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Purpose: The aim of this study was to evaluate the midterm outcomes of fixed, full-arch, fiber-reinforced resin bridges on ultrashort implants in terms of marginal bone loss and overall implant survival., Patients and Methods: Patients with severely atrophic mandibles, corresponding to Cawood and Howell class V and class VI, were included in this prospective temporal cohort study. Mesial and distal peri-implant bone levels were measured on panoramic radiographs taken at the time of implant insertion (baseline) and at follow-up visits., Results: A total of 17 patients with atrophic mandibular jaws with an average follow-up period of 2.9 ± 1.5 years were included. The cumulative 1-, 3-, and 5-year patient-based implant survival rates were 94.1%, and the cumulative implant survival rates were 98.5%. The marginal bone level (MBL) of the mesial implants was 0.0 ± 0.3 mm at the time of loading (n = 33), -0.1 ± 0.3 mm (n = 20) after 1 year, -0.4 ± 0.5 mm (n = 10) after 3 years, and -1.5 ± 1.0 mm (n = 4) after 5 years. The mesial bone level depended significantly on time and insertion depth. The MBL of the distal implants was -0.4 ± 0.4 mm (n = 34) at the time of implantation, -0.4 ± 0.6 mm (n = 20) after 1 year, -0.5 ± 0.5 mm (n = 10) after 3 years, and -2.2 ± 1.7 mm (n = 4) after 5 years. The distal bone level depended significantly on time and insertion depth., Conclusions: Fixed, full-arch, fiber-reinforced resin bridges retained by 4 ultrashort implants provide a comparatively cost-effective, safe, stable alternative for prosthetic restoration of the severely atrophic mandible. The overall implant survival rate and the MBL after 5 years are equivalent to those of threaded implants of conventional lengths., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Forest edges influence more than half of the world's forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.

The Royal College of Veterinary Surgeons now lists 'How to evaluate evidence' as a day one competence for newly qualified vets. In this article, representatives from each of the veterinary schools in the UK discuss how the challenge of delivering and assessing the concepts of evidence-based veterinary medicine in a crowded undergraduate curriculum can be met., (British Veterinary Association.)

The present study investigated the suitability of three different absorbable biocomposites for the repair of critical sized bone defects created at the mandibular angle of adult sheep. Each biocomposite was composed of a three-dimensional individualized polylactide scaffold, containing a tricalcium phosphate biomaterial (chronOS). Either autologous bone marrow (chOS/BoneMarrow) or coagulation factor XIII (chOS/FactorXIII) was added to the biomaterial for osteopromotion. Venous whole blood (chOS/Blood) added to the biomaterial served as a control. A total of 18 adult sheep were used for implantation studies, subdivided into three groups of six animals each. After 12 weeks of observation, the animals were sacrificed and the mandibles were retrieved for qualitative and quantitative histologic assessment within three regions of interest (transitional zone, center, and periphery) throughout the biocomposites. Successful bone regeneration was defined by the absence of scaffold deformation and the presence of new bone formation within the biocomposites. In histomorphometry, only chOS/BoneMarrow showed elevated area fractions of newly formed bone in all regions of interest (transitional zone 50.7 ± 7.5, center 31.9 ± 9.3, periphery 23.1 ± 13.5). This led to preservation of the macroscopic scaffold structure in all specimens. Zero hurdle regression confirmed this by validating the factor biocomposite as significant (p < 0.001) for regeneration success. In our experiment, chOS/BoneMarrow was the only biocomposite passing the hurdle of regeneration in all three regions of interest. In contrast, bone formation was less pronounced and uniform in chOS/FactorXIII and chOS/blood-containing specimens. In these groups, scaffolds showed obvious to significant deformation. Overall, autologous bone marrow showed the most promising results in our experimental setting. As opposed to reports in the literature, we could not confirm the suitability of coagulation factor XIII to promote bone formation, since bone formation rates were comparable only to those of the control venous blood., (Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: To determine the effectiveness of fixed, fiber-reinforced resin bridges on 4 ultrashort implants with a sufficient implant survival success rate of at least 90% in highly atrophic jaws., Materials and Methods: A prospective temporal cohort study was designed, with the inclusion of 10 patients. Of the 10 patients, 8 had atrophic jaws (7 women, 1 man; mean age at implant placement 58.5 years, range 40.7 to 73.9) and 2 had fibula-mandibular transplants (1 woman, aged 76.5 years; and 1 man, aged 69.3 years). All 10 patients had their dentition restored with 4 ultrashort implants. The implant dimensions were 4 mm in diameter and 5 mm long, with a locking taper abutment connection supporting a fixed, fiber-reinforced and composite resin-facetted bridge. The postoperative follow-up period averaged 19.5 months (range 9.1 to 33.1)., Results: The survival and success rate was 97.25%. The average mesial and distal bone level was 0.2 ± 0.3 mm in the atrophic mandibles and 0.4 ± 1.2 mm in the fibula transplants at the last follow-up visit. Prosthetic-related patient issues were limited to decementation events. No chipping or fracturing of the prostheses was observed., Conclusion: Retention of fixed prosthetic restorations using 4 ultrashort implants showed promising short-term cumulative survival and success rates., (Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) is a side effect of BP therapy. Dental implants are believed to be a risk factor for developing BRONJ. In the present study, we analyzed the interval to the development of BRONJ in patients treated with BP who had received dental implants., Patients and Methods: Patients with dental implants and established BRONJ were evaluated at the oral and maxillofacial surgery department (Medical University of Vienna). In addition, studies from 1978 to 2012 were included in a meta-analysis. Three groups were created: implantation before BP treatment, implantation after BP treatment, and implantation during BP treatment. The outcomes were evaluated using linear regression analysis., Results: Patients who underwent dental implantation during (P < .001) and after (P < .001) treatment with BPs developed BRONJ more rapidly. The treatment duration with oral BPs was significantly related to the rapidity of developing BRONJ (P = .03)., Conclusions: The insertion of dental implants during or after BP treatment accelerated the development of BRONJ. BRONJ occurred less frequently when the implants had been inserted before BP therapy had been started., (Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: In the present study, we report an innovative workflow using polyetheretherketone (PEEK) patient-specific implants for esthetic corrections in the facial region through onlay grafting. The planning includes implant design according to virtual osteotomy and generation of a subtraction volume. The implant design was refined by stepwise changing the implant geometry according to soft tissue simulations., Materials and Methods: One patient was scanned using computed tomography. PEEK implants were interactively designed and manufactured using rapid prototyping techniques. Positioning intraoperatively was assisted by computer-aided navigation. Two months after surgery, a 3-dimensional surface model of the patient's face was generated using photogrammetry. Finally, the Hausdorff distance calculation was used to quantify the overall error, encompassing the failures in soft tissue simulation and implantation., Results: The implant positioning process during surgery was satisfactory. The simulated soft tissue surface and the photogrammetry scan of the patient showed a high correspondence, especially where the skin covered the implants. The mean total error (Hausdorff distance) was 0.81 ± 1.00 mm (median 0.48, interquartile range 1.11). The spatial deviation remained less than 0.7 mm for the vast majority of points., Conclusions: The proposed workflow provides a complete computer-aided design, computer-aided manufacturing, and computer-aided surgery chain for implant design, allowing for soft tissue simulation, fabrication of patient-specific implants, and image-guided surgery to position the implants. Much of the surgical complexity resulting from osteotomies of the zygoma, chin, or mandibular angle might be transferred into the planning phase of patient-specific implants., (Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Attached gingiva is a crucial aspect of healthy peri-implant tissue. Severely atrophied jaws have minimal quantities of attached gingiva. Any surgical procedure bears the potential risk of further loss of attached gingiva. The split-thickness flap described here provides excellent access. Using a biopsy punch, the periosteum is easily cut in semicircular fashion on the labial surface of the bone so that it remains pedicled on the lingual or palatal ridge. The split-thickness flap permits fixation of the gingival flap to the periosteum. The periosteal flap is closed with sutures to achieve soft tissue closure over the implants even in case of simultaneous vestibuloplasty.

The palatal sinus lift is a good choice for patients with scarred buccal soft tissue and those with poor wound healing such as smokers or diabetics or when visual side effects such as swelling must be concealed. We provide a surgical protocol for palatal sinus lifting without a vertical release incision. The incision is started in a slightly palatal aspect, at the distal end of the dental arch, and describes a curve laterally on the alveolar crest while running in a mesial direction. As a marginal incision, it can continue to the central incisor. Submucosal exposure will lift the gum and the greater palatine artery. After insertion of a tongue depressor, the sinus is opened on the palatal side, opposite the zygomaticoalveolar crest, using a rose bur or a piezotome. After sinus augmentation, the incision is easy to close, and the wound will heal smoothly., (Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Several observational studies in head and neck cancer have reported that allogenic blood transfusion is associated with increased postoperative complications, increased risk of tumor recurrence, and worse prognosis. The aim of this study was to identify preoperative and intraoperative factors predicting blood transfusion in patients undergoing surgery for oral and oropharyngeal cancer., Patients and Methods: We conducted a retrospective cohort study of patients undergoing tumor resection and free flap reconstruction for locally advanced oral and oropharyngeal squamous cell carcinoma between 2000 and 2008. The primary outcome variable was perioperative exposure to allogenic blood transfusion. Univariate and multivariate logistic regression models were used to determine predictors of blood transfusion., Results: A cohort of 142 participants was found eligible. In a multivariate model, Charlson score ≥ 1 (OR, 5.2; 95% CI, 1.4 to 19.3; P = .01), preoperative hemoglobin levels ≤ 12 g/dl (OR, 4.4; 95% CI, 1.2 to 16.2; P = .03), bone resection (OR, 5.1; 95% CI, 1.5 to 17.8; P = .01), and osseous free tissue transfer (OR, 8.8; 95% CI, 1.0 to 74.8; P = .046) were independently associated with an increased risk of blood transfusion., Conclusion: Our study identified patient- and surgery-related factors predicting a higher risk of exposure to allogenic blood transfusion. This readily available preoperative information could be used to better stratify patients according to their transfusion risk and may thereby guide blood conservation strategies in high-risk patients., (Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to evaluate the impact of expression of epidermal growth factor receptor (EGFR), mesenchymal-epithelial transition factor (c-Met), and insulin-like growth factor receptor 1 (IGF-1R) protein on response to treatment and survival in patients with oral and oropharyngeal squamous cell carcinoma (SCC). EGFR, c-Met, and IGF-1R immunohistochemical (IHC) scores were generated based on the incidence and intensity of expression of the biomarkers evaluated in paraffin-embedded sections of biopsy specimens taken before treatment from 113 patients given neoadjuvant chemoradiotherapy followed by resection for primary locally advanced oral and oropharyngeal SCC. Correlations were assessed between the IHC of the biomarkers and the patients' clinicopathological variables using Spearman's rank test. Cox's regression models were used to evaluate the impact of EGFR, c-Met, and IGF-1R, expression on survival. Almost all the patients showed expression of EGFR, c-Met, and IGF-1R (99%, 100%, and 100%, respectively). None of the biomarkers examined predicted response to neoadjuvant chemoradiotherapy or were associated with survival. In multivariate analysis, age (p=0.05), alcohol consumption (p=0.03), and pathological size/extent of the primary tumour after neoadjuvant treatment (ypT) status (p=0.009) were significantly associated with recurrence-free survival. Age (p=0.02) and alcohol consumption (p=0.02) were independently associated with overall survival. Although none of the biomarkers evaluated could be used as prognostic indicators, their common expression suggested a strong rationale for targeting EGFR, c-Met, and IGF-1R in the treatment of oral and oropharyngeal SCC., (Copyright © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to evaluate the postoperative platelet count changes in patients with oral and oropharyngeal squamous cell carcinoma undergoing preoperative chemoradiotherapy in order to test the hypothesis that the failure of platelets to recover to normal range within 7 days after surgery represents a significant risk factor for poor survival., Materials and Methods: A cohort of 102 patients with primary locally advanced oral and oropharyngeal squamous cell carcinoma undergoing neoadjuvant chemoradiotherapy and surgery was retrospectively analyzed. For each patient, platelet counts were evaluated prior to neoadjuvant treatment, prior to surgery and throughout postoperative days 1 to 7. The Kaplan-Meier method and Cox regression models were used to assess the impact of platelet count changes on survival., Results: Overall survival rate at 5 years was 28% for patients whose platelets did not recover by day 7, with 52% for patients whose platelets remained within a normal level or recovered to this by day 7 (p = 0.005). In multivariate analysis, failure of platelet recovery by day 7 was independently associated with shorter overall survival (p = 0.03)., Conclusions: We demonstrated that the failure of platelets to recover to normal range by the seventh postoperative day is an independent adverse prognostic factor in patients with oral and oropharyngeal cancer undergoing neoadjuvant treatment and surgery., Clinical Relevance: Our results indicate that physicians should pay closer attention to monitoring the postoperative platelet count course, as it may predict the clinical outcome of patients with oral and oropharyngeal cancer.

Objectives: Treatment outcome of patients with oral and oropharyngeal squamous cell carcinoma (OOSCC) achieving complete pathologic response at the primary site (ypT0) but incomplete response in loco-regional lymph nodes after preoperative chemoradiation (ypN+) is poorly described in the literature. This study's objective was to assess the survival of patients with OOSCC with ypT0N+ disease., Study Design: 176 patients with primary locally advanced OOSCC undergoing preoperative chemoradiotherapy were stratified according to the pathologic TNM classification into 6 groups: ypT0N0M0 (46%), ypT0N+M0 (10%), ypTNM I (24%), ypTNM II (4%), ypTNM III (6%), and ypTNM IV (10%)., Results: Three-year overall survival (OS) and recurrence-free survival (RFS) rates for the ypT0N+M0 group were both 61.8% and were similar to those of the ypTNM I group (OS 62.4%; RFS rate of 59.2%)., Conclusions: Survival analyses showed that patients with OOSCC with ypT0N+ disease have a similar prognosis to those with pathologic TNM stage I., (Copyright © 2013 Elsevier Inc. All rights reserved.)

With growing evidence on the role of inflammation in carcinogenesis, the presence of a systemic inflammatory response has been proposed as having prognostic significance in a wide range of cancers. The aim of the study was to assess the value of pretreatment neutrophil-to-lymphocyte ratio (NLR) in predicting disease-specific survival (DSS) in patients with oral cancer undergoing preoperative chemoradiotherapy. A cohort of 97 patients with locally advanced oral squamous cell carcinoma receiving preoperative chemoradiotherapy was retrospectively examined. The impact of NLR and other potential prognostic factors on DSS was assessed with the Kaplan-Meier method and multivariate Cox regression analysis. Sixty-nine patients had a high pretreatment NLR, with NLR > 1.9 considered as high according to receiver operating characteristic curve analysis. In univariate analysis, high pretreatment NLR (p = 0.018), positive perineural invasion (p < 0.001) and advanced pathologic TNM stage after neoadjuvant therapy (p < 0.001) were predictive of shorter DSS. In multivariate analysis, advanced pathologic TNM stage after neoadjuvant therapy (HR 1.71, 95 % CI 1.17-2.48, p = 0.005), positive perineural invasion (HR 3.67, 95 % CI 1.11-12.13, p = 0.033) and high pretreatment NLR (HR 10.37, 95 % CI 1.28-84.08, p = 0.029) remained independently associated with poor DSS. A high pretreatment NLR is a significant independent predictor of shorter DSS in patients with oral cancer receiving preoperative chemoradiotherapy.

Objectives: To compare the accuracy of cone-beam CT (CBCT) and multislice CT (MSCT) with regard to its use in image-guided dental implant surgery in a prospective model based study., Material and Methods: Ten photopolymer-acrylate mandibula models, each with four precise metal reference markers, were scanned with MSCT and CBCT. The six reference distances between the markers were measured by a three-axis milling machine first. The distances were then measured by (1) navigation with the Medtronic StealthStation® TREON™ image-guided surgery system, (2) with the Medtronic planning-tool and (3) on the PC with the Mimics® software. Mean values were calculated for all three methods for CBCT and MSCT and were compared for statistical significance., Results: Of all measurements, 83% of the arithmetic mean values were within the ±0.5 mm range (MSCT 88% and CBCT 78%) and 17% within the ±1.0 mm range (MSCT 12% and CBCT 22%). The absolute difference of the arithmetic mean values showed no statistically significant difference between MSCT and CBCT. The difference of the overall mean values to the reference was 0.43 mm for MSCT and 0.46 mm for CBCT., Conclusions: The data of our study prove that the application of CBCT for the indicated purpose yielded good results comparable to those of MSCT. All three measuring methods were feasible and accuracy was statistically not different between the data acquired by MSCT and CBCT within the setting of this study.

Purpose: To determine patient satisfaction and preference for implant-supported mandibular overdentures (IOD) retained with ball or Locator attachments. In addition, peri-implant conditions and prosthodontic maintenance efforts for the final attachments were evaluated after 1 year of function., Material and Methods: In this crossover clinical trial, 20 edentulous patients were recruited to receive two mandibular implants in the canine region and were provided with implant-retained mandibular overdentures and new complete maxillary dentures. Implant-retained mandibular overdentures were stabilized with either ball attachments or Locator attachments, in random order. After 3 months of function, the attachments in the existing denture were changed. Questionnaires on satisfaction/complaints with the prostheses were administered at baseline (with the old dentures) and after 3 months of function with each attachment, thus providing for an intraindividual comparison. The decision for the final attachment chosen was based on the patient's preference. For the definitive attachment, peri-implant conditions (peri-implant marginal bone resorption, pocket depth, and Plaque Index, Gingival Index, and Bleeding Index) as well as prosthodontic maintenance efforts and satisfaction score were evaluated after an insertion period of 1 year., Results: Nineteen (95%) patients completed the study (1 dropout). Patient satisfaction improved significantly (P<.05) from baseline (old dentures) to the new prostheses retained with each of the two attachment types for all domains of satisfaction. However, there were no differences between ball or Locator attachment for any items of satisfaction evaluated and neither attachment had a significant patient preference. No differences for peri-implant parameters or for patient satisfaction were noted between the definitive attachments (ball, n=10; Locator, n=9) after 1 year. Although the overall incidence rate of prosthodontic maintenance did not significantly differ between both retention modalities, the Locator attachment required more postinsertion aftercare (activation of retention) than the ball anchors.

In the present article, the authors want to present the results of a retrospectively evaluated consecutive series of patients with surgically treated isolated orbital floor fractures (OFF; "blow-out fractures") concerning the functional outcome after OFF and give detailed recommendations based on the clinical and radiological findings. A series of 60 patients with isolated OFF over a 5-year period needing surgically repair at the same institution were evaluated. Patient data were analysed in terms of preoperative and postoperative clinical parameters and radiological findings. The analysed parameters were type of fracture, diplopia, gaze restriction, enophthalmos, materials used for repair, surgical approach and timing of the surgical intervention. Burst type fractures were more often found than punched-out fractures. The most frequently used surgical approach was a preseptal transconjunctival approach. An overall decrease of gaze restriction (93%), diplopia (89%) and enophthalmos (86%) was observed. According to the fracture size, we used Ethisorb patches in smaller fractures and resorbable or titanium meshes or autologous bone in larger fractures in most cases. Patients who underwent surgery more than 7 days after the trauma showed better results with regard to an improvement of diplopia and motility disturbances than patients who were treated immediately. In indicated cases, the surgical repair of OFF leads to very good results if the anatomical and functional properties of the orbit and its contents are respected. The applied strategy and means presented in our study proved of value and can therefore be recommended.

Ameloblastic carcinoma (AC) is a rare tumour which can emerge de novo or from an ameloblastoma. To our knowledge, malignant transformation from an odontogenic cyst into an AC has not been documented yet. This case report describes the manifestation of an AC 10 years after enucleation of a histologically confirmed follicular cyst in the angle of the mandible., (Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Processing and interpreting the face is generally very important because one is often required to make rapid decisions in life on the basis of meagre information. Ninety-two volunteers used a computer-assisted test battery to assess 40 profiles of patients (8 skeletal Class II and 8 skeletal Class III patients, each pre- and postoperatively, with 8 skeletal Class I photographs serving as controls). On a 7-point Likert scale the raters were asked to evaluate aesthetics and a few relevant personality traits (e.g. unintelligent, inhibited, aggressive, brutal). The photographs of the two patient groups were rated significantly less attractive and intelligent prior to surgery than the photographs of the control group. In respect of personality traits, the photographs of the skeletal Class III group differed more strongly from normal ones. In respect of aesthetics and intelligence, both patient groups benefited markedly from surgery. For some personality traits, significant interactions were found between the two groups on pre-post comparison. The method underlying the study is useful for evaluating the outcome of orthognathic surgery, but also indicates the strongly generalized and unconscious processes involved in the estimation of people's personality traits, especially when these concern deviations from the socially normal condition., (Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Our main objective was to apply a standard classification to surgical complications after free flap surgery for reconstructions of the head and neck. We used the modified Clavien-Dindo classification in a cohort of 79 patients who were having reconstructions with jejunal free flaps simultaneously with resections of oral and oropharyngeal cancer. The most common minor complication was the need for a blood transfusion, and the most common major complication of a respiratory nature. The medical complications, and those at the recipient site and the donor site were 53/79 (67%), 44/79 (56%), and 9/79 (11%), respectively. The Clavien-Dindo classification is suitable and can easily be used to evaluate postoperative complications after free tissue transfer., (Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Background: Bisphosphonates are known to be associated with osteonecrosis of the jaw. We assess factors underlying the success of surgical treatment in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ)., Methods: Fifty-eight patients were investigated 6 months after having surgery. Outcome variables included the stage of disease. Factors underlying the success of surgery such as age, sex, dental procedures, underlying disease, and bisphosphonate therapy were subjected to statistical analysis., Results: In all, 41 patients after surgery could be followed up. Twenty-four patients (58.5%) had an intact mucosa after surgical treatment. A statistically significant improvement was registered between preoperative and postoperative staging (p < .01). Routine dental procedures and the underlying illness influenced the outcome of surgery (p < .05). Patients with osteoporosis and multiple myeloma improved to a greater extent by surgery than those with cancer. Discontinuation of bisphosphonates was found to improve the outcome (p < .05)., Conclusions: Surgery is more successful in patients with osteoporosis or multiple myeloma than in those with solid tumors. Discontinuation of bisphosphonate therapy favored the surgical outcome., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: The purpose of this study was to evaluate whether the immunohistochemical expression of p53, p21, p27, cyclin D1, and Ki67 can predict therapy response and survival in patients with oral and oropharyngeal squamous cell carcinoma treated with preoperative chemoradiation., Methods: Biomarker expression was evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded pretreatment biopsies of 111 homogenously treated patients. We assessed the association between clinicopathological variables including response to neoadjuvant chemoradiotherapy as well as the survival of the patients and the expression of the biomarkers as both dichotomized (positive vs. negative) and continuous variables., Results: Biomarker overexpression on the basis of pre-selected cutoff points was seen in 66 of 111 (59%) cases for p53, in 77 (69%) for p21, in 48 (43%) for p27, in 81 (73%) for cyclin D1, and in 54 (49%) cases for Ki67, respectively. None of the examined biomarkers was able to predict response to neoadjuvant chemoradiotherapy or was associated with survival outcome. Post-treatment pathologic TNM stage (P < 0.001), pathologic response (P < 0.001), and perineural invasion (P < 0.001) were the only factors having a significant effect on recurrence-free survival. Post-treatment pathologic N stage (P = 0.005), post-treatment pathologic TNM stage (P < 0.001), pathologic response (P < 0.001), and perineural invasion (P = 0.001) had a significant impact on overall survival., Conclusions: Our results suggest that the biomarkers p53, p21, p27, cyclin D1, and Ki67 have no impact on treatment response and survival in patients with oral and oropharyngeal cancer treated with preoperative chemoradiation., (© 2011 John Wiley & Sons A/S.)

Introduction: The aims of the present study were to compare microbial populations in patients suffering from deep neck space abscesses caused by primary endodontic infections by sampling the infections with aspiration or swabbing techniques and to determine the susceptibility rates of the isolated bacteria to commonly used antibiotics., Methods: A total of 89 patients with deep neck space abscesses caused by primary endodontic infections requiring extraoral incision and drainage under general anesthesia were included. Either aspiration or swabbing was used to sample microbial pus specimens. The culture of the microbial specimens and susceptibility testing were performed following standard procedures., Results: A total of 142 strains were recovered from 76 patients. In 13 patients, no bacteria were found. The predominant bacteria observed were streptococci (36%), staphylococci (13%), Prevotella (8%), and Peptostreptococcus (6%). A statistically significant greater number of obligate anaerobes were found in the aspiration group. The majority of patients presented a mixed aerobic-anaerobic population of bacterial flora (62%). The antibiotic resistance rates for the predominant bacteria were 10% for penicillin G, 9% for amoxicillin, 0% for amoxicillin clavulanate, 24% for clindamycin, and 24% for erythromycin., Conclusions: The results of our study indicated that a greater number of anaerobes were found when sampling using the aspiration technique. Penicillin G and aminopenicillins alone are not always sufficient for the treatment of severe deep neck space abscesses; beta-lactamase inhibitor combinations are more effective. Bacteria showed significant resistant rates to clindamycin. Thus, its single use in penicillin-allergic patients has to be carefully considered., (Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This retrospective study comprises an exploratory analysis of 10 years of surgical treatment of symphysis (S) and parasymphysis/body (P/B). Correlations of complications, as well as dependencies of surgical concepts, are investigated., Materials and Methods: All surgically treated patients in the period of 1995 to 2005 with at least one mandibular fracture mesial to the mandibular angle were included in this study. A total of 63 patients (46 men, 17 women) with 63 symphysis fractures were included and 497 patients (369 men, 128 women) with 553 P/B were included; 99.27% (549) of these fractures were included in the study, 4 had to be dismissed because of inconclusive documentation., Results: Of patients with P/B, 96.04% were successfully treated with 1 open reduction, 3.76% had 2, and 0.20% had 3 surgeries. Of the surgically treated patients, 75.77% (416) were completely free of complications, whereas the other 24.23% of the P/B showed 1 or more complications. The main complication was mild nerve damage (24.8%). Osteosynthesis failure rate (OFR) was 2.4% (7 of 298) for 2 miniplates, 5.7% (3 of 53) for 1 tension screw, and 8.4% (9 of 107) for 1 miniplate. Regarding OFR, 2 miniplates showed to be superior in a Fisher exact test (P = .018, adjusted P = .132). Symphysis fractures were completely free of complications in 81.8% and showed 2 major complications, i.e., 1 severe nerve damage and 1 osteosynthesis failure., Discussion: This study has the limitations of a retrospective study., Conclusion: A high success rate of open reduction and osteosynthesis with 2 miniplates can be guaranteed., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: Osteosynthesis failure rates of 11.3% with 1 miniplate, 6.7% with 2 miniplates, and 4.4% with a single Medartis condyle plate were reported in previous studies of our clinic. Current science is still focused on the osteosynthesis material. Besides clinical parameters, conventional radiographs are still the first choice to detect osteosynthesis failures. This study scrutinized several factors assessable in postoperative orthopantomographs which might elevate the risk of osteosynthesis failure., Study Design: A total of 136 patients (22 with osteosynthesis failure, 114 without) with 151 mandibular condyle fractures were included in this study. Eight parameters were assessed in postoperative orthopantomographs., Results: The best predictor of osteosynthesis failure was a simplified concept of ramus height. In cases of reduced or normal ramus height, the odds of osteosynthesis failure was significantly (P = .000001) reduced to a 10th. Isolated fractures were significantly more error prone (P = .0009)., Conclusions: Postoperative orthopantomographs depict factors which increase the risk of osteosynthesis failure., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: In the past years, various applications of telemedicine have been found. Especially teleconsulting or telementoring has been accepted as a possible answer to upcoming higher quality demands utilizing expert knowledge in everyday clinical routine. In this work we investigate whether video transmission based on universal mobile telecommunication system (UMTS) by means of arthroscopic videos is clinically reasonable. Secondly, we examine the quality of the enabling technology especially for consolidated diagnostics and telementoring., Methods: Twenty arthroscopic video streams with a length of 60 s of each sequence, showing endoscopic craniomaxillofacial interventions such as arthroscopies of the temoporomandibular joint or endoscopic assisted open reductions of mandibular head fractures, were hosted on a server and analyzed on a UMTS cellphone. Each of the arthroscopic video sequences was independently evaluated by two consultants and a medical expert in TMJ surgery. Quality aspects such as identifiability of anatomical details, instruments, and tasks, and pathology were assessed in a questionnaire. Stability of transmission and breakdowns were also registered., Results: The median percentage of completely transmitted videos without interruption was 85 ± 12.5% (interquartile range, IQR). In 6.7% of all video transmissions, complete interruption resulted, requiring restart. Of anatomical structures, 60.7% were correctly identified, while in 39.3% an identification error was detected. Tasks and instruments were recognized in 92.4%. In 94.8%, pathologies could be correctly diagnosed., Conclusions: The need for teleconsultation is given, since orientation in arthroscopy is difficult. UMTS-streamed endoscopic videos still have certain limitations regarding teleconsulting due to instability and delay. Nevertheless, the technology may currently be beneficial for teleteaching and could be used in the future in teleconsultation. Without affecting ongoing surgeries and with no special need for a lecture theater, this technology provides tele-education using standard hospital infrastructure.

Purpose: We evaluated an innovative approach for conventional surgical or transmucosal implantation applying backward planning with bone oriented crown down implant positions, followed by immediate restoration., Materials and Methods: Our workflow combined computer-assisted preoperative planning with the well-known intraoperative handling of surgical templates. To guarantee optimal accuracy, the complete process was bone borne, not soft tissue borne. Furthermore, in this concept, the definite prosthesis was manufactured on a plaster cast and fixed with technical implants inserted into the model using the same drilling template applied for intraoperative guidance of the drill. This bone-based workflow avoids the accumulation of errors throughout all steps of the treatment. In the present study, we have provided a concise quantitative quality control using 4 in vivo implants. This goal was accomplished by image matching of the preoperative plan with the corresponding postoperative computed tomography scan, applying descriptive statistics, the 1-sample t test, and the Student t test., Results: Statistical evaluation showed that the bone-borne drilling template provides sufficient accuracy for immediate restoration with the definite prosthesis at the end of the operation. Deviation in the apex plane was 0.8 ± 0.42 mm, with 0.33 at the maximum. The angular deviation was 3.18° ± 0.78°., Conclusions: Our workflow is a promising approach with respect to handling, accuracy, and intraoperative safety., (Copyright © 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Bone regeneration is required for fracture healing. Various procedures have been used to promote osteogenesis with bone morphogenetic proteins (BMPs). We assessed the effects of BMP-2, BMP-5, and BMP-6 in isolated and combined use on the generation of osteoblasts and osteoclasts by comparing the osteoclastic potency of each on osteoclasts of primary murine bone marrow cells. Subsequently, cells were stained for tartrate-resistant acid phosphatase, and real time PCR analysis of receptor activator of NKκB ligand and osteoprotegerin was conducted. The same combination of BMPs was used to assess their potential to enhance osteoblasts, employing a mineralization assay and real-time PCR analysis of collagen type-1, runx2, and osterix. While BMP-2 alone and the combination of BMP-2 and BMP-5 significantly enhanced osteoclastogenesis, BMP-2, BMP-5, and BMP-6 in combination did not have additional effects. However, the combined use of BMP-2, BMP-5, and BMP-6 had an additive effect on matrix mineralization and osterix expression in osteoblasts. Our study shows that the combination of BMP-2, BMP-5, and BMP-6 stimulates osteoblasts but not osteoclastogenesis. Thus, the synergistic use of various BMPs might improve effective bone regeneration in the clinical setting., (© 2010 Orthopaedic Research Society.)

Objective: The purpose of this retrospective study was to identify the major pathogens responsible for deep space head and neck infections and their current resistance to routinely used antibiotics in a university hospital setting., Study Design: A total of 206 patients suffering from odontogenic deep space infections were treated at our department by means of surgical intervention and intravenous administration of antibiotics., Results: The predominant bacteria were viridans group streptococci (VGS), staphylococci, Prevotella, Peptostreptococcus, and Bacteroides. In the aerobic spectrum, resistance against clindamycin was found in 18%, against macrolides in 14%, and against penicillin G in 7%. The anaerobes were resistant to clindamycin in 11%, to metronidazole in 6%, and to penicillin G in 8%., Conclusion: The high resistance rate for clindamycin and macrolides was especially striking and may necessitate an adaptation of our antibiotic regime in the future., (Copyright 2010 Mosby, Inc. All rights reserved.)

Purpose: The aim of this retrospective study was to evaluate the long-term survival and success rates of screw-type root-shaped (Camlog) implants of various diameters and their implant-prosthodontic reconstructions for more than 5 years of clinical use., Materials and Methods: A retrospective study of patients receiving root-shaped screw-type dental implants placed between May 2001 and July 2003 was conducted. The cumulative implant survival and success rates and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index) as well as the prosthodontic maintenance requirements were evaluated., Results: In all, 541 implants (3.8 mm: 237 implants; 4.3 mm: 211 implants, 5/6 mm: 93 implants) were placed and restored for implant prosthodontic rehabilitation in 216 patients (134 women, 82 men; mean age 54.3 +/- 9.1 years). Of the original 216 patients enrolled, 198 (91.6%; 510/541 implants [94.2%]) were available for a follow-up evaluation after 5 to 7 years (mean follow-up, 68.8 +/- 7.4 months). The overall cumulative 5-year survival and success rates were 98.3% and 97.3%, respectively. A failure rate of 3.7% (9/237) was seen for 3.8-mm-diameter implants; the corresponding figures for the 4.3-mm and wide-diameter (5.0/6.0-mm) implants were 1.4% (3/211) and 1.0% (1/93), respectively. For implants classified as successful, the average peri-implant marginal bone resorption value was 1.8 +/- 0.4 mm, with no differences among the different implant diameters evaluated. Peri-implant soft tissue conditions such as plaque, bleeding, and pocket depth were also satisfactory. All prostheses were functional throughout the observation period, with no fractures of implants, abutments, or screws. Abutment screw (4.5%) or isolated crown loosening (9.8%) for single-tooth restorations requiring recementation, retightening of screws, and adaptation of removable prostheses were the most frequent prosthodontic maintenance needs., Conclusion: The root-shaped implants and the associated prosthetic constructions used in this study showed excellent survival and success rates.

Purpose: Large-scale studies assessing complication rates and correlation of complications are still missing considering different fracture locations in the mandible. In the present retrospective study, complication rates of mandibular angle fractures treated by open reduction were assessed., Materials and Methods: Three hundred twenty-two patients (259 men, 63 women) with 335 surgically treated mandibular angle fractures were included in this study., Results: Fractures were caused by fights (46.6%), falls (19.2%), traffic accidents (14.6%), sports (11.9%), wisdom tooth removal (7.3%), and 0.9% other causes. Successful treatment occurred in 93.69% of fractures with 1 open reduction and in 6.31% with 2 open reductions. Of surgically treated patients, 71.47% (238) were completely free of complications. A detailed complication correlation matrix is given in the text. Ninety-five fractures treated with 1 miniplate, 170 with 2 miniplates, and 70 with other osteosynthesis concepts were compared regarding osteosynthesis failure and pseudarthrosis., Conclusion: Similar osteosynthesis failure rates were shown for 1 miniplate and 2 miniplates., (Copyright (c) 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

This study reports measurements of dental casts in patients up to 6 months of age with bilateral complete cleft lip and palate (BCLP). 25 mouth casts of newborns with BCLP were selected from the hospital archive. They were measured independently by two examiners who assigned numbers to each measurement, referring to the expected reproducibility. The investigators also classified each dental cast according to an established score. The absolute values of all measured distances (P-P', L-C1-C2-T, L'-C1'-C2'-T', P-L, P'-L', L-L', C1-C1', C2-C2', Q1-Q1', Q2-Q2', T-T', I-Q1Q1', I-Q2Q2', I-TT') are reported. Inter-observer reproducibility was acceptable with total measurement errors ranging from 0.5 to 1.4mm. Most reliability scores, ranging from 1 (very high) to 5 (very low), showed a mean between 2 and 3 (min 2.17; max 3.16). The two examiners rated only one patient differently, according to the applied classification scheme. The absolute measurement values of the two classification systems accorded with the literature. This is the first study to measure the distances according to an established protocol in BCLP patients. The measurements between certain landmarks are more precise than others; it may be possible to use the more precise points for a longitudinal study from birth to 18 years.

Introduction: The aim of this study was to review survival and locoregional control in patients with advanced oral and oropharyngeal squamous cell carcinoma treated by multimodal therapy with preoperative radiochemotherapy and radical surgery., Material: Retrospective cohort study., Methods: Included in this analysis are 276 consecutive patients with UICC disease stages III and IV (T2: 13.0%; T3: 16.7%; T4: 70.3%; N0: 29.7%; N1: 20.3%; N2: 45.3%; N3: 4.7%; stage III: 16.3%; stage IV: 83.7%). All patients received preoperative radiochemotherapy (50Gy, Mitomycin and 5-Fluorouracil) and radical locoregional resection., Results: Median surveillance period was 101.4 months (24-202 months). 5-year overall survival probability was 53.9%. 5-year local control probability was 70.2%., Conclusion: These results underline the reliability of preoperative treatment of patients with oral and oropharyngeal cancer.

Tissue engineering offers an exciting prospect for reconstructive surgery by replacing missing natural scaffolds with artificial ones. For optimal success the artificial scaffold should provide an environment closely resembling the natural tissue. Little is known about the direct influence of the scaffold on the expression of regulators of bone development, such as transcription factors. The aim of this study was to investigate the influence of the scaffold material on the expression of V-ets erythroblastosis virus E26 oncogene homolog 2 (avian) (Ets2), a key transcription factor in bone biology. Human primary bone precursor cells were seeded in three-dimensional constructs consisting of hydroxyapatite (HA) or poly (lactic-co-glycolic acid) (PLGA). Cells grown on tissue culture polystyrene dishes served as controls. After cultivation for up to 21 days the expression of Ets2 and other important bone-specific genes was assessed by reverse transcription polymerase chain reaction (RT-PCR) and Western Blotting. Ets2 mRNA showed significantly higher expression in controls than in bone-like constructs, and more Ets2 mRNA was expressed in cells grown in HA than in PLGA constructs. At protein level however, Ets2 expression was higher in constructs than in controls after prolonged culture. Our study showed for the first time a differential expression of Ets2 in tissue engineered bone constructs in vitro, demonstrating that scaffold chemistry has an influence on the expression of genes regulating osteogenesis.

Purpose: The aim of the present study was to evaluate the use of the pedicled buccal fat pad for the closure of oroantral communications (OACs) and to describe our experience with this surgical procedure., Patients and Methods: A retrospective review of 161 patients treated at the University Hospital for Cranio-Maxillofacial and Oral Surgery in Vienna, Austria, from 2000 to 2005, with the diagnosis of an OAC was performed. All defects were closed by application of a buccal fat pad. Data were obtained from chart review, a compiled database, and clinical follow-up and included the location of the defect, the cause of the OAC, the modality of anesthesia, intraoperative complications, any complications during the process of wound healing, and any late adverse effects., Results: The buccal fat pad for closure of an OAC was successfully used in 161 patients at our department. In 12 patients (7.5%), the closure of the OAC was insufficient, and a second operation was necessary. Excluding all severe and complicating cases such as tumor-related defects or previously treated cases, the overall success rate for closure of the OAC was nearly 98%. No late complications occurred, and all patients were free of pain or any limitations after the 6-month follow-up period., Conclusions: According to the recommendations and anatomic limitations reported in published studies and discussed in the present report, the application of the buccal fat pad is a safe and reliable procedure for closing an OAC.

In this study, a CaP biomaterial was used as a carrier for rhBMP-2. Biomaterials were investigated in calvarial and femoral defects using a rabbit animal model, with unloaded biomaterials serving as control. Fluorochrome labels were administered at days 14 and 70. Specimens were retrieved after 12 weeks for histological analysis. When area fractions were assessed by conventional histomorphometry, no significant effect of rhBMP-2 on the amounts of regenerated bone and residual biomaterial were seen by 12 weeks. After mineral appositional rate (MAR) measurement using double labels, calculation yielded significantly higher MARs for defects at both implantation sites, when compared with surrounding bone, whether or not biomaterials were loaded with rhBMP-2. Analyzing the effect of rhBMP-2, both defect sites showed significantly higher MARs in the rhBMP-2 group. MARs of bone surrounding the defects had also been elevated significantly by rhBMP-2 at calvarial and femoral implantation sites. It is concluded that MAR measurement is suitable to identify long-term effects of rhBMP-2 on bone formation at a time when conventional histomorphometry using fractional area determination is inadequate. Also, by MAR assessment, effects of rhBMP-2 on surrounding bone can be documented., (2008 Wiley Periodicals, Inc.)

Purpose: In this study we report our experiences with the treatment of midfacial fractures and various other indications in regions with low load bearing (eg, dysmorphias) using the biodegradable Osteosynthesis System (SonicWeld Rx by KLS Martin, Tuttlingen, Germany), comprising biomechanical and histological aspects., Patients and Methods: Seventy-five patients were included in this study. We describe the application of this system for the treatment of fractures of the zygomamaxillary complex, frontal bone impression fractures, surgical treatment of mukocele in the frontal sinus, isolated fractures of the orbital floor, complex midfacial trauma and bone cap fixation, craniosynostoses, and fixation of a distracted bone fragment., Results: The pin insertion could be finished with a total failure rate of lower than 5%. In 3 patients, soft tissue swellings in regions with less subcutaneous fat were observed 6 to 8 months postoperatively. No fracture dislocations occurred. Scanning electron micrograph of the experimentally acquired connection between the resorbable plate and 2 pins clearly demonstrates a tight and reliable fusion to bone, both at the cortical as well as at the spongy compartment. Conventional histology leads to corresponding findings as scanning electron micrography, and shows a close fusion between all components., Conclusion: This retrospective study shows the general feasibility, sufficient mechanical stability, and efficient intraoperative handling of this angle-stable, ultrasonic-guided resorbable Osteosynthesis System (ResorbX and SonicWeld Rx) for a wide variety of indications in craniomaxillofacial surgery.

Selected workflows combining computer-assisted teleplanning and navigation (including 3D-stereolithography) are presented. It is shown how interactive teleplanning of dental implants or optimization of a surgical treatment of large bone defects is done.

Background: Osteonecrosis of the jaws occurs after the administration of bisphosphonates. An unequivocal treatment strategy is yet to be devised. We assess the treatment of patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ)., Methods: The investigators studied a prospective cohort of 58 patients 6 months after surgical treatment of BRONJ. Outcome variables were the status of the mucosa, the visual analog score of pain, and prosthetic rehabilitation. Preoperative staging results were compared with the postoperative outcome and statistically evaluated., Results: Of 58 patients, 41 surgically treated patients could be followed up after a mean period of 189 (+/-23) days. Twenty-four (58.5%) were free of pain and had an intact mucosa. A statistically significant improvement was registered between preoperative and postoperative staging (p <.01); 11 of 12 patients who had been treated with a flap procedure for soft tissue closure had an intact mucosa., Conclusions: This is the first prospective study to report the outcome of treatment in a cohort of patients with BRONJ. Minimal resection of necrotic bone and local soft tissue closure might be a feasible treatment strategy in patients with established BRONJ.

The present study investigated whether bone regeneration and biomaterial replacement would be improved by loading of biogenous biphasic biomaterial scaffolds (HA/TCP ratio 30/70) with rhBMP-2, and whether the placement of three barrier membranes differing in structure and porosity (prototyped SLA Ti specimens, GORE RESOLUT Adapt specimens, and titanized TiMESH light specimens) would have a synergistic effect. A rabbit calvarial model was used for the implantation studies. Histological specimens were obtained after 12 weeks and evaluated quantitatively for differences between the various material combinations. Loading of the biomaterials with rhBMP-2 significantly enhanced the amount of regenerated bone and caused a pronounced biomaterial replacement. While BMP-induced bone had formed uniformly over the surgical defects, bone regeneration in the absence of BMP depends on bone promotion from the margins of the defects toward the center. No positive effect on bone regeneration was seen for any of the placed barrier membranes. While the present study had shown that rhBMP-2 loading significantly increases bone regeneration using the investigated biomaterial, barrier-membrane placement may be useful in predetermining the final shape of the regenerative site but provides no additional beneficial impact on the amount and quality of the bone regeneration induced by rhBMP-2.

Objective: One step toward motion analysis of the temporomandibular joint is pseudodynamic magnetic resonance imaging (i.e., with stepwise mouth opening controlled by a Burnett device). This study intends to clarify whether and how pseudodynamic motion differs from natural motion. Furthermore, the fixing efficiency (i.e., the reliability of the mechanical connection to the jaw) of the Burnett device was tested., Study Design: In 10 patients we recorded pseudodynamic opening motions by means of MRI and optical tracking technology (as known from image-guided surgery) synchronously; natural opening motions by spatiotemporal tracking only. The MRI was used to allow for interpretation of the pseudodynamic motion as recorded by means of optoelectronic tracking., Results: In 3 subjects the pseudodynamic differed from the natural opening in occurrence of a loop (i.e., a short backward motion of the condyle during the opening process that results from the application of the Burnett device and does not correspond to a natural jaw movement). Fifty percent of the opening steps showed unintended motion and thus did not keep the mandible still during the MRI scan., Conclusion: A method was provided to detect motion during MRI scan using optoelectronic tracking. Pseudodynamic motion may differ from natural motion.

Objective: In this study we report on finite element calculation to verify the mechanical stability induced by the new geometry of a novel condylar process plate. We report our clinical experiences in the treatment of condylar process fractures using the novel plate. The plate has been designed according to finite element calculations in order to optimize mechanical stability and stiffness. The potential influence of this plate on the postoperative complication rate was assessed., Study Design: Thirty-five mandibular condylar process fractures in 30 patients (20 male, 10 female, age: 34.3 +/- 11.5 years) were treated with the Modus condylar process plates (Medartis, Basle, Switzerland) and are included in this study. The time periods for postoperative follow-ups were 6 weeks and 6 months., Results: No plate fractures occurred and there was no injury to the facial nerve. In one patient a screw loosening was observed. Two patients showed inadequate reduction without functional impairment., Conclusion: The newly developed condylar process plate proved to provide sufficient mechanical stiffness to avoid plate fractures. The postoperative complication rate can be reduced significantly. Statistical comparison to other osteosynthesis methods of the condylar process was performed and showed significant differences (single miniplates: P = .006 and minidynamic compression plates: P = .055). We conclude that a single Modus condylar process plate shows results comparable to 2 miniplates.

Objectives: In this study, we present and evaluate a micro-computed tomography (micro-CT)-based method for the calculation of the potential bone/implant contact area (p-BICA) on the surface of dental implants., Material and Methods: For seven commercially available implants (Ankylos implant, Brånemark System, Frialit CELLplus, Replace((R)) Select Tapered, Straumann Solid screw, XiVE S CELLplus, 3i Osseotite XP Threaded Miniplant, the p-BICA surface is determined by means of three-dimensional X-ray computed-tomography and computer-based data processing. Measurements were repeated two times, and the stability and repeatability of the measurement method were evaluated., Results: Our analysis revealed a p-BICA of 118 mm(2) for the XiVE S CELLplus implant, 134 mm(2) for the Ankylos, 136 mm(2) for the Frialit CELLplus, 138 mm(2) for the Brånemark System, 139 mm(2) for the Replace((R)), 159 mm(2) for the 3i Osseotite XP and 199 mm(2) for the Straumann Solid screw implant. The measurement method proved to be stable and led to reproducible results., Conclusions: The micro- and macrostructure of dental implants define the surface and the p-BICA. Precise determination of this parameter can be achieved by means of the micro-CT-based method as presented in this study. The value of p-BICA lies in the predictability of industrial design before preclinical and clinical testing. Based on this method, dental implant properties become comparable even if geometrical details are not disclosed by the manufacturer.

The authors compared the accuracy of laser surface scanning patient registration using the commercially available Fazer (Medtronic, Inc.) with the conventional registration procedure based on fiducial markers (FMs) in computer-assisted surgery. Four anatomical head specimens were prepared with 10 titanium microscrews placed at defined locations and scanned with a 16-slice spiral computed tomography unit. To compare the two registration methods, each method was applied five times for each cadaveric specimen; thus data were obtained from 40 registrations. Five microscrews (selected following a randomization protocol) were used for each FM-based registration; the other five FMs were selected for coordinate measurements by touching with a point measurement stylus. Coordinates of these points were also measured manually on the screen of the navigation computer. Coordinates were measured in the same manner after laser surface registration. The root mean square error as calculated by the navigation system ranged from 1.3 to 3.2 mm (mean 1.8 mm) with the Fazer and from 0.3 to 1.8 mm (mean 1.0 mm) with FM-based registration. The overall mean deviations (the arithmetic mean of the mean deviations of measurements on the four specimens) were 3.0 mm (standard deviation [SD] range 1.4-2.6 mm) with the Fazer and 1.4 mm (SD range 0.4-0.9 mm) with the FMs. The Fazer registration scans 300 surface points. Statistical tests showed the difference in the accuracy of these methods to be highly significant. In accordance with the findings of other groups, the authors concluded that the inclusion of a larger number of registration points might improve the accuracy of Fazer registration.

Purpose: Tissue engineering of bone entails the successful interplay between osteoinductive factors, osteogenic cells, their extracellular environment, and an osteoconductive biomaterial scaffold. Naturally produced ceramics, like hydroxyapatite (HA) calcified from red algae, are the most promising materials for use as scaffolds in this field. We hypothesized that extracellular matrix compartments and osteoinductive factors could further ameliorate the bioactivity of the scaffold., Materials and Methods: Osteosarcoma cells with proven osteogenic phenotype (SaOS-2) were cultured onto type I collagen coated (Coll I/HA) and noncollagen coated HA granules (NC/HA) gained from red algae (C GRAFT/Algipore). Cells grown on tissue culture polystyrene dishes (TCPS) were used as controls. Second, SaOS-2 cells cultured on Coll I/HA, NC/HA, and TCPS were treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) in different concentrations (10, 100, and 500 ng/mL). Non rhBMP-2-treated cultures were used as controls. Cultures of both experiments were grown under osteogenic differentiation conditions and after 24, 48, and 72 hours assays for cell viability, apoptosis, alkaline phosphatase activity (ALP), and osteocalcin (OC) secretion were done., Results: Coating of HA granules with type I collagen showed higher cell viability in rhBMP-2-treated and nontreated cells. Supplementation of cultured cells with exogenous rhBMP-2 showed a dose-dependent effect only in the TCPS group. No alterations of the apoptotic rate within 1 investigation group were found. Addition of rhBMP-2 did not significantly alter the specific OC secretion of cells grown on Coll I/HA and TCPS., Conclusion: These in vitro findings show that in the initial period of cultivation and up to 72 hours, the coating of HA granules with collagen type I had positive effects on cell viability and osteoblastic characteristics of osteoblastic cells. In contrast, the supplementation with exogenous rhBMP-2 shows no dose-dependent effects. The combination of collagen type I and exogenous rhBMP-2 did not ameliorate the bioactivity of hydroxyapatite calcified from red algae in the initial period of cultivation.

Purpose: To analyze mortality and causes of death in patients who received preoperative radiochemotherapy and underwent radical surgery for advanced oral or oropharyngeal cancer., Patients and Methods: A total of 222 patients who underwent multimodality treatment from 1990 to 2000 were included in the study. The inclusion criterion was International Union Against Cancer (UICC) disease stage II to IV (T2, 33.3%; T3, 12.6%; T4, 54.1%). Patients received preoperative radiotherapy 50 Gy and concomitant chemotherapy with mitomycin and 5-fluorouracil. Radical local-regional en bloc resection was performed in all patients. Survival status and causes of death were ascertained from the National Health Registry. Death certificates and autopsy reports were consulted when hospital files failed to provide reliable data., Results: After a median surveillance period of 72.3 months (range, 24 to 152 months), 59% of patients were alive, 21% had died of recurrence, 5% had died perioperatively, and 15% had died from other causes. Of these, a second cancer in the head and neck region or the lower respiratory tract or the upper digestive tract was found in 7.3%. Although 93% of deaths related to recurrent disease occurred within the first 36 months after surgery, the remaining causes of death did not reveal a specific temporal pattern., Conclusion: Favorable survival data were registered for patients with advanced squamous cell carcinoma of the oral cavity who underwent combined treatment protocols. These patients frequently die of comorbidities. Because recurrent disease is a less common cause of mortality than are other causes, the latter should receive attention during surveillance.

Three-dimensional stereolithographic models (SL models), made of solid acrylic resin derived from computed-tomography (CT) data, are an established tool for preoperative treatment planning in numerous fields of medicine. An innovative approach, combining stereolithography with computer-assisted point-to-point navigation, can support the precise surgical realization of a plan that has been defined on an SL model preoperatively. The essential prerequisites for the application of such an approach are: (1) The accuracy of the SL models (including accuracy of the CT scan and correspondence of the model with the patient's anatomy) and (2) the registration method used for the transfer of the plan from the SL model to the patient (i.e., whether the applied registration markers can be added to the SL model corresponding to the markers at the patient with an accuracy that keeps the "cumulative error" at the end of the chain of errors, in the order of the accuracy of contemporary navigation systems). In this study, we focus on these two topics: By applying image-matching techniques, we fuse the original CT data of the patient with the corresponding CT data of the scanned SL model, and measure the deviations of defined parameter (e.g., distances between anatomical points). To evaluate the registration method used for the planning transfer, we apply a point-merge algorithm, using four marker points that should be located at exactly corresponding positions at the patient and at connective bars that are added to the surface of the SL model. Again, deviations at defined anatomical structures are measured and analyzed statistically. Our results prove sufficient correspondence of the two data sets and accuracy of the registration method for routine clinical application. The evaluation of the SL model accuracy revealed an arithmetic mean of the relative deviations from 0.8% to 5.4%, with an overall mean deviation of 2.2%. Mean deviations of the investigated anatomical structures ranged from 0.8 mm to 3.2 mm. An overall mean (comprising all structures) of 2.5 mm was found. The fiducial registration error of the point-merge algorithm ranged from 1.0 mm to 1.4 mm. The evaluated chain of errors showed a mean deviation of 2.5 mm. This study verifies that preoperative planning on SL models and intraoperative transfer of this plan with computer assisted navigation is a suitable and sufficiently reliable method for clinical applications.