Table of Contents

Premaxilla bone of animals

Premaxilla bone of animals forms the anterior part of the upper jaw. here ox, horse, dog and fowl bone will be discussed.

Premaxilla bone of Ox

The premaxilla bone of Ox forms the anterior part of the upper jaw and has a body and two process –nasal and palatine.
The lateral surface of the body is convex and is related to the upper lip.
The buccal surface is concave and related to the dental pad.
The medial edge is concave and forms with its fellow the incisive fissure.
The nasal process projects upward from the body and form the lateral wall of the nasal cavity. The lateral (facial) and medial nasal surfaces of this process are smooth. Its posterior two third fits into the groove on the anterior edge of the body of the maxilla.
The palatine process is smaller than the nasal. It is a thin plate of bone, which forms the anterior part of the bony palate. Its nasal surface slopes medially and with its fellow forms a groove for the vomer and septum nasi. The lateral border of the palatine process is separated from the nasal process and the maxilla by a large oval opening, the palatine fissure.

The bodies of the two bones are fused together.
The body of each bone is thicker and presents three alveoli for the upper incisors.
The medial surface is rough and joins the opposite bone; it presents a groove, which with a similar one of its fellow forms the foramen incisivum.
The nasal process is longer and presents at its junction with the maxillary bone an alveolus for the canine tooth.
The palatine process is wide and the palatine fissure narrow.

The body presents three alveoli for the incisors and with the maxillary bone forms an alveolus for the canine tooth.
Foramen incisivum is very small.
The palatine fissure is short but wide.

The premaxilla forms the skeleton of the upper portion of the beak and fuse to form a solid bone before hatching.
They form the anterior boundary of the external opening of the nasal cavity.
They present three pairs of processes-the palatine process which meets the palatine, the maxillary processes which extend backward and meet the maxilla and the nasal processes which extends dorsally and backward along the median line and between the nasal bones and meet the frontals.