Composite images of upper front teeth--judgment of attractiveness and gender-specific correlation.

UNLABELLED: The esthetic appearance of upper front teeth strongly depends on color, shape, size, width-to-height ratio, and position of teeth. In the past, these single esthetic aspects had been analyzed separately and not as a whole. Thus, the objective of this current study is to investigate the perception of the esthetics of upper front teeth whose image had been manipulated by composite photoimaging. In order to obtain the six composite images, one for each gender and group ("discontent," "average," and "content"), 320 students were photographed. Afterwards, the 6 composite images were rated by 128 independent participants (dentists and laymen), concerning attractiveness and gender. The composite images "average" and "content" were rated significantly more attractive than "discontent" images. The composite images rated as "attractive" were attributed to the female gender by the majority of the participants (61-85%); the "unattractive" images were predominantly (85-75%) related to the male gender. The participants were unable to judge the correct gender yet they assigned attractiveness to be a clearly female attribute. This "bias" can be utilized for the reconstruction upper front teeth, to emphasize the gender of the patient. CLINICAL SIGNIFICANCE: The presented morphing technique can contribute to further study setups considering dental appearance and attractiveness. In the case of restoring upper front teeth, the parameters tooth shape, size, width-to-height ratio, and position of teeth should be individually chosen and can emphasize or dampen the perception of gender.

Orbital floor reconstruction with resorbable polydioxanone implants.

Many different materials are proposed for reconstruction of traumatic orbital floor defects. Donor-site morbidity of autologous transplants and infections or extrusions of nonresorbable implants lead to a widespread use of resorbable, alloplastic materials such as polydioxanone (PDS). The goal of this study was to evaluate the prevalence of orbital floor fracture-related problems after surgical treatment using PDS. Ophthalmologic and clinical examinations were performed at 194 patients before orbital floor reconstruction, 14 days and 6 months after surgery (approximate defect sizes: <1 cm², n=50; 1-2 cm², n=97; >2 cm², n=47). Clinical findings including the ocular motility, the sensibility of the infraorbital nerve, and the position of the globe were evaluated. For statistical analysis of categorical data, confidence intervals of percentages were determined. Linear relationships between 2 variables were assessed with Pearson correlation analysis. A reduced ocular motility was diagnosed in 60 patients (31%) before surgery; in 14 patients (7%), 2 weeks; and in 10 patients (5%), 6 months after surgery. Infraorbital hypesthesia was found in 120 patients (62%) before surgery; in 47 patients (24%), 2 weeks; and in 35 patients (18%), 6 months after surgery. An enophthalmos was present in 10 patients (5%) before surgery, and in 4 patients (2%), 6 months after surgery. Our data suggest that PDS is a suitable implant for orbital floor reconstruction with acceptable low rates of infraorbital hypesthesia, bulbus motility disturbances, and enophthalmos. Polydioxanone can also be used for orbital floor defects exceeding 2 cm².

Facial self-perception, well-being, and aesthetic surgery.

BACKGROUND: It is controversial whether impaired well-being is associated with (a) an increased likelihood of having a negative body/facial image; or (b) dissatisfaction with the postoperative result following aesthetic surgery. We set out to improve current knowledge in this matter. METHODS: A total of 324 subjects (n = 162 females, n = 162 males, 18-30 years) were photographed, asked to complete the adjective mood scale and to rate 46 statements regarding their own appearance, and its impact on social functioning as well as their willingness to undergo aesthetic surgery on a visual analog scale. The photographs of these subjects were also assessed by 50 independent judges. RESULTS: Average self-awarded ratings of appearance were significantly more positive in subjects with normal as compared to those with impaired well-being (P = 0.014). Items regarding the impact of appearance on social functioning were answered significantly more negatively by subjects with impaired well-being as compared with those with the normal well-being (P = 0.001). Subjects with impaired well-being did not declare an increased willingness to undergo aesthetic surgery (P > 0.197). Assessment by the independent judges did not reveal differences in the average level of attractiveness of subjects with impaired well-being and those with normal well-being (P = 0.666). CONCLUSIONS: Impaired well-being is associated with impaired facial selfperception, independent of attractiveness. Willingness to undergo aesthetic surgery seems not to be affected by one's sense of well-being. In the subjects with impaired well-being who undergo aesthetic surgery, facial self-perception seems unlikely to be improved.

Virtual dental surgery as a new educational tool in dental school.

PURPOSE: The virtual environment of the Voxel-Man simulator that was originally designed for virtual surgical procedures of the middle ear has been adapted to intraoral procedures. To assess application of the simulator to dentistry, virtual apicectomies were chosen as the pilot-test model. METHODS: A group of 53 dental students provided their impressions after virtual simulation of apicectomies in the Voxel-Man simulator. RESULTS: Fifty-one of the 53 students recommended the virtual simulation as an additional modality in dental education. The students indicated that the force feedback (e.g. simulation of haptic pressure), spatial 3D perception, and image resolution of the simulator were sufficient for virtual training of dental surgical procedures. CONCLUSION: The feedback from dental students involved in this pilot-test has encouraged our interdisciplinary group to continue further development of the simulator with the goal of creating new training strategies in dental and medical education.

Antimicrobial Peptide immunity protects human nasal and auricular cartilage against infection.

BACKGROUND: Despite being impervious to surveillance by the adaptive immune system because of its lack of vascularity, infection of the nasal and auricular cartilage after surgery such as rhinoplasty or otoplasty is rare. Why is this so? Our goal was to determine whether the expression of antimicrobial peptides provides a previously unrecognized nonepithelial layer of innate immune defense within the nasal and auricular cartilage. MATERIALS AND METHODS: Seven samples of nasal septum cartilage and 2 biopsies from auricular cartilage grafts were harvested during rhinoplasty and otoplasty procedures. Ten cadaveric samples of auricular and 9 samples of nasal cartilage were also obtained. Immunohistochemical staining was directed against the human beta-defensin antimicrobial peptides (hBD) 1, 2, and 3. A semiquantitative analysis was performed to measure immunoreactivity. RESULTS: All 3 human beta-defensins were detected along the perichondral line and within the cartilage matrix in the nasal and auricular samples. Areas with positive immunohistochemical staining were also detected within chondrocyte cytoplasm. CONCLUSIONS: We provide the first evidence of antimicrobial peptide expression (hBD-1, -2 and -3) within the perichondrium and cartilage matrix layers of the nasal and auricular cartilage. This previously unrecognized innate immune function of perichondrocytes and chondrocytes may explain the resistance of the nasal and auricular cartilage to infection after surgical procedures despite the absence of a vascular system.

Tissue engineering of periosteal cell membranes in vitro.

OBJECTIVES: The cultivation of bone is a major focus in tissue engineering and oral implantology. Without a periosteal layer, instant or rapid development of a substantial cortical layer is unlikely for engineered bone grafts. The aim of this study was to test the ability of four collagen membranes to support and promote the proliferation of human periosteal cells. MATERIALS AND METHODS: Human periosteum cells were cultured using an osteogenic medium consisting of Dulbecco's modified Eagle's medium supplemented with fetal calf serum, penicillin, streptomycin and ascorbic acid at 37 degrees C with 5% CO(2). Four collagen membranes served as scaffolds: Bio-Gide, Chondro-Gide, Tutodent and Ossix Plus. Cell vitality was assessed by fluorescin diacetate (FDA) and propidium iodide (PI) staining, biocompatibility with LDH and BrdU, MTT, WST tests and scanning electron microscopy (SEM). RESULTS: After 24 h, all probes showed viable periosteal cells. All biocompatibility tests revealed that proliferation on all membranes after treatment with eluate from membranes after a 24-h immersion in a serum-free cell culture medium was similar to the controls. Periosteal cells formed layers covering the surfaces of all four membranes 7 days after seeding in SEM. CONCLUSION: It can be concluded from our data that the collagen membranes can be used as scaffolds for the cultivation of periosteum layers with a view to creating cortical bone using tissue-engineering methods.

Assessing dentists' knowledge about oral cancer: translation and linguistic validation of a standardized questionnaire from American English into German.

Oral cancer represents a considerable health problem with more than 10,000 new cases each year in Germany. Nevertheless, little information is available on the knowledge of dentists and the public on oral cancer. This project aims at investigating the knowledge and opinions of dentists via a questionnaire. The present article describes the translation process of an internationally accepted instrument into German. The translation was carried out by the Mapi Research Institute, Lyon, France. The translation procedure followed an established linguistic validation process, consisting of the conceptual analysis of the source instrument, a forward and backward translation, the clinicians' review, proofreading, and the finalization. The institute identified nine cultural adaptations. After forward and backward translations, the clinical reviewers suggested 16 stylistic changes, four alternative wordings, two more cultural adaptations, and five changes of nomenclature. After debriefing, the translated questionnaire involved nine stylistic changes, four alternative wordings, and 11 changes for cultural adaptation. The described translation and validation procedure guarantees a high-quality standard instrument for the evaluation of dentists' knowledge and opinions on oral cancer in Germany and prevents misinterpretations due to cultural differences, which allows an international comparison of the data.

The battle against multi-resistant strains: Renaissance of antimicrobial essential oils as a promising force to fight hospital-acquired infections.

Hospital-acquired infections and antibiotic-resistant bacteria continue to be major health concerns worldwide. Particularly problematic is methicillin-resistant Staphylococcus aureus (MRSA) and its ability to cause severe soft tissue, bone or implant infections. First used by the Australian Aborigines, Tea tree oil and Eucalyptus oil (and several other essential oils) have each demonstrated promising efficacy against several bacteria and have been used clinically against multi-resistant strains. Several common and hospital-acquired bacterial and yeast isolates (6 Staphylococcus strains including MRSA, 4 Streptococcus strains and 3 Candida strains including Candida krusei) were tested for their susceptibility for Eucalyptus, Tea tree, Thyme white, Lavender, Lemon, Lemongrass, Cinnamon, Grapefruit, Clove Bud, Sandalwood, Peppermint, Kunzea and Sage oil with the agar diffusion test. Olive oil, Paraffin oil, Ethanol (70%), Povidone iodine, Chlorhexidine and hydrogen peroxide (H(2)O(2)) served as controls. Large prevailing effective zones of inhibition were observed for Thyme white, Lemon, Lemongrass and Cinnamon oil. The other oils also showed considerable efficacy. Remarkably, almost all tested oils demonstrated efficacy against hospital-acquired isolates and reference strains, whereas Olive and Paraffin oil from the control group produced no inhibition. As proven in vitro, essential oils represent a cheap and effective antiseptic topical treatment option even for antibiotic-resistant strains as MRSA and antimycotic-resistant Candida species.

Platelet-rich plasma and platelet-rich fibrin in human cell culture.

OBJECTIVES: The clinical use of platelet-rich plasma (PRP) for preprosthetic surgery has been a matter of controversy until now. Only recently, a new blood preparation has been developed which results in platelet-rich fibrin (PRF). The objective of the present investigation was to examine the growth factor release from PRP and PRF in vitro. STUDY DESIGN: Whole blood samples from healthy participants (n = 10) were drawn to generate PRP and PRF. Human osteoblasts (O), human fibroblasts (F), and human osteoblast-derived osteosarcoma cells (Saos-2) were used for the cell culture. Cells of each cell line were cultivated, and PRP- or PRF-preparations added for ten days. The drawn medium was pooled and the quantities of growth factors (platelet-derived growth factor isomers AB and BB, insulin-like growth factor I, and transforming growth factor (TGF) isomers beta1 and beta2) analyzed by enzyme-linked immunosorbent assay. RESULTS: In osteoblast and Saos-2 cultures, cytokine concentrations were significantly higher for PRP than for PRF (P < .05). In fibroblast cultures, results were the same with the exception of TGF-beta2 (P < .05). CONCLUSIONS: This study demonstrates that PRP application in cell cultures leads to higher levels of growth factors than PRF application.

Psoriasis of the tongue.

INTRODUCTION: Psoriasis is a common, chronic dermatologic disease. Cases affecting the oral mucous membranes are rarely reported in the international literature, in particular tongue lesions are hardly ever documented. MATERIAL AND METHODS: This article presents a 61 year old patient with persistent whitish lesion on his tongue. Biopsy specimens from mid surface and tip of the tongue were taken. Histopathologic sections were stained with haematoxylin-eosin (H-E) as well as with Periodic acid-Schiff (PAS) and examined by light microscopy. RESULTS: Tongue lesions showing epithelial hyperplasia, parakeratosis, long papillae, neutrophils and microabscesses of Munro. CONCLUSIONS: The reported case suggests that the clinical and histological appearances of the lesions are consistent with mucosal psoriasis.

Rapid prototyping: porous titanium alloy scaffolds produced by selective laser melting for bone tissue engineering.

Selective laser melting (SLM), a method used in the nuclear, space, and racing industries, allows the creation of customized titanium alloy scaffolds with highly defined external shape and internal structure using rapid prototyping as supporting external structures within which bone tissue can grow. Human osteoblasts were cultured on SLM-produced Ti6Al4V mesh scaffolds to demonstrate biocompatibility using scanning electron microscopy (SEM), fluorescence microscopy after cell vitality staining, and common biocompatibility tests (lactate dihydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), 5-bromo-2-deoxyuridine (BrdU), and water soluble tetrazolium (WST)). Cell occlusion of pores of different widths (0.45-1.2 mm) was evaluated. Scaffolds were tested for resistance to compressive force. SEM investigations showed osteoblasts with well-spread morphology and multiple contact points. Cell vitality staining and biocompatibility tests confirmed osteoblast vitality and proliferation on the scaffolds. Pore overgrowth increased during 6 weeks' culture at pore widths of 0.45 and 0.5 mm, and in the course of 3 weeks for pore widths of 0.55, 0.6, and 0.7 mm. No pore occlusion was observed on pores of width 0.9-1.2 mm. Porosity and maximum compressive load at failure increased and decreased with increasing pore width, respectively. In summary, the scaffolds are biocompatible, and pore width influences pore overgrowth, resistance to compressive force, and porosity.

Nasal shape and gender of the observer: implications for rhinoplasty.

BACKGROUND: In a previous study we focused on gender specific nasal shapes. The aim of this study was to evaluate if preferences in nasal shape are also dependent on the gender of the observer. METHODS: Stratified on the basis of each photographed subject's (n=311) own evaluation, female and male composite pictures of "average" (n=128, each), "optimal" (n=16, each) and "most unpleasant" (n=8, each) noses were created in a previous study. These composites were assessed by 308 independent female and male judges using a visual analogue scale. RESULTS: On average, female judges were found to accord significantly higher ratings of attractiveness as compared to male judges for the composite images independent of the gender of the person shown (p=0.020). The difference was greatest when assessing most unpleasant male composites (p<0.003) but was not apparent when assessing "optimal" female and "optimal" male noses. Despite this, women displayed the same preferences for "optimal" and "average" noses as compared to the "most unpleasant" noses. In assessing their own noses, women were significantly less satisfied with their appearance in general (p=0.001) as compared to men. CONCLUSIONS: In comparison to men, women are more critical in assessing the appearance of their own nose as opposed to the noses of other people. The implications of this for rhinoplasty, so far as considering the degree of influence of the gender of a person assessing a prospective patient's nose remains a matter of conjecture.

Prospective observation of 41 perforations of the Schneiderian membrane during sinus floor elevation.

OBJECTIVES: The aim of this study was to follow 41 intraoperative perforations of the Schneiderian membrane during sinus floor elevation and to identify potential differences from patients without perforations. MATERIAL AND METHODS: Two hundred and one sinus floor elevations were performed at the department of oral and maxillofacial surgery of the University Hospital of Schleswig-Holstein in the years 2005 and 2006. Forty-one intraoperative perforations (20.4%) were documented and treated according to the following scheme: defects smaller than 5 mm were covered with a collagen membrane. Larger defects were additionally sutured. Particulated jawbone mixed 50 : 50 with bone substitute (25 cases) and a 50 : 50 mix of particulated iliac crest bone and BioOss (six cases) mainly served as graft material in the perforation group. In 12 cases, implants were installed at the time of sinus grafting, and in 27 cases, a second operation was performed. RESULTS: Four sinus lift procedures had to be discontinued intraoperatively. Over a mean control interval of 162 days, one implant of the 93 inserted had to be replaced in the perforation group. After 1 year, the implant survival rate was 14 out of 14 in the perforation group vs. 81/92 in the control group. CONCLUSIONS: With appropriate treatment, intraoperative sinus membrane perforations did not represent an elevated risk for implant loss, infectious complications or displacement of graft material in the investigated population.

Penicillin compared with other advanced broad spectrum antibiotics regarding antibacterial activity against oral pathogens isolated from odontogenic abscesses.

OBJECTIVES: We examined the spectrum of oral pathogens found in odontogenic abscesses and their susceptibility to penicillin as well as to amoxicillin with clavulanic acid, doxycycline, clindamycin and moxifloxacin. The in vitro results were compared with clinical observations. PATIENTS AND METHODS: One hundred and eighty eight swabs were obtained from 94 patients with odontogenic abscesses. Bacterial strains were isolated for susceptibility tests. The same patients were investigated for their clinical outcome after standard therapy. RESULTS: A total of 517 bacterial strains were isolated from 94 patients. Ninety eight per cent of abscesses were polymicrobial. The most prevalent bacteria were Viridans streptococci representing 54% of the aerobic/facultative anaerobic bacteria. Prevotella spp. comprised 53% of the anaerobes. No multiresistant strains were detected. Susceptibility testing revealed a sensitivity of over 99% of aerobes/facultative aerobes and 96% of anaerobes sensitivity for moxifloxacin. The corresponding values for penicillin were lowest at 61% and 79%, respectively. In the clinical collective, patients with minor abscesses and no risk of further progression received surgical treatment without antibiotics (36%). Penicillin was administered additionally in 30%. Amoxicillin with clavulanic acid was given in 18% and clindamycin in 15%. Ninety two of the 94 patients showed significant recovery with the described treatment. Only in two cases was a change to the latest broader spectrum antibiotics necessary. CONCLUSION: In contrast to the moderate in vitro results, penicillin successfully treated the pathogens derived from odontogenic abscess sufficiently when adequate surgical treatment was provided. One third of the patients was treated successfully with incision and drainage only. We suggest that one good reason for its clinical efficacy is the susceptibility of the dominant aerobe/facultative aerobe and anaerobe strains to penicillin.

HDR brachytherapy irradiation of the jaw - as a new experimental model of radiogenic bone damage.

INTRODUCTION: Hitherto, no suitable experimental model exists to test new treatments for radiogenic bone damage, such as new step from knowledge about bone growth factors or angiogenesis factors. The goal of this investigation was to establish such a standardised experimental model. MATERIAL AND METHODS: Twenty-four rats were used in this study. In 12 rats a plastic tube was implanted along the right half of the mandible and treated with a single dose of 20 Gy at a high-dose-rate (HDR) using an afterloading machine, the remainder served as control (n=12). One hundred days after irradiation both sides of the mandible were examined using paraffin embedding and non-decalcified histology. RESULTS: All HDR irradiated rats developed localised alopecia within 2 weeks of radiotherapy. In the irradiated group, a clear growth reduction of the ipsilateral incisor was observed. Paraffin histology revealed minimal damage of the bone structure with slightly increased signs of regeneration. The bone apposition rate was significantly reduced on the irradiated right side, compared with the left side (p=0.028). The average diameter of the mandibular condyles on the irradiated right sides was significantly reduced when compared with the left sides (p=0.023). CONCLUSIONS: It is possible to induce radiogenic damage of the mandible by using HDR brachytherapy with a single dose of 20 Gy comparable to 45 x 2 Gy of conventional irradiation. This new model is easy and predictable and appears to be suitable for the testing of new treatment modalities. It is advantageous for the testing of bone growth and angiogenesis factors that the contralateral side exhibits completely normal bone apposition characteristics enabling a split-mouth design for future experiments.

Missing osteogenic effect of expanded autogenous osteoblast-like cells in a minipig model of sinus augmentation with simultaneous dental implant installation.

OBJECTIVES: With natural bovine bone mineral (BioOss) as carrier, the study aimed at investigating the effect of autogenous osteoblast-like cells on bone regeneration in an orthotopic (maxillary sinus) and an ectopic (muscle) site. MATERIALS AND METHODS: Autogenous osteoblast-like cells were isolated from iliac cancellous bone of six minipigs and expanded in an autogenous serum-supplemented osteogenic medium. After confirmation of osteogenicity, the expanded cells were precultivated on BioOss granules for 1 week. Four milliliter of cell-seeded BioOss were used for sinus augmentation of right sinus and a Straumann solid screw (dental) implant was simultaneously installed. The contralateral (control) side was filled with cell-free BioOss. Besides, 2 ml of the corresponding granules were placed in a pouch in the latissimus dorsi muscles bilaterally. Polychrome sequential labeling was performed postoperatively. Specimens were harvested at week 6. Undecalcified sections were evaluated with microradiography, fluorescence microscopy, histology and histomorphometry. RESULTS: In the test side, the coronal part of dental implant demonstrated higher bone-implant contact (BIC) than the apical part (34.88+/-28.86% vs. 16.68+/-13.80%, P=0.039), as well as higher bone density (BD) in the corresponding zone (14.88+/-6.37% vs. 11.10+/-4.54%, P=0.021). However, the test side demonstrated no advantage over control side in either BD (12.25+/-4.22% vs. 8.45+/-11.04%, P=0.473) or BIC (24.15+/-21.97% vs. 22.05+/-19.00%, P=0.270). Rare bone was formed in the muscles in both sides. CONCLUSIONS: The expanded autogenous osteoblast-like cells failed to enhance bone formation in the minipig model of sinus augmentation.

"Bis-phossy jaws" - high and low risk factors for bisphosphonate-induced osteonecrosis of the jaw.

INTRODUCTION: Bisphosphonates (BPs) have transformed our ability to treat certain malignancies, osteoporosis and hypercalcaemia. This class of drug is assumed to be well tolerated by most. There are some important caveats to this assumption, however, one of the significances being the risk of osteonecrosis of the jaw (ONJ). MATERIAL AND METHODS: This multi-centre retrospective study examined the role of different BPs on the development of ONJ, its clinical presentation and the efficacy of various treatment modalities, comparing these findings with the available literature. RESULTS: A total of 78 patients from 17 centres were identified with ONJ. A majority of patients identified with ONJ had used Pamidronate or Zoledronate (93.6%) intravenously. 94.9% of patients had received BP in the course of treatment for malignancies and a majority had also received prior chemotherapy or exogenous steroids. 82.1% of patients had received BP for more than 1 year. The mean time from the introduction of BP to the development of ONJ in 24 patients from our department was 31.8 months. CONCLUSIONS: The most common intraoral manifestation was exposed necrotic jawbone. Tooth extractions and oral surgical intervention appear to place patients on BP therapy at risk of ONJ, especially after intravenous BP treatments. ONJ proved in this study to be remarkably refractory to treatment, with radical resection being the only curative approach. We recommend that all patients receive necessary dental treatment prior to commencing BP therapy.

Gender and nasal shape: measures for rhinoplasty.

BACKGROUND: Gender-specific nasal shapes are recommended for rhinoplasty. This study was conducted to clarify whether there truly are gender-related differences and to determine optimal nasal shapes in a Caucasian population. METHODS: The authors created female and male composite photographs of "average" (n = 128 each), "optimal" (n = 16 each), and "most unpleasant" (n = 8 each) noses stratified on the basis of each photographed subject's (n = 311) own evaluation of the attractiveness of her or his nose, using a visual analogue scale. These composites were also assessed by 308 independent judges. RESULTS: Optimal female noses showed a horizontally and vertically lower nasion and were concave to straight in profile as compared with optimal male noses, which had a vertically and horizontally higher nasion and a straight profile. A supratip break was not found in any of the composites. At least half of the judges rated average and optimal male composite noses as female. A significant majority mistook the composite of the most unpleasant female noses as male (frontal view, 62.0 percent; lateral view, 72.4 percent; p < 0.001). Optimal and average female and male noses were found to be independently significantly more attractive than the most unpleasant ones (p < 0.001, n = 308 judges). Women and men with a straight or concave profile were significantly (p = 0.017 and p = 0.006, respectively) more satisfied with the appearance of their nose than those with nasal humps. CONCLUSIONS: Gender-related differences in nasal shape appear to be subtle, with nasion position being one of the main factors. A nasal hump and a supratip break are not desirable.

BMP-2 and bFGF in an irradiated bone model.

INTRODUCTION: Basic fibroblast growth factor (bFGF) is considered to enhance angiogenesis and to support bone formation in the presence of vital bone cells. Bone morphogenetic protein-2 (rhBMP-2) is known to induce bone formation. The aim of this study was to analyze the effect of bFGF and rhBMP-2 in the irradiated mandible. MATERIAL AND METHODS: The right mandibles of 24 rats were irradiated with a single dose of 20 Gy at a high-dose-rate (HDR) after loading machine (bio effective equivalent dose to ca. 45 x 2 Gy). After 12 weeks 100 microg rhBMP-2 (n=6 animals, group 1), 100 microg bFGF (n=6 animals, group 2) and 100 microg rhBMP-2 plus 100 microg bFGF (n=6 animals, group 3) were injected along the right mandible (left mandible: no irradiation, no growth factor). Another 6 animals (group 4) remained untreated after the irradiation. After another 7 weeks the specimens were examined by non-decalcified histology. RESULTS: Bone apposition of the experimental versus control sides was not statistically significantly different when one of the growth factors was applied alone (rhBMP-2: p=0.917; bFGF: p=0.345). Average bone apposition was significantly decreased on the experimental sides of group 3 (rhBMP-2+bFGF: p=0.046) and group 4 (p=0.008). Average bone densities were unaffected in all settings (for all p>0.1). CONCLUSIONS: The application of bFGF and the application of rhBMP-2 alone did result in predictable bone generation in the irradiated mandible with the bone apposition being equal to that of the non-irradiated side. The application of both growth factors together or none at all after irradiation results in significantly reduced bone apposition.