Oral examination and radiographic evaluation of the dentition in wild cats from Namibia.

Feline tooth resorption has been widely reported in domestic cats and sporadically described in other felidae. The goal of the present study was to determine the prevalence of tooth resorption and to report other dental problems in a population of wild felidae. Observations of dental disorders and anomalies were made in skulls from 73 wild felidae (cheetahs, leopards, caracals, African wildcats, and lions) originating from Namibia. In addition, radiographs were taken in 43 cases to determine signs of bone and root pathology. Radiographs showed varying stages of tooth resorption in 16.0% of the specimens. Other dental anomalies found included fused teeth, supernumerary roots, or missing teeth. The prevalence of dental resorption in wild felidae was lower than reported in the domestic cat.

Congenital oligodontia of the deciduous teeth and anodontia of the permanent teeth in a cat.

This report describes a rare case of congenital oligodontia of the deciduous teeth and anodontia of the permanent teeth in a cat. According to cat's veterinarian, the patient had only two deciduous upper canines and no permanent teeth had ever erupted. Post-mortem evaluation showed a complete absence of teeth in the oral cavity and inflammatory lesions were not found on the gums. Histopathological analysis of serial sections of maxilla and mandible revealed absence of odontogenic epithelium, inflammatory cells and odontoclastic resorptive lesions. Diagnosis was confirmed after both the establishment that there were no remaining dental structures and the exclusion of other relevant diseases that lead to tooth loss, such as periodontal disease, renal fibrous osteodystrophy, odontoclastic resorptive lesions, ectodermal dysplasia and trauma.

Numerical variation of teeth in the wild house musk shrew Suncus murinus captured from Nagasaki, Japan.

Wild populations of Suncus murinus from Nagasaki were thought to be extinct, although specimens from Nagasaki are kept at the National Science Museum, Tokyo. Variation in the number of teeth, including both congenital and postnatal absence, was observed in 25 of 85 individuals. All 25 abnormal individuals were checked using a micro-CT unit to document the presence or absence of embedded teeth and any traits of postnatal absence. Four of these had congenitally absent teeth, whereas the rest showed signs of postnatal absence. There was no significant difference in the ratio of length of tooth group P(4)M(3) against palatal length between individuals with congenital absent teeth and normal ones. Because S. murinus in captivity shows a high rate of periodontal disease, we suggest that the high rate of postnatal absence of teeth in the wild population is due to oral diseases such as periodontal disease or other traumatic factors.

Unilateral failure of development of mandibular premolars and molars in an Eastern Grey kangaroo (Macropus giganteus) and its effects on molar progression.

An adult male Eastern Grey kangaroo from a wildlife reserve near Melbourne was submitted for necropsy examination and was discovered to have abnormal dentition. There was no evidence that any premolars or molars had ever been present on the right mandible, whilst the incisors were normal. The age of the kangaroo was estimated to be 1 year 9 months using the right maxillary molars and 2 years 4 months old using the contralateral side, presumably due to the asymmetry of the dental arcades. 'Lumpy jaw', a common periodontal disease of kangaroos, from which Bacteroides sp was cultured, was present on the base of the vertical ramus of the left mandible. Complete unilateral absence of premolar and molar teeth in the mandible of a kangaroo has not been described. This condition affected molar progression in both sets of maxillary molars.

Congenital hypotrichosis and partial anodontia in a crossbred beef calf.

Clinical examination, skin biopsies, skull radiographs, and DNA analysis of a 2-day-old Red Angus-Charolais-Simmental cross bull calf confirmed the diagnosis of congenital hypotrichosis and anodontia defect (HAD), also called anhidrotic ectodermal dysplasia, which is a rare anomaly caused by a deletion in the bovine EDA gene on the X chromosome.

Analysis of dental anomalies in the Siberian mole, Talpa altaica (Insectivora, Talpidae).

We re-examined tooth variation in specimens of the Siberian mole, Talpa altaica, from the collection of the Siberian Zoological Museum and discuss the mechanisms of dental evolution. The number of teeth counted in 1789 specimens ranged from 34 to 47, and supernumerary, absent, and connate teeth were observed. The most frequent tooth anomaly was an absent tooth in the premolar region (200 maxillary first premolars and 190 mandibular third premolars), which does not support Fujita and Kirino's terminal reduction hypothesis in the mandible [Fujita T, Kirino T. Ha No Kaibougaku. 21st ed. Tokyo: Kanehara Publishers Inc.; 1976 (in Japanese)]. Supernumerary teeth were found in premolar rows and in the incisor and molar regions. An maxillary fourth molar, positioned distal to the normal third molar, was thought to result from a genetically programmed atavistic event during the natal stages. Connate teeth were observed only in the premolar rows and were thought to have developed with the fusion of two independent tooth germs. Connate premolars appeared to result from an expression of an incomplete division of tooth germ at an early developmental stage or a reunion of independent tooth germs, based on the morphological similarity of the normal and supernumerary premolars. These extraordinarily frequent tooth anomalies of T. altaica are of much interest both in terms of tooth development and classification.

[Polymorphism of dental formula and segregation of its variants in a pedigree of kerry blue terrier dogs].

Polymorphism of the dental formula was analyzed in a sophisticated pedigree of Kerry Blue Terrier. A lack of one or more lower premolars was observed in some dogs. Two different patterns of missing teeth were identified. One pattern consisted in agenesis of a second premolar, often in combination with agenesis of neighbor teeth, including the fourth premolar. In the second pattern, agenesis of a fourth premolar was expressed as an isolated abnormality. It was shown previously that the first pattern is inherited as a recessive trait with near complete penetrance. In this work, the control of a major-gene was demonstrated for the second pattern. This abnormality develops in 70-80% of mutant homozygotes and in no more than 20% of heterozygotes and wild-type homozygotes. It was shown that the two dentition abnormalities are controlled by different genes, which were designated LPA2 and LPA4 (Lower Premolar Agenesis).

[Changes in litter size in Kerry blue terrier dogs with abnormal dentition].

The pleiotropic effects of mutations resulting in abnormal dentition were analyzed in Kerry Blue Terrier. A decrease in litter size was demonstrated for dogs with dentition anomalies. The mean litter size was 5.72 puppies when both parents had normal dentition and 3.64 puppies when the parents had hypodontia. Analysis showed that the decrease in litter size cannot be fully explained by the effect of inbreeding and is most probably associated with the pleiotropic effect of the genes controlling teeth development on the embryonic viability.

Variations in the number of teeth in wild Japanese serow (Naemorhedus crispus).

Skulls of 755 Japanese serow (Naemorhedus crispus) were examined for numerical anomalies of teeth, and these were found in 30 (4.0%) specimens. In addition to supernumerary and congenital missing teeth, embedded teeth were also identified. Supernumerary teeth were found in 10 (1.3%) specimens, congenital missing teeth were found in nine (1.2%) specimens, and embedded teeth were found in 11 (1.5%) specimens. Supernumerary teeth were found among the incisors, the upper and lower premolars, and the lower molars. Based on the appearance of certain tooth classes, their size, and their form, atavism was considered to be a possible cause of the occurrence of some of these teeth. Congenital missing teeth were found at the loci of the lower incisors, canines and P(2). In Japanese serow, there appeared to be a tendency for congenitally missing P(2) as well as P(1). All embedded teeth were found at the locus of P(2). These teeth may have occurred as an intermediate state between normal and congenital missing teeth. Variations in the number of teeth in Japanese serow were concordant with their phylogenetic background. Moreover, although variations in the number of cheek teeth tended to be concentrated in the mesial region of the premolars, the tendency in the incisive region was for teeth to appear mesial as well as distal within an incisor-tooth sequence. These results, which are not in accordance with terminal reduction theory, indicate that the phenomenon of tooth degeneration does not only occur at the end of a tooth row.

[Inheritance of hypodontia in Kerry Blue Terrier dogs]. / Analiz nasledovaniia gipodontii u kerri-bliu-ter'erov.

Integral segregation analysis, which earlier proved efficient in studying complex hereditary diseases in humans and have been introduced in animal genetics for several years, was used to analyze the inheritance of hypodontia by premolars in Kerry Blue Terrier dogs. Dental formulas have been determined in 598 out of 911 animals united into a single large, complex pedigree. The results of integrated segregation analysis indicated heterogeneous genetic control of different forms of hypodontia. The geneses of different premolars in dogs have been demonstrated to be described by different models of inheritance: the absence of the second premolars can be described by the recessive major-gene model, whereas the agenesis of the fourth premolars have a more complex genetic mechanism and cannot be described by the model of a simple major-gene control.

[Oligodontia and its inheritance in Kerry blue terrier]. / Oligodontiia i ee nasledstvennaia obuslovlennost' u sobak porody kerri-bliu-ter'er.

Defects of the premolar tooth formula (oligodontia, tooth number reduction) were studied in dogs of the Kerry blue terrier breed. For this purpose, a database including 480 individuals of 96 litters was constructed. The occurrence of oligodontia was investigated in pedigree groups with inbred and outbred crosses. No selective mating choice for the anomaly under study was found in the sample. The results indicate that oligodontia is inherited, which requires comprehensive study of its genetic control and search for corresponding genes.

Congenital hypotrichosis with anodontia in cattle: a genetic, clinical and histological analysis.

Hypotrichosis, an almost complete lack of teeth and the complete absence of eccrine nasolabial glands, was observed among the progeny of a normal cow of the black and white German Holstein breed. Similar congenital anomalies are known in humans and mice as X-linked anhidrotic ectodermal dysplasia (ED1), leading to the impaired formation of hair, teeth and sweat glands. The pedigree of the four affected male calves in the investigated cattle family indicated that the described phenotype is inherited as a monogenic X-linked recessive trait. We used a diagnostic reverse transcription-polymerase chain reaction (RT-PCR) assay to study the heredity of a previously reported causative large genomic deletion in the bovine ED1 gene. This test allowed the unequivocal classification of disease carriers that were phenotypically normal. As the clinical, pathological and genetic findings in human ED1 show striking similarities to the described phenotype in cattle, this bovine disorder may serve as an animal model for human ED1.

X trisomy in an infertile bitch: cytogenetic, anatomic, and histologic studies.

Three copies of the X chromosome were identified in a 5-year-old mixed breed infertile bitch. One year after the cytogenetic examination, the bitch died due to gastritis hemorrhagica, an inflammation of the mucus coat of the stomach. Dental studies showed congenital lack of some premolar and molar teeth. Ovaries were of normal shape and size. Also, histologic sections of the ovaries revealed their normal structure, with two corpora lutea and primary follicles. Phenotypic effects of X trisomy are discussed.

Multiple dental developmental abnormalities following canine distemper infection.

Multiple dental developmental abnormalities (e.g., dental impaction, partial eruption, oligodontia, enamel hypoplasia, and dentin hypoplasia) in a 10-month-old, female, Tanzanian tropical mixed-breed puppy are reported. Various permanent teeth were involved. These included impacted mandibular canine and first and third premolar teeth; a partially erupted maxillary canine tooth; oligodontia of a mandibular fourth premolar tooth; enamel hypoplasia of the maxillary and mandibular canine teeth, incisors, and premolars; and dentin hypoplasia of the maxillary incisors, maxillary premolars, and mandibular premolars. The puppy had clinical canine distemper at the age of two months and had no history of any other systemic nor generalized infection prior to the time when the dental abnormalities were observed.

[Variations of dentition in raccoon dogs (Nyctereutes Procynoides Viverrinus T.) Anomalies in number of the teeth].

A study on the number of anomalous teeth was made by using gross and radiographic examinations on 179 skulls (male: 68, female: 53, unknown: 58) of raccoon dogs (Nyctereutes Procynoides Viverrinus T.) captured in the northern part of Kyushu. Results were as follows: 1. 8 skulls had 15 supernumerary teeth. They were in the upper incisor, the upper third premolar and the upper and lower first premolar regions. 2. 35 skulls had 58 congenitally missing teeth. Most of them were upper and lower first premolars or lower third molars. 3. One skull had one supernumerary tooth in the upper second incisor region and one congenitally missing tooth, a lower third molar. 4. The anomalous teeth were about 25%, the supernumerary teeth and congenitally missing teeth were about 4.5% and 20% respectively.

A genetic, pathological and virological study of congenital hypotrichosis and incisor anodontia in cattle.

Two Friesian cows, half-sibs by a common dam, produced four bull calves with severe congenital hypotrichosis and incisor anodontia and three normal heifers by six unrelated Holstein, Friesian, Devon and Hereford bulls. The two dams, and their dam, had coats of a short, stubbly nature and the pigmented areas appeared rusty grey rather than black. Pathological examination of skin samples taken from multiple standardised sites from two of the affected calves showed a reduction in the number of large first-formed hair follicles. Smaller calibre hair follicles were present but, unlike those of normal neonatal calves, all were in the telogen (inactive) phase. Although the herd was infected with bovine virus diarrhoea virus there was no convincing evidence that the virus was implicated in the pathogenesis of these cases of congenital hypotrichosis with incisor anodontia. The family breeding information on the few severely affected and normal progeny and mildly affected and normal parents may be explained by the genetic hypothesis of an X-linked incompletely dominant gene.

[Hypotrichosis and oligodontia, combined with an Xq-deletion, in a calf of the Swiss Holstein breed]. / Hypotrichose und Oligodontie, verbunden mit einer Xq-Deletion, bei einem Kalb der Schweizerischen Fleckviehrasse.

Hypotrichosis and oligodontia associated with a chromosomal anomaly (Xq-deletion) are described in a 11-month old cattle (Simmenthal/Red Holstein cross-breed). This chromosomal anomaly was accompanied with hairlessness and grievous teeth abnormalities. The animal had a very thin haircoat, had only one incisor and between one to three molars per mandible or maxilla. This resulted in reduced food intake, reduced rumination, and retarded growth. Post-mortem examination revealed lesions in the kidneys (bilateral chronic interstitial nephritis), adrenals (hyperplasia), pancreas (focal fibrosis) and abomasum (obstipation and multiple ulcers). Some of these abnormalities are comparable with the human "anhidrotic ectodermal dysplasia" (Christ-Siemens-Touraine syndrome) and supports the hypothesis that there are homologies in the X-chromosome of different mammals.

Intraoral radiology.

In this article, the parallel and bisecting angle techniques for proper intraoral radiography will be discussed, as will equipment, film type, technical values, and film processing.