The comparison of visibility of the maxillary sinus septa between cone-beam computed tomography scans and panoramic radiograph images as dependent on the cortical bone thickness: a retrospective comparative study.

PURPOSE: To analyze the visibility of the maxillary sinus septa (MSS) in panoramic radiography (PR) versus cone beam computed tomography (CBCT) and to investigate whether the buccal cortical bone thickness (BT) or the septa dimensions influence their visibility. METHODS: Corresponding PR and CBCT images of 355 patients were selected and examined for MSS visibility. The septa dimensions (width, height, depth) and the BT were measured. Results were analysed statistically. RESULTS: Comparing the corresponding regions on CBCT and PR, 170 MSS were identified; however, only 106 of these were also visible using PR. The MSS visibility was significantly higher on CBCT versus PR images (P1: p = 0.039, P2: p = 0.015, M1: p = 0.041, M2: p = 0.017, M3: p = 0.000), except region C (p = 0.625). Regarding the measurements of MSS dimensions, only the height in region M1 (p = 0.013) and the width in region P2 (p = 0.034) were significantly more visible on CBCT. The BT in the area of the MSS was found to have a marginal influence on its visibility on the PR images only in regions M3 and M1 (M3: p = 0.043, M1: p = 0.047). In terms of MSS visibility based on the dimensions, significance was found for all three influencing variables only in region P2 (width; p = 0.041, height; p = 0.001, depth; p = 0.007). There were only isolated cases of further significance: M3 for width (p = 0.043), M2 for height (p = 0.024), and P1 for depth (p = 0.034), no further significance was noted. CONCLUSION: MSS visibility appears significantly higher on CBCT versus PR images. It is concluded that the septa dimensions and BT can influence MSS visibility on PR images just in certain regions.

Can Loupe magnification be a viable alternative to Operative Microscope magnification for vascular anastomosis in reconstructive surgery? A systematic review and meta-analysis.

PURPOSE: The aim of this study is to compare the outcomes of vascular anastomosis using loupes magnification versus operative microscope magnification in reconstructive surgery. METHODS: We performed a systematic review of MEDLINE (via PubMed), Scopus and Cochrane Library database according to the PRISMA guidelines. Comparative studies between the two techniques and single arm studies reporting on loupes reconstruction were included. Random-effects model meta-analyses were performed. RESULTS: Twelve studies, reporting a total of 3908 of flaps, 3409 of which were performed under loupes magnification and 499 under the operative microscope magnification were selected for analysis. No statistically significant differences were observed regarding total flap loss and vascular complication between the two arms. In the Loupes group the rate of total flap loss was 2.65% (95% CI: 1.15-4.63) and the rate of vascular complications 4.49% (95% CI: 2.58-6.84). CONCLUSION: Loupes magnification under circumstances can provide a safe and effective alternative to microvascular reconstruction in reconstructive surgery. With respect to flap failure and vascular complication rates, there appear to be no statistically significant differences between the anastomoses conducted under Loupes magnification and the standard operative microscope.

Comparative diagnosis of the alveolar antral artery canal in the lateral maxillary sinus wall in corresponding panoramic radiography and cone-beam computed tomography.

PURPOSE: Sinus lift operations are a tried and tested means of providing adequate implant prosthetics to patients with compromised jawbones. Knowledge of the arterial supply of the maxillary sinus region is essential for surgical treatment in this area. The aim of the present comparative study was to determine whether alveolar antral artery (AAA) canal can be diagnosed both in corresponding panoramic radiography (PR) and cone-beam computed tomography (CBCT). METHODS: A total of 335 patients with 635 sites and corresponding maxillary sinus in both PR and CBCT were selected and examined for AAA canal visibility. RESULTS: The visibility of the AAA canal was significantly higher in CBCT than in PR. A total of 154 (46.0%) AAA canals could be identified in the maxillary sinus on the right. However, only four (1.2%) of these were also visible in PR. The detected values of the AAA canals in the maxillary sinus on the left in the PR and CBCT images were similar to those of the right. While 164 AAA canals (49%) were observed in CBCT images, only 1 (0.3%) was identifiable in PR. CONCLUSIONS: The results show that CBCT can be recommended for visualising the AAA canal when surgically planning sinus augmentation procedures.

Evaluation of the contour of edentulous jaw sections in the transversal plane and the buccolingual vertical-level disparity in CBCT and panoramic radiography images: a retrospective comparative study.

PURPOSE: This study investigates whether edentulous jaw sections in the planned implant position exhibit jaw contours funnel-shaped or exhibit pronounced retraction of the jaw (unusual jaw contours) in the transversal plane of the three-dimensional (3D) images, not visible in two-dimensional (2D) images. METHODS: A total of 335 patients with an edentulous section of the jaw that required dental implants were selected. Anonymised radiologic patients' data were collected, comprising cone-beam computed tomography (CBCT) images of the edentulous jaw sections. In the first stage, unusual jaw contours were examined, including funnel-shaped or pronounced retraction of the jaw and hypodense regions with an undercut and/or bone deficit. In the second stage, the variation in the height of the alveolar ridge between the lingual and buccal contour in the edentulous jaw sections was assessed. RESULTS: The CBCT images of an unusual jaw contour were observed in 8 cases (2.4%) in the maxilla on the left and 10 cases (3%) in the maxilla on the right. In the mandible, a jaw contour deviates in 39 cases (12.1%) on the left side and 39 cases (12.1%) on the right side. A height difference was detected in the upper jaw in 307 cases and the lower jaw in 265 cases. The discrepancy was 2.09 mm (± 2.25 mm) in the maxilla and 3.97 mm (± 3.45 mm) in the mandible. CONCLUSIONS: The CBCT scan provides useful information to avoid complications in the preoperative planning phase and surgical planning in implant dentistry.

Evaluation of Mandibular Fractures in a German Nationwide Trauma Center Between 2015 and 2017.

Introduction: This study analyses the treatment of isolated mandibular fractures between 1.1.2015 and 21.31.2017 at Dortmund General Hospital. Materials and Methods: Patient documentation and radiological images have been assessed, and a descriptive statistical analysis has been performed. Results: Three hundred and twenty-eight patients were identified with isolated mandibular fractures (259 male, 69 female). The male-to-female ratio is 3.75: 1. A total of 541 fracture sites have been identified (1.65 fractures/patient). Forty of these were observed in the dentoalveolar region (fracture of the alveolar process, dental injuries), and the other 501 injuries were distributed in the remaining parts of the lower jaw.A detailed analysis of the osteosynthesis implants is provided. A total of 20 serious complications were observed (6% in all primary cases, 4.5% without osseointegrated implants). Discussion: The demographic data and the anatomical distribution of the fracture sites are comparable with international literature. Dentoalveolar injuries mostly occur in younger patients. The complication rate in this study (4.5%) is below the international data; however, we found a considerably higher rate than in the midfacial region (central midface: 0%, lateral midface: 1.43%). Despite this complication rate, the procedure can be considered safe. Supplementary information: The online version of this article (10.1007/s12663-021-01513-4).

Long-term evaluation of treatment protocols for isolated midfacial fractures in a German nation-wide craniomaxillofacial trauma center 2007-2017.

An update on the trends in maxillofacial traumatology provides additional information on the actual and changing needs. This retrospective study aimed to review all patient records of patients treated for isolated midface fractures in the Department of Cranial- and Maxillofacial Surgery at the Dortmund General Hospital between 2007 and 2017. The patient radiographs and patient files were reviewed. The safety and efficacy of the applied methods were controlled by assessing complications based on the Clavien-Dindo classification system. The statistical analysis included descriptive methods including regression analysis and χ2-test. In eleven years, 3474 isolated midface fracture sites have been identified in 2868 patients. The yearly trend is slightly increasing, in elderly clearly worsening, in children and youth decreasing. The male-to-female ratio was 2.16:1 for the whole study population, in the age group 18-25 y.o. 6.95:1 while in elderly above 80 y.o. 1:2.51, the age group specific incidence reflects this result, too. The most common fractures were nasal bone fractures (1405), zygomatic fractures (832) and orbital floor fractures (700). The average hospital stay was 2.7 days, the most fractures were operated within 24 h. The complication rate was 2.02% (Clavien-Dindo class II-V). The incidence of midfacial fractures is increasing in the total population and especially in elderly, but decreasing in children. Development of injury prevention measures is needed in this population. The diagnostic and therapeutic procedures are appropriate, as there is a low complication rate and short inpatient stay observed.

Evaluation of Panfacial Fractures in a German Supraregional Trauma Center between 2015 and 2017 - A Retrospective Study.

INTRODUCTION: Panfacial fractures represent the most severe injuries to the face. The combination of these fractures determines the treatment strategy. This study aims to retrospectively review the data of adult patients treated for complex facial skull fractures in a hospital in Dortmund, Germany from 2015-2017. MATERIALS AND METHODS: We extracted related patient data from the hospital electronic repository and reviewed the patient files and radiological images. The fractures were classified based on the AO-Classification. The statistical analysis was performed by descriptive statistical methods. The main goal was to determine the most common fracture combinations. RESULTS: A total of 188 patients with panfacial fractures were identified (181 adults, 7 children and adolescents). The gender and age distribution corresponded to the international literature (male-to-female ratio: 3.1:1, most common injuries among young men). 2-9 fracture sites were identified per patient, resulting in a fracture frequency of 3.13 per patient. 69 different fracture combinations have been identified. The most common ones were combinations of lateral and central mid-face fractures, and combinations of nasal bone fractures with lateral midface fractures or nasal bone fractures combined with mandibular fractures. Between 1 and 13 osteosynthesis implants per patient were used for osteosynthesis; the most commonly used plates were 2.0 mm and 1.5 mm straight plates. The average inpatient stay was 3 days (standard deviation [SD] = 3.0 days), and the average operation time (incision to suture) was 39.5 min (SD = 53.5 min). DISCUSSION: Panfacial fractures are the most complex maxillofacial injuries. The complication rate in this study (4.5%) is below the international data. The treatment of panfacial fractures requires designated centers with experienced teams and good interdisciplinary cooperation.

Fracture heat map of the facial skull demonstrates a danger zone of concomitant cervical spine injuries.

Concomitant maxillofacial and cervical spine injuries occur in 0.8-12% of the cases. We examined the relation of injury localization and the probability of cervical spine fracture. A retrospective study was conducted on patients that have been treated at Dortmund General Hospital for injuries both to the maxillofacial region and to the cervical spine between January 1st, 2007 and December 31th, 2017. Descriptive statistical methods were used to describe the correlation of cervical spine injuries with gender, age as well as maxillofacial injury localization. 7708 patients were hospitalized with maxillofacial injury, among them 173 were identified with cervical spine injury. The average ages for both genders lie remarkably above the average of all maxillofacial trauma patients (36.2 y.o. in male and 50.9 y.o. in female). In the group of men, most injuries were found between the ages of 50 and 65. Whereas most injuries among women occurred after the age of 80. The relative ratio of cervical spine injuries (CSI) varies between 1.1 and 5.26% of the maxillofacial injuries (MFI), being highest in the soft tissue injury group, patients with forehead fractures (3.12%) and patients with panfacial fractures (2.52%). Further, nasal, Le Fort I and II, zygomatic complex and mandibular condyle fractures are often associated with CSI. Fractures next to the Frankfurt horizontal plane represent 87.7% of all MFI with concomitant CSI. Patients in critical age groups with a high-energy injury are more likely to suffer both, MFI and CSI injuries. Our findings help to avoid missing the diagnosis of cervical spine injury in maxillofacial trauma patients.

The comparison of roof visibility of the mandibular canal between cone-beam computed tomography scans and panoramic radiograph images as dependent on the cortical bone thickness of the mandible.

BACKGROUND: Accurate detection of the mandibular canal is a difficult process despite cutting-edge radiographic methods. The present study analyses whether mandibular canal roof visibility is comparable to panoramic radiography (PR) and cone-beam computed tomography (CBCT) and, further, examines whether the visibility in PR and CBCT is dependent on cortical bone thickness in the mandible. METHODS: This study was conducted on a group of 343 selected patients. It incorporated anonymised data on 343 patients in which a CBCT and PR were available. The first stage examines whether the mandibular canal roof visibility is comparable to PR and CBCT. In the second stage, measurements of cortical bone thickness showed buccal and lingual in the P2, M1, M2 and M3 teeth areas, both to the left and right of the mandible in CBCT images. Statistical analysis was supported by statistical software (IBM SPSS 25; Armonk, NY, USA). RESULTS: The mean age of the patients was 58.8 years with an almost equal gender distribution. When performing a McNemar test on the P2, M1, M2 and M3 on both the left and right jaws, the difference between the two image modalities, with regard to the visibility of the canal roof, was found to be significant (McNemar test, p < 0.001). Statistically (U test, p≥0.05), it follows that the thickness of the cortical bone of the mandible exerts no influence on the visibility of the roof of canalis mandibulae in PR and CBCT images. CONCLUSION: We conclude that the visibility of the mandibular canal in PR and CBCT rays is not identical, and that the thickness of the cortical bone in the mandible does not represent a factor affecting the visibility of the roof of the mandibular canal.

A randomized, prospective trial to assess the safety and efficacy of hilotherapy in patients after orthognathic surgery.

PURPOSE: A post-operative cooling method in oral and maxillofacial surgery is the cooling with hilotherapy. The aim of this study was the post-operative comparison of cooling temperatures of 18°C and 22°C. The parameters of this trial were swelling and the post-operative pain levels. METHODS: This study included 156 patients, divided into two groups among whom a mono-one, bignathic osteotomy or genioplasty was indicated. The post-operative assessment of swelling was performed using a 3D optical scanner. This examination was repeated on post-operative days 1, 2, 3, 7, 14, 30, and 90. The examination on day 90 served as a reference value in respect of swelling and pain. RESULTS: Group 1 (18°C, 78 patients) showed an increase in post-operative swelling on the 1st post-OP day of 52.06 ± 35.41ml. The maximum was reached on the 2nd post-OP day with 75.82 ± 38.97ml. On the 30th post-OP day, residual swelling measured 11.60 ± 12.62ml. Group 2 (22 °C, 78 patients) showed an increase in postoperative swelling on the 1st post-OP day of 76.07 ± 63.15ml. The maximum was reached on the 2nd post-OP day with 106.97 ± 69.63 ml. On the 30th post-OP day, residual swelling measured 14.36 ± 32.26ml. The differences between the two groups and between different visits were statistically significant. CONCLUSION: The study results indicate less residual swelling in group 1 on the 30th post-OP day, possible based on the lower cooling temperature. The post-operative pain exhibits a comparable level of pain intensity between the two groups. In overall terms, a subjectively more agreeable treatment was observed in group 1.

Complications after osteosynthesis of craniofacial fractures-an analysis from the years 2015-2017.

BACKGROUND: Complications mean a recurring problem in everyday clinical practice. Complication rates between 6 and 13% are described for the treatment of bony injuries to the head and neck area. This paper aims to provide a detailed analysis of the complications after osteosynthesis in facial skull fractures. MATERIAL AND METHOD: In this retrospective study, we reviewed all patient records of injured treated in the Department of Cranial and Maxillofacial Surgery at the Dortmund General Hospital between 2015 and 2017. RESULTS: Of the 22,031 head and neck injuries, 685 were treated with osteosynthesis. A clinically significant complication was reported in 32 patients (4.76%). The number of total complications was 63. In total, 66.7% of all complications have been identified in the paramedian mandible (44%), median mandible, mandibular angle, and in the collar area (each 12.7%). Eleven implants (in 5 patients) showed a cancellous bone impaction. Broken implants have been recognized in two cases. In 8 cases, there was a pseudarthrosis in the fracture area; in one case, there was a broken implant and pseudarthrosis in combination. CONCLUSION: Osteosynthesis is a safe method of treating facial skull fractures, which is why we consider it the gold standard of therapy. The complication rate is well below 5%. The 3-dimensional adaptation (bending) and shortening of the osteosynthesis implants do not lead to an increase in complications.

Hidden danger in the neck-a problem of differential diagnostics: benign chronic lymphadenitis following carotid endarterectomy and patch angioplasty (CEAP) or a metastasis due to a squamous cell cancer of the tongue.

INTRODUCTION: Oncological head and neck operations as well as carotid endarterectomy are common surgical procedures. In some occasions, both procedures have occurred in the past, leading to possible diagnostic and therapeutic challenges when follow-up operations seem indicated. CASE REPORT: We report of a patient presenting with carotid endarterectomy including patch operation 8 years ago and neck dissection due to a squamous cell cancer of the tongue 3 months ago, now showing up with a suspected metastatic tumor of the neck during routine follow-up. Intraoperatively, nearly fatal bleeding occurs due to a partial release of the carotid patch and needs to be managed immediately. DISCUSSION: The primarily pre-operated neck remains challenging for the radiologist in terms of differentiating between chronic lymphadenitis and metastasis. Furthermore, it remains challenging for the oncological surgeon in case these entities are in the near proximity of the previously operated carotid artery. The operative treatment according to the guidelines can lead to major bleeding during the second surgery. During the diagnostic process, metastases and chronic lymphadenitis after alloplastic carotid operations must be differentiated remaining however difficult, due to only scarce data in the literature. CONCLUSION: In the case of previous neck surgery, the decision to operate must be chosen individually regarding the specific conditions and their sometimes vital risks. In case an operation is indicated, the team must be trained to treat life-threatening intraoperative bleeding. In reviewing the literature, we were unable to find published recommendations on how to tackle these challenges.

Development of swelling following orthognathic surgery at various cooling temperatures by means of hilotherapy-a clinical, prospective, monocentric, single-blinded, randomised study.

PURPOSE: An alternative cooling method in oral and maxillofacial surgery is post-operative cooling with hilotherapy. It has not yet been clarified how the development of pain and swelling progresses post-operatively at different cooling temperatures. The aim of this study was the post-operative comparison of cooling temperatures of 18 °C and 22 °C. The parameters of this trial were swelling and the post-operative development of pain levels. In addition, the need for analgesics and patient satisfaction were documented. MATERIALS AND METHODS: This study included 36 patients, divided into two groups among whom a mono-one or bignathic osteotomy or genioplasty in orthognathic surgery was indicated. After the intervention, hilotherapy was employed directly instead of the conventional cooling method with moist compresses. The post-operative check of swelling during and after hilotherapy was performed using a 3D optical scanner (FaceSCAN3D®). This examination was repeated on post-operative days 1, 2, 3, 7, 14, 30 and 90. In this process, the final examination on day 90 served as a reference value in respect of swelling and pain. RESULTS: Group 1 (18 °C, 18 patients) showed an increase in post-operative swelling on the 1st post-operative day of 62.22 ± 36.29 ml. The maximum was reached on the 3rd post-operative day with 81.85 ± 40.23 ml. On the 30th post-operative day, residual swelling measured 7.39 ± 15.77 ml (p = 0.016). Group 2 (22 °C, 18 patients) showed an increase in postoperative swelling on the 1st post-operative day of 61.69 ± 34.7 ml. The maximum was reached on the 2nd post-operative day with 92.83 ± 48.03 ml. On the 30th post-operative day, residual swelling measured 28.09 ± 19.04 ml (p = 0.016). DISCUSSION: The study results indicate slightly less residual swelling in group 1 (18 °C) on the 30th post-operative day. One possible reason for this, based on the design of the study, could be the lower cooling temperature. The post-operative pain development exhibits a comparable level of pain intensity between the two groups. In overall terms, a subjectively more agreeable treatment was observed in group 1 (18 °C).

Current concepts in cleft care: A multicenter analysis.

The current surgical techniques used in cleft repair are well established, but different centers use different approaches. To determine the best treatment for patients, a multi-center comparative study is required. In this study, we surveyed all craniofacial departments registered with the German Society of Maxillofacial Surgery to determine which cleft repair techniques are currently in use. Our findings revealed much variation in cleft repair between different centers. Although most centers did use a two-stage approach, the operative techniques and timing of lip and palate closure were different in every center. This shows that a retrospective comparative analysis of patient outcome between the participating centers is not possible and illustrates the need for prospective comparative studies to establish the optimal technique for reconstructive cleft surgery.

Operator safety during the acquisition of intraoral images with a handheld and portable X-ray device.

OBJECTIVES: The present study aims at investigating different radiation protection issues and dose values while acquiring intraoral images with a handheld X-ray device. METHODS: An Aribex NOMAD Pro 2™, a RANDO® male head phantom, a consistency testing body, a PTW NOMEX® Multimeter, and a PTW Farmer® Ionization Chamber Type 30,010 were used to investigate: (1) dose area products; (2) the expansion of the control area (CA); (3) the scattering pattern and (4) the potential risk for operators of the X-ray device. RESULTS: Dose area products at different exposure times were distributed linearly with a high correlation factor (>0.9). At 4000 simulated exposures, the greatest extent of the CA was 42 cm (mean = 16.7 cm, SD = 10.8 cm). The highest occurrence of scattering radiation resulted between the RANDO® phantom and the X-ray device. No scattered radiation was measured at the dorsal part of the phantom or on the operator site of a virtual vertical plane through the focal spot of the X-ray. CONCLUSIONS: Through this study, we could demonstrate that the application of an Aribex NOMAD Pro 2 device for intraoral imaging does not increase the risk for the operator if the device is controlled according to the manufacturer's specifications. Furthermore, we were able to show that the CA was significantly smaller than specified by European and other international radiation protection standards.

Moving the mandible in orthognathic surgery - A multicenter analysis.

Orthognathic surgery has always been a classical focus of maxillofacial surgery. Since more than 100 years, various surgical techniques for mandibular repositioning have been developed and clinically tested. Since the establishment of plate and screw osteosynthesis, orthognathic surgery became more stable and safe. Nowadays, different surgical methods for mobilising the mandible are existing. This international multicenter analysis (n = 51 hospitals) is providing first evidence based data for the current use of different surgical methods. The dominating techniques were Obwegeser/dal Pont (61%) followed by Hunsuck/Epker (37%) and Perthes/Schlössmann (29%). The main osteosynthesis materials were plates (82%), bicortical screws (23.5%), or a combination of both (5.9%). 47% of all centers reported to use several surgical methods at the same time, depending on the anatomical problem and the surgeon's preference. This shows that different surgical methods seem to work as comparable, safe, and reliable procedures in everydays clinical practise. On this basis, further prospective studies could evaluate possible advantages for our patients.

Prognostic value of S100/CD31 and S100/podoplanin double immunostaining in mucosal malignant melanoma of the head and neck.

BACKGROUND: In uncommon mucosal melanomas of the head and neck established prognostic factors are rare and controversially discussed. The purpose of this study was to evaluate outcome and value of S100/podoplanin and S100/CD31 double immunostaining in head and neck mucosal melanomas. METHODS: Retrospectively, patients with head and neck mucosal melanomas treated between 1973 and 2008 were analyzed. S100/podoplanin and S100/CD31 immunostaining were performed to detect lymph vessel invasion (LVI) and blood vessel invasion (BVI). Predictive parameters for disease-specific survival (DSS) were identified using univariate and multivariate statistics. RESULTS: Forty-two patients with head and neck mucosal melanoma were included. Three-year, 5-year, and 10-year DSS rates were 59%, 44%, and 20%, respectively. Age above 70 years, occurrence of distant metastasis, LVI, and BVI were significantly associated with shorter DSS time (p < .05), whereas localization at the conjunctiva showed better outcome. CONCLUSION: S100/podoplanin and S100/CD31 double immunostaining detect reliable LVI and BVI in head and neck mucosal melanoma and both are associated significantly with worse prognosis.

Diagnostic imaging modalities in head and neck disease.

BACKGROUND: Because of the complex anatomy of the head and neck region, conventional projection radiography alone is unreliable and carries a high risk of misdiagnosis. The poor risk-benefit ratio of conventional radiography has led to their replacement by tomographic imaging for nearly all studies in this region. METHOD: This review is based on pertinent articles retrieved by a selective search in the PubMed database (January 1980 to May 2013) as well as on the relevant guidelines from Germany and abroad. RESULTS: The indication for diagnostic imaging in the anatomically complex head and neck region should be established for a specific type of imaging study on the basis of a thorough clinical examination. Conventional films, though easy to obtain, often cannot answer the diagnostic question and may yield confusing information leading to misdiagnosis. Computed tomography (CT) has the best risk-benefit profile and a high diagnostic value, but low-dose protocols have not yet been put into use in all centers. Magnetic resonance imaging (MRI) is best for bone and soft-tissue diagnosis, but consumes more resources. Digital volume tomography (DVT) is another type of three-dimensional, sectional imaging with high local resolution; the associated radiation exposure and image quality are generally both low, but may vary depending on the apparatus used. DVT cannot be used to evaluate the soft tissues. Ultrasonography can be used to evaluate superficial structures in the head and neck region; nuclear imaging can be used to evaluate thyroid disease and cancer. CONCLUSION: Inflammatory, traumatic, and neoplastic diseases of the head and neck are best evaluated with cross-sectional imaging (CT, MRI) in accordance with current guidelines. Conventional x-rays should, in general, only be used for dental evaluation, with rare exceptions.

[Cone beam computed tomography and radiation dosage: application frequency and knowledge of dentists in Switzerland]. / Digitale Volumentomographie und Strahlenbelastung: Kenntnisstand, Anwendungsfrequenz und Indikationsspektrum bei Schweizer Zahnärzten.

The use of cone beam computed tomography (CBCT) among Swiss dentists increases from year to year. The aim of this study was to investigate the application frequency and the knowledge about CBCT and radiation dosage in a representative Swiss dentist sample. A standardized questionnaire about knowledge on CBCT was personally handed out or sent by post to 1,000 dentists in Switzerland (return postage was free of charge). 278 dentists returned the questionnaire. Descriptive statistics, correlation analysis of general variables and written answers of the questionnaires were evaluated. Most dentists were aware of radiation dosage and potential use of the CBCT and are interested in continuing education on CBCT.