader mechanism of action. As many previously conducted studies evaluated either morphological changes or biomechanical properties of treated bones, the conjunction of both structural measures is completely missing. Therefore, it was our aim to evaluate the effects of diclofenac and prednisolone on the fracture callus biomechanically, morphologically and by 3-dimensional (3D) microstructural analysis. METHODS: Femura of diclofenac-, prednisolone- or placebo-treated rats were pinned and a closed transverse fracture was generated. After 21 days, biomechanics, micro-CT (µCT) and histology were examined. RESULTS: The diclofenac group showed significantly impaired fracture healing compared with the control group by biomechanics and µCT (e.g. stiffness: 57.31 ± 31.11 N/mm vs. 122.44 ± 81.16 N/mm, p = 0.030; callus volume: 47.05 ± 15.67 mm3 vs. 67.19 ± 14.90 mm3, p = 0.037, trabecular thickness: 0.0937 mm ± 0.003 vs. 0.0983 mm ± 0.003, p = 0.023), as confirmed by histology. Biomechanics of the prednisolone group showed obviously lower absolute values than the control group. These alterations were confirmed in conjunction with µCT and histology. CONCLUSIONS: The inhibiting effects of both substances were not only mediated by absolute parameters (e.g. breaking load, BV), but we have shown, for the first time, that additional changes occurred in the microstructural bony network. Especially in patients at risk for delayed bone healing (arteriosclerosis, diabetes mellitus, smoking), the administration of these drugs should be weighed carefully.

Biomechanical evaluation of CAD/CAM magnesium miniplates as a fixation strategy for the treatment of segmental mandibular reconstruction with a fibula free flap.

Titanium patient-specific (CAD/CAM) plates are frequently used in mandibular reconstruction. However, titanium is a very stiff, non-degradable material which also induces artifacts in the imaging. Although magnesium has been proposed as a potential material alternative, the biomechanical conditions in the reconstructed mandible under magnesium CAD/CAM plate fixation are unknown. This study aimed to evaluate the primary fixation stability and potential of magnesium CAD/CAM miniplates. The biomechanical environment in a one segmental mandibular reconstruction with fibula free flap induced by a combination of a short posterior titanium CAD/CAM reconstruction plate and two anterior CAD/CAM miniplates of titanium and/or magnesium was evaluated, using computer modeling approaches. Output parameters were the strains in the healing regions and the stresses in the plates. Mechanical strains increased locally under magnesium fixation. Two plate-protective constellations for magnesium plates were identified: (1) pairing one magnesium miniplate with a parallel titanium miniplate and (2) pairing anterior magnesium miniplates with a posterior titanium reconstruction plate. Due to their degradability and reduced stiffness in comparison to titanium, magnesium plates could be beneficial for bone healing. Magnesium miniplates can be paired with titanium plates to ensure a non-occurrence of plate failure.

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+.

Resection status and margin control in intraoperative frozen sectioning analysis of oral squamous cell carcinoma.

PURPOSE: Intraoperative frozen section analysis (IFSA) is a well-established procedure for determining the intraoperative soft tissue resection status in patients with oral squamous cell carcinoma (OSCC). Margin status is a major predictor of the patient´s outcome, histologically free margins of ≥ 5 mm are demanded. This study evaluates the accuracy of IFSA, the impact of margin status and the impact of intraoperative margin revision on disease-free survival (DFS) and overall survival (OS). METHODS: This retrospective study included 213 patients with OSCC. IFSA results were compared with definitive histopathological reports, Kaplan-Meier analysis was performed. Cut-off values were calculated for resection margins considering known risk factors. RESULTS: IFSA showed positive margins in 8 cases (3.8%). Kaplan-Meier analysis revealed no significant differences for OS or DFS if R0-status was achieved by initial resection or immediate re-resection. Final histopathological evaluation revealed false-positive IFSA in 3/8 cases (37.5%) and false-negative IFSA in 1/205 cases (0.5%). Sensitivity was 83.3% and specificity was 98.6%. Analysis of optimal cut-off values showed no general need for larger resection margins in patients with risk factors. Cut-off values were slightly higher for patients with the risk factor alcohol consumption (7 mm for OS and DFS) or pN + ECS- disease (7 mm for DFS). Optimal cut-off values for tumour-margin-distance were around 6 mm. CONCLUSION: IFSA provides a valuable assessment method for intraoperative soft tissue resection margins. Risk factors seemingly do not significantly influence the extent of tumour resection.

The impact of time between surgery and adjuvant chemoradiotherapy in advanced oral cavity squamous cell carcinoma.

Objective: In advanced oral squamous cell carcinoma (OSCC), adjuvant therapy (AT) is an important part of the treatment to ensure extended locoregional control after primary surgical resection. The impact of the time interval between surgery and AT on the oncological prognosis remains unclear, particularly in high-risk constellations. The aim of this study is to categorize treatment delays and to determine their impact on the oncological prognosis within the context of the histopathological risk parameters of patients with advanced OSCC. Methods: In this single-institutional retrospective cohort study, all patients treated for OSCC between 2016 and 2021 and who received postoperative chemoradiation (POCRT) were included. Patients were divided into two groups: Group I: ≤ 6 weeks between surgery and POCRT; and Group II: > 6 weeks between surgery and POCRT. Results: Overall, 202 patients were included (Group I: 156 (77.2%) vs. Group II: 46 (22.8%)). There were no statistically significant differences in epidemiological aspects and histopathological risk factors between the two groups. The maximum time to initiation of POCRT was 11 weeks. Delayed POCRT initiation had no statistically significant influence on the 5-year OS (61.6% vs. 57.3%, p = 0.89), locoregional control rate (38.6% vs. 43.3%, p = 0.57), and RFS (32.3% vs. 30.4%, p = 0.21). On multivariate analysis, extracapsular spread (HR: 2.21, 95% CI: 1.21 - 4.04, p = 0.01) and incomplete surgical resection (HR: 2.01, 95% CI: 1.10 - 3.69, p = 0.02) were significantly correlated with OS. For RFS, ECS (HR: 1.82, 95% CI: 1.15 - 2.86, p = 0.01), incomplete resection (HR: 1.67, 95% CI: 1.04 - 2.71, p = 0.04), and vascular infiltration of the tumor (V-stage; HR: 2.15, 95% CI: 1.08 - 4.27, p = 0.03) were significant risk predictors. Conclusion: Delays in POCRT initiation up to 11 weeks after surgical resection for advanced OSCC were not statistically significantly associated with impaired survival. In cases of prolonged surgical treatment due to management of complications, a small delay in AT beyond the recommended time limit may be justified and AT should still be pursued.

Oncologic Outcome in Advanced Oral Squamous Cell Carcinoma After Refusal of Recommended Adjuvant Therapy.

Importance: Clinicians may be confronted with patients refusing recommended adjuvant therapy (AT) after the primary resection of an advanced oral squamous cell carcinoma (OSCC). However, for this tumor entity, data are lacking regarding the oncological outcomes and associated factors after refusal of AT. Objective: To evaluate the difference in survival and disease recurrence for patients with and without recommended AT after resection of advanced OSCC. Design, Setting, and Participants: In this single-center retrospective matched cohort study, patients with advanced OSCC who refused recommended AT between January 2010 and December 2021 were matched 1:1 according to Union for International Cancer Control tumor staging with patients who completed AT. Exposures: Patients with advanced OSCC who refused or completed recommended AT between 2010 and 2021. Main Outcomes and Measures: The primary outcome of this study was the comparison of overall survival (OS) and recurrence-free survival (RFS) between the 2 study groups. Results: A total of 82 patients (mean [SD] age at time of surgery, 68.0 [11.3] years; 38 [46.3%] female, 44 [53.7%] male) with and without AT (41 per study group) were included in the analysis. Patients refusing AT developed more frequent disease recurrence than patients who completed AT (61.0% vs 26.8%; difference, 34.2%; odds ratio, 4.26; 95% CI, 1.68-10.84). In addition, patients who refused AT presented with lower 2-year OS (72.7% vs 88.6%; difference, 15.9%; 95% CI, 8.6%-40.6%) and much lower 2-year RFS (39.1% vs 74.2%; difference, 35.1%; 95% CI, 0.2%-70.5%). In the patient cohort who rejected AT, a worse OS was associated with female sex (48.6% vs 90.5%; difference, 41.9%; 95% CI, 0.6%-84.4%), pT1-2 category (57.1% vs 92.3%; difference, 35.2%; 95% CI, 3.3%-73.6%), and pN1 or higher category (61.2% vs 82.6%; difference, 21.4%; 95% CI, 14.1%-56.8%). Lower RFS was associated with female sex (37.9% vs 90.9%; difference, 53.0%; 95% CI, 8.0%-97.9%), advanced T category (pT3-4, 35.3% vs 80.0%; difference, 44.7%; 95% CI, 6.4%-95.3%), lymph node yield of 20 or greater (31.4% vs 80.6%; difference, 49.2%; 95% CI, 4.9%-93.4%), and lymph node ratio of less than 4.6% (36.6% vs 84.4%; difference, 47.8%; 95% CI, 1.8%-93.1%). Conclusions and Relevance: In this cohort study of patients with advanced OSCC, refusal of AT was associated with worse oncological outcomes. The prevalence of disease recurrence during follow-up was 34% higher in patients who refused AT than in patients who completed AT. The results from this study may assist clinicians in guiding patients who are considering refusal of or withdrawal from AT.

Patient-specific 3D-printed mini-versus reconstruction plates for free flap fixation at the mandible: Retrospective study of clinical outcomes and complication rates.

This study aimed to compare the clinical outcomes and complication rates of patient-specific 3D-printed mini- and reconstruction plates for free flap fixation in mandibular reconstruction. A retrospective monocentric study was carried out between April 2017 and December 2021 to analyze patients undergoing immediate mandibular reconstruction using fibula free flaps and osteosynthesis using patient-specific 3D-printed implants. Eighty-three patients with a mean age of 63.6 years were included. The mean follow-up period was 18.5 months. Patient-specific 3D-printed plates were designed as reconstruction plates (38 patients), miniplates (21 patients) or a combination of reconstruction- and miniplates (24 patients). With miniplates, plate removal was performed significantly more often via an intraoral approach (p < 0.001) and in an outpatient setting (p = 0.002). Univariate analysis showed a higher fistula rate with reconstruction plates (p = 0.037). Multivariate analysis showed no significant differences in complications. Case-control matching demonstrated significantly lower rates of fistula (p = 0.017) and non-union (p = 0.029) in the combined group. This retrospective study shows a tendency towards reduced complication rates with patient-specific 3D-printed miniplates in comparison to patient-specific 3D-printed reconstruction plates for immediate mandibular reconstruction with fibula free flaps.

Patient-specific miniplates versus patient-specific reconstruction plate: A biomechanical comparison with 3D-printed plates in mandibular reconstruction.

BACKGROUND: Patient-specific 3D-printed miniplates for free flap fixation in mandibular reconstruction were recently associated with enhanced osseous union. Higher mechanical strains resulting from these plates are discussed as reasons, but biomechanical studies are missing. This study aims to examine, whether patient-specific 3D-printed miniplates provide an increased interosteotomy movement (IOM) and lower stiffness compared with reconstruction plates. METHODS: Polyurethane (PU) mandible and fibula models (Synbone AG, Malans, Schweiz) were used to simulate mandibular reconstruction with a one segment fibula flap equivalent. Osteosynthesis was performed using either four patient-specific 3D-printed miniplates (3D-Mini) or one patient-specific 3D-printed reconstruction plate (3D-Recon). Mastication was simulated using cyclic dynamic loading with increasing loads until material failure or a maximum load of 1000 N. Continuous IOM recording was carried out using a 3D optical tracking system (ARAMIS, Carl Zeiss GOM Metrology, Braunschweig, Germany). FINDINGS: The averaged stiffness at a load of 100-300 N load did not differ between the groups (p = 0.296). There was a faster 1.0 mm vertical displacement in the 3D-Mini group (26 376 ± 14 190 cycles versus 44 817 ± 30 430 cycles, p = 0.018). The IOM were higher with miniplate fixation in the distal gap (p = 0.040). In the mesial gap, there was no significant difference between the groups (p = 0.160). INTERPRETATION: Fixation with patient-specific 3D-printed miniplates results in higher mechanical strains. Lower rates of pseudarthrosis, as seen in clinical studies, might be caused by this phenomenon. Surgeons should evaluate the primary use of 3D-printed miniplates in mandibular reconstruction due to advantages of intraoral plate removal alongside safe osteosynthesis.

Sentinel lymph node biopsy in recurrent or secondary oral squamous cell carcinoma after previous neck dissection.

OBJECTIVES: The aim of this retrospective study was to evaluate the potential of sentinel lymph node biopsy (SLNB) in patients with recurrent or a secondary oral squamous cell carcinoma (OSCC) without clinical signs of lymph node metastases (cN0), who were previously treated with a surgical approach. PATIENTS AND METHODS: Retrospective analysis of all patients with cN0 recurrent or secondary OSCC, who were treated using SLNB after previous neck dissection. Endpoints were sentinel lymph node (SLN) detection rate, negative predictive value (NPV) and sensitivity. RESULTS: A total of 17 patients with a mean age of 68.6 years were included. SLN were detected in 15 of 17 cases (detection rate: 88.2%). In seven patients (41.2%), a bilateral or contralateral lymph drainage of a unilateral carcinoma was found. Two patients (11.8%) demonstrated a positive SLN upon pathohistological analysis, which led to an upstaging. In one case, a non-SLN was positive, which is considered a false-negative result. The mean follow-up for all patients with histologically negative SLN including the patients without a detected SLN was 11.8 months (range: 0-31 months). Of these, one patient developed (isolated) neck recurrence after 12 months resulting in an overall NPV of 86.7% and a sensitivity of 50.0% for the SLNB as a neck staging procedure. CONCLUSION: SLNB can improve the staging of patients with recurrent or secondary OSCC, who present with a history of a previous neck dissection. Further studies are required to demonstrate the oncological benefit of SLNB in this patient cohort.

Management of the Contralateral Neck in Unilateral Node-Positive Oral Squamous Cell Carcinoma.

INTRODUCTION: In lateralized oral squamous cell carcinoma (OSCC) with ipsilateral cervical lymph node metastasis (CLNM), the surgical management of the unsuspicious contralateral neck remains a matter of debate. The aim of this study was to analyze this cohort and to compare the outcomes of patients with and without contralateral elective neck dissection (END). MATERIAL AND METHODS: A retrospective analysis of patients with lateralized OSCC, ipsilateral CLNM (pN+) and contralateral cN0-stage was performed. Patients were divided into two groups according to the surgical management of the contralateral neck: I: END; and II: no END performed. Adjuvant radiotherapy was applied bilaterally in both groups according to individual risk. RESULTS: A total of 65 patients (group I: 16 (24.6%); group II: 49 (75.4%)) with a median follow-up of 28 months were included. Initially, there was no case of contralateral CLNM after surgery. During follow-up, 6 (9.2%) patients presented with recurrent CLNM. In 5 of these cases (7.7%), the contralateral neck (group I: 3/16 (18.8%); group II: 2/49 (4.1%)) was affected. Increased ipsilateral lymph node ratio was associated with contralateral CLNM (p = 0.07). END of the contralateral side showed no significant benefit regarding OS (p = 0.59) and RFS (p = 0.19). CONCLUSIONS: Overall, the risk for occult contralateral CLNM in patients with lateralized OSCC ipsilateral CLNM is low. Our data suggest that END should not be performed routinely in this cohort. Risk-adapted radiotherapy of the contralateral neck alone seems to be sufficient from the oncological point of view.