Lateral throat form classification using a customized gauge and Neil’s method – a comparative study

Introduction: Lateral throat form (LTF) is the critical area which has to be recorded properly for obtaining proper retention and stability in complete denture especially in geriatric patients with resorbed ridges. Popular method used for determining LTF is Neil’s method which depends on the forces applied by the floor of mouth when the tongues protrude out. Since the perception of the forces differs among different operators, there are high chances of error in the classification. So, customized instrument was fabricated to prevent this inter-observer variation. The aim of the study was to compare the inter-observer accuracy between Neil’s method of classifi­cation and classification done by customized gauze. Methods and methodology: Total 30 edentulous patients were taken. Two observers measured the LTF depth by customized tool and also by Neil’s method. Cohen’s kappa test was used to evaluate the agreement between two operators in two different classifications. Result: The agreement between the two observers was evaluated by means of Cohen’s kappa value. There was good agreement between observers in proposed classification done by customized tool with kappa value 0.658 and fair inter-observer agreement with kappa value 0.0492. Conclusion: The method of measuring the depth of LTF with fabricated instrument was more accurate and reliable than Neil’s method.

Estimating observer error and steelhead redd abundance using a modified Gaussian area-under-the-curve framework

This study examined how a suite of habitat and environmental variables relate to the ability of a stream surveyor to identify (observer efficiency) and distinguish (observer accuracy) steelhead (Oncorhynchus mykiss) redds from other stream features. Two existing spawning survey protocols that included one or two redd observers were used to develop models to estimate redd observer error. In most cases, steelhead redd abundances using raw redd counts were underestimated. Mean annual rates of observer efficiency ranged from 0.44 to 0.57, and observer accuracy ranged from 0.67 to 0.83. Regardless of the observer error model used, adjusted annual redd abundance estimates were generally unbiased (range 1.6–0.6 redds). A Gaussian area-under-the-curve methodology that incorporates redd count data and observer error rates was used to generate unbiased estimates of steelhead redd abundance in the Wenatchee (170 redds, coefficient of variation (CV) = 44%) and Methow (106 redds, CV = 41%) rivers. Unbiased estimates of redd abundance will help inform new population viability analyses to better prioritize those populations with the greatest conservation need.