Sabe-se que para determinados procedimentos cirúrgicos em Odontologia, como a exodontia, a cirurgia ortognática, cirurgia ortopédica, cirurgia de neoplasias e a colocação de implantes dentários, é importante conhecer a localização exata do trajeto do canal mandibular (CM) que contém o feixe vasculonervoso. O objetivo desta pesquisa foi determinar por meio da tomografia computadorizada (TC) o trajeto do canal mandibular através da mandíbula com relação as suas faces (vestibular, lingual e ventral), a crista alveolar e as raízes dentárias em duas classes de crânios de cães. Assim, foram avaliados 10 crânios de cadáveres de cães mesaticefálicos e 10 crânios de cadáveres de cães braquicefálicos no Serviço de Diagnóstico por Imagem do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Os tomogramas foram realizados no plano transversal tomando como referência para cada corte as raízes dentárias. No tomógrafo foram mensuradas as distâncias do canal mandibular até as faces vestibular, lingual, ventral e crista alveolar da mandíbula. As medidas coletadas foram submetidas à análise estatística que indicou que o trajeto do canal mandibular foi similar nos dois tipos de crânios. Observou-se que o canal mandibular desce suavemente desde o forame mandibular acompanhando o formato da mandíbula em direção à região dos dentes molares, onde alcança a sua máxima profundidade junto ao 1o molar e 4o pré-molar, continua rostralmente aumentando ligeiramente a distância com relação a borda ventral da mandíbula justo antes de terminar no forame mentoniano. O canal mandibular localizou-se em contato ou muito próximo da cortical lingual da mandíbula desde o forame mandibular até a região dos dentes molares, assim, continuou rostralmente ocupando a região ventral do corpo da mandíbula mantendo-se eqüidistante entre a superfície vestibular e lingual. Já na região do dente 3o pré-molar o canal mandibular originou o forame mentoniano caudal na face vestibular da mandíbula antes de incrementar ligeiramente a sua distância em relação a face ventral e lingual da mandíbula, para terminar assim no forame mentoniano médio na face vestibular, ventral à raiz mesial do dente 2o pré-molar. / For some surgical procedures in dentistry, as the exodontia, the orthognathic surgery, orthopedic surgery, oral neoplasm resection, and the dental implants placement, it is important to know the accurate localization of the mandibular canal (MC), which contains the vascular and nerve package. The aim of this research was to determine the course of the mandibular canal through the mandible with relation to the structures that surround it (lingual surface, vestibular surface and ventral surface), alveolar crest and dental roots in two kinds of dog skulls by means of computerized tomography (CT). For that, 10 skulls of mesaticephalic dogs and 10 skulls of brachycephalic dogs were evaluated in the Image Diagnosis Service of the Veterinary Hospital of the Veterinary and Zootechny School of the São Paulo University. In order to determine the localization of the canal passage in the mandible, measures were taken, in relation with: lingual surface, vestibular surface, ventral mandible surface and alveolar crest with CT help. The measurements were submitted to statistical analysis and showed that the mandibular canal course was similar in brachycephalic and mesaticephalic dogs, the measurements indicated that the mandibular canal descends slightly from the mandibular foramen to the molar area, slightly closer to the lingual surface than the vestibular surface until the molar region. The MC continues rostrally occupying the ventral region of the mandible body, reaching its maximum depth in relation with the alveolar crest border at the level of the 1st molar and 4th premolar teeth area. In the 4th and 3rd premolar region the MC maintains a similar distance between the vestibular and lingual border. At the level of the 3rd premolar the MC originates the mental caudal mental foramen before increases the distance in relation with the lingual and ventral border just before its termination at the medial mental foramen on the vestibular surface, ventral to the 2nd premolar roots.

Sabe-se que para determinados procedimentos cirúrgicos em Odontologia, como a exodontia, a cirurgia ortognática, cirurgia ortopédica, cirurgia de neoplasias e a colocação de implantes dentários, é importante conhecer a localização exata do trajeto do canal mandibular (CM) que contém o feixe vasculonervoso. O objetivo desta pesquisa foi determinar por meio da tomografia computadorizada (TC) o trajeto do canal mandibular através da mandíbula com relação as suas faces (vestibular, lingual e ventral), a crista alveolar e as raízes dentárias em duas classes de crânios de cães. Assim, foram avaliados 10 crânios de cadáveres de cães mesaticefálicos e 10 crânios de cadáveres de cães braquicefálicos no Serviço de Diagnóstico por Imagem do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Os tomogramas foram realizados no plano transversal tomando como referência para cada corte as raízes dentárias. No tomógrafo foram mensuradas as distâncias do canal mandibular até as faces vestibular, lingual, ventral e crista alveolar da mandíbula. As medidas coletadas foram submetidas à análise estatística que indicou que o trajeto do canal mandibular foi similar nos dois tipos de crânios. Observou-se que o canal mandibular desce suavemente desde o forame mandibular acompanhando o formato da mandíbula em direção à região dos dentes molares, onde alcança a sua máxima profundidade junto ao 1o molar e 4o pré-molar, continua rostralmente aumentando ligeiramente a distância com relação a borda ventral da mandíbula justo antes de terminar no forame mentoniano. O canal mandibular localizou-se em contato ou muito próximo da cortical lingual da mandíbula desde o forame mandibular até a região dos dentes molares, assim, continuou rostralmente ocupando a região ventral do corpo da mandíbula mantendo-se eqüidistante entre a superfície vestibular e lingual. Já na região do dente 3o pré-molar o canal mandibular originou o forame mentoniano caudal na face vestibular da mandíbula antes de incrementar ligeiramente a sua distância em relação a face ventral e lingual da mandíbula, para terminar assim no forame mentoniano médio na face vestibular, ventral à raiz mesial do dente 2o pré-molar. / For some surgical procedures in dentistry, as the exodontia, the orthognathic surgery, orthopedic surgery, oral neoplasm resection, and the dental implants placement, it is important to know the accurate localization of the mandibular canal (MC), which contains the vascular and nerve package. The aim of this research was to determine the course of the mandibular canal through the mandible with relation to the structures that surround it (lingual surface, vestibular surface and ventral surface), alveolar crest and dental roots in two kinds of dog skulls by means of computerized tomography (CT). For that, 10 skulls of mesaticephalic dogs and 10 skulls of brachycephalic dogs were evaluated in the Image Diagnosis Service of the Veterinary Hospital of the Veterinary and Zootechny School of the São Paulo University. In order to determine the localization of the canal passage in the mandible, measures were taken, in relation with: lingual surface, vestibular surface, ventral mandible surface and alveolar crest with CT help. The measurements were submitted to statistical analysis and showed that the mandibular canal course was similar in brachycephalic and mesaticephalic dogs, the measurements indicated that the mandibular canal descends slightly from the mandibular foramen to the molar area, slightly closer to the lingual surface than the vestibular surface until the molar region. The MC continues rostrally occupying the ventral region of the mandible body, reaching its maximum depth in relation with the alveolar crest border at the level of the 1st molar and 4th premolar teeth area. In the 4th and 3rd premolar region the MC maintains a similar distance between the vestibular and lingual border. At the level of the 3rd premolar the MC originates the mental caudal mental foramen before increases the distance in relation with the lingual and ventral border just before its termination at the medial mental foramen on the vestibular surface, ventral to the 2nd premolar roots.

This study aimed to investigate the course of the nasolacrimal drainage system in three different brachycephalic dog breeds in comparison to normocephalic dogs and to draw conclusions on potentially adverse consequences for the drainage function. A computed tomographic-dacryocystography (CT-DCG) was performed in 51 brachycephalic dogs, consisting of 23 Pugs, 18 French and 10 English bulldogs. Six normocephalic dogs of different breeds and body size served as a comparison. Two- and three dimensional images were obtained and evaluated. Several parameters (length, angulation, gradient) were used to describe the nasolacrimal drainage system and to quantify distinctions between different breeds. Furthermore several additional characteristics were analysed, including the relative position of lacrimal foramen and nasolacrimal ostium, crossing of the nasolacrimal duct below the root of the upper canine tooth, the patency of the lacrimal drainage system and the presence of an accessory opening. While the length of the nasolacrimal duct is substantially reduced in brachycephalic dogs, their lacrimal canaliculi have much larger dimensions than those of normocephalic dogs. Additionally varying parts of the nasolacrimal drainage system follow an inverse direction in short-headed dogs, giving the entire nasolacrimal apparatus a characteristic U- or V-shaped appearance. The nasolacrimal duct exhibits a much steeper alignment in brachycephalic dogs compared to normocephalic ones. This strong slope however does not interfere with drainage function because of a consistently present accessory opening, being the main or only outflow pathway in all brachycephalic dogs and hence facilitating proper tear drainage regardless of the steepness.

This study aimed to investigate the course of the nasolacrimal drainage system in three different brachycephalic dog breeds in comparison to normocephalic dogs and to draw conclusions on potentially adverse consequences for the drainage function. A computed tomographic-dacryocystography (CT-DCG) was performed in 51 brachycephalic dogs, consisting of 23 Pugs, 18 French and 10 English bulldogs. Six normocephalic dogs of different breeds and body size served as a comparison. Two- and three dimensional images were obtained and evaluated. Several parameters (length, angulation, gradient) were used to describe the nasolacrimal drainage system and to quantify distinctions between different breeds. Furthermore several additional characteristics were analysed, including the relative position of lacrimal foramen and nasolacrimal ostium, crossing of the nasolacrimal duct below the root of the upper canine tooth, the patency of the lacrimal drainage system and the presence of an accessory opening. While the length of the nasolacrimal duct is substantially reduced in brachycephalic dogs, their lacrimal canaliculi have much larger dimensions than those of normocephalic dogs. Additionally varying parts of the nasolacrimal drainage system follow an inverse direction in short-headed dogs, giving the entire nasolacrimal apparatus a characteristic U- or V-shaped appearance. The nasolacrimal duct exhibits a much steeper alignment in brachycephalic dogs compared to normocephalic ones. This strong slope however does not interfere with drainage function because of a consistently present accessory opening, being the main or only outflow pathway in all brachycephalic dogs and hence facilitating proper tear drainage regardless of the steepness.