Anomalias e patologias dentárias em Arctocephalus G. Saint-Hilaire &amp; Cuvier (Pinnipedia, Otariidae) da costa do Rio Grande do Sul, Brasil

Drehmer, César Jaeger; Ferigolo, Jorge

doi:10.1590/s0101-81751996000400008

Cited by 10 publications

(17 citation statements)

References 6 publications

(3 reference statements)

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“…Supernumerary teeth in Otariids possibly represent a reversion to the primitive dentition of terrestrial carnivores, according to the phylogenetic relationships of Pinnipeds (DREHMER & FERIGOLO 1996, DREHMER et al 2004, CRUWYS & FRIDAY 2006. DREHMER et al (2004) reported supernumerary teeth in mandibular PC/6, which represents the atavic reappearance of the lower second molar in some specimens of O. flavescens, reconstructing the origins of Pinnipedimorpha evolution in the Oligo/Miocene (BERTA & WYSS 1994, DREHMER et al 2004.…”

Section: 7mentioning

confidence: 99%

“…Maxillary supernumerary teeth have been described in Otariid species in different positions (MILES & GRIGSON 1990, DREHMER & FERIGOLO 1996, DREHMER et al 2004, ABBOTT & VERSTRAETE 2005. As no pinniped ancestor has more than four pre-molars and two molars, totalizing the six post-canine teeth (DREHMER et al 2004), the appearance of maxillary supernumerary teeth in A. tropicalis also does not seem to have any evolutionary or phylogenetic implication.…”

Section: 7mentioning

confidence: 99%

“…The loss of teeth in life is considered to be relatively common in pinnipeds (CHIASSON 1957, DREHMER & FERIGOLO 1996. When a tooth is lost and is not subsequently replaced, the alveolus is filled with bony tissue of porous consistency during the process of alveolar resorption or reossification (VILÀ et al 1993).…”

Section: 7mentioning

confidence: 99%

“…These cases are characterized by the porosity and irregularity of the bony tissue as a consequence of alveolar resorption, in contrast with the absence of alveoli in the typical cases of dental agenesis (VILÀ et al 1993, DREHMER & FERIGOLO 1996.…”

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confidence: 99%

“…Dental agenesis in South American Otariids has already been investigated in A. australis and A. tropicalis and in O. flavescens (MILES & GRIGSON 1990, DREHMER & FERIGOLO 1996, DREHMER et al 2004. According to the authors concerned, the absence of teeth, particularly of the most posterior ones such as PC/5 and PC/6, represents a trend towards reduction of the postcanine teeth in Otariids.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Numerical anomalies in the dentition of southern fur seals and sea lions (Pinnipedia: Otariidae)

Loch¹,

Simões‐Lopes²,

Drehmer³

2010

Zoologia (Curitiba, Impr.)

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Section: 7mentioning

confidence: 99%

Section: 7mentioning

confidence: 99%

Section: 7mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Numerical anomalies in the dentition of southern fur seals and sea lions (Pinnipedia: Otariidae)

Loch¹,

Simões‐Lopes²,

Drehmer³

2010

Zoologia (Curitiba, Impr.)

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Dental anomalies in pinnipeds (Carnivora: Otariidae and Phocidae): occurrence and evolutionary implications

2015

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Dental anomalies comprise variations in number, shape, size, position and occlusion of teeth, mainly caused by genetic mechanisms. This study aimed to investigate the nature and prevalence of dental anomalies in a large sample of pinnipeds (Otariidae and Phocidae) and to discuss potential evolutionary and ecological implications. Thirty-four species in twenty genera were sampled. The dentition of the specimens examined was compared with the normal dental formula for the species, and supernumerary and congenitally missing teeth were identified and recorded. Agenesis was observed in 0.93 % of the specimens analyzed (n = 10), being more frequent in otariids. The posteriormost upper postcanines were the teeth absent most frequently. Supernumerary teeth were observed in 1.8 % of the specimens (n = 19), more commonly in phocids. Supernumerary teeth can be interpreted as either atavistic manifestations (particularly for the posteriormost postcanines in Otariidae) or cases of disturbances in dental morphogenesis leading to the formation of extra teeth when they occur in other positions of the tooth row. Morphological dental variants such as ectopic and geminated teeth were also recorded. Cases of dental anomalies should have a limited effect on the functional morphology of the feeding apparatus in pinnipeds, with little influence on the fitness and performance of the animals. Nevertheless, understanding patterns of dental variation should contribute to future studies aiming to elucidate aspects of dental evolution and the phylogenetic relationships of pinnipeds.

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Dental wear in dolphins (Cetacea: Delphinidae) from southern Brazil

Loch

Simões‐Lopes

2013

Archives of Oral Biology

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(1) Dental wear is a common phenomenon in mammals. Its occurrence is influenced by tooth anatomy, animal physiology, biomechanics and behaviour. So far, investigations of dental wear in cetaceans have been scanty and superficial. We compare the frequencies of occurrence, location and intensity of dental wear in some species of dolphins from southern Brazil, South Atlantic Ocean. (2) Teeth of ten species were evaluated using a stereoscopic microscope to identify wear facets, which were classified according to location, anatomical position and wear intensity. (3) Frequencies of dental wear were high for all species with exception of Delphinus capensis, with less than 50% of teeth worn. Simultaneous wear facets in the apex and lateral of teeth were more common than facets restricted to the apex or lateral faces. Wear on the dental crown was more common, but some species showed less frequent wear down to the cingulum or root level. Superficial wear seems to be the general trend for dolphins, but Stenella coeruleoalba and Pseudorca crassidens showed a higher frequency of severe wear. Only for Tursiops truncatus the frequencies of wear were significantly different between males and females. When considering the ontogeny of dental wear, only for T. truncatus and Stenella frontalis indexes of dental wear were correlated with body length. (4) Whether dental wear has implications or not in fitness and feeding behaviour, severely worn teeth may expose the pulp cavity and increase the susceptibility to local infections.

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Anomalias e patologias dentárias em Arctocephalus G. Saint-Hilaire & Cuvier (Pinnipedia, Otariidae) da costa do Rio Grande do Sul, Brasil

Cited by 10 publications

References 6 publications

Numerical anomalies in the dentition of southern fur seals and sea lions (Pinnipedia: Otariidae)

Numerical anomalies in the dentition of southern fur seals and sea lions (Pinnipedia: Otariidae)

Dental anomalies in pinnipeds (Carnivora: Otariidae and Phocidae): occurrence and evolutionary implications

Dental wear in dolphins (Cetacea: Delphinidae) from southern Brazil

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