Changes in the nasolabial angle associated with advance and maxillary impact surgery

Abstract

Objectives: The aim of this study is to determine changes that occur in the nasolabial angle (ANL) in patients who received Le Fort I advancement surgeries with or without maxillary impaction. Methods: A cephalometric evaluation of McNamara was performed in 16 healthy Chilean patients after orthognathic surgeries. Only patients with pre- and postsurgery teleradiography were included in this study. The radiographs were standardised in head posture position, with olives and first tooth contact. Pre- and postsurgery images were on the same scale (1:1). A comparison was made between two types of surgeries: (1) forehead and maxillary impaction (eight patients); (2) pure maxillary advancement (eight patients). The efficiency of the ANL change in degrees was demonstrated. Cephalometric analysis was measured with Nemoceph 11 software, by a calibrated operator, between 2 and 4 weeks after surgery. Findings: Maxillary movement showed that maxillary impaction and maxillary impaction surgery produced an average increase of 15.125°, while pure advancement determined an average increase of 8.625°. Thus, it was established that the maxillary impaction and advancement surgery is more efficient in the change of nasolabial angulation. Conclusion: The objective of this study was to determine the most efficient maxillary movement to achieve changes in ANL. This is of paramount importance in surgical planning, because when considering these results, the clinician will be able to predict what kind of movement is convenient and how much the patient's soft profile may change after one or the other type of maxillary movement.