耳鼻喉科Otolaryngology topic six: Basics about nasal cavity and paranasal sinuses

Basics about nasal cavity and paranasal sinuses

1. Nasal cavity: 8 bones

-- maxilla bone

-- ethmoid bone 

-- frontal bone

-- lacrimal bone

-- palatine bone

-- sphenoid bone

-- vomer bone

-- inferior concha

2. Post-nasal dripping

-- mechanism 1 : hypersecretion

-- mechanism 2: too dry to flow out smoothly

-- normal secretion amount: 20-30ml/kg/day

3. Sinus and its effects
-- lighten the weight of cranial bones
-- secrete NO (↓pathogen)
-- affect eyes and related to teeth (maxillary sinus)

4. Cartilages of nose
-- lateral crus of greater alar
-- medial crus of greater alar
-- accessory alar
-- lesser alar
-- septal cartilage
-- lateral nasal cartilage

5. Concha
-- terminology: concha(bone) + mucosa = turbinate
-- function: create turbulent flow, ↑ surface area ( ↑ temperature, ↓ dusts)

6. Cavernous sinus ( DO NOT contain CN2, CN5-3)
-- pituitary gland
-- carotid artery
-- CN3
-- CN4
-- CN5-1
-- CN5-2
-- CN6, first influenced by sphenoid sinus lesions
*** Consider cavernous sinus lesions if headache(60%), cranial nerve related symptoms

7. Diagnostic tools in OPD
Indirect mirror: inferior concha

Endoscope

Rhinomanometry
-- check flow/pressure (steep slope=unobstructed, flat=obstructed )
-- 1, 3 quadrant= right nasal outlet; 2,4 quadrant= left nasal outlet

Acoustic rhinometry
-- sono
-- locate the obstruction site

Sinus echo: back wall echo (+) if effusion is present, good sensitivity

Olfactory test: GPCR-->cAMP-->Ca2+/Na+ in-->Cl- out-->depolarization

MAST (multiple antigens simultaneous test)  
-- for mites, cockroaches, seafood, pets...

Sinus routine
-- Caldwell view(forward 10~15°): for ethmoid sinus
-- Waters view(backward 45°): for maxillary sinus
-- lateral view

CT

Panorex

8. Rhinosinusitis
-- anterior / posterior sinus: divided by E-tube outlet
-- virus infection: within 10 days
-- secondary bac. infection: >10 days (aerobic earlier than anaerobic)

-- acute: <4 wks
-- recurrent: >4 episodes, 7~10 days
-- chronic: >12 wks, often iatrogenic/odontogenic ( 1st molar )

-- treatment: Otrivin nasal spray(use <5 days), irrigation, steroid(oral-->spray), FESS, Caldwell-Luc operation ...

9. Allergic rhinitis
--  One air way one disease: allergic rhinitis associated with asthma
-- treatment: antihistamine, antileukotriene, steroid, cromolyn sodium, desensitization

10. Epistaxis
-- anterior:  Little’s area＝Kiesselbach's plexus
-- posterior: Woodruff‘s area, use Foley packing, flow↑