Skulls, jaws and teeth of wild terrestrial small mammals (Sciuridae, Soricidae, Erinaceidae, Talpidae, Gliridae, Arvicolidae, Muridae) are occasionally affected by anomalies and pathologies. The present study documents a total of 362 anomalies and 122 pathological changes across 20 different species. These are all based on data published in Germany, supplemented by our own records. Cases were classified into 14 different categories, according to bone and dental anomalies, fractures and inclusions, bone proliferation, dental disease and extreme wear of teeth. An additional category to specifically account for bone proliferation of the skull was not needed, but such findings are to be expected. The most frequent finding was abnormal tooth growth, particularly the elongation of the upper incisors. In individual cases, there was evidence that small mammals are able to recover even from serious injuries to the skull.
Morphometric skull variation was studied in Rhinolophus mehelyi, R. euryale and R. blasii by means of 50 cranial, mandibular and dental measurements. In R. euryale differences between age groups (subadults, adults and old adults) were not significant. Poorly pronounced sexual dimorphism (male skulls were, on average, larger than those of females in some measurements) and low geographical variability within Bulgaria were observed in R. euryale. We propose a simple biplot (length of cheek teeth against the rostral posterior width), a stepwise discriminant analyses of some criteria and numerical keys that allow the clear determination of crania or their parts. A large additional sample of incomplete crania was determined on the basis of these keys which, in turn, allow data to be obtained on species distribution patterns. Rhinolophus euryale is the most frequent and probably the most abundant horseshoe bat species examined, and occurs throughout Bulgaria. Rhinolophus mehelyi is widespread but appears to be relatively rare. Rhinolophus blasii is confined mainly to the southern regions of Bulgaria, but may be abundant locally.
The research was aimed at examining 230 skulls and mandibles (113 males and 117 females) of the red fox (Vulpes vulpes) in the territory of the Republic of Lithuania. The object of the study was macroscopic evaluation of dental and periodontal pathologies, including changes in the structure of the skull and mandible. The most common teeth pathology was indicated to be hypodontia 13.27% in males and 5.98% in females (excluding M3 molar tooth). The hypodontia of the M3 was found to be common in males 6.19% and 7.69% in females. The findings of the research reveal that pathologies such as hyperdontia, dental fractures, enamel hypoplasia, abrasion, periodontitis stage 3 and stage 4 were less common: 1-4% in both males and females. In four skulls and mandibles of females a complex of severe pathologies of teeth and periodontium were found. There were no similar cases observed in males. This was the only significant difference between males and females. Other pathologies, including fractures of the skull or mandible, atypical form of foramen magnum, and changes in bone structure were rare overall, though slightly more common in males but not significantly.
The purpose of the study was to test the hypothesis of different distribution spaces of elements in the rat mandibular bone and teeth. We used six adult males of Wistar laboratory rats for the study. After killing the animals, we extracted the molars and removed incisor crowns. The mandibular bone was divided into four parts (mesial-central-distal-ridge). Inductively coupled plasma mass spectrometry was used to determine the presence of 41 elements in the bone and tooth. Evidence of 14 elements was found in all samples (incisors-molars-bone). Generally, significant differences between the left and right side were found for K and Rb in the bone locations. As regards statistically significant differences in incisors-molars-bone locations, the elements for which these differences were found for all comparisons are listed as incisors versus individual molars, incisors versus bone locations, and individual molars versus bone locations: a) incisors-molars: Ba, Mn, Mo, Sr, Zn, K, Mg and Rb; b) incisors-bone: Fe, K, Mg, Mn, Na, Zn and Ba; c) molars-bone: Mn, Mo, Na and Mg. Statistically significant differences were also found between molars for Fe, Mg, Mn, and Sr and between bone locations for Ba, Ca, Mn, Sr, K, Rb, Zn, Mo, Mg, and Na. The elements Cu, Ni and Co were without pronounced differences. Twenty-seven elements were below the detection limit. Our results indicate different distributions of some elements in the rat mandibular incisors-molars-bone. We assume that the knowledge of chemical element contents in the laboratory rat bone and teeth will prove useful in experimental research of both these hard tissues. and Corresponding author: Ivo Němec