Wednesday, 19 December 2007

Osteomeatal complex

Osteomeatal complex:
Ostium: opening within the maxillary sinus
Infundibulum: the canal like struture
Hiatus semilunaris: slit like air space, situated superior to uncinate process, anteroinferior to bulla ethmoidalis
Uncinate process: sickle shaped bone extension of the medial wall, rarely pneumatized
Bulla ethmoidalis: largest ethmoidal bulla, situated anteroinferiorly
Middle meatus: where hiatus semilunaris opens

Patterns of obstruction (Sonkens et al):
1. Infundibular pattern:
Sinus disease is limited to infundibulum and maxillary sinus; fromtal and ethmoidal sinuses are spared
Secondary to swollen mucosa, polyps, Haller cells
Rx - infundibulotomy

2. Osteomeatal unit pattern:
Middle meatus, anterior-middle ethmoidal air cells, maxillary and frontal sinuses are involved.
Secondary to swollen mucosa, polyp, concha bullosa, septal deviation, nasal tumor
Rx - infundibulotomy and ethmoid bullectomy

3. Sphenoethmoidal recess pattern:
Sphenoid and posterior ethmoid cir cells are involved.

4. Sinonasal polyp pattern:
Polyps fill nasal cavity and sinuses bilaterally

5. Unclassifiable pattern:
Secondary to retension cysts, mucocels, post-op changes