Nasal Floor Asymmetry Is Associated With Nasal Obstruction

CT comparison of the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction

BACKGROUND

Nasal airway stenosis may lie anterior and/or posterior to the piriform aperture. We intended to compare the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction.

METHODS

Segmented computed tomography cross-sectional areas of the nasal airway anterior (CT-CSAant) and posterior to the piriform aperture (at the level of the head of the inferior turbinate; CT-CSApost) were compared between patients with nasal obstruction (cases) and trauma controls. CT-CSA were approximately perpendicular to the direction of the nasal airflow. Anterior to the piriform aperture, they were tilted about 30o, 60o and 90o to the nasal floor. Posterior to the piriform aperture, they were tilted about 50o, 80o and 100o to the nasal floor. In cases, we examined the Pearson's correlation of active anterior rhinomanometry with CT-CSAant and CT-CSApost.

RESULTS

Narrow and bilateral CT-CSApost were similarly large between 56 cases and 56 controls (all p > 0.2). On the contrary, narrow and bilateral CT-CSAant were significantly smaller in cases than in controls (all p < 0.001). The ratio of the size of CT-CSAant-30 to that of CT-CSApost-80 was significantly lower in cases (median: 0.84; lower to upper quartile: 0.55-1.13) than in controls (1.0; 0.88-1.16; Mann-Whitney U test; p = 0.006). Bilateral CT-CSAant correlated significantly with total inspiratory flow (all p < 0.026) in contrast to bilateral CT-CSApost (all p > 0.056).

CONCLUSIONS

The nasal airway anterior to the piriform aperture was smaller in patients with nasal obstruction due to skeletal nasal stenosis than that in controls. On the contrary, the nasal airway posterior to the piriform aperture was similarly large between patients with and without nasal obstruction. Furthermore, in patients with nasal obstruction, the anterior nasal airway was narrower compared to that located posterior to it. On the contrary, control patients' anterior nasal airway was as large as the posterior one.

CT analysis of the anterior nasal airway based on the direction of nasal airflow in patients with nasal obstruction and trauma controls

PURPOSE

The anterior nose is the nasal segment with the highest resistance to airflow. In a hospital-based case-control study, we compared cross-sectional areas of the nasal cavities anterior to the piriform aperture determined by computed tomography (CT-CSA) in patients with nasal obstruction (cases) and unselected patients with trauma unrelated to the head and face (controls).

METHODS

CT-CSA could be reproducibly identified at angles of 0^o, 30°, 60°, and 90° to the nasal floor approximately perpendicular to the arcuate direction of nasal airflow using bony landmarks. CT-CSA were manually segmented and compared in cases and controls. In cases, we compared CT-CSA at 30° (CT-CSA_30-narrow) with the minimum cross-sectional area determined by acoustic rhinometry (AR-MCA_1-narrow), each on the narrower side.

RESULTS

CT-CSA ranged from 7 to 250 mm² with an average of 100 mm² per nasal side. Side differences of the nasal airways indicating asymmetry of the nasal airways were greater in 40 cases than in 44 controls (p < 0.003). Moreover, bilateral CT-CSA were significantly smaller in cases than in controls (p < 0.001). CT-CSA_30-narrow did not significantly correlate with AR-MCA_1-narrow (r = 0.33; p = 0.07) and on average was 58% smaller than AR-MCA_1-narrow.

CONCLUSIONS

Cross-sectional areas of the anterior nose perpendicular to the direction of nasal airflow, which is considered relevant in terms of flow physics, can be reliably measured using CT. Anterior nasal cavities in patients with nasal obstruction were more asymmetric and, as a whole, narrower than in controls, the latter of which is not corrected by routine septoplasty.

Are preoperative CT parameters predictive for the outcome of septoplasty?

Background

Despite successful septoplasty surgery, some patients still complain of nasal obstruction (NO).

Aim

Our aim in the present study is to determine whether preoperative computed tomographic (CT) parameters have prognostic significance for the success of septoplasty.

Material and Methods

Retrospective data from 61 patients in a secondary care hospital who had undergone septoplasty met the inclusion and exclusion criteria. The effects of demographic and preoperative CT parameters (internal nasal valve [INV], external nasal valve area, angle of septal deviation, choana area, aperture pyriformis area, high septal deviation [HSD], transverse diameter of midnose, anterior/posterior deviation, concha and meatus diameter [superior, middle, inferior]) were studied in relation to the change in NOSE scores and the success of surgery.

Results

Of the 61 patients studied, 31 were male (51%) aged 18-55 years with a mean age ± SD (26.59 ± 9.41). It was found that the changes in NOSE scores were significantly different from each other (P < 0.01). Male gender, trauma history, moderate septal deviation, HSD, mucosal pathology, posterior deviation, bullous turbinate (right and left middle, right superior), and in the absence of allergy, paradoxical turbinate (right and left middle and superior), S-shaped deviation were found to have a significant correlation in the change of NOSE scores (P < 0.05). Age and internal valve differed with respect to outcome (P < 0.05). Variables in multiple linear regresion models of all parameters were found to be insignificant (P < 0.05).

Conclusion

Preoperative CT parameters are informative, but do not predict the postoperative success of septoplasty.

Nasal ventilation and rapid maxillary expansion (RME): a randomized trial

OBJECTIVE

To assess three rapid maxillary expansion (RME) appliances in nasal ventilation.

TRIAL DESIGN

Three-arm parallel randomized clinical trial.

METHODS

Sixty-six growing subjects (10-16 years old) needing RME as part of their orthodontic treatment were randomly allocated (1:1:1 ratio) to three groups of 22 patients receiving Hyrax (H), Hybrid-Hyrax (HH), or Keles keyless expander (K). The primary outcome of nasal ventilation (pressure and velocity) and secondary outcomes (skeletal, dental, soft tissue, and nasal obstruction changes) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone-beam computed tomography (CBCT) data by applying computational fluid dynamics (CFD) method. Differences across groups were assessed with crude and adjusted for baseline values and confounders (gender, age, skeletal maturation, expansion amount, mucosal/adenoid hypertrophy, nasal septum deviation) regression models with alpha = 5%.

RESULTS

Fifty-four patients were analysed (19H, 21HH, 14K). RME reduced both nasal pressure (H: -45.8%, HH: -75.5%, K: -63.2%) and velocity (H: -30%, HH: -58.5%, K: -35%) accompanied with nasal obstruction resolution (H: 26%, HH: 62%, K: 50%). Regressions accounting for baseline severity indicated HH expander performing better in terms of post-expansion maximum velocity (P = 0.03) and nasal obstruction resolution (P = 0.04), which was robust to confounders. Mucosal/adenoid hypertrophy and nasal septum deviation changes were variable, minimal, and similar across groups. The HH resulted in significantly greater increase in the nasal cross-sectional area (62.3%), anterior (14.6%), and posterior (10.5%) nasal widths. Nasal obstruction resolution was more probable among younger (P = 0.04), skeletally immature (P = 0.03), and male patients (P = 0.02) without pre-treatment mucosal hypertrophy (P = 0.04), while HH was associated with marginal greater probability for obstruction resolution.

CONCLUSIONS

RME resulted in improvement of nasal skeletal parameters and simulated ventilation with the former being in favour of the HH and the latter not showing significant differences among the three appliances.

LIMITATION

Attrition in the K group due to blocked activation rods possibly leading to limited sample to identify any existing group differences.

HARMS

Replacement of blocked Keles expanders for finalizing treatment.

PROTOCOL

The protocol was not published before the trial commencement.

REGISTRATION

Australian and New Zealand Clinical Trial Registry; ACTRN12617001136392.