Abstract
The effects of Le Fort I osteotomy on the nasal airway are controversial. This study aimed to evaluate nasal airway changes after Le Fort I. 25 patients underwent conventional Le Fort I osteotomy and were separated into three groups depending on the type of surgery they underwent. 11 patients needed maxillary impaction, 9 underwent maxillary advancement, and 5 had both maxillary impaction and advancement. Rhinological examinations, anterior rhinomanometry and acoustic rhinometry were carried out 1 week before surgery and 3 months after that. Wilcoxon and χ 2 tests were used for data analysis. The samples included 19 females and 6 males with a mean age of 22.4 ± 3.32 years. Rhinomanometric assessment showed that total nasal airflow was increased from 406 ± 202 ml/s to 543 ± 268 ml/s in all three groups. Significant decrease in nasal airway resistance was seen in all three groups. Acoustic rhinometry revealed a significant decrease in total nasal volume but an increase in the cross-sectional areas of isthmus nasi (IN) and inferior concha. The rhinomanometric measurements showed improvements in the total nasal airflow after Le Fort I osteotomy with alar base cinch suture in cases where the impaction was not higher than 5.5 mm.
Different movements of the maxilla in Le Fort I osteotomies have distinct effects on the nasal morphology. Kunkel and Hochban were the first to describe the effect of maxillary movement on nasal volume assessed by acoustic rhinometry. Turvey et al. found that superior repositioning of the maxilla, with or without involvement of the nasal floor, usually results in decreased nasal resistance. Erbe et al. found no nasal airway changes after Le Fort I impaction or advancement. Spalding et al. reported that no prediction could be made for any patient regarding the effect of maxillary surgery on nasal function parameters and there was no consistent association between the amount or direction of maxillary surgical movement or the position of the maxilla and nasal respiration. These contradictory results might be due to different types of Le Fort I osteotomy and whether the patient had alar base cinch suture. The contradictory results in the literature encouraged the authors to carry out new research. The purpose of this study is to evaluate nasal airflow and resistance after maxillary impaction, maxillary advancement, or a combination of both. The investigators hypothesized that improvements might be seen after Le Fort I osteotomy with alar base cinch suture. The specific aims of the study are to evaluate nasal airflow, nasal resistance and the patient’s nasal volume before and after Le Fort I osteotomy.
Materials and methods
The investigators designed and implemented a clinical prospective study composed of patients who were referred to the Oromaxillofacial Department for Le Fort I surgery. All participants signed an informed consent agreement. To be included in the study sample, the patients had to have dentofacial deformity which required Le Fort I osteotomy for correction. Patients were excluded as study subjects if they had sinusitis, allergic rhinitis, adenoid hyperplasia, craniofacial syndromes, segmental Le Fort I, previous trauma and surgery, especially rhinoplasty.
The patients were separated into 3 surgical groups depending on the type of orthognathic surgery they had received, including maxillary impaction (Group 1), maxillary advancement (Group 2) or a combination of both (Group 3). All the patients underwent conventional Le Fort I osteotomy with alar base cinch suture.
The research began 1 week before surgery when the patients filled out a questionnaire and underwent rhinological examination, anterior rhinomanometry and acoustic rhinometry. The examinations were repeated by the same otorhinolaryngologist 3 months after surgery.
Examinations carried out included documentation of luxations, presence of septal deviations, perforations, spurs, mucosal changes and enlarged turbinates ( Table 1 ). Uninasal anterior active mask rhinomanometry was performed using a NR6 rhinomanometer (GM Instruments Ashgrove, Kilwinning, UK) to assess the nasal airflow and airway resistance of each patient. In rhinomanometry, total nasal flow and total nasal resistance were measured. Acoustic rhinometry, described by Jackson et al., was used to evaluate total nasal volume, cross-sectional areas of nostrils at the isthmus nasi (IN) and head of the inferior concha in cm. An A1 acoustic rhinometer (GM Instruments Ashgrove, Kilwinning, UK) was used for evaluations before and after surgery.
| Anterior rhinoscopy | Preoperative | Postoperative |
|---|---|---|
| Luxations | 0 | 2 |
| Septal deviations | 18 | 16 |
| Perforations | 0 | 0 |
| Spurs | 19 | 3 |
| Mucosal changes | 1 | 3 |
| Enlarged turbinate | 21 | 12 |
5 randomly selected patients were re-evaluated to determine the level of error in the measurements. There was no significant difference between the measurements. Wilcoxon matched-pairs signed rank test was used for pre- and postoperative findings. The χ 2 test was used for intergroup evaluations. The data were analyzed using the Statistical Package for the Social Sciences (version 18, SPSS, Chicago, IL, USA).
Results
25 patients (6 males, 19 females) with a mean age of 22.4 ± 3.32 years were evaluated. The patients were separated into 3 surgical groups based on the type of orthognathic surgery they had received. Group 1 comprised 11 patients who needed maxillary impaction. Group 2 included 9 patients who underwent maxillary advancement. Group 3 was composed of 5 patients undergoing both maxillary impaction and advancement. The amount of maxillary movement in each of the groups is shown in Table 2 All the patients underwent conventional Le Fort I osteotomy with alar base cinch suture.
| Group | Maxillary impaction (mm) | Maxillary advancement (mm) |
|---|---|---|
| 1 | 5.14 ± 1.78 | — |
| 2 | — | 5.22 ± 1.72 |
| 3 | 3.6 ± 0.89 | 2.8 ± 1.3 |
Table 1 shows the pre- and postoperative findings of anterior rhinoscopy. Table 3 shows the rhinomanometric measurements of nasal airflow and nasal resistance. Total nasal airflow increased from 406 ± 202 to 543 ± 268 ml/s ( P < 0.0005) and total nasal resistance decreased from 0.62 ± 0.78 to 0.41 ± 0.4 ml/s ( P < 0.0005). Tables 4 and 5 show the acoustic rhinometry measurements for the total nasal volume and cross-sectional areas at the IN and concha inferior before and after surgery. Total nasal volume decreased from 7.8 ± 1.3 to 7.3 ± 1.5 cm 3 ( P < 0.001). The total cross-section of the IN increased significantly from 0.49 ± 0.1 to 0.52 ± 0.1 cm 2 ; while, the total cross-section of the concha inferior showed no significant changes.
| Groups | Preoperative | Postoperative | P value |
|---|---|---|---|
| Total nasal airflow | 406 ± 202 | 543 ± 268 | 0.0005 |
| Group 1 (NA) | 473 ± 197 | 618 ± 262 | 0.008 |
| Group 2 (NA) | 296 ± 205 | 460 ± 308 | 0.008 |
| Group 3 (NA) | 456 ± 147 | 530 ± 195 | 0.08 |
| Total nasal resistance | 0.62 ± 0.78 | 0.41 ± 0.4 | 0.0005 |
| Group 1 (NR) | 0.37 ± 0.15 | 0.27 ± 0.09 | 0.01 |
| Group 2 (NR) | 1.07 ± 1.19 | 0.62 ± 0.62 | 0.008 |
| Group 3 (NR) | 0.36 ± 0.13 | 0.32 ± 0.13 | 0.08 |
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