Thickness of the hard palate : A new criterion for the diagnosis of osteoporosis?

BACKGROUND: We were looking for an osteoporosis screening in computed tomography (CT) exams, simple and without additional examinations. We hypothesized that the criterion of "decreasing cortical thickness", may have an influence on the hard palate. Therefore, we investigated whether thickness of the hard palate (HPT) may serve as an indicator of osteoporosis for patients imaged for other reasons. METHODS: Patients with dual-energy x-ray absorptiometry (DXA) and CT were identified by a radiology information system (RIS)-based, full-text search. Measurement of thickness of hard palate done in existing CT image by radiologist and dentist and compared with available findings and DXA measurements. RESULTS: We identified a "test group": 57 patients with DXA and CT available out of 449 patient population and we selected further 70 patients without bone diseases as "control groups". The measurements showed that HPT correlated with age and bone density. The mean HPT was 2.4 mm in normal, 0.9 mm in osteopenia, 0.8 mm in osteoporosis and 5.3 mm in osteopetrosis case. No bone "healthy" patient fell below 1 mm. The relationship between bone density and HPT has not been described previously. HPT was highest in the bone-healthy group and decreased with age, osteopenia, and osteoporosis. Osteopetrosis, as a disease with increased bone density showed an increase in HPT. CONCLUSIONS: HPT correlates with bone disease. We propose a new criterion for assessment on CT and digital volume tomography (DVT) or cone beam computed tomography (CBCT). A threshold of 1.0 mm when applying a simple measurement of HPT on Head CT or DVT may serve as an indicator for potential osteopenia or osteoporosis as incidental finding without extra imaging further diagnosis and treatment leading to early notice of Osteoporosis.

Comparison of parental and practitioner's acceptance for dental treatment under general anaesthesia in paediatric patients.

BACKGROUND: Practitioner's knowledge and parental perspectives on dental general anaesthesia (GA) have been surveyed separately in the past. But in daily routine both need to collaborate for the benefit of the child. The aim of this paper was to compare parental and practitioner's acceptance of GA with special focus on identifying factors which influence their differences in decision making. METHODS: Questionnaires were conducted among 142 participants in a specialized paediatric dental clinic in Germany from February 2020 to February 2021. 51 German practitioners from private practices and clinics participated. Data collection included: age, gender, experience with GA, fear of GA, risk evaluation and indications for GA. RESULTS: There were no gender related differences in decision making. Emotional factors are present in parents of younger children. Parents are more likely to express fear and uncertainty regarding GA than dentists. Prior experience with GA significantly decreases fears in GA for parents. Both agree that extent of the treatment and low compliance are a suitable indication for GA. Dentists are more likely to accept GA due to a mental disability than parents. Parents were more likely to accept GA than dentists when multiple extractions were needed (regardless of compliance) or acute pain was present. CONCLUSIONS: A significant divergence in risk evaluation, acceptance and decision-making could be found in parents compared to dentists. Influencing factors are previous experience, younger age of the child, lack of knowledge and indication for GA.

Country and gender differences in the motivation of dental students-An international comparison.

PURPOSE: The objective of this study, conducted in Germany, Finland and Turkey, was to identify whether motivations to study dentistry varied by country, gender or year of study. METHODS: The multicentre pilot study was conducted in English language in 2014. Participants (n = 469 dental students) were either in the first or last year of study. The response rate was 91%. RESULTS: The sample comprised 63% females and 37% males, reflecting the common gender distribution in dental education. A total of 236 first year students (50.3%) and 233 final year students (49.7%) took part in the study. The participants were aged 21-25 years and of 15 different nationalities, mostly from Turkey, Germany and Finland. Considering who motivated them most to become a dentist, the most common answer was "self-motivated" (49.5%). 23.4% of the students stated having been motivated by a "family member or friend, who is a dentist," while 24.3% said they had been motivated by a "family member or friend, who is not a dentist." -Very few students (2.8%) recorded having been motivated by a "high school or college counsellor." Motivations for choosing dentistry as a career included "ability to help people," "self-employment," "income potential," "working with hands" and "status and prestige," all of which were rated as highly important. "Time management" and "career variety" were rated as moderately important. Significant statistical differences were observed by country and gender. For the German students, a dental relative was significantly more often relevant than for the Finnish and Turkish students, who were more often influenced by family members or friends not working in the dental field. "Time management" seemed to be significantly more important to female than to male students. CONCLUSION: In line with a feminisation of the workforce in dentistry, a well-structured working environment and well-thought-out time management may play an increased role in future work force planning (Gender dentistry: International vergleichende Studie zu Karrierewahl und Spezialisierungswünschen von Zahnmedizinstudenten. Ulm: Universität Ulm).

Characterisation of apical bone lesions: Comparison of MRI and CBCT with histological findings - a case series.

PURPOSE: The aim of this case series was to compare magnetic resonance imaging (MRI) with cone beam computed tomography (CBCT) in the representation of periapical osteolyses. Based on the histological findings, the potential of MRI for further lesion characterisation was investigated. MATERIALS AND METHODS: Thirteen patients (average age: 41 ±â€…27 years) with a total of 15 periapical lesions (five molars, five premolars, and five front teeth) were examined. Lesion characterisation was based on the homogeneity/heterogeneity of the lesions, the signal intensity within the lesion compared to the surrounding tissue and differences in the signal intensities between different MRI contrast weightings. Results were compared with CBCT and histological findings. RESULTS: Although all patients presented with dental restorations, such as fixed partial dentures and filling materials, all periapical lesions could be diagnosed with either imaging modality. Histologically, 13 cysts and two apical granuloma were confirmed. In CBCT, the similar appearance of all lesions did not allow any further characterisation. In MRI, radicular cysts and granuloma could be characterised by their appearance in the MRI images with different contrast weightings. The MRI-derived characterisations were consistent with the histological findings. CONCLUSIONS: The presented study shows that the application of multi-contrast MRI may lead to better characterisation of apical lesions, thus enabling an improved patient-specific selection of the optimal treatment option. Conflict-of-interest statement: MAG, ESS, and LKS do not report any potential conflict-of-interest; EH and JU are employees of Sirona Dental Systems; VR is receiving a research grant by Sirona Dental Systems.

Radiographic diagnosis of proximal caries-influence of experience and gender of the dental staff.

OBJECTIVES: The aim of this study was to examine the influence of experience and gender on the radiographic detection of proximal caries lesions and on therapeutic decisions. MATERIALS AND METHODS: A survey of 220 examiners (students and employees at three universities and dentists in the field) was taken using a standardized written questionnaire concerning radiographic diagnosis and therapy planning. An expert opinion of four dentists was determined as radiographic reference. A mixed effect logistic regression model was used for statistical evaluation and the odds ratio and p values were calculated (α = 0.05). RESULTS: Examiners with experience had an almost four times greater chance of a correct assessment, if proximal caries lesion was present or not, than examiners with low experience (OR 3.7 (95% CI 2.4-5.8)). No gender-specific differences were discovered (OR women vs. men 0.9 (95% CI 0.6-1.4)). There was a relationship between the severity of the burnout effect on the x-ray and false positive caries diagnosis. Overall, 43% of respondents would plan invasive treatment in the enamel on a patient at low risk of caries and 78% on a high-risk patient. The results showed that the more experienced practitioners would be more likely to postpone restorative therapy on proximal caries until the lesion reached a later stage. CONCLUSIONS: The results of this study suggest that examiner's experience influences the radiographic diagnosis of proximal lesions. No gender-specific differences could be found. CLINICAL RELEVANCE: Examiner's professional experience is an important factor when radiography is included for detection and treatment planning of proximal lesions.

A self-gating method for time-resolved imaging of nonuniform motion.

PURPOSE: To develop a self-gating method capable of assessing nonuniform motion, e.g., in cardiovascular magnetic resonance imaging of patients with severe arrhythmia, or for imaging of the temporomandibular joint. METHODS: The proposed method allows cyclic motion trajectories with a nonuniform pace by replacing the one-dimensional gating signal of conventional image-based self-gating with a two-dimensional gating matrix. The resulting image quality is compared with conventional self-gating and real-time MRI. RESULTS: Nonuniform self-gating resulted in superior image quality compared with conventional self-gating and the feasibility study showed significantly improved image sharpness (P < 0.01). Further, improvements in image quality were shown compared with golden angle radial parallel sparse MRI. CONCLUSION: A new self-gating method was proposed that allows cardiovascular magnetic resonance of arrhythmic patients, which is a common problem in clinical practice. Further, the proposed method enables self-gated imaging of the temporomandibular joint. Magn Reson Med 76:919-925, 2016. © 2015 Wiley Periodicals, Inc.

Golden ratio sparse MRI using tiny golden angles.

PURPOSE: The combination of fully balanced SSFP sequences with iterative golden angle radial sparse parallel (iGRASP) MRI leads to strong image artifacts due to eddy currents caused by the large angular increment of the golden angle ordering. The purpose of this work is to enable the combination of iterative golden angle radial sparse parallel MRI with balanced SSFP using the recently presented tiny golden angles. METHODS: The tiny golden angle trajectories are analyzed for their incoherence properties in relation to sparse imaging using the time-resolved point-spread functions. Tiny golden angle radial sparse parallel (tyGRASP) MRI is introduced and evaluated with applications in cardiac imaging and dynamic imaging of the temporomandibular joint. The results are analyzed in detail for 3 T and verified for 1.5 T. RESULTS: The incoherence properties of the tiny golden angle trajectory are comparable to the incoherence properties of the golden angle trajectory and are well suited for sparse MRI reconstruction. The proposed tiny golden angle radial sparse parallel MRI method strongly reduces eddy current related artifacts for both applications. CONCLUSION: This work enables sparse, golden-ratio-based imaging with balanced SSFP sequences. Magn Reson Med 75:2372-2378, 2016. © 2015 Wiley Periodicals, Inc.

Comparative analysis of intraoral radiographs with variation of tube angulation to detect insufficient crown margins.

Variations in angulation of the x-ray tube affect the appearance of insufficient approximal crown margins on intraoral radiographs. This study examines the impact of such angular variation on the assessment of digital radiographs using three different X-ray tubes--Heliodent DS (Sirona), Gendex Expert DC (KaVo Dental) and Focus (KaVo Dental)--as well as the Gendex Visualix eHD CCD sensor (KaVo Dental). The test specimens, crowned teeth 46 from two mandibles provided by the Institute of Anatomy and Cell Biology, were examined with each tube. The results indicate great differences in the angles indicative of insufficient crown margins on X-ray images. Because of beam divergence and the crown marginal gap, the length and width of which frequently varies, it is difficult to infer any optimum angle from the data. This leads to the conclusion that at present, it is not possible to establish ideal angles for visualization of insufficient approximal crown margins.

Polymerase chain reaction-based simultaneous detection of selected bacterial species associated with closed periapical lesions.

PURPOSE: The aim of this study was to identify microorganisms which might be present in closed periapical lesions and to determine their relationship to conventional clinical parameters. - METHODS: In 11 patients, samples were taken with paper points from 14 teeth with periapical radiolucency, in seven cases two samples were taken from two different sites of the same tooth (n=21). Clinical parameters were determined. The 16S rDNA of eleven bacterial species could be simultaneously detected via a modified polymerase chain reaction (PCR) based technique. - RESULTS: All samples contained more than one bacterial species. Most frequently, M. micros was detected alone or in combination with E. faecalis, P. aeruginosa, E. coli, F. nucleatum or S. sanguinis. When apical palpation was positive, often M. micros and F. nucleatum were both present. Other clinical symptoms like tenderness to percussion were not associated with a particular microflora. - CONCLUSIONS: In closed periapical lesions detected by radiography, specific bacteria were identified by means of a modified PCR technique. No clear associations between clinical symptoms and these bacteria were found. Surgical intervention might be indicated for some of the persistent lesions.