Paranasal Sinuses

Question 1

What are the main paranasal sinuses of a horse?

Answer 1

Frontal Sinus
Dorsal Conchal Sinus
Dorsal conchal bulla
Ventral conchal bulla
Caudal Maxillary Sinus
Rostra Maxillary Sinus

Question 2

Which of the main sinuses communicate?

Answer 2

Frontal, Dorsoconhcal and caudal Maxillary, sphenopalantine

Rostral maxillary and ventral conchal

Separated by bulla

Question 3

Where is the nasomaxillary aperture/Sinus drainage angle?

Answer 3

Where the nasal region meets the caudal maxillary region
-Very thin and a little inflammation can have a big affect

Question 4

How do you determine whether or not you have a fluid line in your x-ray?

Answer 4

Look at the mitchel marker and beads, see where there is an almost soft tissue opacity going straight across

Question 5

What are the x-rays that should always be taken when investigating the sinuses?

Answer 5

Lateral, oblique, dorsoventral

Question 6

When is CT used?

Answer 6

For complex disorders
-Tooth root disease
-Sphenopalatine sinus
-Complex trauma
-Use if recurrent disease

-Great for the delicate boney structures in sinus, surgery prep, standing sedation

Question 7

What is sinus trephination?

Answer 7

Drilling hole into the sinus under standing sedation
-Can use to lavage or investigate, biopsy
-Standing sedation and local analgesia

Question 8

What are the sites of sinus trephination?

Answer 8

Choncofrontal - frontal, dorsal cohchal, caudal maxillary, sphenopalpatine
-60% distance from midline to medial canthus, 0.5cm caudal to medial canthus

Caudal maxillary site - communicate with choncofrontal through lavage
-2cm rostral and 2cm ventral medial canthus

Rostral Maxillary site - rostral and ventral
-40% from rostral end of facial crest to medial canthus, 1cm ventral from infraorbital foramen and medial canthus

-Need fenestration through maxillary septal bulla to make all sinus compartmentc communicate

Question 9

What structure is between sinus compartments that if penetrated will make all sinuses connect?

Answer 9

Maxillary septal bulla

Question 10

What is sinoscopy?

Answer 10

It is cutting a portion of bone away to get into the sinus
-1 inch diameter
- visualization
- for cystand tooth root abscesses, biopsy

Question 11

What are bone flaps used for?

Answer 11

Treatment after diagnosis using sinuoscopy or if large lesion on diagnostic image
-Allows access to sinus

Question 12

What are the most common differential for sinonasal diseases?

Answer 12

Primary Sinusitis
Dental Sinusitis
Sinus cyst
Sinus neoplasia
Ethmoid hematoma
trauma
mycosis
cheeck tooth infection
Polyp

Question 13

What is primary sinusitis?

Answer 13

When you cannot find a cause for the sinusitis

Inflammation of the sinus that can block off normal sinus drainage
-Viral common
-Mucus accumulates and bacteria gorws
-Acute - broad antimicrobials
-Lavage if chronic

Question 14

What is secondary sinusitis?

Answer 14

second to a primary disease - dental common (08, 09, 10, 11 maxillary cheek teeth)
-Sinus mass obstructs sinus drainage (paranasal sinus cyst, sinus neoplasia, progressive ethmoid hematoma

Question 15

What is the most common cause of sinusitis?

Answer 15

Dental disease

Question 16

What is a circular lesion you may find on an oblique radiograph that is fluid filled (yellow fluid), can cause deformation of facial bones and loss of bon) - it can obstruct as well and lead to sinusitis ?

Answer 16

Sinus Cyst

Question 17

How do we remove a sinus cyst?

Answer 17

Surgically - need to get all of the lining

Question 18

What looks like a soft issue opacity on radiograph, loss of bone archetecture, facial deformities can be seen?

Answer 18

Sinus Neoplasia

Question 19

What are common types of neoplasia that may be found in the sinus?

Answer 19

SSC, Adenocarcinoma, fibroma, chondroma, hemagiosarcoma, osteoma

Question 20

What is the prognosis for sinus neoplasia?

Answer 20

Poor - even with surgical resection and radiation
-Less than 6 months

Question 21

What disease is common in young horses, can be seen on oblique rads as a gap and periosteal proliferation of the facial structures, can be secondary to trauma?

Answer 21

Suture Periostitis

Question 22

What is a facial suture of a horse?

Answer 22

Fibrous connective tissue between flat bones of the face

Question 23

What disease:
-Clinical signs: acute epistaxis, disruption of resp mucosal lining sinus, fresh to brown, secondary mucopurulent nasal discharge, bacteria in lining grow in blood, emphysema,X-ray to see gap due to trauma in older horse:

Answer 23

Sinus Trauma Fractures

Question 24

What else should you examine if you suspect a fracture of the sinus from trauma?

Answer 24

Evaluate the eye, endoscopy and neurologic exam
-Multiple oblique rads or CT

Question 25

How do you treat sinus trauma fractures?

Answer 25

Reduce soft tissue swelling - antibiotics and antinflamatories
-surgical repair indented fractures
-can treat conservatively but poor prettiness cause of callus
-Orbital fracture need surgery to prevent harm to globe

Question 26

What disease:
Clinical signs: intermittent unilateral epistaxis? Abnormal resp noise, on endoscopy has dark red to tan brown encapsulated mass, usually in ethmoid region, can see on rads, ct and sinoscopy

Answer 26

Progressive Ethmoid Hematoma

Question 27

How can you treat progressive ethmoid hematomas?

Answer 27

Formalin Injection - 1st line, repeat every 3-4 weeks, 5 repeat injections, scab and slough, laser ablation
-Careful can cross cribriform plate and harm brain

Question 28

Why may ethmoid hematomas recur?

Answer 28

Involvement of sphenopalatine sinus (ct)