The absence of the mental foramen was investigated in 1,435 dry human mandibles (2,870 sides). The foramen was absent twice in the right side (0.06%) and once in the left side (0.03%). The meaning of this anatomical variation was commented.

The direction of the mental canal was calculated in the horizontal and vertical planes with a view to aiding anaesthetic techniques. Based on our data, it is advisable to give the following approximate inclinations to the needle when penetrating the mental canal in anaesthetic procedures: 55 degrees postero-anteriorly in relation to a horizontal plane and 40 degrees latero-medially in relation to a horizontal line tangent to the body of the mandible at the level of the mental foramen.

The bull is essential for the realization of natural breeding, which is still the majority in Brazilian livestock, and for the genetic improvement of its descendants. The bull's external genitalia are made up of the foreskin and penis and its vital function is to effect copulation. However, these organs are vulnerable and susceptible to injury due to variation in morphological characteristics, such as the width of the preputial ostium orifice, the pendulum and the length of the preputial sheath. Therefore, the aim of this study was to carry out a literature review of the morphological aspects of the external genitalia of bulls associated with coeundi impotence due to preputial diseases. The prepuce or preputial sheath consists of the external (LPE) and internal (LPI) preputial leaflets. The first is formed by a fold of mobile skin attached to the belly of the abdomen. The IPL or preputial mucosa is characterized as a tubular organ that houses the free part of the penis. The preputial ostium is the opening through which the exteriorization of the penis takes place. The foreskin has sebaceous glands that produce a lipid secretion, which makes up the smegma, and which is important in prepucial and penile health. In this study, basic research was used as an analysis tool, according to veterinary anatomical nomenclature, on aspects of the anatomy and morphology of the external genitalia, specifically the prepuce, the free part of the penis and the preputial sebaceous glands, points rarely mentioned in the specialized literature, which demonstrates the importance of this line of study.