Morphometry of infraorbital foramen applied to local anesthesia in hoary fox (Lycalopex vetulus Lund, 1842)

Abstract

Whilst considering the need anesthetic techniques supported by species-specific morphology, it has been sought to describe the morphometry of the Hoary Fox's infraorbital foramen with aims at correlating its topography with points of anatomic reference in the skull, thereby providing subsidy for a more effective local anesthetic block in that species. Four skulls of Lycalopex vetulus had been used, from which all of the measurements in each antimere were performed. The infraorbital foramen was located at the maxilla bone, dorsally-wise from the third upper pre-molar tooth, and, from the ventral end of its caudal margin, it would stand apart from the alveolar margin of that bone by 4.19 mm, in average; from the orbital margin at the level of the lacrimal foramen by 14.10 mm; from the dorsal end of the frontal process of the zygomatic bone by 37.10 mm; from the rostral end of the alveolar margin of the first upper incisor tooth by 38.54 mm; and, from the caudal end of the nuchal crest by 100.53mm - at the level of the median sagittal plane; as it also presented a sagittal axis of 5.21 mm in average. It is suggested that, for the Hoary Fox, the needle be introduced by 4.19 mm in contact with the maxilla bone, in a perpendicular fashion, and in a ventral-dorsal orientation from the alveolar margin of the same - whilst using, as an anatomic reference, the diastema that exists between the third and the fourth upper pre-molar teeth.

The Anatomy of the Stomatognathic System in Different Skull Types in Dogs

“…19 It is necessary for the surgeon to be familiar with, and to preserve as much as possible all vascular and neural structures involved, with concern not only for surgical risk, but also for preservation of the tissue and the structures responsible, in order to maintain their vitality and normal function. [20][21][22][23] In agreement with a previous study, 14 this study showed that dogs have an advantage in that their arteries can form multiple anastomoses, re-establishing the blood supply in damaged areas.…”

“…14,29 Alterations of the peripheral innervation of the head can also be due to neural dysfunctions and tumors originating from the neuronal fibers themselves, 30,31 and this knowledge is essential for local anesthesia in the head. [20][21][22][32][33][34][35] Healing of the oral mucosa is faster than that of the skin due to several factors, including a more abundant blood supply. 36 The temporary bilateral occlusion of the external carotid artery before major surgical procedures, such as maxillectomy and total mandibulectomy, in order to minimize blood loss due to accidental rupture of large vessels located in the infraorbital region or close to the temporomandibular joint is commonly performed in veterinary surgery.…”

“…14,29 Alterations of the peripheral innervation of the head can also be due to neural dysfunctions and tumors originating from the neuronal fibers themselves, 30,31 and this knowledge is essential for local anesthesia in the head. 20‐22,32‐35…”

Topography and morphometry of the infraorbital and mandibular foramen of the common sloth (Bradypus variegatus) for use in the application of perineural anaesthesia

“…The common sloth has a skull with a small and compact shape, with a reduced opening of the oral cavity, foramina with a reduced circumference and a different positioning when compared to domestic animals, which alters access to the IF and MF using the techniques recommended for domestic animals such as dog and cat (Konig & Liebich, 2016;Snyder et al, 2018); and techniques described for wild animals such as rabbits, canids and primates (Engel et al, 2019;Magalhães et al, 2019Magalhães et al, , 2020Peña et al, 2020).…”

“…In this scenario, anatomical descriptions and morphometrics have become necessary and important sources for establishing more targeted protocols for such species. In the hoary fox (Lycalopex vetulus), a carnivorous canid, because of its anatomy and morphometry, both the IF and MF techniques were adapted in line with the particularities of the species (Magalhães et al, 2019(Magalhães et al, , 2020. For rhesus monkeys (Macaca mulata), the IF technique used is like the intraoral technique used in domestic animals, and for MF, the extraoral technique takes the mandible angle as a reference point instead of the angular process (Engel et al, 2019).…”