Influence of gender on epithelial host defence peptide gene expression under non-infected and infected conditions: A basic medical research study.

Bacterial resistance against conventional antibiotics is increasing. This introduces challenges, for example, in the treatment of infected surgical wounds. Host defence peptides (HDP), which are endogenous peptide antibiotics, show broad-spectrum antimicrobial effectiveness. They protect the organism against pathological microorganisms. Synthetic HDP might supplement or even become alternatives to conventional antibiotics. Knowledge of their quantities under physiological and pathophysiological conditions is therefore required. The influence of gender on HDP expression is unknown. This study evaluates whether gender influences HDP expression in infected or healthy epithelium. Expression levels of HDP human beta-defensin (hBD)-1, -2 and -3 and psoriasin (S100A7) were analysed, by using real-time polymerase chain reaction, in samples of epithelium from infected surgical wounds (n = 20) and healthy epithelium (n = 14) from the neck in a basic medical research study (analytic observational design). The results demonstrated a significantly elevated expression of hBD-2, hBD-3 and psoriasin (P = 0.001 each) in infected epithelium compared with healthy epithelium. No difference in HDP expression levels was evident between samples from female and male patients, either within infected samples or within healthy epithelium samples. Thus, gender does not affect the cutaneous expression of the investigated HDP. This is fundamental knowledge for the study and potential use of HDP derivates as alternative antibiotic substances.

Surgical management of severe osteoradionecrosis of the mandibular bone by using double free flap reconstruction.

PURPOSE: Osteoradionecrosis (ORN) of the jaws represents one of the most severe complications after primary or adjuvant radiation therapy (RT) of large head and neck tumors. In advanced ORN cases, surgical management is generally considered the therapy of choice. However, in several severe ORN patients with extensive bone and soft tissue defects, functional and aesthetic reconstruction represents a huge challenge for any surgeon, with an increased risk of post-operative wound healing disorders. Our aim here was to perform a double free flap technique as a therapeutic option in this difficult patient collective and to evaluate the post-operative outcome. MATERIALS AND METHODS: 15 patients with advanced and severe ORN undergoing mandibular and soft tissue reconstruction with a double free flap were retrospectively reviewed. In one single operation involving a three-team approach, an obligatory free fibular flap (FFF) was freely combined with another free flap according to the desired features: anterolateral thigh (ALT) or vastus lateralis flap (VLF), radial forearm flap (RFF) and latissimus dorsi flap (LDF). RESULTS: We found sufficient wound healing in the head and neck region in all patients with no need for any additional surgical intervention. The overall flap success rate was 93.3%, although three revisions of anastomosis were necessary. Furthermore, prolonged stay on the intensive care unit (ICU) and extended hospitalisation were avoided. CONCLUSION: The double free flap technique with an obligatory FFF provides a suitable surgical solution for the treatment of patients with severe ORN of the mandibular bone for which other conservative or surgical therapy strategies have reached their limits.

Mandible reconstruction with free fibula flaps: Outcome of a cost-effective individual planning concept compared with virtual surgical planning.

PURPOSE: The free osteomyocutaneous fibular flap has become one of the primary options for mandibular reconstruction, because of the later introduction and development of virtual surgical planning (VSP). However, VSP is associated with high additional pre-operative effort and costs. Therefore, the purpose of the study was to develop a new individual cost-effective pre-operative planning concept for free fibula mandible reconstruction and to compare it with VSP regarding clinical parameters and post-operative outcome. MATERIALS AND METHODS: 31 patients undergoing mandibular reconstruction with a microvascular free fibular flap were divided into two groups and retrospectively reviewed. For the first group A (18 of 31 patients), an individual method with stererolithographic (STL) models, silicon templates and hand-made cutting guides was used (about 250 € planning costs/patient). For the second group B (13 of 31 patients), VSP including pre-fabricated cutting guides was used (about 2500 € planning costs/patient). RESULTS: We found no statistically significant differences with respect to intra-operative time of mandibular reconstruction, duration of hospitalisation or post-operative complications between the two groups (p ≥ 0.05). CONCLUSION: The surgical outcomes and operative efficiency of this individual and cost-effective planning concept are comparable with the much more expensive complete VSP concept.

NOS1-, NOS3-, PIK3CA-, and MAPK-pathways in skin following radiation therapy.

BACKGROUND: Essential molecular pathways such as the MAPK pathway, NO system, or the influence of PIK3CA as an oncogene are known to regulate fundamental signalling networks. However, few knowledge about their role in the occurrence of wound healing disorders (WHD) following radiation therapy (RT) exists. This study aims to evaluate the expression profiles of specific molecular pathway marker genes. METHODS: Expression profiles of the genes encoding MAPK, NOS1, NOS3, and PIK3CA were analyzed, by RT-PCR, in specimens from patients with and without a history of RT to the head and neck. Clinical data on the occurrence of cervical WHDs were analyzed. RESULTS: Expression analysis of patients with postoperative WHDs revealed a significant increase in MAPK expression compared to the control group without occurrence of postoperative WHDs. PIK3CA showed a significantly increased expression in patients with a history of RT. Expression analysis of all other investigated genes did not reveal significant differences. CONCLUSIONS: This current study is able to show the influence of RT on different molecular pathways. This underlines the crucial role of specific molecular networks, responsible for the occurrence of long-term radiation toxicity such as WHDs. Additional studies should be carried out to identify possible starting points for therapeutic interventions.

An Immunohistochemical Study on the Role of Oxidative and Nitrosative Stress in Irradiated Skin.

BACKGROUND/AIM: The effects of ionizing radiation through the generation of free radicals, reactive aldehydes, and other oxidative and nitrosative by-products account for skin injuries as side effects of radiation therapy (RT). This study aims to identify cellular pathways in oxidative and nitrosative stress in irradiated skin using well-established marker proteins in an immunohistochemical analysis. MATERIALS AND METHODS: Tissue specimens of 51 patients were obtained during operative access to the neck. Twenty patients (39.2%) received RT prior to the surgical intervention. Immunohistochemical analysis of stable degradation products of reactive oxygen and nitrogen species (RONS), 3-nitrotyrosine, 8-isoprostane, phosphorylated AKT (p-AKT), and phosphorylated extracellular signal-regulated kinase (p-ERK) was performed in specimens which were exposed to RT and those without a history of RT. RESULTS: Immunohistochemical staining showed a significantly increased expression of nitrotyrosine in superficial and basal epidermal regions of interest (ROI), p-AKT in all epidermal ROI, and p-ERK in all the investigated epidermal and dermal ROI, as well as in an overall analysis. No significance could be detected in immunostaining against isoprostane. DISCUSSION: This study summarizes the influence of RONS in RT. Moreover, a detailed histological analysis was able to identify epidermal ROI as a main starting point of RONS in irradiated skin. Even though the role of RONS in high-dose therapeutic radiation remains a subject for further research, these data underlines the crucial role of RONS in high-dose radiation.

Sympathomimetic effects of chronic methamphetamine abuse on oral health: a cross-sectional study.

BACKGROUND: Methamphetamine, a highly addictive sympathomimetic stimulant, is currently widely abused worldwide and has been associated with devastating effects on oral health, resulting in the term "meth mouth". However, "meth mouth" pathology is primarily based on case reports with a lack of systematic clinical evaluation. Therefore, we have conducted a systematic study to investigate (1) the pharmacological impact of methamphetamine on oral health with regard to saliva function, including the parameters saliva flow rate and total saliva production (ml/5 min) and the buffering capacity of saliva; (2) the contribution of the symptoms of bruxism and muscle trismus to potential oral health damage. METHODS: We assessed the data of 100 chronic methamphetamine abusers and 100 matched-pair comparison participants. Primarily, we conducted an anamnesis with all methamphetamine abusers with regard to saliva dysfunctions, jaw clenching and pain in the temporomandibular joint. Subsequently, in the first part of the clinical enquiry, we tested the saliva flow rate and the total saliva production (ml/5 min) by using the sialometry method and the buffer capacity of saliva by determining the pH-value. In the second part of the clinical enquiry, we evaluated bruxism symptoms with respect to generalized tooth attrition, dentine exposure and visible enamel cracks and examined a potential muscle trismus by measuring the maximal opening of the mouth. RESULTS: The majority of methamphetamine abusers reported a dry mouth (72 %) and jaw clenching (68 %). Almost half of all methamphetamine abusers experienced pain in the temporomandibular joint (47 %). With regard to the clinical findings, methamphetamine abusers showed significantly lower total saliva production (ml/5 min) (p < 0.001), lower pH-values of their saliva (p < 0.001) and more bruxism symptoms (p < 0.001). However, we found no relevant trismus symptoms on comparing the two groups (p > 0.05). CONCLUSIONS: The sympathomimetic effects of chronic methamphetamine abuse may lead to dry mouth and extensive bruxism and therefore can increase the risk for caries decay, periodontal lesions and tooth wear. Furthermore, a significant decline of saliva buffer capacity in methamphetamine abusers may trigger the risk for dental erosions. Methamphetamine abusers and practitioners should be aware of these symptoms.

The impact of the new scene drug "crystal meth" on oral health: a case-control study.

OBJECTIVE: The use of methamphetamine (MA), a highly addictive stimulant, is rapidly increasing, with MA being widely abused as the scene drug "Crystal Meth" (CM). CM has been associated with severe oral health effects, resulting in so-called "Meth mouth". This term appeared for the first time in 2005 in the literature and describes the final complex of symptoms including rampant caries, periodontal diseases and excessive tooth wear. The aim of this study was to investigate the effects of chronic CM abuse on teeth and intraoral tissue with respect to potential symptoms of Meth mouth. MATERIALS AND METHODS: In cooperation with two centres for addiction medicine, we performed clinical intraoral investigations in 100 chronic CM users and 100 matched-pair controls. We undertook a caries and periodontal examination by using the clinical parameters DMF-T/DMF-S, bleeding on probing index (BOP) and periodontal screening index (PSI) and tested individual oral hygiene by using approximal space plaque index (API). All clinical data were analysed by the t test for independent samples. RESULTS: We found significantly larger numbers of caries (p < 0.001) and higher levels of gingival bleeding (p < 0.001) and periodontal disease (p < 0.001) among CM users. Oral hygiene was significantly lower in CM users (p < 0.024). CONCLUSION: Chronic CM use can lead to extensive potential damage within the intraoral cavity. When CM is used over a long period of time and in the absence of treatment, clinical symptoms in terms of Meth mouth syndrome cannot be excluded. CLINICAL RELEVANCE: Based on our results, we recommend a specific prevention and therapeutic concept including educational campaigns for MA users and specialized dental care for CM patients.

Special training in maxillofacial surgery for medical students--economic burden or investment in the future?

We measured the motivation and interest of medical students in oral and maxillofacial surgery at a German university. After a detailed cost-benefit analysis of a course that used an ex-vivo animal model and active participation in the operating theatre, we measured changes in the students' interest in taking up a surgical specialty in the future. We found that practical experience could lower the expenses of the course by almost 70%. Twenty per cent of students chose oral and maxillofacial surgery as an elective in their final year. These students could be residents one day.

An expression analysis of markers of radiation-induced skin fibrosis and angiogenesis in wound healing disorders of the head and neck.

BACKGROUND: Radiation-induced fibrosis (RIF) is one of the severe long-term side effects of radiation therapy (RT) with a crucial impact on the development of postoperative wound healing disorders (WHD). The grades of fibrosis vary between mild to severe depending on individual radiosensitivity. In this study, we have investigated the molecular pathways that influence RIF and have correlated data from immunohistochemistry (IHC) for von -Willebrand Factor (vWF) and from Real-Time Polymerase Chain Reaction (RT-PCR) concerning markers such as Transforming Growth Factor (TGF)-ß 1, and vWF, with clinical data concerning the occurrence of WHD during follow-up. METHODS: Expression profiles of the genes encoding TGF-ß 1, vWF, and α-procollagen (PC) were analyzed, by RT-PCR, in specimens from patients with (n = 20; 25.6 %) and without (n = 58; 74.4 %) a history of previous RT to the head and neck. Moreover, IHC against vWF was performed. Clinical data on the occurrence of cervical WHDs were analyzed and correlated. RESULTS: A statistically significant increase in the expression profiles of α-PC and TGF-ß 1 was observed in previously irradiated skin samples (occurrence of RT >91 days preoperatively). vWF showed a statistically significant increase in non-irradiated tissue. Moreover, analysis of expression profiles in patients with and without WHDs during follow-up was performed. IHC showed a reduced amount of vessels and structural changes in epidermal tissue post-RT. CONCLUSIONS: The expression of markers of fibrosis and angiogenesis was analyzed in order to gain insight into molecular pathways that account for structural changes in irradiated skin and that eventually lead to WHDs. The results are congruent with reports from the literature and are a possible starting point for further research, as anti-TGF-ß 1 treatment, for example, could represent new therapeutic opportunities in the management of previously irradiated patients.

Surface-optimized free flaps for complex facial defects after skin cancer.

INTRODUCTION: Advanced non-melanocytic skin cancer (NMSC) in the facial region causes extensive tissue loss, possibly coverable by local flaps. Remote free flaps are the reconstructive method of choice, despite disadvantages such as color and texture mismatch, and bulkiness with regard to facial skin. MATERIAL AND METHODS: Post-ablative facial NMSC defects in four patients were reconstructed using remote free flaps, including radial forearm, scapular, parascapular, and anterolateral thigh flaps. Four months later, a split-thickness skin graft (STSG) was acquired from the retroauricular region to generate a non-cultured autologous epidermal cell (NCAEC) suspension. The flap surfaces were de-epithelialized, and the NCAEC suspension was sprayed onto the flap surface to improve the mismatch between facial and flap color. Debulking was also carried out. The aesthetic outcome was examined by photography and clinical examination 3, 6, 9, and 12 months after the first operation. RESULTS: All flaps survived the 11- to 21-month follow-up. The secondary operation was accompanied by a delay in re-epithelialization in one case. No STSG donor-site problems occurred. Follow-up photographs showed significant improvements in the color and texture of the flaps. CONCLUSIONS: Facial reconstruction with a free flap results in a mismatch of color and texture. Secondary correction of the flap surface by de-epithelialization and NCAEC application significantly improves the aesthetic outcome.

The value of perioperative antibiotics on the success of oral free flap reconstructions.

The subject of the presented study was to monitor and compare problems and outcomes of reconstructive surgery with microvascular free flaps in the head and neck region between groups of patients treated with perioperative antibiotics and a group of patients without antibiotics. Patients requiring oral reconstructive surgery following cancer resections with microvascular free flaps were prospectively evaluated (2007-2012). Antibiotic therapy was started 30 min before the operation and administered for 10 days. Three hundred and fifty patients were included (208 male, 59.4%; 142 female, 40.6%; mean age 59.8 ± 13.2 years). 330 patients received perioperative antibiotics. Twenty patients (5.7%) who received no antibiotics for specific reasons served as the control group. Wound infections developed in 33 of 122 patients (27%) who received benzylpenicillin, 17 of 88 patients (19.3%) who received amoxicillin combined with sulbactam and 25 of 120 patients (20.8%) who received cefuroxime. Ten patients (50%) who did not receive antibiotics developed wound infections. Receiving no antibiotics or penicillin showed no benefit (P = 0.11). Those receiving cefuroxime showed significantly lower incidence of wound infections (P = 0.034; risk decreased by the factor 2.88). The use of amoxicillin combined with sulbactam showed the lowest rate of wound infections (P = 0.018; risk decreased by the factor 3.46). The use of amoxicillin combined with sulbactam appears to be the most appropriate prophylactic antibiotic followed by cefuroxime in oral microsurgical free flap reconstructions. These data may serve as a guide until a controlled multicenter prospective trial is performed comparing newer antibiotics against current standards.

Evaluation of methamphetamine-associated socioeconomic status and addictive behaviors, and their impact on oral health.

BACKGROUND: Chronic methamphetamine abuse can lead to multiple health hazards. In particular, the substance is associated with devastating effects on oral health including symptoms such as rampant caries, gingiva inflammation, and xerostomia, whereby the term "Meth Mouth" occurs in the current literature. However, "Meth Mouth" pathology is primarily described on the basis of individual cases or has been evaluated without consideration of the mass of potential influencing factors. Therefore, we have conducted a systematic study to investigate the effects of accompanying factors and circumstances on oral health in cases of chronic methamphetamine abuse. METHODS: In cooperation with two centers for addiction medicine, we assessed the data of 100 chronic methamphetamine users and 100 matched-pair controls between March 2012 and November 2013. We investigated their socioeconomic status, details of methamphetamine consumption behavior, collateral consumption of sugar beverages, nicotine alcohol, and other addictive substances including cannabis, opioids, other stimulants, and hallucinogens, and dental care. RESULTS: We found considerably greater unstable social circumstances, a high collateral consumption of substances with pathogenic potential for the stomatognathic system, and significantly poorer dental care in the methamphetamine-user group. CONCLUSIONS: Various factors have to be considered with regard to methamphetamine use and its influence on oral health. These factors can trigger potential damage by the drug methamphetamine possibly leading to the symptoms of "Meth Mouth", and should be considered in prevention and therapy strategies.

Biomechanical loading test on reconstructed mandibles with fibular, iliac crest or scapula graft: a comparative study.

Advantages and disadavantages of the three most commonly-used bone grafts for mandibular reconstruction are widely known, but biomechanical experimental studies are rare. We have done loading tests on cadaveric mandibles reconstructed with fibular, iliac crest, and scapular grafts using 3 different osteosynthesis systems to detect and compare their primary stability. Loading tests were done on mandibles with grafts from the fibula and iliac crest and published previously. A 4.5cm paramedian L-type defect was reconstructed with scapula using 2 monocortical non-locking plates, 2 monocortical locking plates, or a single bicortical locking plate/fracture gap in 18 human cadaveric mandibles. These were loaded on to the "Mandibulator" test bench and the movement of fragments in 3 dimensions was assessed and quantified by a PONTOS® optical measurement system. Comparison of the osteosynthesis groups showed that the miniplate was significantly superior to the 6-hole TriLock® plate for both fibular and iliac crest grafts. The fibular graft gave greater stability than the iliac crest and scapular grafts for all 3 osteosynthesis systems. All bony specimens offered sufficient resistance to mechanical stress within the recognised range of biting forces after mandibular reconstruction, independently of the choice of bone graft and osteosynthesis system used. Anatomical and surgical advantages need to be taken into account when choosing a graft. Stability can be maximised with a fibular graft, and further optimised by enlarging the binding area by using the "double barrel" method. Computer simulated experiments could segregate factors that biased results, such as morphological differences among cadavers.

Evaluation of human amniotic membrane as a wound dressing for split-thickness skin-graft donor sites.

Human amniotic membrane (HAM) has been used as a biomaterial in various surgical procedures and exceeds some qualities of common materials. We evaluated HAM as wound dressing for split-thickness skin-graft (STSG) donor sites in a swine model (Part A) and a clinical trial (Part B). Part A: STSG donor sites in 4 piglets were treated with HAM or a clinically used conventional polyurethane (PU) foil (n = 8 each). Biopsies were taken on days 5, 7, 10, 20, 40, and 60 and investigated immunohistochemically for alpha-smooth muscle actin (αSMA: wound contraction marker), von Willebrand factor (vWF: angiogenesis), Ki-67 (cell proliferation), and laminin (basement membrane integrity). Part B: STSG donor sites in 45 adult patients (16 female/29 male) were treated with HAM covered by PU foam, solely by PU foam, or PU foil/paraffin gauze (n = 15 each). Part A revealed no difference in the rate of wound closure between groups. HAM showed improved esthetic results and inhibitory effects on cicatrization. Angioneogenesis was reduced, and basement membrane formation was accelerated in HAM group. Part B: no difference in re-epithelialization/infection rate was found. HAM caused less ichor exudation and less pruritus. HAM has no relevant advantage over conventional dressings but might be a cost-effective alternative.

Immunolocalization of antimicrobial and cytoskeletal components in the serous glands of human sinonasal mucosa.

Secretory cells in the seromucous glands of paranasal sinuses secrete antibacterial proteins for innate immune mucosal integrity. We studied the localization of antimicrobial and cytoskeletal components of the human seromucous glands and respiratory epithelium of the maxillary sinus and the ethmoidal cells by immunohistochemical methods. The presence of a variety of defense proteins such as lysozyme, lactoferrin, cathelicidin, and defensin-1, -2, -3 point to a crucial role in the immune defense for the respiratory tract. Cytoskeletal proteins such as actin, myosin 2, cytokeratin 7 and 19, α- and ß-tubulin, investigated for the first time in glands of paranasal sinuses, showed a stronger expression at the apical and lateral cell membrane. The localization of the cytoskeletal proteins might point to their participation in exocrine secretory processes and stabilizing effects.

Can tissue spectrophotometry and laser Doppler flowmetry help to identify patients at risk for wound healing disorders after neck dissection?

OBJECTIVE: Microcirculation and oxygen supply in cervical skin were measured with an optical, noninvasive method in patients with or without radiotherapy before neck dissection. The course of wound healing was monitored after the surgical procedure to identify predictive factors for postoperative wound healing disorders. STUDY DESIGN: Tissue spectrophotometry and laser Doppler flowmetry were used to determine capillary oxygen saturation, hemoglobin concentration, blood flow, and blood velocity at 2-mm and 8-mm depths in the cervical skin of 91 patients before neck dissection in a maxillofacial unit of a university hospital in Munich, Germany. Parameters were evaluated for differences between patients with irradiation (24) and without (67) and patients with wound healing disorders (25) and without (66) (univariate or multivariate statistical analyses). RESULTS: Velocity at 2 mm was lower in irradiated skin (P = .016). Flow at 2 mm was higher in patients with wound healing disorders (P = .018). CONCLUSIONS: High flow values could help to identify patients at risk for cervical wound healing disorders.

Development of a haptic model for teaching in reconstructive surgery--the radial forearm flap.

OBJECTIVES: The great value of the radial forearm flap (RFF) for reconstructive surgery stresses the importance of developing effective teaching methods. Our aim was to develop a realistic anatomic model that concisely simulates vital surgical steps while offering a haptic and visual experience. It should be cost-effective, easy to use, reusable, and quick to set up. MATERIALS AND METHODS: The development commenced by constructing a prototype presenting basic features. Together with photographic surgery documentation, it served as a blueprint for the advanced model. The flap-raising process was condensed into the 6 most important steps to illustrate the procedure concisely and chronologically. RESULTS: Our final version consists of polyurethane, and a customized forearm flexor muscle model serves as the basic structure. Diverse plasticizers give different degrees of hardness to mimic anatomic structures. Special didactic features of the model include a movable elastic ramus superficialis nervi radialis. The flap island is attachable/detachable by a patrix/matrix mechanism. The brachioradialis muscle is elastic and detachable, and the fascia antebrachii is additionally severable. Vessels can be disconnected, and the removable forearm skin features a wave-shaped incision for the flap pedicle. To investigate the didactic benefit of the RFF model, we used it in a teaching course for medical students. The group receiving teaching supported by the RFF model showed a statistically significant improvement of knowledge (P = 0.007) in comparison with the group solely receiving a standard lecture supported by surgery images. CONCLUSIONS: In our opinion, the RFF model is an excellent compromise with regard to realism, didactic benefit, and cost-/time-effectiveness and has proven successful in the teaching of medical students.

Amniotic membrane in oral and maxillofacial surgery.

PURPOSE: Following its renaissance in ophthalmology during the 1990s, preserved human amniotic membrane (HAM) has become an attractive biomaterial for all surgical disciplines. This article reviews the current and potential use of HAM in oral and maxillofacial surgery, its postulated properties and common preservation techniques. METHODS: Literature was identified by an electronic search of PubMed in July 2012; this was supplemented from the reference lists of the consulted papers. RESULTS: HAM has been used in the field of oral and maxillofacial surgery from 1969 onwards because of its immunological preference and its pain-reducing, antimicrobial, mechanical and side-dependent adhesive or anti-adhesive properties. The effects of HAM on dermal and mucosal re-epithelialisation have been highlighted. Typically, HAM is applied after being banked in a glycerol-preserved, DMSO-preserved or freeze-dried and irradiated state. Whereas the use of HAM in flap surgery and in intra-oral and extra-oral lining is reported frequently, novel HAM applications in post-traumatic orbital surgery and temporomandibular joint surgery have been added since 2010. Tissue engineering with HAM is a fast-expanding field with a high variety of future options. CONCLUSIONS: Preserved HAM is considered to be a safe and sufficient biomaterial in all fields of oral and maxillofacial wound healing. Recently published novel indications for HAM application lack a high level of evidence and need to be studied further.

Head and neck salivary gland carcinomas--elective neck dissection, yes or no?

PURPOSE: Surgical resection and subsequent neck dissection (ND) in cases of clinically positive lymph nodes is an accepted primary treatment strategy for salivary gland carcinomas. Because of uncertainty in the extent of lymphogenic metastasis, the authors advocate a strategy of surgical resection and elective ND (END) for all patients. The authors evaluated their treatment by estimating the frequency of metastatic disease and identifying factors associated with an increased risk for metastatic disease. MATERIALS AND METHODS: A retrospective cohort study was implemented using patient data obtained from the university's interdisciplinary board for head and neck tumors. Data were screened for age, gender, tumor entity, localization, grade, and TNM Classification of Malignant Tumors (by UICC, International Union Against Cancer) status. Statistical analysis was performed to identify possible predictors of lymph node metastasis. Nodal status groups (N(+) and N0) were compared with respect to age by t tests; other comparisons involved χ(2) tests. RESULTS: Ninety-four patients (50% female, 50% male; mean age, 59.12 yr) were identified, of whom 87 had an indication for END. On postsurgical histopathologic examination, 34 (39%; 17 male, 17 female) were diagnosed with N(+). Statistical analysis for nodal status produced explorative P values (age, P = .001; gender, P = .792; anatomic region, P = .114; tumor entity, P = .854; tumor status, P = .263; grade, P = .000). CONCLUSION: All studied malignancies were capable of lymph node dissemination. Therefore, no reliable preoperative predictors for lymphogenic metastasis are currently identifiable. Because of difficulties in safely predicting lymphogenic metastasis and the high rate of N(+) results on postoperative examination, the authors strongly advise END for all patients with salivary gland carcinoma.

Repair of oronasal fistulae by interposition of multilayered amniotic membrane allograft.

BACKGROUND: Oronasal fistulas are a frequent complication after cleft palate surgery. Numerous repair methods have been described, but wound-healing problems occur often. The authors investigated, for the first time, the suitability of multilayered amniotic membrane allograft for fistula repair in a laboratory experiment (part A), a swine model (part B), and an initial patient series (part C). METHODS: In part A, one-, two-, and four-layer porcine and human amniotic membranes (n = 20 each) were fixed in a digital towing device and the force needed for rupture was determined. In part B, iatrogenic oronasal fistulas in 18 piglets were repaired with amniotic membrane allograft, autofetal amniotic membrane, or small intestinal submucosa (n = 6 each). Healing was evaluated by probing and visual inflammation control (no/moderate/strong) on postoperative days 3, 7, 10, and 76. Histological analysis was performed to visualize tissue architecture. In part C, four patients (two women and two men, ages 21 to 51 years) were treated with multilayered amniotic membrane allograft. RESULTS: In part A, forces needed for amniotic membrane rupture increased with additional layers (p < 0.001). Human amniotic membrane was stronger than porcine membrane (p < 0.001). In part B, fistula closure succeeded in all animals treated with amniotic membrane with less inflammation than in the small intestinal submucosa group. One fistula remained persistent in the small intestinal submucosa group. In part C, all fistulas healed completely without inflammation. CONCLUSIONS: Amniotic membrane is an easily available biomaterial and can be used successfully for oronasal fistula repair. The multilayer technique and protective plates should be utilized to prevent membrane ruptures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.