Comparison of extra-articular radiographic parameters of distal radius fractures on plain radiographs and CT scans

The aim of this study was to compare extra-articular radiographic parameters of distal radial fractures measured on plain radiographs and CT scans. Two researchers independently measured four extra-articular radiographic parameters (dorsal tilt, carpal alignment, radial inclination and ulnar variance) on both radiographs and CT scans in 85 patients. Inter-observer reliability for both techniques was assessed, along with the agreement between CT scans and radiographs using the intraclass correlation coefficient and Bland–Altman plots. The results showed that dorsal tilt, carpal alignment, radial inclination and ulnar variance can be measured reliably on both radiographs and CT scans. At a patient level, carpal alignment, radial inclination and ulnar variance CT scan measurements are an acceptable alternative to plain radiograph measurements in the vast majority of patients. In contrast, dorsal tilt CT scan measurements are not comparable with radiographs in 40% of the cases. Therefore, caution should be taken in measuring dorsal tilt on CT scans.

Associations between orbicularis oris thickness and skeletal and dental variables in mixed dentition

AIM: To evaluate the association between orbicularis oris thickness and skeletal and dental variables in children with mixed dentition. MATERIAL AND METHOD: A convenience sample of 22 children, aged 7 to 12 years, with skeletal Class I and Class II malocclusion and subdivisions were selected. The upper and lower fascicles of the orbicularis oris thicknesses were measured using ultrasound (US) by one calibrated examiner, at rest and in the contracted state. Cephalometric radiograph measurements of the hard and soft tissues were calculated by one trained examiner. The results were analyzed by the Pearson and Spearman coefficients. RESULT: The upper and lower fascicles of the orbicularis oris in the contracted state showed a negative correlation with the distance between Ricketts' E-line and the labrale superius (E ┴ Ls). There were positive correlations between the lower face height and the distance between the AB plane and the labrale superius (AB-Ls) and between the ANB angle and the distance between E ┴ Ls and Ricketts' E-line and the labrale inferius (E ┴ Li). The lower-incisor distance from the N-Pg plane correlated positively with the distance between AB-Ls and the distance between the E ┴ Ls and E ┴ Li. Overbite and interincisal angle were negatively correlated with the distance between the pogonion and the soft tissue pogonion and the distance between E ┴ Li, respectively. CONCLUSION: Skeletal and dental variables were associated with upper and lower lip position and pogonion thickness, while the upper and lower fascicles of the orbicularis oris thicknesses in the contracted state were associated only with upper lip retrusion.

Pelvic rotations: a pelvic phantom study

Background: Radiographic measurements made on standard pelvic radiographs are commonly used in studying conditions related to the hip joints. Effects caused by variations in pelvic orientation may be a source of error in comparing measurements between sequential radiographs. Purpose: To define and characterize parameters able to measure rotational differences separately around two axes and altered radiographic focusing along two axes when sequential standard anteroposterior (AP) pelvic radiographs are compared. Material and Methods: A pelvic phantom was constructed based on direct three-dimensional measurements of five defined landmarks in a pelvic model. Two ratios, the vertical and transversal rotation ratios, were defined using radiographs of the phantom. The phantom was radiographed in 33 different orientations and with 16 different radiographic focuses using a specially constructed tilt table. On each radiograph, measurements were made and the two rotation ratios were calculated using a measurement program. Results: Linear correlations between pelvic rotations around one axis and the corresponding rotation ratio were found with almost no influence of simultaneous rotation around the other axis. Also, linear correlations were found between altered radiographic focusing along one axis and the non-corresponding rotation ratio. Conclusion: Rotational differences around two axes or altered radiographic focusing along two axes can be measured independently. Effects caused by rotations cannot be distinguished from effects caused by altered radiographic focusing.