A New Methodology for 2d Imaging of Murine Dentition

The murine dentition is a valuable model in investigating the role of genetic and environmental factors in dental development. Accurate phenotyping is an important component of such studies. Objectives: To establish a novel imaging technique for measuring morphological variation in murine mandibular incisors and to investigate its reliability. Methods: Standardised two dimensional images of twenty extracted Wild type murine mandibular incisors were acquired using a development of our image analysis system (Brook et al 1999, 2002 and 2006). Images were taken against a matt black background, permitting automatic image selection for measurement after linear calibration using a 5mm scale included in the original image. Images were saved in Tagged Image Format using Adobe Photoshop CS software. Tooth variables (proximal view area, perimeter, length between the tooth ends and angle between the two located ends to a point mid-way between the two end–points on the labial side of the proximal image) were obtained using Image Pro Plus 5.1 software. These variables were selected as the degree of curve is described using the ‘length' and ‘angle' variables as well as an indication of tooth bulk which can be obtained by dividing the ‘area' by the ‘perimeter'. The imaging, calibration and measurement process' were repeated independently by two trained operators and the intra-operator repeatability and inter-operator reproducibility were measured. Results: The Intra-and inter-operator reliability for all variables was within the ‘excellent' range. Table 1. Intra- and Inter-class Correlation Coefficients for operator reliability

Conclusions: This new methodology can measure morphological variation in murine mandibular incisors with high degrees of inter and intra operator reliability.