Head, Horn Blocks, Eye, Sinuses, Dentition- Assignment 2 Flashcards
What branch of cranial nerve V supplies the upper eyelid?
Ophthalmic
What branch of cranial nerve V supplies the lower eyelid?
Maxillary
The dog has a large maxillary sinus. True or false?
False
Where is the frontal sinus?
Between the eyes and extends to the horns
What is the name of the diverticulum of the frontal sinus in the horn and at what age is it developed?
cornual diverticulum; 6 months
What are the names of the diverticula of the frontal sinus?
cornual, postorbital, and nuchal
How does the frontal sinus differ between large and small ruminants?
large ruminants- the frontal sinus extends caudally over the brain
small ruminants- frontal sinus does not extend over the brain, and the base of the horn is physically very close to the brain
What are the components of the frontal sinus?
Caudal compartment, 1-4 rostral ones
Describe the maxillary sinus of the ox (communication).
Communicates freely with the palatine sinus over the infraorbital canal
Describe the maxillary sinus of the ruminant (communication).
Infraorbital canal divides maxillary sinus into lateral and medial parts. Medial part communicates with the palatine sinus.
What is the lacrimal bulla?
Extension of maxillary sinus
Which teeth extend into the maxillary sinus?
last 3 or 4 cheek teeth roots
What does the frontal cavity open into?
Opens into the nasal cavity via the middle nasal meatus, above its opening into the palatines sinus
What are the surgical limitations of the maxillary sinus?
Dorsal- medial angle of eye to infraorbital foramen
ventral- facial tuberosity to zygomatic arch
rostral- just rostral to facial tuberosity
caudal- ventral margin of bony orbit
How do the palatine and frontal sinuses communicate?
Over infraorbital canal
How does the palatine sinus communicate with the nasal cavity?
via the maxillary sinus; there is no independent communication between the palatine sinus and the nasal cavity
What is the sphenoid sinus?
Located in the wing of the presphenoid bone
Communicated with nasal cavity via ventral ethmoid meatus
What is the lacrimal sinus?
No independent communication to nasal cavity
Communicates freely with the caudodorsal portion of the maxillary sinus
How many permanent premolars are in each side of the upper arcade of the dog?
4
What covers the outer surface of the canine tooth root?
cementum
Describe incisors and canines in the ruminant.
No upper incisors or canines in either deciduous or permanent teeth. The lower canines look like incisors and often referred to as such.
How is the age of a ruminant determined?
It can be estimated by eruption dates and wear of deciduous and permanent teeth, especially incisors and canines.
What type are ruminant incisors and canines?
brachydont- the crown wears off almost completely to the neck of the tooth over time
What is the dental formula for ruminants?
2 (Di 0/3, Dc 0/1, Dp 3/3) = 20
2 (I 0/3, C 0/1, P 3/3, M3/3) = 32
When do deciduous teeth erupt?
ox- all deciduous teeth erupt within 2 weeks of birth
small ruminants- premolars erupt a few weeks later
When do incisors and canines erupt?
I1 –> 1.5-2 years
I2 –> 2.-2.5 years
I3 –> 3-3.5 years
I4 (canine) –> 3.5-4 years
When do molars and premolars erupt?
PM2 - 2-2.5 years PM3 - 1.5-2.5 years PM4 - 1.5-3 years M1 - 6 months, 4 cheek teeth M2 - 1-1.5 years; 5 cheek teeth M3 - 2-2.5 years; 6 cheek teeth
cheek teeth count includes deciduous premolars
Which branch of trigeminal nerve supplies the upper incisors in the dog?
Maxillary
At what age do incisors “level” in the ox? What does level mean?
6-9 years old
lingual edge of the occlusal surface becomes smooth
At what age are incisors pegs? What age are incisors and canines pegs?
10-12 years; by age 15
Which cranial nerve does not exit a foramen in the orbit?
VII
