Changes

==Species Differences==

==Species Differences==

*In the '''Dog''' the sinus system is generally poorle developed. The Maxillary sinus is a cavity, freely communicating with the nasal cavity, and is known as the '''Maxillary Recess'''. The Frontal sinus has 3 chambers which drain separately into the nasal cavity.  

*In the '''Dog''' the sinus system is generally poorly developed. The Maxillary sinus is a cavity, freely communicating with the nasal cavity, and is known as the '''Maxillary Recess'''. The Frontal sinus has 3 chambers which drain separately into the nasal cavity.  

*In the '''Horse''' the Maxillary sinus has caudal and rostral parts which together occupy a large part of the upper jaw. In addition, the horse has Sphenopalatine and Ethmoidal sinuses which are of less clinical importance than the Frontal, Caudal Maxillary and Rostral Maxillary Sinuses on each side of the skull.

*In the '''Horse''' the Maxillary sinus has caudal and rostral parts which together occupy a large part of the upper jaw. In addition, the horse has ''Sphenopalatine'' and ''Ethmoidal'' sinuses which are of less clinical importance than the ''Frontal, Caudal Maxillary'' and ''Rostral Maxillary Sinuses'' on each side of the skull.

*'''Cattle''' do not have a fully developed sinus system until the age of 7. The Frontal sinus in cattle has a 'diverticle' for the Cornual Process (horn).

*'''Cattle''' do not have a fully developed sinus system until the age of 7, by which time it is an extremely complex system.  

The complete set of sinuses is complex. In addition to the frontal sinus, there is a ''Palatomaxillary sinus'' (named because the Maxillary Sinus is continuous with the Palatine Sinus) within the caudal part of the hard palate and face, a ''lacrimal sinus'' within the medial orbit, ''sphenoidal sinuses'' which lie past the orbit and within the conchae themselves is the ''conchal sinuses''.

In addition to the Frontal sinus, there is a ''Palatomaxillary sinus'' (named because the Maxillary Sinus is continuous with the Palatine Sinus) within the caudal part of the hard palate and face, a ''Lacrimal sinus'' within the medial orbit, ''Sphenoidal sinuses'' which lie past the orbit and within the conchae themselves are the ''Conchal sinuses''. The Frontal sinus in cattle has a 'diverticle' for the Cornual Process (horn).

*The '''Pig''' has lacrimal, sphenoid and conchal sinuses in addition to the Maxillary and Frontal systems.

*The '''Pig''' has ''Lacrimal, Sphenoid'' and ''Conchal'' sinuses in addition to the Maxillary and Frontal systems.