Table II.
Common anatomic variations in CT scans of 140 patients with chronic paranasal sinusitis.
| Common anatomic variations | Unilateral, N (%) | Bilateral, N (%) | Total, N (%) | ||
|---|---|---|---|---|---|
| Right, N (%) | Left, N (%) | Total, N (%) | |||
| Septal deviation | 36 (25.7) | 46 (32.85) | - | - | 82 (58.5) |
| Hypertrophic ethmoidal bulla | 9 (6.4) | 19 (13.6) | 28 (20) | 18 (12.8) | 46 (32.8) |
| Large agger nasi cell | 5 (3.6) | 7 (5) | 12 (8.6) | 22 (15.7) | 34 (24.3) |
| Middle turbinate | |||||
| Concha bullosa | 20 (14.3) | 23 (16.4) | 43 (30.7) | 26 (18.6) | 69 (49.3) |
| Paradoxical | 4 (2.8) | 3 (2.1) | 7 (5) | 2 (1.4) | 9 (6.4) |
| Uncinate process | |||||
| Lateral deviation | 10 (7.1) | 6 (4.3) | 16 (11.4) | 14 (10) | 30 (21.4) |
| Medial deviation | 10 (7.1) | 4 (2.9) | 14 (10) | 18 (12.8) | 32 (22.8) |
| Hypertrophy | 2 (1.4) | 7 (5) | 9 (6.4) | 5 (3.5) | 14 (10) |
| Atelectatic | 1 (0.7) | 4 (2.8) | 5 (3.5) | 4 (2.8) | 9 (6.3) |
| Haller's cell | 8 (5.7) | 8 (5.7) | 16 (11.4) | 16 (11.4) | 32 (22.8) |
| Onodi cell | 4 (2.8) | 6 (4.3) | 10 (7.1) | 2 (1.4) | 12 (8.5) |
| Maxillary sinus | |||||
| Hypoplastic | 1 (0.7) | 5 (3.6) | 6 (4.3) | 2 (1.4) | 8 (5.7) |
| Septated | 2 (1.4) | 4 (2.9) | 6 (4.3) | 1 (0.7) | 7 (5) |
| Roof of the ethmoid # | Type I : 22 (15.7) | Types II : 11 (7.8) | Types III : 2 (1.4) | 35 (25) | |
| Frontal cells * | Type I : 11 (7.8) | Type II : 6 (4.3) | Type III : 1 (0.7) | 17 (12.1) | |
| Pneumatization of crista galli | 19 (13.6) | ||||
| Pneumatization of nasal septum | 13 (9.3) | ||||
#
Roof of the ethmoid: Keros type I, olfactory fossa is 1-3 mm deep; Keros type II, olfactory fossa is 4-7 mm deep; Keros type III, olfactory fossa is 8-16 mm deep (41).
*
Frontal cell types: type I, single frontal recess above agger nasi cell; type II, tier of cells in frontal recess above agger nasi cell; type III, single massive cell pneumatizing cephalad into frontal sinus; type IV, single isolated cell within the frontal sinus (42).