Prevalence and correlation with sex, age, and dental status of bone apposition at the mandibular angle and radiographic alterations of the temporomandibular joints: a retrospective observational study in an adult Swiss population.

BACKGROUND: The purpose of this study was to determine the prevalence of radiographic changes in the mandibular angle (bone apposition) and osseous alterations in the temporomandibular joints (TMJs) in the adult population of Switzerland. In addition, the study intended to investigate possible correlations between the two sites of contour bone changes (mandibular angle and TMJ) and to analyze various patient-related factors, including sex, age, dental status, and medical history. METHODS: Panoramic radiographs of 600 patients distributed into six age groups (283 females, 317 males, aged 20 to 79 years) were included to evaluate radiographic changes. The bone in the mandibular angle region and the shape of the condylar heads were examined for contour changes (bone apposition at the jaw angles and osseous changes of the TMJs). General estimating equations, binormal tests, and chi-squared tests were used for statistical analysis. RESULTS: Approximately half of the mandibular angles (47.8%) showed bone apposition, mostly bilateral. TMJ alterations were less common (27%), often unilateral, with flattening being the most frequent finding. No significant correlation was found between the two sites. Bone apposition at the mandibular angle showed a significant male predominance, whereas TMJ changes did not differ by sex. Alterations in both sites increased with age, and were not related to dental status or analgesic use. CONCLUSIONS: Bone apposition at the mandibular angle should be interpreted as part of the natural functional adaptation of the bone associated with aging. Assuming that parafunctional habits may influence the development and progression of alterations in the mandibular angle or TMJs, the presence of radiographic changes in these areas should prompt dental clinicians to investigate further in this direction. TRIAL REGISTRATION: The study was approved by the Swiss Association of Research Ethics Committees (swissethics), BASEC reference number: 2020-00963 (25.05.2020).

Feasibility of frozen soft tissues to simulate fresh soft tissue conditions in cone beam CT scans.

OBJECTIVES: To evaluate the feasibility of frozen soft tissues in simulating fresh soft tissues of pig mandibles using cone beam CT (CBCT). METHODS: Two fresh pig mandibles with soft tissues containing 2 tubes filled with a radiopaque homogeneous solution were scanned using 4 CBCT units and 2 field-of-view (FOV) sizes each. The pig mandibles were deep-frozen and scanned again. Three cross-sections were exported from each CBCT volume and grouped into pairs, with one cross-section representing a fresh and one a frozen mandible. Three radiologists compared the pairs and attributed a score to assess the relative image quality using a 5-point scale. Mean grey values and standard deviation were obtained from homogeneous areas in the tubes, compared using the Wilcoxon matched-pair signed-rank test and subjected to Pearson correlation analysis between fresh and frozen physical states (α = .05). RESULTS: Subjective evaluation revealed similarity of the CBCT image quality between fresh and frozen states. The distribution of mean grey values was similar between fresh and frozen states. Mean grey values of the frozen state in the small FOV were significantly greater than those of the fresh state (P = .037), and noise values of the frozen state in the large FOV were significantly greater than those of the fresh state (P = 0.007). Both mean grey values and noise exhibited significant and positive correlations between fresh and frozen states (P < 0.01). CONCLUSIONS: The freezing of pig mandibles with soft tissues may serve as a method to prolong their usability and working time when CBCT imaging is planned.

The use of CBCT in orthodontics with special focus on upper airway analysis in patients with sleep-disordered breathing.

Applications of cone-beam CT (CBCT) in orthodontics have been increasingly discussed and evaluated in science and practice over the last two decades. The present work provides a comprehensive summary of current consolidated practice guidelines, cutting-edge innovative applications, and future outlooks about potential use of CBCT in orthodontics with a special focus on upper airway analysis in patients with sleep-disordered breathing. The present scoping review reveals that clinical applications of CBCT in orthodontics are broadly supported by evidence for the diagnosis of dental anomalies, temporomandibular joint disorders, and craniofacial malformations. On the other hand, CBCT imaging for upper airway analysis-including soft tissue diagnosis and airway morphology-needs further validation in order to provide better understanding regarding which diagnostic questions it can be expected to answer. Internationally recognized guidelines for CBCT use in orthodontics are existent, and similar ones should be developed to provide clear indications about the appropriate use of CBCT for upper airway assessment, including a list of specific clinical questions justifying its prescription.

Guided endodontics versus conventional access cavity preparation: an ex vivo comparative study of substance loss.

BACKGROUND: To compare the outcomes of conventional access cavity preparation (CONV) versus guided endodontics (GE) for access cavity preparation in anterior teeth with pulp canal calcification (PCC) regarding root canal detection, substance loss, procedural time, and need for additional radiographs. METHODS: Extracted, sound human teeth with PCC (n = 108) were matched in pairs, divided into two groups and used to produce 18 models. An independent endodontist and a general dentist performed access cavity preparation under simulated clinical conditions on nine models each (54 teeth). The endodontist used the conventional technique and the general dentist GE. Time needed to access the root canals and the number of additional radiographs were recorded. Pre- and postoperative cone-beam computed tomography scans were obtained to measure substance loss. Statistical significance was tested by examining the overlap of 95% confidence intervals (CIs) between the groups. RESULTS: All root canals were successfully accessed by both methods. There were no significant differences in substance loss (CI: CONV 15.9-29.6 mm3 vs. GE 17.6-27.5mm3) or procedural time (CI: CONV 163.3-248.5 s vs. GE 231.9-326.8 s). However, 31 additional radiographs were required for GE compared to none for CONV. CONCLUSIONS: For access cavity preparation in teeth with PCC, both CONV by a specialist and GE by a general dentist produce good results in terms of substance loss and time requirements.

Accuracy of a dynamic navigation system for dental implantation with two different workflows and intraoral markers compared to static-guided implant surgery: An in-vitro study.

PURPOSE: To investigate the accuracy of a miniaturized dynamic navigation system with intraoral markers and two different workflows for dental implantation and to compare with static computer-assisted implant surgery (sCAIS) surgery. MATERIALS AND METHODS: Two operators performed a total of 270 implant insertions in polyurethane mandibular models under simulated clinical conditions. Implants were placed after CBCT-based virtual planning in three different groups: two workflows utilizing dynamic computer-assisted implant surgery (dCAIS; DG1: marker in CBCT; DG2: 3D-printed marker) and the others with sCAIS (TG: template guided). Postoperative surface scans were matched to the planning data and allowed an evaluation of the angular and spatial deviation between the planned and the actually achieved implant position. Descriptive statistics were followed by a Mixed Model Analysis to determine the influence of the operator, the method, and operating area on different accuracy parameters and the random effect of the model number. RESULTS: The mean angular deviation ranged from 2.26° (DG1) to 2.96° (TG). The mean 3D deviation at the implant's tip ranged from 1.08 mm (TG) to 1.51 mm (DG2) and at the implant's base from 0.69 mm (TG) to 1.49 mm (DG2). The operator showed no significant influence on the accuracy. The method showed significant influence on singular parameters and the operating area on all spatial accuracy parameters. CONCLUSIONS: Dynamic navigation systems with intraoral markers enable accurate implant positioning, which is comparable to the static-guided implant surgery. 3D-printed markers provide less accurate results compared to prefabricated markers, attached before CBCT scan.

The use of protection measures in dento-maxillofacial radiology in Europe: a survey among experts.

Patient contact shielding to reduce radiation exposure to radiosensitive organs of patients is known to be used inconsistently in the field of dento-maxillofacial radiology (DMFR). There is an ongoing discussion if its use is still justified with regard to recent technical enhancements in the field. Thus, the aim of this study was to investigate the recommended and applied safety standards regarding dose protection measures in dental radiology within European countries. With an online questionnaire the use of safety measures, especially lead protection and collimation, in different patient groups (adults, children, pregnant women) was interrogated including leading experts in the field of DMFR. Among the 24 participants from 13 different countries, there was a tendency towards lead protection for intraoral radiography and towards collimation for extraoral radiography. Participants based their decision mainly on law and societal guidelines. Overall, the application of radiation protection measures varies within Europe. It seems safe to say that lead protection as a measure of radiation dose limitation is still recommendable even though collimation and technical advancements have led to great dose reductions. Collimation should be used more broadly and a standardization of protection measures and an update of radiation protection guidelines in Europe is desirable.

Evaluation of five methods to identify composite restorations in human teeth on a forensic purpose-an ex vivo comparative study.

The use of tooth-colored composite resin materials in dentistry is increasing. As composite restorations appear similar to the natural tooth structure, their detection is becoming more challenging. The aim of this study was to compare five diagnostic methods for detection of dental restorations and to create reliable postmortem dental records for forensic purposes. A conventional examination method without a direct light source (CONV), with a dental loupe light (DL), Galilean loupes with a direct light source (GDL), a fluorescence-inducing device (FIT), and intraoral radiographs (RX) were compared. Dentists specializing in conservative dentistry or oral surgery and dentistry students participated. Regarding sensitivity, specificity, positive predictive value, and negative predictive value, FIT and RX showed significantly higher results than CONV, DL, and GDL. RX and FIT showed comparable results in identifying composite restorations but depending on their location. The combination of both methods may lead to even better results. In conclusion fluorescence-inducing devices show good results in identifying composite restorations and therefore should be considered as a standard tool in forensic examinations. Another advantage is their small size, low cost, and mobility. Good illumination and magnification devices are recommended to enhance performance during conventional examinations. Involving dentists specialized in conservative dentistry could contribute to dental identification.

Guided Endodontics: Three-dimensional Planning and Template-aided Preparation of Endodontic Access Cavities.

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, pulpitis or apical periodontitis may develop in the long term. Root canal treatment of teeth with severe PCO and pulpal or periapical pathosis is challenging for general practitioners and even for well-equipped endodontic specialists. To ensure detection of the calcified root canal and avoid excessive loss of tooth structure or root perforation, static navigation using templates ("Guided Endodontics") was introduced a few years ago. The general workflow includes three-dimensional imaging using cone-beam computed tomography (CBCT), a digital surface scan, and superimposition of both in a planning software. This is followed by virtual planning of the access cavity and the design of a template that will guide the drill to the desired target point. To do this, a true-to-scale virtual image of the drill must be placed in a way that the tip of the drill reaches the orifice of the calcified root canal. Once the template has been fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) or a 3D printer, guided preparation of the access cavity can be performed clinically. For research purposes, a postoperative CBCT image can be used to quantify the accuracy of the access cavity performed. This work aims to present the technique of static guided endodontics from imaging to clinical implementation.

Effect of field of view (FOV) positioning and shielding on radiation dose in paediatric CBCT.

OBJECTIVE: To investigate the effect of two different large field of view (FOV) positions in the vertical dimension and shielding (thyroid collar and eyeglasses) on the effective dose and the local doses of various sites of the craniofacial complex. METHODS: Organ doses and effective doses were calculated based on the measured doses using 27 pairs of thermoluminescent dosemeters in a paediatric tissue-equivalent of a 10-year-old anthropomorphic phantom. The large FOV of the 3D Accuitomo F170 CBCT scanner was used to image parts of the craniofacial complex. Six protocols were performed: (A) cranial position without shielding; (B) cranial position with shielding; (C) caudal position without shielding; (D) caudal position with shielding, (E) similar to C with 3600 rotation and (F) similar to D with 360° rotation. Measurements were obtained in duplicate, and the relative δ value (%) was applied to compare the average doses between the protocols. RESULTS: Changing the FOV position from cranial to caudal without using shielding resulted in an increase of the effective dose of 18.8%. Use of shielding in the caudal position reduced the dose by 31.6%. Local absorbed dose of the thyroid had the most relevant impact on calculation of the effective dose, followed by oesophagus, bone marrow and bone surfaces, especially when comparing the different protocols. CONCLUSIONS: Application of shielding devices for thyroid in combination with a most caudal positioning of FOV led to the lowest local absorbed doses as well as the effective dose in a child phantom model.

Image quality assessment of three cone beam computed tomography scanners-an analysis of the visibility of anatomical landmarks.

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate large field of view (FoV) subjective image quality of three cone-beam computed tomography (CBCT) machines to assess the threshold for reliable diagnostic perceptibility when lowering exposure settings. MATERIALS AND METHODS: One entire cadaver's head was scanned using three CBCT scanners. The largest available FoV of each device, imaging orthodontic relevant structures, was applied. CBCT datasets with different image quality based on standard to minimum scanning parameters were acquired. Five dentists evaluated the visibility of selected anatomical structures of the upper and lower jaw using a 5-point rating scale. RESULTS: Image quality depends on parameters such as a minimum voxel size of 0.2 to 0.4mm or a minimum of 4mA. A reduction in number of images (scanning protocol) reduces image quality. Visualization of different anatomical structures for orthodontic treatment planning requires distinct scanning protocols to support adequate perception of these structures. LIMITATIONS: This study does not account for the evaluation of paediatric anatomical structures due to the availability of cadaver's head. CONCLUSIONS: CBCT scans performed for orthodontic purposes using a large FoV with reduced parameters (400 µm, 2 to 4 mA and low dose protocols) are acceptable for visualization of large anatomical structures. Further lowering these parameters will not be sufficient to view small anatomical structures. Orthodontic indications will have to define specific anatomical structures to choose adequate scanning protocols to reduce dose and ensure reliable diagnostic visibility.

Real-Time Guided Endodontics with a Miniaturized Dynamic Navigation System Versus Conventional Freehand Endodontic Access Cavity Preparation: Substance Loss and Procedure Time.

INTRODUCTION: This study aimed to evaluate substance loss and the time required for access cavity preparation (ACP) using the conventional freehand method (CONV) versus a miniaturized dynamic navigation system of real-time guided endodontics (RTGE) in an in vitro model using 3-dimensional-printed teeth. METHODS: Nine human anterior maxillary teeth were selected and micro-computed tomographic scanned. Root canals were virtually reduced to 2 mm below the cementoenamel junction. The teeth were digitally duplicated and mirrored to yield 6 different models with 6 single-rooted teeth each. The models were 3-dimensionally printed using radiopaque resin and consecutively mounted on a dental mannequin for ACP. Two operators with 12 and 2 years of clinical experience, respectively, received 6 models (36 teeth) each and performed ACP on half of the models using RTGE (after digital planning) and CONV on the other half 2 weeks later. The time was recorded. Postoperative substance loss was measured by cone-beam computed tomographic imaging. The differences in time and substance loss between the methods and operators were evaluated by the t test. RESULTS: Overall, substance loss was significantly lower with RTGE than CONV (mean = 10.5 mm3 vs 29.7 mm3), but both procedures took a similar time per tooth (mean = 195 vs 193 seconds). Operator 1 (more experienced) achieved significantly less substance loss than operator 2 with CONV (mean = 19.9 vs 39.4 mm3) but not with RTGE (mean = 10.3 vs 10.6 mm3). CONCLUSIONS: RTGE is a practicable, substance-sparing method performed in comparable time as CONV. Moreover, RTGE seems to be independent of operator experience.

Suitability of Magnetic Resonance Imaging for Guided Endodontics: Proof of Principle.

INTRODUCTION: This proof-of-principle study aimed to demonstrate that magnetic resonance imaging (MRI) is sufficiently accurate for the detection of root canals using guided endodontics. METHODS: One hundred extracted human teeth (anterior and premolar) were mounted onto 5 mandibular and 5 maxillary models, fitted with splints designed to accommodate a thin layer of aqueous gel for indirect imaging, and scanned by MRI. After MRI and intraoral scans were aligned using planning software, access cavities were planned virtually, and templates were manufactured with computer-aided design/computer-aided manufacturing, the access cavities were prepared. Cone-beam computed tomographic scans were performed and matched with the virtual preoperative planning data to determine the accuracy of access cavity preparation in terms of deviation between planned and prepared cavities in the mesiodistal and buccolingual dimensions and angle. Descriptive statistical analysis was performed, and the mean values were compared using the t test. RESULTS: Ninety-one of 100 root canals were successfully scouted after MRI-guided access cavity preparation. The mean angle deviation was 1.82°. The mean deviation ranged from 0.21-0.31 mm at the base of the bur and from 0.28-0.44 mm at the tip of the bur. Preparation in the buccolingual dimension was significantly more precise in mandibular compared with maxillary teeth, and accuracy in the mesiodistal dimension was more precise in anterior teeth compared with premolars. CONCLUSIONS: This in vitro study demonstrated the suitability of MRI for guided endodontic access cavity preparation.

Dental trauma splint color preference of adults.

The prevalence of dental trauma among children and adults is high. Most luxated teeth need splinting. The Titanium Trauma Splint (TTS) is a widely used appliance with good performance properties. Esthetics is increasingly important for most patients. Splints placed on the front teeth have a clearly visible impact on patients' appearance and, thus, on their quality of life during splint therapy. Therefore, the aim of the present study was to evaluate the esthetic preferences of adult patients with regard to different splint color and surface finish characteristics. TTS appliances were fabricated in four different colors (silver, gold, green and violet) and two different surface finishes (matt or polished) to yield a total of eight variants. The finished splints were applied to the teeth of a human model, photographed by a professional photographer, and printed as posters. Adults aged between 18 and 79 years were asked to complete a written survey containing items regarding their TTS color and surface preferences based on the posters with photographs as well as questions about previous tooth bleaching treatments, the importance of having esthetic teeth in general, and the prioritization of esthetic versus function-driven dentistry. Over 80% of participants preferred the silver matt splint over the other variants. Neither gender nor age nor other parameters had a significant influence on the choice of splint color or surface. Women placed greater importance on esthetic rather than function-driven treatment.

Impact of CBCT image quality on the confidence of furcation measurements.

BACKGROUND: To investigate the impact of scanning parameter in cone-beam computed tomography (CBCT) images on accuracy and confidence with measurements of furcation involvement (FI) in maxillary molars. MATERIAL AND METHODS: Six half cadaver heads with present maxillary molars (n = 10) were available. CBCT scans with the fixed-parameter field of view (4 × 4 cm, 12 × 17 cm) amperage and voltage (4 mA, 90 kV) and with varying scan modes (SM), that is images/scan (IS), voxel sizes (VZ) and rotation (R), were performed using one CBCT apparatus. The images were analysed by two calibrated investigators. Horizontal FI's were measured in mm or a "through and through" destruction (FI degree III) was recorded. Each rater scored the FI measurements performed in each scan as "confident" or as "not confident". Data were statistically analysed using chi-square tests. RESULTS: The agreement between CBCT FI measurements and intra-surgical FI measurements varied according to SM (SM HiSp 180°, 0.08: kappa 0.538, CI; 95%: 0.362-0.714; SM Std. 360°, 0.25: kappa 0.698, CI; 95%: 0.534-0.861). The number of measurements scored as "confident" varied according to SM (SM Std. 360°, 0.08:52 out of 60 measurements; SM Std. 360°, 0.25:16 out of 60 measurements; p < .001). CONCLUSIONS: SM of CBCT significantly affect the confidence with FI measurements in maxillary molars.

Evaluation of magnetic resonance imaging for diagnostic purposes in operative dentistry-a systematic review.

OBJECTIVES: Magnetic resonance imaging (MRI) is a well-established diagnostic tool in various areas of medicine. The technique provides radiographic images in the absence of ionizing radiation. The aim of the present analysis was to evaluate the best available current external evidence for application of MRI in operative dentistry. MATERIAL AND METHODS: A systematic literature search was performed for studies published by August 2019 in three electronic databases (MEDLINE, Embase via Ovid, Cochrane Library) supplemented by a hand search. The PRISMA criteria were applied to a PICO question. Data were extracted and summarized in data extraction files, and a quality assessment of the included studies was performed. RESULTS: From 287 titles identified, 12 case series with two studies on caries detection, six studies on endodontic, and four studies on anatomical aspects were eligible for inclusion. The studies included showed a high level of heterogeneity and summarized data from 343 subjects. The data available indicate potential of certain MRI settings for diagnostic of caries lesions, presentation of pulp tissues and periapical lesions, and the localization of impacted teeth. CONCLUSIONS: The limited currently available evidence shows potential of certain MRI settings for the use in operative dentistry. Further research needs to assess the applicability and accuracy for dental hard tissues as well as cost-benefit aspects of the MRI technique. CLINICAL RELEVANCE: Certain MRI settings may have the potential as diagnostic tool in operative dentistry.

Comparison of Two-Dimensional and Three-Dimensional Radiographs Using Clinically Relevant Parameters.

This work compared the assessment of clinically relevant parameters by two-dimensional, that is, full-mouth intraoral radiograph (I-O) and panoramic radiograph (OPT), and three-dimensional, that is, cone beam computed tomography (CBCT), imaging methods. Different radiographic images (CBCT, I-O and OPT) were available for a 53-year-old female patient with dental and periodontal problems. A total of 14 dental and periodontal parameters were assessed by two independent examiners and compared among the three radiographic imaging modalities. For 10 parameters (71%), the CBCT images were superior to both I-O and OPT images. In contrast, CBCT demonstrated an inferior performance compared to I-O and OPT in the assessment of caries and dental restorations. Compared to OPT, I-O provided more clinically relevant findings for 10 out of 14 parameters (71%). Agreement between I-O and OPT was found with respect to dehiscence, fenestration, the number of bone walls and the root canal cross-section. Differences between the radiographic images were more likely to be detected when maxillary teeth rather than mandibular teeth were assessed with regard to furcation involvement, root proximity and root fusion.

Role of ambient light in the detection of contrast elements in digital dental radiography.

OBJECTIVE: This study aimed to evaluate the effect of different ambient light levels on observer detection of small contrast differences in a contrast phantom by using a high-end liquid crystal display (LCD) monitor. STUDY DESIGN: An aluminum step wedge was converted into a contrast phantom by the addition of bore holes. Radiographic images of the contrast elements were presented to 20 observers. Images were displayed in random order under different ambient light levels (0, 50, 200, and 500 lux) twice, and the observers had to determine if contrast elements were visible. Sensitivity and specificity were determined to calculate areas under receiver operating characteristic curves and Friedmann's test was applied to evaluate the influence of the ambient light level on observer performance. RESULTS: Mean AZ values were moderate for each ambient light level at 0.715, 0.793, 0.764, and 0.722 for 0, 50, 200, and 500 lux, respectively. The influence of the ambient light level on observer performance was not statistically significant (P > .05). CONCLUSIONS: There was no significant influence of ambient light between 0 and 500 lux on observer ability to detect small contrast details displayed on a high-end LCD monitor.

Influence of Three-dimensional Imaging on Implant Treatment Planning: Implant Diameter and Length.

AIM: To investigate the influence of the radiographic modalities panoramic radiography (PR) and cone beam computed tomography (CBCT) on selection of implant length and diameter. MATERIALS AND METHODS: Potential implant sites (59 sites, 40 patients) with available PRs and CBCTs were selected from the databases of two University dental schools. Six experienced clinicians were asked to select the appropriate implant length and diameter based on PR and CBCT. Results were compared with the actual surgical procedure and intra- /interrater agreement was calculated using Cohen's kappa. RESULTS: On average, greater implant length was more often planned based on PR (24.2 vs 8.8% with CBCT), while wider implants were generally more frequently planned based on CBCTs (19.9 vs 29.7% with PR). Implant treatment planning based on PR and on CBCT images was equal in 50 to 67%. Compared with the actual surgery, CBCT revealed a higher agreement (46% for implant length), while for PR, 34.4% equal implant length was observed. CONCLUSION: The radiographic modality used for implant treatment planning affects implant selection. CLINICAL SIGNIFICANCE: The CBCT scans are advantageous for choosing the appropriate implant dimension. Caution should be exercised when selecting implant length planned from PR.

Do periapical and periodontal pathologies affect Schneiderian membrane appearance? Systematic review of studies using cone-beam computed tomography.

OBJECTIVES: This systematic review analyzed the relationship between periapical and periodontal pathologies in the posterior maxilla and the appearance of the Schneiderian membrane in cone-beam computed tomography (CBCT) compared with sound dentitions. METHODS: Five electronic databases (Cochrane Library, Embase, OpenGrey, PubMed, Web of Science), complemented by hand searching, were screened up to May 9, 2016. Human clinical studies that used CBCT and contained information on the periapical/periodontal status in the posterior maxilla and Schneiderian membrane appearance were included. A weighted vote counting (WVC) method was applied to summarize results across studies. RESULTS: Out of 413 records, 20 studies were included. In the WVC, the studies that observed a positive association between periapical lesions and the appearance of the Schneiderian membrane outweighed those that found no such association (WVC 51 % and WVC 33 %, respectively), with some studies yielding indeterminate results (WVC 16 %). Regarding the relation between periodontal pathologies and the appearance of the Schneiderian membrane, WVC produced a tie between studies demonstrating a positive association (WVC 46 %) and those showing no association (WVC 44 %); one study (WVC 10 %) reported indeterminate results. CONCLUSIONS: On CBCT scans, periapical lesions in the posterior maxilla are likely to be associated with Schneiderian membrane thickening. In contrast, current evidence regarding the relation between periodontal diseases and the appearance of the Schneiderian membrane in CBCT is inconclusive. CLINICAL RELEVANCE: Incidental maxillary sinus findings on CBCT scans warrant thorough differential diagnosis. Frequently, they may be related to dental pathologies.

Detection of peri-implant bone defects with different radiographic techniques - a human cadaver study.

OBJECTIVES: Two- and three-dimensional radiographic techniques are available to determine peri-implantitis-related bone loss around dental implants. PURPOSE: To compare the performance of detecting different peri-implant bone defects in intraoral radiography (IR), panoramic radiography (PR), Cone Beam Computer Tomography (CBCT) and Computer Tomography (CT). MATERIAL AND METHODS: Six implants were inserted under ideal conditions into the lower jaw of an edentulous human cadaver. IR, PR, CBCT and CT were performed. Two-wall, three-wall and four-wall defects with 1 mm depth were artificially created around two of the implants (one anterior and one posterior), and radiographies were repeated. The identical set-up was used for 3-mm-deep bone defects. All images were presented to seven observers. Sensitivity (SN) and specificity (SP) were determined for each modality, defect type and depths, and likelihood ratios were calculated. RESULTS: The highest sensitivity was found with IR and CBCT for 1 mm (0.67; 0.68) and 3-mm defects (0.81; 0.79). The highest specificity was found with IR for both defect depths (0.51). The best classification of defect type revealed PR for both 1-mm and 3-mm-deep defects. Both likelihood ratios (LR+ and LR-) were best for IR with 1-mm (1.37 and 0.65) and with 3-mm defects (1.65 and 0.37). CONCLUSIONS: IR should still be recommended as favourable method evaluating bone loss around dental implants, while CT demonstrated the lowest performance in detecting peri-implant bone defects.