Coincidence of mandibular fractures with isolated posterior maxillary sinus fractures.

BACKGROUND/AIM: There are no data available to show whether there is a relationship between mandibular fractures and isolated fractures of the posterior and/or lateral walls of the maxillary sinus. The aim of this study was to determine whether there is a coincidence between these fracture patterns. METHODS: Four hundred large volume cone beam computed tomography scans (CBCT) of patients with a fracture of the mandible between 2008 and 2013 were analyzed retrospectively. Patients with multiple midfacial fractures were excluded. The radiographic findings were correlated with epidemiological and clinical data of the patients such as gender, age, treatment methods, or complications. RESULTS: The most frequent fracture sites of the mandible were the jaw angle, the parasymphysis region, and the condyle. Nineteen of the 400 patients (4.75%) had an isolated fracture of the lateral and/or posterior maxillary sinus. Odds-ratio analysis revealed a high tendency for significant correlation of condylar process fractures with isolated maxillary sinus fractures. Chi-square test demonstrated a P-value near statistical significance (P=.054). No other fracture site of the mandible could be associated with an isolated fracture of the maxillary sinus. CONCLUSION: A condylar process fracture of the mandible after trauma without any further injury of the midface may be associated with an isolated fracture of the lateral and/or posterior maxillary sinus.

A contact-free volumetric measurement of facial volume after third molar osteotomy: proof of concept.

OBJECTIVE: The present study tested the reliability of an optical scanning device for the objective assessment of postoperative facial swelling. STUDY DESIGN: Twenty control subjects bearing a defined volume of water (10-30 mL) in an intraorally carried balloon were tested to assess the measurement accuracy of the device. As a proof of concept, facial volumes of 59 surgical cases were recorded before osteotomy and 1 and 7 days after intervention with the use of a structured light scanner. RESULTS: The median difference between the applied and the measured volumes was 0.67 mL for the control test with the artificial swelling simulated using water balloons. For subjects having third molar osteotomy, extraoral volume increased to 5.29 cm(3) 1 day after surgery (95% CI 5.22-8.52) and decreased to 0.00 mL (95% CI 0.85-2.55) after 7 days. CONCLUSIONS: Contact-free visible-light 3-dimensional scanning is reliable for the objective assessment of postoperative facial swelling.

Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials.

OBJECTIVES: The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM). MATERIALS AND METHODS: Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular proliferation and morphology were evaluated after 1, 3, 5 and 8 days using CLSM-visualization and image recognition software. RESULTS: The rate of cellular proliferation was different among treatment modalities examined (p = 0.019). Except treatment with NHA paste all treatment modalities improved cellular proliferation on root surfaces at all different points of time compared with the control specimens. A significant difference between treatment modalities was observed between EMD and NHA paste (p = 0.008). No synergistic effect could be demonstrated comparing root surface conditioning with 24% EDTA and EMD application compared to 24% EDTA or EMD application only. CONCLUSION: The present results suggest that initial root surface colonization by PDL fibroblasts may be enhanced by root surface conditioning with 24% EDTA and application of EMD, application of 24% EDTA or EMD alone and OCHS. The addition of 24% EDTA for root surface conditioning prior to EMD application provided no synergistic effects in terms of early root surface colonization by PDL fibroblasts.

Contrast curves of five different intraoral X-ray sensors: a technical note.

OBJECTIVES: The aim of this article is to compare the contrast and resolution properties of five different sensors using a known technical target. METHODS: Stripe patterns with defined amounts of line pairs per mm (2.5-20 LP/mm) were recorded using five commercial digital sensors. Image data were analyzed using ImageJ and MatLab to calculate different contrast curves using logistic regression. RESULTS: The Dexis Platinum Sensor reached a calculated 10% contrast at 29.52 LP/mm. The Duerr VistaRay 6 Sensor reached a 10% contrast at 9.9 LP/mm. The 10% contrast was found at 18.8 LP/mm for the Duerr VistaRay 7. The Sirona Xios+ Sensor reached a calculated 10% contrast at 13.9 LP/mm. The Sirona Fullsize charge-coupled device (CCD) Sensor exhibited 10% contrast at 10.3 LP/mm. CONCLUSIONS: The contrast transfer function assessment used in the study confirmed that the spatial frequency at 10% contrast was much lower than the theoretical resolution computed from the pixel size.

Advantages of fitting contrast curves using logistic function: a technical note.

OBJECTIVE: The aim of this article is to demonstrate how the contrast properties of an imaging system can be ideally fitted with the use of stripe patterns and the logistic function. STUDY DESIGN: Stripe patterns with defined amounts of line pairs (lp/mm) per mm (10-20 lp/mm) were recorded with the use of digital photostimulable storage phosphor. Scan data and normalized image data were analyzed with the use of ImageJ and MatLab to calculate different contrast curves. RESULTS: For original scan data, the goodness of fit was 0.0000019 (sum of squared error [SSE]). The R-square was 0.9998. For normalized data the goodness of fit was 0.0007 (SSE) and the R-square 0.998. An amount of 50% contrast could be calculated to be found on 11.67 lp/mm in normalized images. CONCLUSIONS: This article addresses a potentially new approach to compare digital x-ray modalities using a direct assessment of a known technical target.

Evaluation of ultrasound transmission velocity and 3-dimensional radiology in different bone types for dental implantology: a comparative ex vivo study.

OBJECTIVE: To evaluate ultrasound transmission velocity (UTV) for assessment of mechanical bone quality, an ex vivo comparison of different bone types measured with UTV, 2-dimensional (2D) histomorphometry and with 3-dimensional (3D) radiology (cone-beam computerized tomography [CBCT], computerized microtomography [µCT]) was conducted. STUDY DESIGN: Clinical cortical, cancellous, and mixed bone (each n = 6) was measured via UTV (m/s), CBCT (white pixel/black pixel ratio [WP/BP]), µCT (bone volume/total volume [µBV/TV]), and histomorphometry (bone volume/total volume [hBV/TV]). UTV values were correlated with 2D-histomorphometry and 3D-radiologic results. RESULTS: For the cortical, cancellous, and mixed bone samples, respectively, UTV values were 1,945.17, 1,266.9,and 1472.2 m/s, WP/BP quotients were 0.96, 0.15, and 0.33, µBV/TV quotients were 0.94, 0.2, and 0.47, and hBV/TV quotients were 0.96, 0.24 and 0.39. Significant correlations between UTV and the other methods were seen (P < .0001). CONCLUSIONS: Similar to the other methods, UTV is able to discriminate between different bone types ex vivo.

Promotion of osteogenic cell response using quasicovalent immobilized fibronectin on titanium surfaces: introduction of a novel biomimetic layer system.

PURPOSE: Despite the undeniable potential of cell adhesion molecules such as fibronectin to support osteogenic cell responses and consecutive dental implant healing, the most beneficial mode of application onto titanium implant surfaces still requires investigation. Unspecific fibronectin adsorption on titanium dioxide (TiO(2)) surfaces can result in low-loading, high-desorption rates and protein-metal interactions with impaired biologic activity. The aim of the present study was to monitor the osteogenic cell responses (cell adhesion, proliferation, and differentiation) specifically to fibronectin biofunctionalized TiO(2). MATERIALS AND METHODS: An innovative biomimetic streptavidin-biotin layer system allows flexible, but stable, specific binding of biotinylated biomolecules such as fibronectin on TiO(2) surfaces. Transparent glass disks were sputtered with TiO(2). The biomimetic layer system was immobilized by self-assembly and consisted of silane, biotin-derivate, streptavidin, and biotinylated fibronectin (bFN). For the control group, unbiotinylated fibronectin was directly coated onto TiO(2). Early cell adhesion dynamics were quantified using automated processing of light microscopy images within the first 24 hours. Relative mRNA expression of integrin-ß1, cyclin D1, runt-related gene 2, alkaline phosphatase, and osteocalcin was obtained using quantitative real-time polymerase chain reactions 3 and 7 days after incubation. RESULTS: Although untreated TiO(2) preserved a rather immature osteogenic phenotype, both unbiotinylated fibronectin and bFN promoted osteogenic cell adhesion and cell differentiation. In particular, runt-related gene 2 expression was significantly promoted by bFN after 3 days. In contrast, cyclin D1 expression was decreased for unbiotinylated fibronectin and bFN after 7 days. CONCLUSIONS: The introduced biomimetic layer system contributes a coherent immobilization approach of adhesion molecules with promotion of osteogenic cell response in vitro.

Comparison of 4% articaine with epinephrine (1:100,000) and without epinephrine in inferior alveolar block for tooth extraction: double-blind randomized clinical trial of anesthetic efficacy.

OBJECTIVE: The purpose of this clinical prospective, randomized, double-blind study was to compare the anesthetic efficacy of 4% articaine with epinephrine (1:100,000) and without epinephrine in inferior alveolar nerve block anesthesia for extractions of mandibular teeth. STUDY DESIGN: Eighty-eight patients received intraoral inferior alveolar nerve blocks using 4% articaine with 1:100,000 epinephrine (n = 41; group 1) or without epinephrine (n = 47; group 2) for extractions of mandibular teeth. The primary objectives were differences in onset as well as in length of soft tissue anesthesia. The amount of anesthetic solution, need of a second injection, pain while injecting, pain during treatment, postoperative pain, and possible complications were surveyed. RESULTS: In both groups, anesthesia was sufficient for dental extractions. In group 1, a significantly faster onset of the anesthetic effect (7.2 min vs. 9.2 min; P = .001) and a significantly longer duration of soft tissue anesthesia (3.8 h vs. 2.5 h; P < .0001) were seen. There was no significant difference in the amount of anesthetic solution needed, in the need for a second injection, in the injection pain, in pain during treatment, or in postoperative analgesia. In both groups, no complications were seen. CONCLUSIONS: To minimize the epinephrine-induced side effects, 4% articaine without epinephrine is a suitable anesthetic agent for dental extractions in the mandible after inferior alveolar nerve block anesthesia. There could be less postoperative discomfort due to the shorter duration of anesthesia without increased postoperative pain.

Counting touching cell nuclei using fast ellipse detection to assess in vitro cell characteristics: a feasibility study.

In this article, we describe a new image analysis software that allows rapid segmentation and separation of fluorescently stained cell nuclei using a fast ellipse detection algorithm. Detection time ranged between 1.84 and 3.14 s. Segmentation results were compared with manual evaluation. The achieved over-segmentation rate was 0.11 (0.1 double counts and 0.01 false positive detections), and the under-segmentation rate was of 0.03 over all images. We demonstrate the applicability of the proposed algorithm to automated counting of fluorescent-labeled cell nuclei and to tissue characterization. Moreover, the performance of the proposed algorithm is compared with preexisting automated image analysis techniques described by others.

Correlation of cone beam computed tomography (CBCT) findings in the maxillary sinus with dental diagnoses: a retrospective cross-sectional study.

This study was conducted to assess the coincidence of mucosal hyperplasia in the maxillary sinus and related clinical diagnoses of posterior maxillary teeth found in cone beam computed tomography (CBCT) scans. A total of 204 patients who underwent CBCT examinations between 2006 and 2008 were evaluated retrospectively. Clinical and CBCT findings were correlated using patient records. Absolute frequencies, odds ratios (OR), and 95% confidence intervals (95% CI) were calculated for statistical evaluations. There was a pronounced association between periodontitis and radiological signs of sinusitis. Basal mucosal wall thickening was more likely in patients with decayed and non-vital teeth compared to patients with sound teeth (OR = 5.2; 95% CI = 1.2-23.1). Basal mucosal wall thickening was also more likely than total mucosal thickening (OR = 10.4; 95% CI = 2.6-42.2). Patients with decayed and endodontically treated teeth were more likely to exhibit involvement of the basal wall (OR = 9.2; 95% CI = 3.3-25.2) than were patients with healthy teeth. CBCT examinations revealed a correlation between basal mucosal thickening in the maxillary sinus and decayed posterior maxillary teeth or periodontitis. Chronic symptoms involving the sinuses are one of the most common reasons for patients to consult physicians. One reason for chronic orofacial pain is the prevalence of undiagnosed sinus conditions.

Intraoral cameras as a computer-aided diagnosis tool for root canal orifices.

The aim of this study was to evaluate the diagnostic advantage of a new software tool in combination with an intraoral camera for automatic detection of root canal orifices in life videos via the access cavity of extracted human molars. The performance of a predoctoral dental student analyzing the images of the camera (without automatic detection) was compared with that of an experienced observer. Sensitivity and confidence intervals were provided and compared with histological slices of 200 teeth used for evaluation. The software's sensitivity for detection of root canal orifices was 0.957 (95 percent confidence interval: 0.936 to 0.972). The sensitivity for the observer was 0.906 (95 percent confidence interval: 0.877 to 0.929) compared to 0.847 (95 percent confidence interval: 0.813 to 0.877) achieved by the predoctoral student. The tested software reaches a high sensitivity for automatic real-time detection of root canal orifices with intraoral cameras in direct comparison to histological images. The system might be a useful help for both pre-and postdoctoral students as an aid for the detection of second mesiobuccal root canal orifices.

Recognition of root canal orifices at a distance - a preliminary study of teledentistry.

The remote recognition of root canal orifices was tested on 50 images of endodontically accessed teeth acquired with an intra-oral camera. The images were stored on a laptop computer and were presented to 20 observers who marked the visible canal orifices using software which stored the canal locations in standard files. The marked positions were verified on histological slices. In 87% of the cases, the canal locations were marked correctly. Inter-observer reliability depended on the location of the reviewed root canal (kappa = 0.44-0.77). The detection rate was related to the professional experience of the observers. The maximum proportion of accurate detections was found for the observers with more than 10 years of professional experience. The minimum proportion of accurate detections, 79%, was by the observer with one year of experience. The results of the study suggest that remote recognition of root canals by experienced dentists can help younger colleagues in the detection of root canal orifices.

Bisphosphonates: restrictions for vasculogenesis and angiogenesis: inhibition of cell function of endothelial progenitor cells and mature endothelial cells in vitro.

Bisphosphonate-associated osteonecrosis of the jaws (BP-ONJ) is one of the main side effects in patients treated with bisphosphonates for metastasis to the bone or osteoporosis. BP-ONJ usually occurs in patients treated with highly potent nitrogen-containing bisphosphonates. The exact mechanism of action and etiopathology is still unknown. In addition to inhibition of bone remodelling, an anti-angiogenetic effect has become the focus of research. The aim of these study was to investigate the effect of different bisphosphonates on human umbilicord vein endothelial cells (HUVEC) and endothelial progenitor cells (EPC), which play an important role in angiogenesis. Using varying concentrations, the impact of one non-nitrogen-containing bisphosphonate (clodronate) and three nitrogen-containing bisphosphonates (ibandronate, pamidronate and zoledronate) on HUVEC and EPC was analysed. The biologic behaviour of HUVEC after incubation with different bisphosphonates was measured in a Boyden migration assay as well as in a 3D angiogenesis assay. The number of apoptotic cells was measured by Tunnel assay. To underline the importance of neoangiogenesis in the context of BP-ONJ, we measured the EPC number after incubation with different bisphosphonates in vitro. HUVEC and EPC were significantly influenced by bisphosphonates at different concentrations compared with the non-treated control groups. The nitrogen-containing bisphosphonates pamidronate and zoledronate had the greatest impact on the cells, whereas clodronate followed by ibandronate was less distinct on cell function. These results underline the hypothesis that inhibited angiogenesis induced by bisphosphonates might be of relevance in the development and maintenance of BP-ONJ. The increased impact by highly potent bisphosphonates on HUVEC and EPC may explain the high prevalence of BP-ONJ in patients undergoing this treatment.

Alignment of cone beam computed tomography data using intra-oral fiducial markers.

This article illustrates a new method to align and merge two partially overlapping volumes each of them generated by cone beam computed tomography (CBCT). The aggregate volume covers a larger area of investigation and is determined by localizing one fixed LEGO brick in both of the primal volumes. Based on the LEGO brick an approximate registration of the volumes is determined. Afterwards we improve the transformation by minimizing the difference in overlapping space. In this paper we present a method which automates these two steps and provides an aligned volume.

Implementation of new software for fast screening of cell compatibility on surface modifications using low-contrast time-lapsed microscopy.

Assessment of cell adhesion and cell size provides valuable information on surface biocompatibility. However, most investigations on cell morphology dynamics are time and resource consuming, of rather descriptive character and lack procedures for appropriate quantification. The aim of the study was to develop a software programme which allows automated cell segmentation and identification as well as calculation and further processing of cell size in low-contrast images. The software utilises modified edge detection and morphologic operations for automatic cell analysis in light microscopy images. In an application study, osteogenic cell-adhesion dynamics were quantified for the ECM proteins collagen type I (COL) and fibronectin (FIB) over a period of 12 hrs. Untreated tissue culture polystyrene (TCPS) served as control. The software programme proofed full function in automatic cell tracking and quantification of cell size. After 11 h, cell sizes were highest for COL (6391 ± 1167 µm(2)) and FIB (6036 ± 411 µm(2)) compared with TCPS (3261 ± 693 µm(2)). The developed software allows quantification of initial cell size changes on translucent surface modifications and is suitable as a reliable tool for fast biocompatibility screening. Osteogenic cell adhesion was significantly promoted by COL and FIB indicating the potential of respective functionalized biomaterial surfaces.

Ex vivo radiographic tooth length measurements with the reference sphere method (RSM).

A reference-based radiographic "reference sphere method" (RSM) for accurate length measurements in (dental) projection radiographs for the assessment of tooth length in dry human mandible sections is evaluated. RSM determines the depth coordinates of reference spheres placed in the object plane from the elliptical distortion of their shadows. Two segments (one canine and one molar) of dry human mandibles were exposed 95 times at different angulations (0-40°) on a dental charge-coupled device receptor. Three steel spheres (diameters d (1) = 2.00 mm, d (2) = 3.00 mm) were attached roughly coplanar with the tooth's main axis. Radiographs were assessed once by visual inspection plus manual landmark identification with a mouse-driven cursor. The results were compared to the true tooth length assessed after extraction and to a conventional method (C), i.e., the rule of proportion based on magnification of the sphere shadows. Mean relative length error was 2.28% (d (1)) and 0.46% (d (2)) for RSM and -13.58% (d (1)) and -9.90% (d (2)) for C. For both methods, length errors were significantly (p < 0.0001) correlated with the inclination relative to the receptor. RSM allows for complete a posteriori determination of the imaging geometry under the assumption of a known source-to-receptor distance. One specific application is foreshortening correction of objects coplanar with the reference spheres. Remaining errors are mainly due to incorrect landmark definition. In our setup, these were exaggerated by the visual/manual image-evaluation process. Automated image analysis has been shown for similar tasks to minimize these errors considerably.

The treatment of anterior dental trauma.

BACKGROUND: Avulsed frontal teeth often cannot be saved because of improper or lack of initial treatment. The result is a need for multiple interventions over the patient's lifetime, which also carry a high financial cost. METHODS: We explored the subject of lost anterior teeth in young patients with a PubMed search based on the term "prevalence of traumatic dental injuries" over the time period 2000-2010. In this article, we selectively review the publications retrieved by the search and give case examples to illustrate the proper initial treatment of children and adolescents (ages 6 to 17) with broken anterior teeth. RESULTS: The search retrieved 138 articles. Here, we review retrospective clinical studies of dental trauma between the ages of 6 and 17: only 6 adequately designed studies of this type were found. The estimated prevalence of anterior dental trauma in this age group ranged from 6.4% to 37.9%. The recommended initial steps for the preservation of traumatized teeth are easy to take. Avulsed teeth can and should be replanted at once. If there is no time, or if the patient simultaneously has other, life-threatening injuries, the avulsed teeth can be stored in a special nutrient medium until they can be replanted. Commercially available tooth rescue boxes enable replantation to be performed up to 24 hours after the injury. CONCLUSION: The authors of the selected studies agree that dental trauma is often improperly treated. Timely treatment of injured anterior teeth prevents much further damage and expensive treatment for the affected young patients.

Recognition of root canal orifices in video sequences as a future support system during endodontic treatment.

INTRODUCTION: The objective of this study was to show the practical application of computer-aided techniques for detecting root canal orifices through the access cavity using a video camera mounted on a microscope. METHODS: A minimum distance classification image recognition algorithm was tested in an in vitro study to assess the possibilities of computer-aided recognition of root canal orifices. A Motic DM143 digital stereo microscope (Motic Germany GmbH, Wetzlar, Germany) was used because it includes a video camera that can be connected via USB1.1 to any computer. RESULTS: The newly developed software is capable of communicating with a video camera and can automatically detect the root canal orifices in all teeth used in this study. A total of 165 extracted human teeth (molars and premolars) were used as test data to collect 8,250 images via screenshots for the evaluation of the detection quality. The software provided a detection sensitivity of 90.1%, with only 11.9% of the images as false-positive detections. CONCLUSION: The study shows that computer-aided recognition of root canal orifices with video cameras is possible.

Fast algorithm for detection of reference spheres in digital panoramic radiography.

In this paper, an algorithm for detection of reference spheres from digital panoramic radiographic images is presented. The proposed algorithm was tested on a database of 107 digital panoramic radiographic images which were used for dental diagnostics. Results show that the proposed method exhibits for detection of reference spheres, a sensitivity of 97.33% and specificity of 93.85%. Performance time differed between 0.55 and 2.36s depending on image size. The aim of this work was to provide a fast ellipse detection algorithm to reduce measuring time on preoperative implant planning by lowering the computational cost.