Lesions of the lateral pterygoid muscle-an overestimated reason for temporomandibular dysfunction: a 3T magnetic resonance imaging study.

The aim of this study was to examine the lateral pterygoid muscle (LPM) parenchyma, myotendinous junction, and tendon in temporomandibular disorder (TMD) patients using 3T magnetic resonance imaging (MRI). Results were compared with findings reported in the literature, in which the LPM has been attributed a major role in triggering TMD. 3T MRI was used for temporomandibular joint (TMJ) imaging. The MRI images of 63 patients were analysed for muscle contracture and atrophy, tendon rupture, signal alterations of the tendon, tendon contrast enhancement, and peritendinous fluid collection. Descriptive statistics and the coefficient estimate method were used for statistical analysis. Focus was placed on the association between LPM tendon pathology and TMJ lesions like osteoarthritis and disc displacement. Severe lesions of the LPM tendon and muscle parenchyma, like rupture or fibrosis, were detected in very few cases. Only moderate signs of tendinosis were found in TMD patients. In contrast, there was a clear correlation between tendon lesions and osteoarthritis or anterior disc displacement. These results indicate the need to discuss and question the role of the LPM and its tendon in TMD. Data suggest that LPM and tendon lesions are part of complex degenerative changes of the TMJ, and it seems less likely that a LPM disorder is causative in TMD.

Fluorescence imaging of invasive head and neck carcinoma cells with integrin αvß6-targeting RGD-peptides: an approach to a fluorescence-assisted intraoperative cytological assessment of bony resection margins.

We assessed the use of peptides containing arginylglycylaspartic acid (RGD) that target integrin αvß6 as a potential approach for a fluorescence-assisted intraoperative cytological assessment of bony resection margins (F-AICAB) in patients who had bone-infiltrating squamous cell carcinoma (SCC) of the head and neck. This was assessed to demarcate invasive carcinoma cells that stained for αvß6. Specimens from bony resection margins (n=362) were defined as either malignant or benign according to the results of cytological and histological examinations. Integrin αvß6-targeting fluorescence-labelled RGD peptides were added to the cytological samples and the accuracy of the resulting signal assessed by comparing it with the cytological findings. The value of F-AICAB was evaluated to find out if it could help to improve future diagnoses, tests, and treatments. Integrin αvß6 was strongly expressed in invasive SCC cells and qualified as a marker for bone-infiltrating carcinoma cells. It showed a high affinity to bind to invasive SCC cells and enabled swift and specific demarcation of αvß6-stained carcinoma cells. It was also diagnostic, with a sensitivity of 100% (95% CI 81.3% to 99.3%), specificity of 98.3% (95% CI 94.4% to 99.0%), positive predictive value of 92% (95% CI 70.2% to 94.3%), and negative predictive value of 100% (95% CI 96.9% to 99.9%), compared with the cytological findings. The targeting of specific integrin subtypes with selective, synthetic ligands, adapted for multimodal imaging, is a promising new approach to diagnosis. Further studies are necessary to provide more evidence for successful clinical translation and to establish the impact on clinical procedures.

Influence of venous stasis on survival of epigastric flaps in rats.

Venous congestion results in tissue damage and remains the most common reason for failure of transfer of microvascular free flaps if it is not recognised early. The purpose of this study was to measure the critical duration of venous congestion and the resultant survival of flaps according to the duration of venous stasis. A standard epigastric flap was raised and repositioned in 35 rats, seven of which acted as controls. The superficial inferior epigastric vein was fully occluded for four, five, six, or seven hours in the rest (n=7 each group). Subsequently, the rats were monitored for one week, and the resultant necrotic areas were photographed. After five, six, and seven hours of venous stasis, the incidence and area of necrosis were significantly increased (p=0.04 in each) above that of the control. The degree of necrosis after seven hours of venous stasis was significantly greater than that after four or five hours (p=0.01 and 0.02, respectively). The duration of venous congestion is therefore a potential risk for the survival of free flaps, as it results in operative complications and may jeopardise the whole procedure. After a critical period of venous stasis we reach a point of no return, and any attempt to salvage the compromised flap will be in vain. Based on these results, we think that monitoring by an experienced surgeon at intervals of no longer than three hours is essential for the successful salvage of venous congestion in microvascular free flaps.

New aspects in free flap surgery: Mini-perforator flaps and extracorporeal flap perfusion.

BACKGROUND: The scope of microvascular tissue transfer in the Head and Neck reaches from coverage of simple soft tissue defects to complex 3-D reconstructions using multiple or chimeric flaps. This paper summarises the presentation given at the Congress of the French Society of Oral and Maxillofacial Surgery in Marseille 2017. It was the aim of our work to add further elements to this wide spectrum of reconstructive possibilities. METHODS: For patients with small intraoral soft tissue defects in whom the use of a radial forearm flap would not be justified because of its donor site morbidity, but who nevertheless would take a benefit from a small free flap, we used mini-perforator flaps from the lower leg. These flaps were raised with negligible morbidity. Moreover, for patients necessarily needing a free flap, but having vessel depleted, irradiated necks, we have developed a first idea of extracorporeal flap perfusion to make microvascular anastomoses unnecessary. RESULTS: Using donor sites from the lower leg, mini-soleus and medial sural perforator flaps were raised to cover defects of 2×3 to 2×4cm at the anterior floor of the mouth or lateral tongue. The success rate was 91%, and despite their small size, the flaps helped to maintain the mobility of the tongue. The donor site morbidity was minimal. After extensive experimental work on small animals and human tissue, four flaps could successfully be transferred so far by means of extracorporeal perfusion. In these patients, autonomisation took place between 5 and 12 days. CONCLUSIONS: Although microvascular tissue transfer already allows for reconstruction in almost any possible defect constellation, mini-perforator flaps and machine-perfused transplants seem to represent new aspects of free flap surgery, being useful extensions of the reconstructive surgeon's armament.

Perioperative serum levels of procalcitonin, C-reactive protein, and leukocytes in head and neck free flaps.

Microvascular free flaps are considered to be the gold standard in reconstructive head and neck surgery. However, reduced postoperative transplant perfusion is one of the serious postoperative complications and calls for close and reliable monitoring. Procalcitonin, C-reactive protein, and leukocytes are closely associated with local and systemic inflammatory reactions and might have prognostic capacity concerning tissue necrosis. This study aimed to evaluate perioperative serum levels of these three biomarkers to assess their potential in postoperative flap monitoring. A total of 100 patients with microvascular head and neck reconstructions were included in the study. Perioperative serum levels of parameters were measured and the clinical data were analyzed and correlated. A total of 13% of all flaps developed reduced postoperative perfusion. Analysis of the parameters revealed statistically significant differences in the overall patient collective over time, irrespective of clinically reduced flap perfusion. Co-factors such as sex and history of tobacco and alcohol abuse showed significant differences. The efficacy of the parameters in free flap monitoring has not been verified, although the role of procalcitonin in postoperative monitoring, with special regard to the early detection of infections, is underlined by the present study results.

Intraoperative cell isolation for a cytological assessment of bone resection margins in patients with head and neck cancer.

The intraoperative cytological assessment of bony resection margins (ICAB) is a feasible diagnostic approach to support frozen section for assessment of invasion of margins of soft and hard tissue. However, complex resection margins could challenge both diagnostic approaches. Our objective here was to identify the limitations of intraoperative diagnostic methods for assessing margins. We present an advanced cytological approach to assess complex margins that may solve the problem. Data from 119 patients in whom frozen section was supported by ICAB, were reviewed and the reasons for false results analysed. In 35 patients with squamous cell carcinoma infiltrating bone, specimens (n=100) from the resection margin went through an intraoperative cell isolation process for the cytological assessment of bony margins (ICAB). The results were compared with the histological results of the corresponding margins of bone as a reference. Limitations to the assessment of operative bony margins intraoperatively included an infiltrative histological pattern of growth of the carcinoma, with carcinoma cells disseminated within the cancellous bone, complex and uneven resection margins with soft and bony tissue, inflammation, and signs of previous radiotherapy. Intraoperative cell isolation plus (ICICAB) allowed the microscopic assessment of up to 1cm3 of bony tissue to detect disseminated carcinoma cells within the cancellous bone with a sensitivity of 92.3% (95% CI 74.9% to 99.1%), and a specificity of 100% (95% CI 95.1% to 100%), and positive and negative predictive values of 100% (95% CI 85.8% to 100%) and 97.4% (95%CI 90.8% to 99.7%), respectively. Intraoperative cell isolation is a feasible new technique to support ICAB and frozen section in the assessment of bony and soft tissue margins.

Influence of possible predictor variables on the outcome of primary oral squamous cell carcinoma: a retrospective study of 392 consecutive cases at a single centre.

The successful treatment of oral squamous cell carcinoma (OSCC) depends on the treatment strategy. The prognosis is most often linked to the stage at initial presentation, but the effect of patient-related parameters on overall survival remains uncertain. In this study, 392 consecutive cases of OSCC seen between 2007 and 2013 at a single centre were analyzed retrospectively. Overall survival was assessed and univariate and multivariate Cox proportional hazards regression was used to identify associations between possible tumour-specific and patient-related variables and survival. The 5-year overall survival rate of the 392 patients (T stage 1-4) was 62.5%. Univariate analysis showed that sex, age, T stage, N stage, Union for International Cancer Control (UICC) stage, American Society of Anesthesiologists (ASA) status, operating time >400min, and length of in-patient stay >15 days were significantly associated with overall survival (all P<0.05). Tumour location, alcohol abuse, and smoking were found not to have a significant influence (all P>0.05). Age, T, N, and M stages, UICC stage, residual tumour status, recurrence, ASA status, and operating time >400min were found to have a significant influence on overall survival in the multivariate analysis (each P<0.05). These findings confirm that postoperative survival does not depend only on tumour-related characteristics. ASA status needs to be considered in treatment planning, as it significantly predicts patient survival.

Can the inferior alveolar nerve be used as a marker in frozen section for free margin control after segmental mandibulectomy in tumour ablation?

This study critically assessed the possibility of tumour spread along the inferior alveolar nerve (IAN) and its sensitivity as an intraoperative marker for clear bony margin control in frozen section during segmental mandibulectomy. Fifteen patients with oral squamous cell carcinoma (OSCC) involving the mandible and requiring a segmental mandibulectomy were included in this prospective trial. The ends of the IAN were analyzed using quick section analysis and the results compared with those of the definite pathological report. Nerve tissue could be identified in 25 of the 27 specimens collected. No specimen revealed tumour invasion. All histological diagnoses were finally confirmed. Three positive bony margins with microscopic carcinoma infiltrates were found, whereas corresponding nerve tissue did not confirm tumour invasion. This study supports the assumption that the pattern of tumour invasion is rarely primarily along the IAN in OSCC involving the mandible. Quick section analysis of the nerve tissue alone is therefore not a valid marker for intraoperative bony margin control. However, it can be used as an additional intraoperative diagnostic tool combined with other methods in rare cases of primary tumour spread along the IAN. A review of current knowledge regarding bony margin control published in the literature is provided.

Radiotherapy for oral cancer decreases the cutaneous expression of host defence peptides.

INTRODUCTION: Bacterial resistance against antibiotics has become an increasing challenge in the treatment of cutaneous infections. Consequences can be severe, especially in infected wounds following previous local radiotherapy. Certain endogenous peptide antibiotics, the host defence peptides (HDPs), exhibit broad-spectrum antimicrobial activity and promote wound healing. Their use as supplements to conventional antibiotics is a current topic of discussion; however, knowledge of their quantities in healthy and compromised tissue is a prerequisite for such discussion. To date, no data concerning HDP quantities in irradiated skin are available. METHODS: Expression profiles of the genes encoding HDPs, namely human beta-defensin-1 (DEFB1, hBD-1), beta-defensin-2 (DEFB4A, hBD-2), beta-defensin-3 (DEFB103, hBD-3) and S100A7, were assessed in samples of non-irradiated and irradiated neck. RESULTS: A reduction in the expression of all of the examined genes was observed in irradiated skin when compared with non-irradiated skin (statistically significant in the case of S100A7, P = 0.013). Immunohistochemistry revealed differences in HDP distribution with respect to the epithelial layers. CONCLUSION: The study demonstrates a significant reduction in HDP gene expression in neck skin as a result of radiotherapy. These findings might represent a starting point for novel treatments of cutaneous infections in irradiated patients, such as topical supplementation of synthetic HDP.

Accuracy of mandibular reconstruction by three-dimensional guided vascularised fibular free flap after segmental mandibulectomy.

Mandibular reconstruction with a fibular free flap has become standard in specialised centres for head and neck reconstruction, particularly for defects with more than one osteotomy that are challenging even for experienced surgeons. Virtual surgical planning is a potential tool to facilitate harvesting of the fibula and the osteostomy. The purpose of this study was to compare the two methods of mandibular reconstruction - conventionally planned (conventional group) and "virtually" planned (virtual group) - with regard to accuracy, bony consolidation, complications, and operating time. Fifty patients who required mandibular reconstruction after segmental mandibulectomy were evaluated retrospectively, 24 virtually planned and 26 conventionally planned. The overall survival of flaps was 92% (46/50). The bony consolidation rate in the virtual group was significantly better than that in the conventional group (p=0.002). The difference between the angle of the mandible before and after was highly significant with a median of 11.5° (range 2°-75°) in the conventional group and 4.5° (range 0-18°) in the virtual group (p=0.0001). Operations were mean (SD) of 34 (21.2) minutes shorter in virtually-planned cases (p=0.12). The overall morbidity did not differ significantly between the groups. The use of virtual surgical planning in mandibular reconstruction by fibular free flap is beneficial for optimising accuracy, consolidation of bony segments, and operating time, while increasing the predictability of results for the surgeon. However, additional costs have to be carefully weighed against the benefits.

Sandwich flaps as a feasible solution for the management of huge mandibular composite tissue defects.

In the current therapy of head and neck defects, surgical reconstruction with the aid of pedicle or free flaps is common practice. Suitable single flaps are available to solve most reconstructive challenges. However, reconstruction can become a problem in extensive mandibular defects, as they are often caused by large primary tumors or osteoradionecrosis. These composite defects often lead to large intraoral or extraoral fistulas due to the involvement of mucosa, skin, mandible and soft tissue. These issues call for a double flap approach in order to achieve adequate reconstruction. Therefore, we developed a surgical sandwich technique as presented in this study. The procedure features the acquisition and use of two vascular flaps which can be freely combined according to their desired features (for example being of high tissue volume or osteomyocutaneous). In our study we included 11 patients (ten male, one female) with a mean age of 57 years. Seven of the patients had defects due to osteoradionecrosis and four due to tumor resection. A sandwich technique was performed in a single operation in eight patients, whereas for three patients several operations were necessary. The flaps used included: fibula free flap (FFF); anterolateral thigh (ALT); radial forearm flap (RFF); deltopectoral flap (DPF) and tensor fascia lata (TFL). The following combinations were used: FFF and ALT (three cases), FFF and RFF (two), FFF and DPF (three), ALT and TFL (two), and two ALT flaps (one). The sandwich technique proved suitable for complex reconstructions and led to desirable esthetic and functional results. The flexibility in combining different free or pedicle flaps made it possible to address various defect situations and consequently offer satisfactory surgical reconstruction for complex cases.

Perforator flaps: the next step in the reconstructive ladder?

Perforator flaps are claimed to be a sign of major progress in head and neck reconstruction, but are they a further step up the reconstructive ladder? In this paper I provide a short summary of the development and current clinical use of perforator flaps in the head and neck, which is based on a presentation to the annual meeting of the British Association of Oral and Maxillofacial Surgeons in 2014. I will describe 4 flaps from the lower leg, which are useful specifically for covering intraoral defects, as examples. When we consider the spectrum of new donor sites, and the precision of flap design that is offered by perforator flaps, it becomes evident that the potential of this new technique has not yet been reached.

Loco-regional recurrence after surgical treatment of oral squamous cell carcinoma: Proposals for follow-up imaging based on literature, national guidelines and institutional experience.

The recurrence rate following the treatment of oral squamous cell carcinoma (OSCC) by primary surgery is about 10%-26%. The earliest possible diagnosis of residual tumour, recurrence of local tumour disease, and subsequent metastasis is essential for an improvement of the overall survival and of the survival period for affected patients. No international consensus exists for a post-therapeutic surveillance schedule for OSCCs. Based on a review of the literature, existing guidelines, and our institutional experience, we have established an algorithm for the follow-up of these patients regarding the timing and techniques of postoperative imaging. We recommend a follow-up interval of 6 weeks during the first half-year after discharge from hospital by single clinical and alternating clinical check-ups combined with computed tomography (CT) or magnetic resonance imaging (MRI), followed by an interval of 3 months in the second half-year, with clinical and radiological check-ups. In year 2, we recommend a follow-up interval of 3 months with single clinical and alternating clinical check-ups combined with CT or MRI. In year 3, we recommend screening every 6 months, both clinically and via imaging, because of the decreased risk of recurrence. From year 5 onwards, our recommendation is a clinical and imaging-based examination every 6-12 months, depending on patient risk factors and disease progression. Four standard imaging techniques, namely positron emission tomography (PET), CT, MRI, and ultrasound (US), are discussed concerning their range of application, sensitivity, and specificity. Furthermore, the technical aspects of our institutional protocols are described in detail. In highly frequented head and neck cancer centres, PET and US are of secondary importance, since CT and MRI are nowadays highly efficient tools in primary diagnostic and post-therapeutic surveillance.

Analysis of computer-aided techniques for virtual planning in nasoalveolar moulding.

We compared two methods of planning virtual alveolar moulding as the first step in nasoalveolar moulding to provide the basis for an automated process to fabricate nasoalveolar moulding appliances by using computer-assisted design and computer-aided manufacturing (CAD/CAM). First, the initial intraoral casts taken from seven newborn babies with complete unilateral cleft lip and palate were digitised. This was repeated for the target models after conventional nasoalveolar moulding had been completed. The initial digital model for each patient was then virtually modified by two different modelling techniques to achieve the corresponding target model: parametric and freeform modelling with the software Geomagic(®). The digitally-remodelled casts were quantitatively compared with the actual target model for each patient, and the comparison between the two modified models and the target model showed that freeform modelling of the initial cast was successful (mean (SD) deviation n=7, +0.723 (0.148) to -0.694 (0.157)mm) but needed continuous orientation and was difficult to automate. The results from the parametric modelling (mean (SD) deviation, n=7, +1.168 (0.185) to -1.067 (0.221)mm) were not as good as those from freeform modelling. During parametric modelling, we found some irregularities on the surface, and transverse growth of the maxilla was not accounted for. However, this method seems to be the right one as far as automation is concerned. In addition, an external algorithm must be implemented because the function of the commercial software is limited.

The functional and aesthetic reconstruction of midfacial and orbital defects by combining free flap transfer and craniofacial prosthesis.

OBJECTIVES: The reconstruction of complex facial defects should satisfy both aesthetic and functional requirements. In the midfacial area, the nasal passage should be sufficiently separated from the orbit and the oral cavity to avoid both dysphagia and articulation disorders and to allow unimpaired nasal breathing. In the case of large defects, the use of craniofacial prostheses alone is ineffective in the restoration of functional units in the majority of patients. Therefore, we evaluated the combination of microvascular tissue transfer and episthetic constructions in a series of patients. MATERIAL AND METHODS: Our case series included ten patients requiring one or more free flaps in combination with extraoral implants and episthetic work. RESULTS: Four women and six men with a mean age of 68 years were included. All patients were treated because of tumours in the midface area. Eight patients were free of recurrence, one patient died during the follow-up. For the reconstructions, we used anterolateral thigh flaps, radial forearm flaps, fibular flaps and iliac crest bone flaps. On average, we inserted four extraoral implants in the periorbital region. Seven implants of four patients did not osseointegrate and had to be removed. CONCLUSIONS: For complex reconstructions of extensive defects in the midfacial area, microvascular free tissue transfer in combination with extraoral implants and craniofacial prosthetic work yields reasonable functional and aesthetic outcomes and noticeably improves the quality of life. CLINICAL RELEVANCE: This work investigates patient cases with extensive defects in which free flap or episthetic work alone proved ineffective for reconstruction.

Which kind of frontal mandibulotomy is the smartest? A biomechanical study.

PURPOSE: Retrospective clinical evaluation and biomechanical tests were performed to compare the primary stability and the rate of pseudarthrosis formation after irradiation for two types of mandibular split osteotomies: the stairstep osteotomy (SSO) and the straight-line osteotomy (SLO). METHODS: The postoperative occurrence of pseudarthrosis was retrospectively analysed in 46 non-consecutive clinical cases of SSO and SLO between 2003 and 2013. Biomechanical tests were performed on 12 standardised synthetic mandibles (Synbone) to compare the SSO and SLO approaches. Two 2.0 mm monocortical miniplates (Medartis) were used for osteosynthesis. The artificial mandible specimens were loaded to 300 N on the Mandibulator test bench while interfragmentary motion was measured using the PONTOS optical measurement device. RESULTS: The retrospective clinical analysis showed a rate of pseudarthrosis of 19% in the SLO group versus only 5% in the SSO group (p = 0.17). In the biomechanical investigation, the average interfragmentary movement was 14.3 ± 7.70 for the SLO group and 4.57 ± 2.33 for the SSO group under a maximum load of 300 N, resulting in a statistically significant difference between the two approaches (p = 0.014). CONCLUSION: To minimise the rate of postoperative pseudarthrosis formation, SSO is superior to SLO for mandibular split procedures, because SSO provides greater resistance to vertical loads and allows less interfragmentary movement. LEVEL OF EVIDENCE: 2C (Outcomes research).

[Certification of head and neck tumor centers by the German Cancer Society : an overview]. / Zertifizierung von Kopf-Hals-Tumor-Zentren durch die Deutsche Krebsgesellschaft : Ein Überblick.

The German Cancer Society has certified centers of oncological care since 2003. This is realized by clearly specified criteria that are implemented in the centers' clinical practice and thus enable holistic care of oncology patients. The most important instrument here is the interdisciplinary and multiprofessional teamwork of all relevant disciplines. This transsectoral cooperation leads to continuous cooperation between out- and inpatient partners and contributes significantly to the high-quality care of oncology patients in all stages of disease. Validation of the fulfillment and implementation of the required criteria proceeds in the form of audits, the feedback from which enables the centers to continually improve their quality of care. The integration of these sustainable approaches into clinical practice not only increases patient satisfaction, but also improves the motivation of the center staff.

Flow analyses of microvascular bifurcation using laser Doppler anemometry.

INTRODUCTION: Vascular surgery affects, among other factors, vessel geometry and might result in significant flow changes. For this reason a basic understanding of flow behavior at bifurcations plays an important role for microsurgeons. The aim of the present work was to establish an experimental model that enables rheological analyses of microvascular techniques. METHODS: Laser Doppler anemometer (LDA) measurements in a total of four cross-sections of a true-to-scale silicone model were performed. The model was installed in a circulatory experimental setup that simulates the physiologic human blood flow. The flow velocity data measured with the LDA system was processed and analyzed with an image-processing system. RESULTS: The flow curve at each cross-section was recorded for sevem cycles. A physiologic flow separation at bifurcational level was seen. Maximal and minimal horizontal velocities of all measurement points were between 0.32 and -0.15 m/s. No signs of turbulentlike flow were seen in the cross-sections distal to the bifurcation. A total, centrally located backflow in the diastolic phases in all four cross-sections was registered, resembling an oscillatorylike flow. CONCLUSIONS: The LDA analysis represents a valid experimental method for rheological evaluation of microvessels. Due to its unique high spatial and temporal resolution, it represents a worthwhile alternative to other flow investigations.

Evaluation of a new optical measuring system for experiments on fractured human mandibles: a biomechanical feasibility study in maxillofacial surgery.

OBJECTIVES: Biomechanical loading on human mandibles was performed and a new optical measurement device was introduced for the quantification of interfragmentary movement in fractured mandibles stabilized with different osteosynthesis systems. MATERIALS AND METHODS: Comparison tests were performed with monocortical non-locking double plates and bicortical single locking plate. For the experiments on a specialized test bench, 18 ex vivo fractured human cadaveric mandibles were tested. Interfragmentary motion was detected in all three spatial dimensions using the optical measurement device PONTOS®. The movement was investigated over increasing incisal force and one summarized parameter was investigated. RESULTS: For the maximal tested load of 300 N m, the resultant interfragmentary movements in the two investigated groups were 2.96 ± 1.85° for the fixation with two conventional miniplates (six hole, profile 1.0 mm) and 4.53 ± 2.49° for single bicortically fixed locking plates (four hole, profile 1.5 mm). For both plate systems, we used the 2.0 mm screw system. CONCLUSIONS: The test bench in combination with the new optical device PONTOS(®) can test the primary stability of osteosynthesis. We offer a solution to the problem of rate of twist of the mandible as well as typical rotational problem in recent measurements. Further, the method can be used for development of new osteosynthesis products. CLINICAL RELEVANCE: Pseudoarthrosis formation is a common problem based on unsatisfying fixation of the fracture gap. The here presented combination of mechanical tests and numerical simulations can provide support for an improved treatment of fractured mandibles.