Background:
Preserving nasal function is crucial when performing rhinoplasty. It is known that osteotomy of the nasal bones has a potential for altering the nasal airway. Moreover, different techniques of lateral osteotomy may affect the nasal airway, specifically the internal nasal valve, the narrowest segment of the nose.
The purpose of this study was to compare the effect of two widely used methods of osteotomy used in rhinoplasty on the Internal Nasal Valve, by measuring Minimal Cross-sectional Area (MCA) using Acoustic rhinometry (AR) and Computed Tomography (CT).
Methods:
Thirty adult patients (24 males and 6 females aged 20 to 45 years old with a mean of 25.7 +/- 5.9 years) noting nasal deformity and requiring rhinoplasty were enrolled in this study. Patients were divided into three groups with ten patients each. Patients in the first group had lateral osteotomies by the internal continuous technique. Patients in the second group had lateral osteotomies by an external perforating technique. In the third group, osteotomies were performed out externally on the left side and internally on the right side.
All patients had their internal nasal valve (INV) area measured preoperatively bilaterally and at six weeks postoperatively using AR and CT of the nasal bones followed by statistical analysis.
Results:
Lateral osteotomy decreases the INV (as measured by the acoustic rhinometry and by CT scan) with a p <0.009. There was no statistical significant difference between the two types of osteotomies, the internal continuous and the external perforating techniques, with respect to the effect on INV (CT derived P value was 0.240 and AR derived P was 0.596). Pearson correlation tests revealed a 0.972 correlation indicating very high statistical correlation between INV measured by acoustic rhinomanometry and CT scan.
Conclusion:
Rhinoplasty is a potential nasal airway altering procedure that may affect the INV regardless the type of lateral osteotomy used. All patients undergoing rhinoplasty may benefit from careful history and exam to identify patients who may be predisposed to a narrowed INV postoperatively following nasal bone osteotomy. These patients may benefit from nasal valve stabilizing techniques to prevent nasal obstruction.
Figure Caption:
Figure 1: Box-plot showing CT scan derived preoperative and postoperative nasal valve values (Y-axis= cm2, p < 0.05).
Figure 2: Box-plot showing acoustic rhinomanomety derived preoperative and postoperative nasal valve values (Y-axis= cm2, p < 0.05).