Study of Morphological Changes in the Inferior Turbinate After Le Fort I Osteotomy

Abstract

Objective: There are cases in which patients complain of nasal obstruction after Le Fort I osteotomy, but the relationship with postoperative morphological changes in the nasal cavity, including the septum and inferior turbinate, is not clear. Study Design: The authors evaluated the three-dimensional relationship of the morphological changes in the inferior turbinate before and after surgery in 84 patients who underwent Le Fort I osteotomy. Three classifications were made according to superior amount of maxillary movement at the base of nasal cavity. Results: The high elevation group (4.0 mm or more) had 31 sides, the moderate elevation group had 93 sides, and the low elevation group (less than 2.0 mm) had 44 sides. The volume of inferior turbinate was 76.9 ± 12.8% of that before surgery in the high elevation group. The high- and moderate-elevation groups had significantly higher changes than the low elevation group, and the rate of contact between inferior turbinate and nasal cavity floor was 67.7%. Conclusions: After Le Fort I osteotomy, the volume of inferior turbinate tissue decreased in proportion to the amount of elevation of the maxilla. Although the soft tissue volume may be reduced due to adaptation of respiratory function, the inferior nasal passage was not completely ventilated in the high elevation group. If the elevation exceeds 4.0 mm counterclockwise with maxillary movement, it is necessary to consider the concomitant inferior turbinate resection because it may lead to nasal obstruction.

Study of Anatomical Changes of the Inferior Nasal Passage After Le Fort I Osteotomy With Superior Repositioning

“…In addition to reports on respiratory disorders associated with maxillary-mandibular movement, 2–5 there are some reports concerning the condition of the nasal passage and nasal obstruction after Le Fort I osteotomy 6–17 . We reported that the contact rate between the inferior turbinate and the nasal cavity floor was 67.7% when the elevation exceeded 4.0 mm with maxillary movement 18 . The inferior turbinate may be an obstacle to the superior movement of the maxilla.…”

“…The conditions and settings for the CT examinations have been described in the literature. 18 The CT data were exported in Digital Imaging and Communications in Medicine format and rendered into hard tissue surface representations (bone conditions at our facility: window width: 3700, window level: 500), after which they were converted into 2-dimensional (D) images using 3D analysis software (ProPlan CMF 3.0; Materialize; Fig. 2A).…”

“…The maxillary superior movement in the nasal cavity (the anterior-posterior position of the distal part of the first maxillary molar, near the center of the inferior turbinate) was measured as in a previous study. 18 Contact between the nasal cavity floor and the inferior turbinate was considered to be ≥ 5 mm. In this study, contact was considered to lead to obstruction of the inferior nasal passage, as in a previous study.…”

“…Contact between the nasal cavity floor and the inferior turbinate was considered to be ≥5 mm. In this study, contact was considered to lead to obstruction of the inferior nasal passage, as in a previous study 18 . The bone volume of the inferior turbinate was evaluated in 2 groups (large and small, with the median as the threshold).…”

“…[6][7][8][9][10][11][12][13][14][15][16][17] We reported that the contact rate between the inferior turbinate and the nasal cavity floor was 67.7% when the elevation exceeded 4.0 mm with maxillary movement. 18 The inferior turbinate may be an obstacle to the superior movement of the maxilla. There is concern that nasal symptoms may occur due to stenosis of the inferior nasal passage, even after superior movement of the maxilla (Fig.…”