Persisting dental foci increase the risk for bacterial infections before and after liver transplant.

BACKGROUND: Patients awaiting liver transplant are usually assessed for presence of dental foci to prevent bacterial infection post-transplant, but evidence to support dental examination and treatment is limited. We investigated if treatment of dental foci decreased bacterial infections before and after transplant. METHODS: Patients transplanted at the university hospital of Bonn were retrospectively assessed for occurrence of bacterial infections before and after transplant according to presence and treatment of dental foci. RESULTS: 35/110 patients showed good oral health, 39/110 patients received dental care and 36/110 patients did not receive dental care despite poor oral health. Patients with alcohol-associated liver disease presented with the highest rate of dental foci. Bleeding complications due to oral care occurred in five patients with poor coagulation. After transplant, the number of infections per patient was higher in patients with poor oral health (2.9) compared to patients after dental care (1.9) or with good oral health (1.8) (p = .02), with streptococcal infections being more frequent in patients with poor oral health. Before transplant, bacterial infections, in particular bacteraemia and spontaneous bacterial peritonitis, were also more common in patients with untreated dental foci. Streptococci and Staphylococci were more often detected in patients with dental foci. Dental treatment was associated with a reduction in bacterial infections. CONCLUSION: Presence of dental foci is associated with an increased risk for bacterial infections not only after but also before liver transplant. Dental treatment might be a safe and effective procedure to mitigate this risk.

Non-Invasive Physical Plasma Reduces the Inflammatory Response in Microbially Prestimulated Human Gingival Fibroblasts.

Non-invasive physical plasma (NIPP), an electrically conductive gas, is playing an increasingly important role in medicine due to its antimicrobial and regenerative properties. However, NIPP is not yet well established in dentistry, although it has promising potential, especially for periodontological applications. The aim of the present study was to investigate the effect of NIPP on a commercially available human gingival fibroblast (HGF) cell line and primary HGFs in the presence of periodontitis-associated bacteria. First, primary HGFs from eight patients were characterised by immunofluorescence, and cell numbers were examined by an automatic cell counter over 5 days. Then, HGFs that were preincubated with Fusobacterium nucleatum (F.n.) were treated with NIPP. Afterwards, the IL-6 and IL-8 levels in the cell supernatants were determined by ELISA. In HGFs, F.n. caused a significant increase in IL-6 and IL-8, and this F.n.-induced upregulation of both cytokines was counteracted by NIPP, suggesting a beneficial effect of physical plasma on periodontal cells in a microbial environment. The application of NIPP in periodontal therapy could therefore represent a novel and promising strategy and deserves further investigation.

Influence of cold atmospheric plasma on dental implant materials - an in vitro analysis.

BACKGROUND AND OBJECTIVES: Alterations in the microenvironment of implant surfaces could influence the cellular crosstalk and adhesion patterns of dental implant materials. Cold plasma has been described to have an influence on cells, tissues, and biomaterials. Hence, the mechanisms of osseointegration may be altered by non-thermal plasma treatment depending on different chemical compositions and surface coatings of the biomaterial. The aim of the present study is to investigate the influence of cold atmospheric plasma (CAP) treatment on implant surfaces and its biological and physicochemical side effects. MATERIALS AND METHODS: Dental implant discs from titanium and zirconia with different surface modifications were treated with CAP at various durations. Cell behavior and adhesion patterns of human gingival fibroblast (HGF-1) and osteoblast-like cells (MG-63) were examined using scanning electron microscopy and fluorescence microscopy. Surface chemical characterization was analyzed using energy-dispersive X-ray spectroscopy (EDS). Quantitative analysis of cell adhesion, proliferation, and extracellular matrix formation was conducted including real-time PCR. RESULTS: CAP did not affect the elemental composition of different dental implant materials. Additionally, markers for cell proliferation, extracellular matrix formation, and cell adhesion were differently regulated depending on the application time of CAP treatment in MG-63 cells and gingival fibroblasts. CONCLUSIONS: CAP application is beneficial for dental implant materials to allow for faster proliferation and adhesion of cells from the surrounding tissue on both titanium and zirconia implant surfaces with different surface properties. CLINICAL RELEVANCE: The healing capacity provided through CAP treatment could enhance osseointegration of dental implants and has the potential to serve as an effective treatment option in periimplantitis therapy.

Bevacizumab and sunitinib mediate osteogenic and pro-inflammatory molecular changes in primary human alveolar osteoblasts in vitro.

Antiangiogenic medications target the de novo blood vessel formation in tumorigenesis. However, these novel drugs have been linked to the onset of medication-related osteonecrosis of the jaw (MRONJ). The aim of this in vitro study was to examine the effects of the vascular endothelial growth factor A (VEGFA) antibody bevacizumab (BEV) and the receptor tyrosine kinase inhibitor (RTKI) sunitinib (SUN) on primary human osteoblasts derived from the alveolar bone. Primary human alveolar osteoblasts (HAOBs) were treated with BEV or SUN for 48 h. Cellular metabolic activity was examined by XTT assay. Differentially regulated genes were identified by screening of 22 selected osteogenic and angiogenic markers by quantitative real-time reverse transcriptase polymerase chain reaction (qRT2-PCR). Protein levels of alkaline phosphatase (ALP), collagen type 1, α1 (COL1A1) and secreted protein acidic and cysteine rich (SPARC) were examined by enzyme-linked immunoassay (ELISA). Treatment with BEV and SUN did not exhibit direct cytotoxic effects in HAOBs as confirmed by XTT assay. Of the 22 genes examined by qRT2-PCR, four genes were significantly regulated after BEV treatment and eight genes in the SUN group as compared to the control group. Gene expression levels of ALPL, COL1A1 and SPARC were significantly downregulated by both drugs. Further analysis by ELISA indicated the downregulation of protein levels of ALP, COL1A1 and SPARC in the BEV and SUN groups. The effects of BEV and SUN in HAOBs may be mediated by alterations to osteogenic and catabolic markers. Therapeutic or preventive strategies in MRONJ may address drug-induced depression of osteoblast differentiation.

Effect of Cold Atmospheric Plasma (CAP) on Osteogenic Differentiation Potential of Human Osteoblasts.

Bone regeneration after oral and maxillofacial surgery is a long-term process, which involves various mechanisms. Recently, cold atmospheric plasma (CAP) has become known to accelerate wound healing and have an antimicrobial effect. Since the use of CAP in dentistry is not yet established, the aim of the present study was to investigate the effect of CAP on human calvaria osteoblasts (HCO). HCO were treated with CAP for different durations of time and distances to the cells. Cell proliferation was determined by MTT assay and cell toxicity by LDH assay. Additionally, RT-qPCR was used to investigate effects on osteogenic markers, such as alkaline phosphatase (ALP), bone morphogenic protein (BMP)2, collagen (COL)1A1, osteonectin (SPARC), osteoprotegerin (OPG), osterix (OSX), receptor activator of NF-κB (RANK), RANK Ligand (RANKL), and Runt-related transcription factor (RUNX)2. There were small differences in cell proliferation and LDH release regarding treatment duration and distance to the cells. However, an increase in the expression of RANK and RANKL was observed at longer treatment times. Additionally, CAP caused a significant increase in mRNA expression of genes relevant to osteogenesis. In conclusion, CAP has a stimulating effect on osteoblasts and may thus represent a potential therapeutic approach in the regeneration of hard tissue defects.

Mapping the microbiological diversity of odontogenic abscess: are we using the right drugs?

OBJECTIVES: The aim of this study was categorizing the microbial flora and susceptibility to antibiotics and to clarify to which degree the empiric administered antibiotics are suitable for therapy. MATERIALS AND METHODS: A 3.5-year retrospective study evaluated hospital records of 206 patients who suffered from head and neck infections of odontogenic origin. All patients underwent surgical incision and drainage and received intravenous antibiotics and inpatient treatment. The specimens were obtained by performing a swab. RESULTS: Two hundred six patients were included with 251 strains isolated (1.22 per patient). One hundred eight strains showed antibiotic resistance. Eighty-seven patients showed at least one bacterial strain that showed antibiotic resistance (42.2%). The most frequent isolated bacteria were Streptococcus spp. (n = 116), with a high rate of antibiotic resistance (50.8%). We investigated 205 cases of antibiotic resistance in 87 subjects. Nine bacterial strains showed no susceptibility to unacid (4.3%) and 36 strains to clindamycin (17.5%). CONCLUSION: Antibiotic resistance against clindamycin was rather high. The distribution of the afflicted spaces and isolated bacteria was alike recent findings. It is mandatory to understand that immediate surgical treatment in terms of incision and drainage is the basis in abscess treatment. Antibiotic treatment is adjunct therapy. CLINICAL RELEVANCE: Streptococcus species were the most frequently identified bacteria presenting antibiotic resistance in more than 50%. Increased resistant rates for clindamycin require reconsiderations regarding an empiric antibiotic treatment.

Trismus Due to Hyperplastic Coronoid Process: Series of Five Cases and Review of Literature.

ABSTRACT: Hyperplasia of the coronoid process is a rare condition, potentially leading to a mechanical mouth opening restriction. Diagnostic workup and treatment will be discussed based on 5 cases. This article presents 5 cases of true coronoid process hyperplasia. In addition, we reviewed accessible literature on the topic with special attention to pathophysiologic theories, surgical approach, and postoperative physiotherapy. The improvement in the maximal intercuspidal opening ranged from 4 and 31 mm. Greater maximal intercuspidal opening improvement was connected to compliant patients, while poor outcome occurred in the case of a patient that neither followed the recommendations for physical therapy nor showed up for his follow up appointments. The success of the therapy is defined by a long-lasting and stable improvement of the mouth opening compared to the preoperative situation. In the presented cases, the outcome was strongly dependent on the patients' postoperative compliance. Based on the cases described, we conclude that a good outcome is accomplishable for patients using the methods presented, as long as patients cooperate well after surgery.Diagnostic workup in patients with trismus should be thorough to correctly diagnose rare entities such as coronoid hyperplasia. If treated correctly this condition has a good outcome, as long as the compliance of the patient is adequate.

Cold Atmospheric Plasma Promotes Regeneration-Associated Cell Functions of Murine Cementoblasts In Vitro.

The aim of the study was to examine the efficacy of cold atmospheric plasma (CAP) on the mineralization and cell proliferation of murine dental cementoblasts. Cells were treated with CAP and enamel matrix derivates (EMD). Gene expression of alkaline phosphatase (ALP), bone gamma-carboxyglutamate protein (BGLAP), periostin (POSTN), osteopontin (OPN), osterix (OSX), collagen type I alpha 1 chain (COL1A1), dentin matrix acidic phosphoprotein (DMP)1, RUNX family transcription factor (RUNX)2, and marker of proliferation Ki-67 (KI67) was quantified by real-time PCR. Protein expression was analyzed by immunocytochemistry and ELISA. ALP activity was determined by ALP assay. Von Kossa and alizarin red staining were used to display mineralization. Cell viability was analyzed by XTT assay, and morphological characterization was performed by DAPI/phalloidin staining. Cell migration was quantified with an established scratch assay. CAP and EMD upregulated both mRNA and protein synthesis of ALP, POSTN, and OPN. Additionally, DMP1 and COL1A1 were upregulated at both gene and protein levels. In addition to upregulated RUNX2 mRNA levels, treated cells mineralized more intensively. Moreover, CAP treatment resulted in an upregulation of KI67, higher cell viability, and improved cell migration. Our study shows that CAP appears to have stimulatory effects on regeneration-associated cell functions in cementoblasts.

Modulation of Inflammatory Responses by a Non-Invasive Physical Plasma Jet during Gingival Wound Healing.

Gingival wound healing plays an important role in the treatment of a variety of inflammatory diseases. In some cases, however, wound healing is delayed by various endogenous or exogenous factors. In recent years, non-invasive physical plasma (NIPP), a highly reactive gas, has become the focus of research, because of its anti-inflammatory and wound healing-promoting efficacy. So far, since NIPP application has been poorly elucidated in dentistry, the aim of this study was to further investigate the effect of NIPP on various molecules associated with inflammation and wound healing in gingival cells. Human gingival fibroblasts (HGF) and human gingival keratinocytes (HGK) were treated with NIPP at different application times. Cell viability and cell morphology were assessed using DAPI/phalloidin staining. Cyclooxygenase (COX)2; tumour necrosis factor (TNF); CC Motif Chemokine Ligand (CCL)2; and interleukin (IL)1B, IL6 and IL8 were analysed at the mRNA and protein level by a real-time PCR and ELISA. NIPP did not cause any damage to the cells. Furthermore, NIPP led to a downregulation of proinflammatory molecules. Our study shows that NIPP application does not damage the gingival tissue and that the promotion of wound healing is also due to an anti-inflammatory component.

Non-Invasive Physical Plasma Generated by a Medical Argon Plasma Device Induces the Expression of Regenerative Factors in Human Gingival Keratinocytes, Fibroblasts, and Tissue Biopsies.

After oral surgery, intraoral wound healing and tissue regeneration is an important factor for the success of the entire therapy. In recent years, non-invasive medical plasma (NIPP) has been shown to accelerate wound healing, which would be particularly beneficial for patients with wound healing disorders. Since the application of NIPP in dentistry has not been sufficiently understood, the aim of the present study was to investigate the effect of a medical argon plasma device on gingival cells. Human gingival fibroblasts, keratinocytes, and tissue biopsies were treated with NIPP for different durations. Crucial markers associated with wound healing were examined at the mRNA and protein levels by real-time PCR, ELISA and immunohistochemistry. NIPP treatment led to an increase in Ki67 and MMP1 at mRNA and protein levels. NIPP application lasting longer than 60 s resulted in an increase in apoptotic genes at mRNA level and superficial damage to the epithelium in the tissue biopsies. Overall, our experimental setup demonstrated that NIPP application times of 30 s were most suitable for the treatment of gingival cells and tissue biopsies. Our study provides evidence for potential use of NIPP in dentistry, which would be a promising treatment option for oral surgery.

Sinus floor augmentation with recombinant human growth and differentiation factor-5 (rhGDF-5): a pilot study in the Goettingen miniature pig comparing autogenous bone and rhGDF-5.

AIM: The aim of this study was to test the hypothesis that recombinant human growth and differentiation factor-5 (rhGDF-5) in combination with a beta-tricalcium phosphate (beta-TCP) scaffold material results in superior bone formation in sinus floor augmentations in miniature pigs compared with a particulated autogenous bone graft combined with the scaffold material. MATERIAL AND METHODS: Six adult female Goettingen minipigs underwent a maxillary sinus floor augmentation procedure. In a split-mouth design, the sinus floors were augmented with beta-TCP mixed with autogenous cortical bone chips, in a ratio of approximately 1 : 1, on one side. The contralateral test site was augmented using beta-TCP coated with two concentrations of rhGDF-5 (400 microg rhGDF-5/g beta-TCP or 800 microg rhGDF-5/g beta-TCP; three animals in each case). Simultaneously, one dental implant was inserted into each sinus floor augmentation. After 12 weeks, a histological and histomorphometric assessment of non-decalcified histological specimens was made. RESULTS: There were significantly higher mean values of volume density of newly formed bone using beta-TCP coated with two concentrations of rhGDF-5 (400 microg: 32.9%; 800 microg: 23.9%) than with the corresponding control (autogenous bone/beta-TCP) (14.6%, 12.9%) (P=0.012, P=0.049). The bone-to-implant contact rates (BIC) were significantly enhanced in test sites (400 microg: 84.2%; 800 microg: 69.8%) compared with the corresponding control sites (24.8%, 40.8%) (P=.027, P=.045). CONCLUSION: rhGDF-5 delivered on beta-TCP significantly enhanced bone formation compared with beta-TCP combined with autogenous bone in sinus lift procedures in miniature pigs.

Antiresorptive drug-related changes of the mandibular bone densitiy in medication-related osteonecrosis of the jaw patients.

OBJECTIVES: Medication-related osteonecrosis of the jaw (MRONJ) is a well known side-effect of anti-resorptive drugs. Changes in bone density might potentially constitute the development of ONJ. This study aimed to investigate, to which degree bisphosphonates (bp) and denosumab (db) induce changes in bone density that can be determined from routine diagnostic CT. METHODS: CT scans of 101 patients were investigated. MRONJ was present in 61 patients (n = 26: db-treated; n = 35 bp-treated). 40 patients were included as a reference group. Bone density was measured at two distinct locations in the mandible (M1: anterior of the mental foramen; M2: retromolar), each on the contralateral side to the necrosis. RESULTS: The bone density values measured at both locations were found to be significantly higher in the bp-group compared to the db-group (p = 0.027) and to the reference-group (p = 0.016). Almost no difference (p = 0.84) in bone density value was found between the db- and reference-groups.Investigating the effect of duration of treatment, none of the measured values showed significant differences in both locations of db- and bp-group. CONCLUSION: The findings from this study suggest that that bisphosphonates change the microarchitecture of the alveolar bone by being embedded in the mandible, which may subsequently lead to a bp-specific corticalization, and a decrease in vascularization of the lower jaw. This process may be distinctive for bp-treatment and seems to induce the congestion of cancellous bone rather rapidly after the first administrations. This effect could not be determined in denosumab-treated patients.

Predictability of pharyngeal airway space dimension changes after orthognathic surgery in class II patients: A mathematical approach.

INTRODUCTION: Angle Class II malocclusion due to mandibular retrognathia is a common dentofacial deformity. It is well known that mandibular advancement increases pharyngeal airway dimensions. The aim of this study was to evolve a mathematical method for predicting posterior pharyngeal airway space (PAS) changes based on 2D lateral cephalographic radiographs (LCRs) and expected extent of mandibular advancement prior to BSSO. MATERIALS AND METHODS: Linear regression analyses were performed in order to investigate the relation between the posterior airway space and mandibular advancement. LCRs where carried out to assess skeletal landmarks and pharyngeal airway space pre- (T0) and postoperatively (T1). To detect changes postoperatively, the posterior airway space was divided into three units: nasopharyngeal airway space (superior airway space - SPAS), oropharyngeal airway space (mid airway space - MAS) and hypopharyngeal airway space (inferior airway space - IAS). The differences between the distances of distinct measurement points (DIFF) were measured pre- and postoperatively. DOA referred to the distance of mandibular advancement and DP to the distance between the measurement points preoperatively. The parameters a, b1 and b2 were the regression coefficients that were determined separately for each unit (SPAS, MAS, and IAS). RESULTS: 49 patients (16 male and 33 female) with a mean age of 27.2 years (SD: 10.09), ranging from 18 to 51 years, who underwent mandibular advancement surgery (BSSO) were enrolled in this study. The mean distance of mandibular advancement was 5.05 mm (SD: 1.63). Regarding SPAS and IAS, mandibular advancement did not affect dimensions significantly: SPAS DIFF, 0.33 mm ± 1.13 mm (b1, p = 0.0881; b2, p = 0.087); IAS DIFF, 0.66 mm ± 2.45 mm (b1, p = 0.342; b2, p = 0.765). DOA and DP did not influence DIFF significantly in both sections. Regarding MAS, the mean effect of mandibular advancement was an expansion of 2.47 mm ± 2.24. The linear regression model showed a statistically significant (b1, p = 0.0064; b2, p = 0.0240) influence of DOA and DP on DIFF in posterior airway dimensions pre- and postoperatively. DISCUSSION: Based on preoperative LCR imaging data, a linear regression model was developed as a mathematical approach to allow prediction of PAS development in patients with Angle Class II malocclusions of different degrees. Increasing mandibular advancement was shown to be linked to increasing PAS, while a greater distance between the measuring points preoperatively led to smaller predicted PAS increases postoperatively. CONCLUSION: Predicting pharyngeal airway space (PAS) development after mandibular advancement by analysing lateral cephalometric radiographs (LCR) may be useful in the screening and treatment of obstructive sleep apnea syndrome (OSAS) patients. Our mathematical approach is a simple and sustainable prediction tool based on LTR data for patients with Class II malocclusions.

Experimental application of a biomaterial in bifocal transport osteogenesis for craniofacial reconstruction.

PURPOSE: Bifocal transport osteogenesis is an alternative technique of callus distraction, in which movement of a transport segment results in the formation of new bone in order to close a continuity defect. The aim of this experimental pilot study was to replace a bone graft by a biomaterial as a transport segment. MATERIAL AND METHODS: Critical size defects of the calvaria in four adult sheep were treated with transport segments consisting either of an autogenous free bone graft of the calvaria (n=2) or of the biomaterial (deproteinized bovine cancellous bone; n=2). Latency period was 5 days; the rate of distraction was 1mm per day and was planned for 40 days. The consolidation period was 28 days. Specimens were investigated by conventional radiography, CT-scans and histologically, including immunofluorescence. RESULTS: In both groups, transport osteogenesis resulted in a "de novo" formation of bone, indicating that this biomaterial may contribute successfully to bone formation in bifocal transport osteogenesis. However, volume and thickness of the newly formed bone at the defect site were smaller when using the biomaterial than when using autogenous bone grafts. CONCLUSION: The application of a biomaterial as transport segments in bifocal transport osteogenesis in cranial critical size defects resulted in the formation of new bone thus excluding bone graft donor site morbidity.

Perioperative complications following sagittal split osteotomy of the mandible.

INTRODUCTION: The aim of this study was to review complications in a series of 1264 consecutive patients who were operated in a single centre during a 20-year-period. MATERIAL AND METHODS: Complications were documented, their incidences calculated and compared with data from the literature. RESULTS: In 35 patients (2.8%) infection developed requiring extraoral incision and drainage; in 27 patients (2.1%) the inferior alveolar nerve was inadvertently cut; 18 patients (1.4%) had to undergo re-operation due to bending or fracture of osteosynthesis material; 15 patients (1.2%) suffered from bleeding complications; in 12 patients (0.9%) an unfavourable split occurred. In 8 patients (0.6%) foreign bodies were left in situ; in 7 patients a partial weakness of the facial nerve occurred, which was permanent in 1 patient. Six patients (0.5%) with a significantly higher age than average (mean: 33.6 years in comparison with 23.1 years) developed non-union at the site of osteotomy, and the mandible had to be bone grafted. Two patients (0.2%) developed osteomyelitis, and in one patient airway problems led to a need for tracheostomy (0.1%). CONCLUSION: Although some of these complications of bilateral sagittal split with osteotomy carry severe limitations in health related quality of life, it remains an overall safe procedure, demanding, however, comprehensive informed consent. Good knowledge of technical reasons for these complications should help to reduce their incidence.

Measurement of the midpalatal suture width.

OBJECTIVE: To conduct a pilot study to investigate the potentiality to determine the midpalatal sutural width radiographically with a flat-panel volume computed tomography (fpVCT) in a porcine model. MATERIALS AND METHODS: Bone samples from the midpalatal suture of five young (16 weeks) and five old (200 weeks) sus scrofa domestica were gathered. The midpalatal suture width was measured via fpVCT and compared to respective histological preparations. Results with P < .05 were considered significant. RESULTS: The data obtained by fpVCT and by histomorphometric analysis reveal a highly significant age dependency of the measured suture width (both P < .0001), with lower suture width values in older subjects compared to the younger group. The averaged suture widths measured in the fpVCT images shows a distinctively higher mean compared to the histomorphometric data with high statistical significance (P < .0001). The evaluated difference between both methods was almost constant. CONCLUSION: fpVCT is a powerful tool for determining midpalatal sutural width.

TGFB3 displays parent-of-origin effects among central Europeans with nonsyndromic cleft lip and palate.

Mice with a deletion of Tgf-beta3 (-/-) and association studies in humans of different ethnicities support the involvement of TGFB3 in the etiology of orofacial clefts. In this study, we investigated the relevance of TGFB3 in the development of cleft lip and palate (CL/P) among 204 triads of central European origin. Transmission-disequilibrium test (TDT) analysis revealed no significant transmission distortions for each marker alone, and none for any possible haplotypes. However, we found strong evidence for parent-of-origin effects, with lower risk of maternal transmission compared with paternal transmission [I (M) = 0.38; confidence interval (CI): 0.17-0.86] of the risk allele T to an affected offspring at marker rs2300607. This is also expressed in an increased risk of heterozygous children having the T allele inherited from the father (R (P) = 3.47; CI: 1.32-9.11). Our data support the involvement of TGFB3 in the development of oral clefts in patients of central European origin.

Implants in children with ectodermal dysplasia: a case report and literature review.

The replacement of teeth by implants is usually restricted to patients with completed craniofacial growth. Implant insertions in children or adolescents are circumvented due to several unfavorable potential effects including trauma to tooth germs, tooth eruption disorders and multidimensional restrictions of skeletal craniofacial growth. Moreover, the functional and esthetic results of the oral rehabilitation are only temporary acceptable. However, to a small number of pediatric patients suffering congenitally from severe hypodontia caused by syndromes such as ectodermal dysplasia, conventional prosthodontic rehabilitations are insufficient. We report the case of a boy with ectodermal dysplasia who exhibited a severe hypodontia and who was treated with implants inserted into the anterior mandible at the age of 8 years. The implants were functionally loaded and resulted in a high patient satisfaction. We recommend the early insertion of dental implants in children with severe hypodontia. Reviewing the current literature, several aspects of syndromic hypodontia, patient selection and implant planning are discussed.

Navigated vs. conventional implant insertion for maxillary single tooth replacement.

UNLABELLED: Abstract Introduction: Computer-guided navigation has proven a valuable tool in several surgical disciplines. During oral implant placement, its application is intended to accomplish optimal implant localization and to reduce the risk of damage to adjacent structures. The aim of this study was to compare the precision limits of conventional vs. navigated implant insertion in practice. MATERIALS AND METHODS: In cast models of the maxilla, implants were inserted to replace the left central incisor (n = 40) and the right canine (n = 40); each of those were inserted either conventionally (n = 20) or navigated (n = 20). Implant position, angulation and insertion depth were calculated from computer tomography scans of the implants that were connected to an index abutment of 40 cm length. RESULTS: The variations of implant positions were reduced for implants that were inserted by navigation (P < 0.05). In both the axial and the transversal plane, the variations of implant angulations were reduced for implants that were inserted by a navigation protocol (P < 0.05). The variations of insertion depth were less (P < 0.05) when the implants were placed by navigation in comparison with conventional insertion procedures. CONCLUSIONS: Given the experimental conditions, although they tried to mimic a clinical situation, no final conclusions can be drawn. The in vitro application of a navigation system resulted in an improved precision of insertion surgery regarding the position, angulation and depth of an implant. Clinical studies will have to prove if routine image guidance will result in superior surgical outcome.

Efficacy of dental implants placed into fibula-free flaps for orofacial reconstruction.

OBJECTIVES: The transfer of the osseofasciocutaneus fibula-free flap has become a routine procedure in the reconstruction of comprehensive orofacial defects. Besides its length, major advantages of the fibula-free flap include the trigonal diameter of the fibular bone, which usually allows the placement of dental implants. PATIENTS AND METHODS: In a prospective study, 16 consecutive patients who received free fibula grafts and in total 51 dental implants between 1999 and 2001 were examined. All implants were inserted secondary after bone grafting and loaded after 3 months of submerged healing. The observation period extended 2.5 years on average. The implant success was controlled clinically, radiographically and by resonance frequency analysis. RESULTS: One implant that was located at the interface between the fibula graft and the mandible was lost due to dehiscence and local infection during the healing period. In two other patients, one implant had to remain unexposed as 'sleeper' due to an unfavourable soft tissue situation. The success rate calculated by Kaplan-Meier analysis was 96.1% after an observation period of 1400 days. Resonance frequency analysis (ISQ-values) revealed significant differences related to the orientation (vestibulo-oral/mesio-distal; vo/md) of the transducer unit (P < 0.01). In general, a high primary stability for implants placed in free fibula grafts could be achieved (vo/md 66/74.1), which on average increased slightly during the healing period (vo/md 67.4/75.4) and within 12 month of functional loading (vo/md 72.1/79.9). Additional augmentation with iliac bone grafts or reconstructions with a double barred fibula resulted in an improved reconstruction of the alveolar process, thus allowing superior individual implant positions or angulations, but no elevation of the ISQ-values. CONCLUSION: The fibula-free flap provides a consistent bone graft that allows a reliable and predictable restoration with dental implants.