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Teeth variations and pathologies in stone martens from Croatia

Two years ago a study on variations in teeth size, shape, number and occurrence of dental pathologies was launched within the framework of scientific project entitled Dental pathology of Wild Mammals. The preliminary study included analysis of 35 skulls, the results of which were published as article in the Natura Croatica journal (Konjević et al., 2011). Major part of this note is derived form the mentioned article. The visual inspection of skulls was performed according to instruction given by Abbot and Verstraete (2005), and complete dentition with special respect to noticed alterations were thoroughly examined. In the case of tooth absence, the alveolar bone was thoroughly examined to determine whether the respective tooth was lost during the life or post mortem. Irregular arrangement of lower incisors was observed in 9 individuals (25.7 %). It isworth mentioning that irregular arrangement of incisors is so common finding that in certain taxa authors consider them as normal finding. The P1 was absent bilaterally in 6 (17.1 %) and unilaterally in 5 individuals (14.3 %). In contrast, the P1 was absent only unilaterally in 2 cases (0.57 %). From the observed it is clear that P1 is predisposed to complete reduction, which is in accordance with terminal reduction theory and the fact that P1 is reduced in size and probably without any function in feeding process. Of the other teeth, I1 was absent in 2 cases unilaterally (0.57 %), while I2, C1 and P3 were missing in one case each (0.29 %). Differently, we noted only one supernumerary tooth, the upper right premolar, followed with rotation of P2 and P3 as a consequence of overcrowding. Rotation was observed on 6 premolars in total (two lower and four upper). Complicated crown fractures were observed on three skulls (0.86 %). Kryštufek and Polak (1996) reported 13.7 % incidence of dental injuries in stone marten skulls (95 examined). According to their observations the most frequently affected were the incisors and lower premolars, while for carnivorans essential canines and carnassials were rarely damaged. This is not in accordance with our observations, where we found complicated crown fractures of one or all canines in three animals. Furthermore we noted traumatic losses of three incisors (two animals) and one P3. Similarly, Van Valkenburgh (2009) also reports that canines are the most frequently fractured teeth in mustelids. The associated porous alveolar bone was observed just over the one fractured canine. Finally, excessive wear was recorded in 9 skulls (25.7 %). The excessive wear was quite commonly found, which was a result of the fact that observed wear of P1 was also included. An observed absence of teeth is a frequent finding in all carnivores, reflecting the trend to reduce the number of teeth. The relatively low incidence of tooth fractures and almost complete absence of periodontal diseases can be attributed to the fact that the majority of skulls examined originated from adolescent animals.

stone marten; teeth; variations; dental pathology; island; Croatia

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