Marco Antonio Gioso

Mandible and Mandibular First Molar Tooth Measurements in Dogs: Relationship of Radiographic Height to Body Weight

Height measurements of the mandible and the mandibular first molar tooth were obtained from 234 dogs. Statistical analysis was performed to determine possible associations between these measurements and body weight, sex, age, and body condition. There was a statistically significant association between the mandible: mandibular first molar tooth height measurement ratio and body weight (p< 0.0001) in all body weight groups. Small dogs had proportionally larger mandibular first molar teeth relative to mandibular height compared with larger dogs. This relationship may contribute to an increased susceptibility in small dogs for periodontitis and subsequent tooth loss. There was no statistically significant association between the mandible: mandibular first molar tooth height measurement ratio and other parameters evaluated in this study.

Oral Fractures in Dogs of Brazil — A Retrospective Study

A retrospective study was performed in 100 dogs with 121 mandibular and 21 maxillary fractures. Dogfight (43.0 %) and automobile (12.0 %) trauma were the most common etiologies for fracture. The cause of fracture was unknown in 23.0% of the cases, while pathologic fractures occurred in 13.0 % of cases. Young dogs (< 1-year-old) and dogs > 8-years of age were most affected. Mandibular fractures occurred in 90 dogs (90.0 %), with two dogs (2.2 %) having concurrent maxillary fractures. Maxillary fractures only were diagnosed in 10 dogs (10.0 %). The molar region (47.1 %) was the most commonly affected location for mandibular fracture, followed by fractures of the symphysis and parasymphysis (30.6 %), premolar region (17.4 %), angular process (4.1 %) and vertical ramus (0.8 %). In fractures of the mandibular region, the mandibular first molar tooth was often (85.9%) involved while the canine teeth were involved in 67.5 % of symphyseal and parasymphyseal fractures. The most common fracture of the maxilla was the maxillary bone (52.4 %), followed by the incisive (33.3 %), palatine (9.5 %), and nasal (4.8 %) bones.

Detection of putative periodontal pathogens in subgingival specimens of dogs

In this study, the presence of putative periodontal organisms, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Fusobacterium nucleatum, Dialister pneumosintes, Actinobacillus actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens and Treponema denticola were examined from subgingival samples of 40 dogs of different breeds with (25) and without (15) periodontitis, by using the PCR method. The PCR products of each species showed specific amplicons. Of the 25 dogs with periodontitis, P. gingivalis was detected in 16 (64%) samples, C. rectus in 9 (36%), A. actinomycetemcomitans in 6 (24%), P. intermedia in 5 (20%), T. forsythensis in 5 (20%), F. nucleatum in 4 (16%) and E. corrodens in 3 (12%). T. denticola and D. pneumosintes were not detected in clinical samples from dogs with periodontitis. Moreover, P. gingivalis was detected only in one (6.66%) crossbred dog without periodontitis. Our results show that these microorganisms are present in periodontal microbiota of dogs with periodontitits, and it is important to evaluate the role of these putative periodontal microorganisms play in the periodontitis in household pets particularly, dogs in ecologic and therapeutic terms, since these animals might acquire these periodontopahogens from their respective owners.

Maxillary dentigerous cyst in a cat.

A dentigerous cyst was diagnosed in the right rostral maxilla of a 6-month-old Siamese cat affecting the maxillary right canine tooth. The deciduous maxillary right canine tooth was extracted and the dentigerous cyst wall was curetted. The permanent tooth was not removed, however it was mobile following the surgical procedure. Examination 6-months following surgery indicated appropriate development of the tooth with no mobility or periodontal pocket formation. The maxillary right canine tooth had an abnormal shape but was functional with an acceptable appearance.

Localization of the mandibular canal in brachycephalic dogs using computed tomography.

For some surgical procedures in veterinary dentistry including exodontia, orthognathic surgery, orthopedic surgery, oncologic surgery, and for the placement of dental implants, it is important to know the accurate location of the neurovascular structures within the mandibular canal. The aim of this research was to determine the course of the mandibular canal in the mandible and its relationship with other anatomical structures in brachycephalic dogs using computerized tomography. Mandibles from 10 brachycephalic cadaver dogs were evaluated. Measurements were taken in relation to the lingual, vestibular, alveolar crest, and ventral surfaces. These measurements indicated that the mandibular canal descends slightly from the mandibular foramen to the molar area, decreasing the distance of the mandibular canal from the mandibular ventral border. The mandibular canal is slightly closer to the lingual surface than the vestibular surface except in the molar tooth region. The mandibular canal continues in a rostral direction occupying the ventral region of the mandibular body, reaching its maximum distance from the alveolar crest at the level of the first molar and fourth premolar teeth. In the third and fourth premolar tooth region, the mandibular canal maintains a similar distance between the vestibular and lingual borders; then, at the level of the second premolar tooth, the distance of the mandibular canal from the lingual and ventral border increases before its termination at the mental foramen. The study reported here documents the feasibility of using CT to determine the location of the mandibular canal in relation to bony and dental parameters. Although the difference in mandible size of the group of brachycephalic dogs reported here resulted in broad ranges of measurements, it is clear that the MC course may vary between individual dogs.

Oral cavity evaluation and dental chart registration of coati (Nasua nasua) in captivity

The aims of this study were to develop a dental chart, evaluate any oral cavity disease, develop gypsum models of the dental arches, and to register the occlusions found in coatis (Nasua nasua) in captivity. Formulation of the dental chart was assisted by intraoral radiographs from the head of an adult coati cadaver of the same species with the following dental formula: I 3/3, C 1/1, P 4/3, M 2/2. Seven live coatis of the Nasua nasua species were evaluated. Five of the seven coatis presented with various dental abnormalities as follows: dental plaque (71.4 %), gingivitis (71.4 %), periodontitis (57.1 %), dental stain (42.9 %), dental abrasion (57.1 %), dental fracture (57.1 %), pulp exposure (42.9 %), malocclusion (57.1 %) and supernumerary teeth (14.2 %).

Estudo comparativo sobre prevalência de doença periodontal em Panthera onca mantida em cativeiro e em indivíduos de natureza

The aim was to survey the main oral lesions related with periodontal disease of jaguars, Panthera onca, living in captivity or in the wild, as conservation of threatened animals from extinction, as in case of the jaguar, and the preservation of such species in free life may be determined by environmental conditions which can influence oral health. Forty-two jaguars (P. onca) kept in captivity in 18 institutions in the state of Sao Paulo were studied. The animals to be examined were anesthetized by the Plan of Neotropical Handling of Felids. Additionally, 4 jaguars (P. onca) proceeding from wild life were captured for the study on Farm Sete, municipality of Miranda, Mato Grosso do Sul, in the southern Pantanal. All animals surveyed in captivity showed various degrees of oral lesions related to periodontal disease. The animals living in the wild did not present any clinical signs of oral lesions.

Holographic interferometry method for assessment of static load stress distribution in dog mandible

This study compared the transmission of tensions in fresh, fixed and macerated dog mandibles in order to clarify the diversity of behavior of bone tissues under dry and moist conditions. Double-exposure holographic interferometry was applied and holograms were obtained from 12 fresh hemi-mandibles under static load (control group), which were randomly assigned to 2 groups: 6 were fixed in 10% formalin and 6 were macerated. The specimens were submitted to the same initial force and their respective holograms were obtained. Analysis of the holograms showed that the fresh specimens transmitted significantly less tension than the fixed and macerated ones (p<0.05), and the tension direction was different. An average two-fold tension increment was observed in the experimental conditions. The holographic interferometry method was efficient in quantifying and qualifying tension transmission. However, depending on the type of analysis, the anatomical specimens must be fresh because macerated specimens will produce different results.

Análise microbiológica de ossos de cães conservados por longo período de tempo na glicerina a 98% à temperatura ambiente, objetivando a extertia óssea

Objective: verify the microorganism growth in bone plus glycerin samples stocked for at least nine years. Methods: microbiology analisys of epiphisis and bone marrow stocked at glycerin 98% was done. Results: No statistically significant growth was verified. Conclusion: This result means that glycerin is an excellent bone conservation substance for long periods of stockage.

Cell proliferation and expression of connexins differ in melanotic and amelanotic canine oral melanomas

Melanoma is a malignant neoplasm occurring in several animal species, and is the most frequently found tumor in the oral cavity in dogs. Melanomas are classified into two types: melanotic and amelanotic. Prior research suggests that human amelanotic melanomas are more aggressive than their melanotic counterparts. This study evaluates the behavior of canine melanotic and amelanotic oral cavity melanomas and quantifies cell proliferation and the expression of connexins. Twenty-five melanomas (16 melanotic and 9 amelanotic) were collected from dogs during clinical procedures at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of São Paulo, Brazil. After diagnosis, dogs were followed until death or euthanasia. Histopathology confirmed the gross melanotic or amelanotic characteristics and tumors were classified according to the WHO. HMB45 or Melan A immunostainings were performed to confirm the diagnosis of amelanotic melanomas. Cell proliferation was quantified both by counting mitotic figures and PCNA positive nuclei. Expressions of connexins 26 and 43 were evaluated by immunohistochemistry, qRT-PCR and Western blot. Dogs bearing amelanotic melanomas presented a shorter lifespan in comparison to those with melanotic melanomas. Cell proliferation was significantly higher in amelanotic melanomas. Expressions of Connexins 26 and 43 were significantly reduced in amelanotic melanomas. The results presented here suggest that oral cavity melanotic and amelanotic melanomas differ regarding their behavior, cell proliferation and connexin expression in dogs, indicating a higher aggressiveness of amelanotic variants.