The anterior loop of the inferior alveolar nerve is a sensitive anatomical feature that should be taken into account during installation of dental implants anterior to the mental foramen. This study was conducted to explore the controversy regarding prevalence and length. A total of 452 mandible quadrants of 234 patients (age: 50.1 ± 13.3 years, 113 males, 121 females) were studied using cone-beam computerized tomography. After reconstructing axial, frontal, and sagittal slices, the region between the most anterior point on the mental foramen and the most anterior part of the mandibular nerve was inspected for signs of anterior loop presence. If positive, the length of the anterior loop was measured in mm as the distance between the anterior border of mental foramen and the anterior border of the loop. Prevalence and length of the anterior loop were compared statistically between sexes and age groups. The anterior loop was observed in 106 quadrants (23.5% of 451 quadrants) of 95 patients (40.6% of 234 patients), of whom 11 had bilateral anterior loops. Prevalences were similar in males (41%) and females (39%, chi-square P =.791). The mean anterior loop length was 2.77 ± 1.56 mm (95% CI: 2.5-3.1 mm), without significant sex (regression beta = -0.159, P = .134) or age (beta = -0.059, P = .578) differences. The anterior loop might exist in about 40% of patients, regardless of their gender. The mean safe anterior distance from the anterior loop is about 3 mm + (2.5-3.1 mm) = 5.5-6.1 mm, regardless of age.

Background: Point-of-care Ultrasound (POCUS) is becoming an important diagnostic tool for internal medicine and ultrasound educational programs are being developed. An ultrasound course is often included in such a curriculum. We have performed a prospective observational questionnaire-based cohort study consisting of participants of a POCUS course for internal medicine in the Netherlands in a 2-year period. We investigated the usefulness of an ultrasound course and barriers participants encountered after the course. Results: 55 participants (49%) completed the pre-course questionnaire, 29 (26%) completed the post-course questionnaire, 11 participants (10%) finalized the third questionnaire. The number of participants who performs POCUS was almost doubled after the course (from 34.5 to 65.5%). Almost all participants felt insufficiently skilled before the course which declined to 34.4% after the course. The majority (N = 26 [89.7%]) stated that this 2-day ultrasound course was sufficient enough to perform POCUS in daily practice but also changed daily practice. The most important barriers withholding them from performing ultrasound are lack of experts for supervision, insufficient practice time and absence of an ultrasound machine. Conclusions: This study shows that a 2-day hands-on ultrasound course seems a sufficient first step in an ultrasound curriculum for internal medicine physicians to obtain enough knowledge and skills to perform POCUS in clinical practice but it also changes clinical practice. However, there are barriers in the transfer to clinical practice that should be addressed which may improve curriculum designing.

Objective The aim of this study was to assess the diagnostic value of point-of-care bedside ultrasound (PoCUS) as in usual clinical practice in suspected ankle and fifth metatarsal bone fractures, compared to the standard of radiographic imaging. Methods This prospective study included patients ≥17 years presenting to the Emergency Department with ankle trauma and positive Ottawa Ankle Rules. All patients underwent PoCUS of the ankle by a (resident) emergency physician, the images were assessed by an ultrasound expert. Both were blinded for the medical history and clinical findings of the patients. Radiography of the ankle followed, evaluated by a radiologist blinded from the PoCUS findings. Primary outcome measures were sensitivity and specificity of PoCUS. Results A total of 242 patients were included, with 35 (22%) clinically significant (non-avulsion) fractures observed with radiography. The sensitivity of PoCUS in detecting clinically significant fractures by all sonographers was 80.0% (95% Confidence Interval (CI) 63.0 to 91.6%), specificity 90.3% (95% CI 83.7 to 94.9%), positive predictive value 70.0% (95% CI 57.0 to 80.3%) and the negative predictive value 94.1% (95% CI 89.1 to 96.9%). The sensitivity of PoCUS in detecting clinically significant fractures by the expert was 82.8% (95% CI 66.3 to 93.4%), specificity 99.2% (95% CI 95.5 to 99.9%), positive predictive value 96.7% (95% CI 80.3 to 99.5%) and the negative predictive value 95.3% (95% CI 91.0 to 98.2%). Conclusion PoCUS combined with the OAR has a good diagnostic value in usual clinical practice in the assessment of suspected ankle and fifth metatarsal bone fractures compared to radiographic imaging. More experience with PoCUS will improve the diagnostic value. Trial registration Registered in the local Research Register, study number 201500597.

Objective: Tension Pneumothorax (TP) can occur as a potentially life threatening complication of chest trauma. Both the 2 nd intercostal space in the midclavicular line (ICS2-MCL) and the 4 th /5 th intercostal space in the anterior axillary line (ICS 4/5-AAL) have been proposed as preferred locations for needle decompression (ND) of a TP. In the present study we aim to determine chest wall thickness (CWT) at ICS2-MCL and ICS4/5-AAL in normal weight-, overweight-and obese patients, and to calculate theoretical success rates of ND for these locations based on standard catheter length. Methods:We performed a prospective multicenter study of a convenience sample of adult patients presenting in Emergency Departments (ED) of 2 university hospitals and 6 teaching hospitals participating in the XXX consortium. CWT was measured bilaterally in ISC2-MCL and ISC4/5-AAL with point of care ultrasound (POCUS) and hypothetical success rates of ND were calculated for both locations based on standard equipment used for ND.Results: A total of 392 patients was included during a 2 week period. Mean age was 51 years (range 18-89), 52% was male and mean BMI was 25.5 (range 16.3-45.0). Median CWT was 26 [IQR 21-32] (range 9-52) mm in [26][27][28][29][30][31][32][33] (range 10-78) mm in ICS4/5-AAL (p < 0.001). CWT in ISC2-MCL was significantly thinner than ICS4/5-AAL in overweight-(BMI 25-30, p < 0.001), and obese (BMI > 30, p = 0.016 subjects, but not in subjects with a normal BMI. Hypothetical failure rates for 45mm Venflon and 50mm Angiocatheter were 2.5% and 0.8% for ICS2-MCL and 6.2% and 2.5% for ISC4/5-AAL ( p = 0.016 and p = 0.052 respectively). Conclusion:In overweight-and obese subjects, the chest wall is thicker in ICS 4/5-AAL than in ICS2-MCL and theoretical chances of successful needle decompression of a tension pneumothorax are significantly higher in ICS2-MCL compared to ICS 4/5-AAL.