Martin Lanzer

The 3dMD photogrammetric photo system in cranio-maxillofacial surgery: Validation of interexaminer variations and perceptions.

BACKGROUND Three-dimensional photography of the face is increasingly used to overcome the downsides of conventional photography or anthropometry regarding reliable evaluation. However, the precision of such a system has to be validated before it can be implemented for clinical use. MATERIAL AND METHODS Eight people were photographed with the 3dMDface system using lighting from sets of 2 × 4 compact fluorescent lights in a clinical photography room without natural light sources. Two different operators then individually, and without interaction, marked 27 different anatomical landmarks using the 3dMD Patient software. During this process, the operators were fully blinded against each other. The purpose of the study was to determine the repeatability and accuracy of the system when used by different operators and at different times. The 3D differentiation was analyzed using mixed ANOVA with person as the random factor, and operator, repetition, and landmark as the fixed factors. The ANOVA was followed by a Ryan-Einot-Gabriel-Welsch F post-hoc test for landmarks. RESULTS Statistical analysis grouped the landmarks into three subgroups: high precision, medium precision and low precision. CONCLUSIONS Virtual 3D models derived from the 3dMDface system not only provide a high level of technical precision but also of intra- and interobserver reliability regarding landmark identification. However, some of the classical landmarks are not reliable when it comes to virtual models; these are generally landmarks that examiners of real patients would tend to identify using palpation of underlying bony structures, such as the soft gonion.

Closed versus open treatment of mandibular condylar process fractures: A meta-analysis of retrospective and prospective studies

INTRODUCTION The treatment of fractures of the mandibular process remains controversial, although there is a trend towards open reduction and internal fixation. This study compared open and closed treatments and assessed the results with a meta-analysis. MATERIALS AND METHODS A literature search of PubMed found eight studies that met the search criteria and were included in the meta-analysis. RESULTS The studies increasingly suggest better results for open treatment, in terms of mouth opening, protrusion, laterotrusion, pain, and malocclusion. In the meta-analysis, the outcome was significantly better for laterotrusion and protrusion in patients treated by open reduction and internal fixation. CONCLUSION Due to the different study protocols and lack of information on classification, follow-up time, and inclusion criteria, comparison of the studies remains difficult and further prospective, randomized studies should examine these issues.

Preservation of ipsilateral submandibular gland is Ill advised in cancer of the floor of the mouth or tongue

Preservation of the submandibular gland (SMG) during a neck dissection is gaining popularity and is showing an increasing tendency. The potential benefit, if the SMG is preserved, can be manifold. The aim of this study was to assess the benefit of the preservation of the SMG and the associated risk of recurrent disease in patients with oropharyngeal or oral cavity squamous cell carcinoma.

Influence of histopathologic factors on pattern of metastasis in squamous cell carcinoma of the head and neck

Knowledge of histopathological factors, such as perineural invasion (PNI), extracapsular spread (ECS), angiolymphatic vessel invasion, and conglomerate lymph nodes, in patients with head and neck squamous cell carcinoma is important for appropriate treatment decisions. Given the availability of aggressive therapeutic options with known side effects and burdens for the patient, choosing the correct treatment option is vital.

Scapular Free Vascularised Bone Flaps for Mandibular Reconstruction: Are Dental Implants Possible?

ABSTRACT Objectives Free fibula flap remains the flap of choice for reconstruction of mandibular defects. If free fibula flap is not possible, the subscapular system of flaps is a valid option. In this study, we evaluated the possibility of dental implant placement in patients receiving a scapular free flap for oromandibular reconstruction. Material and Methods We retrospectively reviewed 10 patients undergoing mandible reconstruction with a subscapular system free-tissue (lateral border of the scapula) transfer at the University Hospital Zürich between January 1, 2010 and January 1, 2013. Bone density in cortical and cancellous bone was measured in Hounsfield units (HU). Changes of bone density, height and width were analysed using IBM SPSS Statistics 22. Comparisons of bone dimensions as well as bone density were performed using a chi-square test. Results Ten patients were included. Implantation was conducted in 50%. However, all patients could have received dental implants considering bone stock. Loss of bone height and width were significant (P < 0.001). There was a statistical significant increase in bone density in cortical (P < 0.001) and cancellous (P = 0.004) bone. Conclusions Dental implants are possible after scapular free flap reconstruction of oromandibular defects. Bone height and width were reduced, while bone density increased with time.

Decelerated vascularization in tissue-engineered constructs in association with diabetes mellitus in vivo

AIMS Rapid blood vessel ingrowth in transplanted tissue engineering constructs is the key factor for successful incorporation, but many potential patients who may use engineered tissues suffer from widespread diseases that limit the capacity of neovascularization (e.g. diabetes). Thus, in vivo vascularization analyses of tissue-engineered constructs in angiogenically affected organisms are required. METHODS We therefore investigated the in vivo incorporation of collagen-coated and cell-seeded poly-L-lactide-co-glycolide scaffolds in diabetic B6.BKS(D)-Lepr(db)/J mice using repetitive intravital fluorescence microscopy over a time period of two weeks. For this purpose, scaffolds were seeded with osteoblast-like or bone marrow mesenchymal stem cells and implanted into the dorsal skinfold chambers of diabetic and non-diabetic (C57BL/6) mice. RESULTS Apart from slightly increased inflammatory parameters, diabetic mice showed significantly reduced capillary densities compared with non-diabetic animals from day 6 onward. In line with previous studies, more densely meshed microvascular networks were demonstrated in cell-seeded than in collagen-coated scaffolds from day 6 onward within the single groups (diabetic and control). CONCLUSIONS A large number of patients who suffer from systemic diseases that affect angiogenesis would profit from tissue engineering. Therefore, the challenge for the clinical introduction of tissue-engineered constructs will be to overcome the decreased angiogenesis in diabetic organisms.

Demodicidosis: an uncommon erythema after cranio-maxillofacial surgery.

Demodex mites are commonly found in the healthy population, but the pathogenesis of demodicidosis has still not been clarified, though it is usually found in cases of immune deficiency. A 45-year-old man presented with an unusual outbreak of erythema and swelling 6 months after resection and chemoradiotherapy for a squamous cell carcinoma of the anterior floor of the mouth. The cheek was biopsied and histological examination showed demodicidosis. In cases of erythema with a normal blood cell count and no history of allergy, particularly in patients with reduced immunity, demodicidosis should be considered as a diagnosis and should be confirmed by examination of a biopsy specimen.

Total virtual workflow in CAD-CAM bony reconstruction with a single step free fibular graft and immediate dental implants

The Surgical reconstruction of defects of the face is challenging. Local and regional flaps have an important part to play, but large defects of bone and soft tissue are a greater problem. Microvascular tissue transfer has become the standard for such patients, and preoperative planning of bony reconstructions is now common. To use these preplanning tools best the implants should be placed in the prosthetically ideal place, and the bone positioned to surround the implants - that is, truly backward planning of the position of the bone. The buccolingual angulation and the actual position of the implants during operation can be difficult to verify. Using commonly available software and 3-dimensional printing solutions, therefore, we have constructed an algorithm to optimise the position of these implants during the operation, and to get their position as close to the planned outcome as possible. This algorithm is adaptable to any implant system and is potentially possible in any implant or preplanning software unit.