Maxilla bone of animals

Maxilla bone of animals is the bone of upper jaw. this carries upper teeth and It is located on the lateral aspect of the face.

Maxilla bone of Ox

Maxilla bone of Ox is the largest bone of the upper jaw and carries the upper cheek tooth. It is situated on the lateral aspect of the face. It is made up of a body and two processes-the palatine and zygomatic.

• The external surface of the body is convex and presents about the level of the first cheek tooth, the infra orbital foramen,the external opening of the infra orbital canal for infra orbital artery and maxillary nerve.
• About the level of the third cheek tooth is the facial tuberosity extending from which is the facial crest.
• The internal surface form the lateral walls of the nasal cavity and presents about the middle the ventral turbinate crest for the ventral turbinate bone.
• Immediately below this is the lacrimal groove for the membranous naso lacrimal duct.
• The dorsal border is irregular, scaly and articulates with the nasal process of premaxilla nasal, lacrimal and malar bones.
• The ventral or alveolar border shows six alveoli posterior and is free anteriorly.
• The anterior extremity is pointed and joins the premaxilla.
• Behind last alveolus is a rough mark-the alveolar tuberosity.
• The maxillary tuberosity forms posterior extremity of the bone and has the maxillary sinus prolonged into it.
• Medial to this is the maxillary hiatus, which presents the spheno-palatine, maxillary and posterior palatine foramina for nerves and vessels of the same name.
• The zygomatic process is small a projection from the posterior extremity and is overlapped by the malar.
• The palatine process forms a large part of the bony palate. Its oral surface shows the palatine groove for the greater palatine artery and nerve. It is excavated to form part of the palatine sinus.

Maxilla bone of horse

• The facial crest is prominent.
• The infra-orbital foramen is at the level of the third cheek tooth and a small canal from this extends into the pre-maxilla.
• The palatine can is formed between the medial face of the body of the maxilla and the vertical part of the palatine bone.
• The medial borders of the palatine processes bear nasal crests in their nasal aspect and these form a groove for the vomer.
• At the junction of the maxilla and pre-maxilla is an alveolus for the canine tooth.

Maxilla bone of dog

• The facial crest is absent.
• The infra-orbital foramen is as in the horse.
• Frontal process fits into a deep notch between nasal and orbital parts of frontal bone.
• Maxillary and alveolar tuberosities are absent, but behind the last alveolus is a pointed pterygoid process.
• There is a large alveolus for the canine tooth at the junction with premaxilla.

Maxilla bone of fowl

• There is slender rod like bones placed on the sides and partly on the floor of the nasal cavity. 
• The two palatine processes do not meet, but join the palatine and vomer posteriorly. 
• The maxilla joins the pre-maxilla and nasal anteriorly while it is continuous with malar posteriorly.