Surgical site infections in orthognathic surgery: prolonged versus single-dose antibiotic prophylaxis.

The oral cavity is densely populated with microorganisms. As a result, intraoral surgical sites are prone to contamination by pathogens, potentially triggering surgical site infections (SSIs). Prophylactic antibiotics have proven beneficial in reducing the rate of SSIs. However, no consensus has been reached regarding the most effective regimen. The purpose of this study was to investigate two different antibiotic regimens - single-dose and prolonged antibiotic prophylaxis - regarding the rate and severity of postoperative SSIs in patients undergoing orthognathic surgery. Data were analysed retrospectively. Patients who underwent bilateral sagittal split ramus osteotomy or bimaxillary surgery in the study department in 2017 were screened for eligibility. Ninety-nine patients were included in the study and were divided into two groups. The prolonged-antibiotic prophylaxis group (PAP; n = 49) received a 5-day antibiotic prophylaxis regimen, while the single-dose antibiotic prophylaxis group (SDAP; n = 50) received single-dose antibiotic prophylaxis. The groups were assessed for the rate and severity of SSIs following orthognathic surgery. Five patients (10.2%) in the PAP group and seven (14%) in the SDAP group developed infections; no statistically significant difference in the occurrence of SSIs was found (P = 0.380). Single-dose antibiotic prophylaxis is as effective as a 5-day antibiotic prophylaxis regimen in preventing SSIs in orthognathic surgery and is a suitable antibiotic prophylaxis option when considering the risk of antibiotic resistance.

Determination of blood loss in bimaxillary surgery: does the formula and the time point affect results?

The amount of blood loss determined in orthognathic surgery differs greatly among studies. This can be attributed to the inhomogeneity in study cohorts analysed, but may also be a result of the varying methodologies used for blood loss determination. However, this has yet to be explored. Thus, the aim of this study was to investigate the extent to which the formula and time point used to measure blood loss affect the blood loss volume, determined in a homogeneous cohort undergoing bimaxillary surgery. Blood loss was calculated at 24 and 48 hours postoperatively using the haemoglobin balance method and the formula of Hurle et al. The estimated total blood volume was established based on the formulae of Nadler et al. and Choi et al. Differences in blood loss volume with respect to time point and formula were analysed and compared. Fifty-four patients were included in the final analysis. Statistically significant differences in blood loss were observed: a significant increase in the blood loss volume from 24 hours to 48 hours postoperatively was detected. When comparing the formulae used, blood loss differed significantly at 24 hours after surgery; however no such difference resulted at 48 hours postoperatively. These findings imply that the time point of measuring blood loss is highly relevant, whereas the formulae applied seem to have less of an impact on the blood loss volumes calculated.

Combining midfacial degloving, LeFort-I osteotomy and inferiorly extended lateral orbitotomy (Krönlein) for removal of an orbital cavernous haemangioma: a new approach.

Orbital tumours, located in the medial extraconal and intraconal compartment of the orbit, represent a challenge, with regard to surgical exposure. In the present paper removal of a cavernous haemangioma, located in the medial intraconal compartment was accomplished by combining lateral orbitotomy, midfacial degloving and LeFort-I osteotomy. Resection of the tumour could be performed under direct vision. Surgical exposure and removal of the lesion were obtained, without causing damage to surrounding tissues. Aesthetical results and postoperative eye function proved to be highly satisfactorily. With regard to limitations, concerning the combination of these methods, extended surgery duration and invasiveness have to be named. According to the technical feasibility and postoperative results, this new surgical approach represents a reliable and fully viable alternative method for the removal of medial orbital tumours.

The phosphorous necrosis of the jaws and what can we learn from the past: a comparison of "phossy" and "bisphossy" jaw.

INTRODUCTION: The osteopathology of the jaws associated with bone resorption inhibitors is a current topic that engages a variety of clinical specialists. This has increased after the approval of denosumab for treatment of osteoporosis and skeletal-related events in patients with solid malignancy. Early after the first publications, there is a possible connection between phosphorous necrosis of the jaws, a dreadful industrial disease mentioned, and bisphosphonate-induced pathology. The nineteenth century was the prime time for phosphorus necrosis of match factory workers. RESULTS: This occurrence provides an interesting insight into the medical and surgical profession in the nineteenth century. There are striking parallels and repetition of current and old ideas in the approach to this "new disease." There are similar examples in case descriptions when compared with today's patients of bisphosphonate-related osteonecrosis of the jaws (BRONJ). DISCUSSION: Phosphorus necrosis was first described in Austria. Soon after this, surgeons in German-speaking countries including well-known clinicians Wegner (1872) and von Schulthess-Rechberg (1879) pioneered the analysis, preventative measures, and treatment of this disease. The tendency at this time was to approach BRONJ as a "special kind of osteomyelitis" in pretreated and metabolically different bone. Not only the treatment strategy to wait until sequestrum formation with subsequent removal and preventative measures but also the idea of focusing on the periosteum as the triggering anatomical structure may have been adopted from specialists in the nineteenth century. Therefore, phosphorous necrosis of the jaw is an excellent example of "learning from the past."

Osteopathology associated with bone resorption inhibitors - which role does Actinomyces play? A presentation of 51 cases with systematic review of the literature.

BACKGROUND: Bone resorption inhibitor-related osteopathology of the jaw (BRIOJ) is a severe complication in patients treated with bisphosphonates or denosumab. However, the precise pathogenesis of BRIOJ is not yet fully understood. Recent studies discovered the presence of Actinomyces colonies in biopsy material from BRIOJ patients. The aim of this study was to analyze current knowledge concerning the impact of Actinomyces on the pathogenesis of this condition and to present data from our own patients. METHODS: Data from 51 patients with histopathological diagnoses of BRIOJ were retrospectively analyzed. In addition, a systematic literature search for studies describing the presence of Actinomyces was performed. RESULTS: Actinomyces was present in 86% of our cases and 63.3% of 371 cases presented in the literature. All of our patients and 85% of patients described in the literature had a clearly defined local focus in association with osteopathology. A clear picture of whether Actinomyces colonizes the previously necrotic bone or contributes to inflammation causing subsequent bone necrosis is lacking in the literature. CONCLUSION: The pathogenesis of BRIOJ remains unknown; however, there seems to be a role for Actinomyces, and possibly other pathogens, in the development of osteopathology of the jaws, which is not exclusive to bisphosphonate therapy. This study supports the hypothesis that an infectious component is of utmost importance for the pathogenesis of BRIOJ.

Surgically assisted rapid maxillary expansion: feasibility of not releasing the nasal septum.

Surgically assisted rapid maxillary expansion (SARME) is commonly used to correct maxillary transverse deficiency. The aim of this study was to analyse the need for intraoperative liberation of the nasal septum during the procedure. SARME was performed in 25 patients by combining a lateral osteotomy with an inter-radicular maxillary osteotomy. The deviation of the nasal septum after SARME was evaluated by comparing measurements between radiologically defined landmarks on pre- and postoperative computed tomographic images. Two defined angles (angle I, between crista galli-symphysis mandibulae and crista galli-septum nasi; angle II, between maxillary plane and septum nasi) were measured based on four representative planes and septal movement was analysed. The mean changes in angles I (0.03° ± 0.78°) and II (0.25° ± 1.04°) did not differ significantly from zero (p=0.87 and p=0.24, respectively). Observed variations and displacements were considered to be acceptable because they were insignificant in every respect. Intranasal airway function was also examined pre- and postoperatively to evaluate any loss of ventilation. The described surgical technique is a successful method of maxillary segment distraction. The authors found no compelling reason to release the nasal septum in the context of SARME.

Computer assisted maxillofacial surgery.

Technical developments strongly influence modern medicine. This is especially obvious in imaging technology. Today, one of the most difficult tasks for surgeons is transferring all the available imaging information for their patients into one "complete picture". In the operation theatre, this picture then has to be applied to the patient. Computer-assisted surgery (CAS) promises to help in fulfilling this task and, thereby, to fully utilize the possibilities offered by modern imaging techniques. Today's standard procedures for CAS in the maxillofacial region are described in technical principles and clinical applications. They are evaluated and discussed based on the available literature and in light of practical experience of more than ten years in the field of CAS. In addition, an outlook is given into developments of the near future that have appeared in the current literature. While technical development is leading toward a complete integration of all processes surrounding the patient and his or her surgery, basic CAS has moved from research to clinical care. Before it is routinely used, more investigation about its effectiveness and benefits has to be done, especially since increasing medical care costs are an issue in all countries.

Removal of a pellet from the left orbital cavity by image-guided endoscopic navigation.

In the cranio-maxillofacial field, computer-aided surgery based on computed tomography data is becoming increasingly important. Complex surgical procedures can be performed utilizing preoperative imaging to provide real-time localization of surgical instruments in the surgical field. Image-data-based navigation plays an ever-increasing role in cases of minimal invasive surgery. The case is presented here of a 58-year-old male patient referred after a hunting accident with a pellet in the left orbit. After transferring the preoperatively acquired computed tomography data to a commercially available navigation system, the bullet was removed through the original wound canal using an intraoperatively calibrated high-resolution endoscope.

Cardiac metastasis after squamous cell carcinoma of the oral cavity: case report.

A 58-year-old woman presented with respiratory problems 6 months after she had had a squamous cell carcinoma in the oral cavity resected. We found on computed tomography a large lesion in the cardiac muscle. There were no abnormalities in the electrocardiogram. The patient died 7 days later and necropsy confirmed a solitary metastasis in the myocardium that originated from a squamous cell carcinoma of the mouth.

Extraosseous schwannoma of the mental nerve clinically simulating intraosseous.

We report a case of a benign neurilemmoma arising from the right mental nerve. Schwannomas are rare neurogenic tumours that originate from Schwann cells of the peripheral nervous system. Frequent locations are the head and neck region. Most of the tumours occur in the soft tissue whereas intraosseous schwannomas are rare. This case report deals with a young patient who was referred to our hospital with an unidentified fast-growing tumour located mainly in the premolar region of the right mandible. The tumour presented as an expansive, unilocular, well defined, radiolucent lesion on orthopantomography. No expansion of the mandibular canal could be seen. Computerized tomography scans of the mandible helped to identify the solid nature of the tumour. A biopsy was necessary to make the final diagnosis and the tumour was then excised surgically. Postoperative magnetic resonance imaging scans and a histological examination of the surgical specimen showed no signs of neurofibromatosis type 2.

Analysis of midface asymmetry in patients with cleft lip, alveolus and palate at the age of 3 months using 3D-COSMOS measuring system.

INTRODUCTION: Patients suffering from unilateral cleft lip, alveolus and palate exhibit a varying degree of asymmetry of the midface. Evaluation of this asymmetry can be carried out by means of 3D-CT, or a laser surface scanner. MATERIAL AND METHODS: In this paper, 3D-CT-scan data of 21 patients with unilateral clefts of lip, alveolus and palate were analysed using three-dimensional models. Evaluations of the 3D-models were carried out with the computer-aided 3D-operation simulator 3D-Cosmos. RESULTS: Asymmetry was found in the orbital, nasal and maxillary regions. The infraorbital rims were displaced craniocaudally and horizontally as well as laterally of the cleft-sided piriform aperture. This asymmetry corresponded to a dislocation of the maxillary segment on the cleft side. A deficit in volume was not reliably found.

NMR study of the interaction between the lac repressor and the lac operator.

Binding of the lac repressor headpiece, the N-terminal region of the lac repressor, to the lac operator of Escherichia coli was studied by 1H-NMR spectroscopy. Two DNA fragments, of 51 base pairs and 62 base pairs, containing the lac operator region, were investigated. The signals of their hydrogen-bonded imino protons were well resolved in the 500-MHz NMR spectra. The spectra of the free lac operator DNA are similar to those obtained from ring-current-shift calculations for a B-DNA structure. Complex formation with the headpiece led to small but nevertheless characteristic changes in the spectra. The fact that very few imino resonances shifted upon addition of headpiece, as well as the variety in direction and size of these chemical shifts, indicate the formation of a specific complex between the lac repressor and the lac operator. The observed changes in the resonance positions exclude the intercalation of tyrosine residues of the headpiece between adjacent base pairs of the lac operator as well as the formation of a cruciform structure. They rather reflect a small conformational transition in the DNA itself, caused for example by an alteration in the tilt of a few base pairs or a shift of the keto-enol tautomeric equilibrium of the bases towards the enolic form.