Criterion Validity of the Newly Developed Occlusal Cant Index.

OBJECTIVES: To assess the criterion-related (concurrent) validity of the newly developed occlusal cant index (OCI). MATERIALS AND METHODS: Four standardized posterior-anterior (PA) cephalometric radiographs of four patients were obtained at a 0° occlusal cant (OC) and manipulated to create various degrees of OC from 1° to 4° on the right and left sides, with a total of 36 PA images. The angle between the actual horizontal line and the occlusal plane was manually drawn on each PA radiographic image. The set of radiographic images was displayed to 36 orthodontists, who were asked to measure the drawn angle and apply the OCI to each PA radiographic image. RESULTS: The overall criterion-related validity of the OCI was statistically significant among all grades. CONCLUSION: The OCI is highly valid and recommended for clinical consideration.

Auditory temporal resolution in adaptive tasks. Gap detection investigation.

OBJECTIVES: To study auditory temporal resolution skills using adaptive auditory tasks designed with a computer-based experimental program, and to provide normative valuesfor gap detection thresholds (GDTs) of young listeners in 3 listening conditions. Methods:  The GDTs were established under 3 stimulus conditions: 1) broadband noise (BBN), 2) narrowband noise within-channel (NBN WC) using similar leading and trailing markers centered at 1.0 KHz, and 3) narrowband noise across-channel (NBN AC) with the leading marker centered at 2.0 KHz and the trailing marker centered at 1.0 KHz. In within-subjects design, the GDTs were obtained from 27 normal hearing young Saudi adults at Speech and Hearing Laboratories, Department of Rehabilitation Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia between April 2017 and April 2018. Results: The mean GDTs for the BBN condition was 3.19 millisecsond (msec), NBN WC was 14.53 msec, and NBN AC was 29.71 msec. Our findings for the GDTs measured in the 3 conditions were consistent with those of earlier investigations that used different instrumentations. Also, no correlations among the GDTs of the 3 stimulus conditions were found. Conclusion: The present study showed that experimental program is a reliable tool with clinical potential to estimate GDTs across different conditions. Also, the findings of no correlations in the GDTs across stimulus conditions suggest that different processes were involved in the perception of the temporal gap for different stimulus conditions.