Reliability of eruption rate measurements of the rat incisor.

The reliability of the easy method to measure rat tooth eruption proposed by Schour and Van Dyke has frequently been challenged. To assess its true trustworthiness an experiment was set up using three different groups of rats and two different methods for eruption assessment. One group was used for 'control'. The second group received a potent lathyrogen, while the third group was used as pair-fed+ for the second group. Measurements were made clinically and radiographically. Comparison between the three groups led to the conclusion that the much easier and less expensive method, using the clinical manual measuring method is reliable and may be used in future calculations of eruption rate of rat incisors. It furthermore provides an excellent method to assess the lathyrogenic condition of these animals.