Rosen HM. Lip-nasal aesthetic following Le Fort I osteotomy. Plastic Reconstr Surg. 1988; 81:171-182
Proffit WR, White Jr RP, Sarver DM. Contemporary Treatment of Dentofacial Deformity, 1st edn. Oxford: Mosby; 2008
Armijo BS, Brown M, Guyuron B. Defining the nasolabial angle. Plast Reconstr Surg. 2011; 129:759-764
Orten SS, Hilger P. Facial Analysis of the Rhinoplasty Patient. Facial Plastic and Reconstructive Surgery, 2nd edn. New York: Thieme; 2002
Soncul M, Bamber MA. Evaluation of facial soft tissue changes with optical surface scan after surgical correction of class III deformities. J Oral Maxillofac Surg. 2004; 62:1331-1340
Honrado CP, Lee S, Bloomquist DS Quantitative assessment of nasal changes after maxillomandibular surgery using a 3-dimensional digital imaging system. Arch Facial Plast Surg. 2006; 8:26-35
Chew MT. Soft and hard tissue changes after bimaxillary surgery in Chinese class III patients. Angle Orthod. 2005; 75:959-963
Schendel SA, Carlotti AE. Nasal considerations in orthognathic surgery. Am J Orthod Dentofacial Orthop. 1991; 100:197-208
McFarlane RB, Frydman WL, McCabe SB. Identification of nasal morphologic features that indicate susceptibility to nasal tip deflection with Le Fort I osteotomy. Am J Orthod Dentofacial Orthop. 1995; 107:259-267
O'Ryan F, Schendel S. Nasal anatomy and maxillary surgery. 1. Esthetic and anatomic principles. Int J Adult Orthodon Orthognath Surg. 1989; 4:27-37
Engel GA, Quan RE, Chaconas SJ. Soft tissue change as a result of maxillary surgery. A preliminary study. Am J Orthod Dentofacial Orthop. 1979; 75:291-300
Bisase B, Johnson P, Stacey M. Closure of the anterior open bite using mandibular sagittal split osteotomy. Br J Oral Maxillofac Surg. 2010; 48:352-355
Millard DR. The alar base cinch in the flat, flaring nose. Plastic Reconstr Surg. 1980; 65:669-672
Collins PC, Epker BN. The alar base cinch: a technique for prevention of alar base flaring secondary to maxillary surgery. Oral Surg Oral Med Oral Pathol. 1982; 53:549-553
Loh FC. A new technique of alar base cinching following maxillary osteotomy. Int J Adult Orthodon Orthognath Surg. 1993; 8:33-36
Westermark AH, Bystedt H, von Konow L Nasolabial morphology after Le Fort I osteotomies. Int J Maxillofac Surg. 1991; 20:25-30
Guymon M, Crosby D, Wolford LM. The alar base cinch suture to control nasal width in maxillary osteotomies. Int J Adult Orthodon Orthognath Surg. 1988; 3:89-95
Rauso R, Gherardini G, Santillo V Comparison of two techniques of cinch suturing to avoid widening of the base of the nose after Le Fort I osteotomy. Br J Oral Maxillofac Surg. 2010; 48:356-359
Muradin MS, Seubring K, Stoelinga PJ A prospective study on the effect of modified alar cinch sutures on nasolabial changes after Le Fort I intrusion and advancement osteotomies. J Oral Maxillofac Surg. 2011; 69:870-876
Becelli R, De Ponte FS, Fadda MT Subnasal modified Le Fort I for nasolabial aesthetics improvement. J Craniofac Surg. 1996; 7:399-402
Mommaerts MY, Abeloos JV, De Clercq CA, Neyt LF. The effect of the subspinal Le Fort I-type osteotomy on interalar rim width. Int J Adult Orthodon Orthognath Surg. 1997; 12:95-100
Orthognathic surgery involves the correction of severe dentofacial deformities through a combination of orthodontics, surgery and, occasionally, restorative dentistry. This procedure, when involving surgical movement of the maxilla, can lead to changes in the overlying nasal morphology. In this paper, the standard nasal assessment that is undertaken prior to a Le Fort I osteotomy is outlined along with the reported nasal changes seen following this procedure. In addition, the various risk factors associated with adverse nasal changes are considered, as are the management techniques adopted by clinicians to minimize these changes
CPD/Clinical Relevance: Clinicians should be aware of the adverse nasal changes associated with the Le Fort I osteotomy.
Article
A Le Fort I osteotomy is performed to correct an underlying midface skeletal deformity and to improve facial aesthetics.1 It can be used to correct discrepancies in both the antero-posterior and vertical dimensions and is widely adopted by maxillofacial surgeons owing to its relative simplicity and efficiency. Although complications associated with this procedure are uncommon, careful evaluation of the nose should take place prior to this procedure. Typically, undesirable changes in the nasal region, such as widening of the alar base or upturning of the nose, can accompany this procedure.1,2,3 Careful pre-surgical planning, as well as intra-operative preventive techniques, have the potential to limit these undesirable changes. This article aims to cover the clinical evaluation of the nose prior to a Le Fort I osteotomy, the reported nasal changes seen following this procedure, the risk factors associated with these adverse nasal changes and the techniques employed to minimize possible adverse outcomes.
Clinical nasal evaluation
It is imperative that clinicians develop the clinical acumen to evaluate nasal morphology as part of a wider assessment of facial aesthetics.
Initially, the overall proportion and symmetry of the face should be analysed. This examination is carried out with the patient in the natural head position (NHP). This is a standardized and reproducible position with the subject focusing on a distant point at eye level. In order to achieve ideal aesthetics, the nose should be symmetrical in shape and be positioned in the midline of the face. The projection and size of the nose should be considered in relation to lip and chin projection.3 In addition, as with any assessment of facial aesthetics, the ethnicity of the patient should be considered. There is wide variation in the nasal prominence, shape and alar width amongst differing ethnic groups.3 It is imperative that the clinician is sensitive to the ethnicity of the patient as this will have an important influence on nasal aesthetics.
Detailed examination of the nose can take place in four dimensions:
In the frontal view, the alar base width, outlines of the alar rims and the columella are assessed (Figure 1). The width of the alar base should approximate the intercanthal distance. In Caucasians, this measures 32 ± 3 mm. In Africo-Americans, however, the width of the alar base is greater (35 ± 3 mm). In individuals where the intercanthal distance is narrower than an eye width, the alar base width should be slightly wider.3 For ideal aesthetics, the nares should be scarcely visible and the columella should appear marginally below and parallel to the alar rims.
Figure 1. Frontal view analysis of the nose.
Lateral nasal analysis
In the lateral view, the nasal length, nasal dorsum, tip projection and nasolabial angle are assessed (Figure 2). The nasal length should equal the distance from stomion to menton. The nasal dorsum should be free of depressions and humps and should project from the face at an angle of 30°−35°. The length of tip projection (alar tip to cheek-alar junction) should equal two-thirds of the nasal length, whilst the degree of tip rotation is assessed via the nasolabial angle. This is the angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort plane while intersecting subnasale.4 It is influenced by the shape of the columella. In males, the average nasolabial angle is between 90°−95°, whilst in females it is more obtuse, measuring between 95°−105°.5 The pre-treatment nasolabial angle is of crucial importance when planning maxillary surgery.4
Figure 2. Lateral nasal analysis.
Basal nasal analysis
In the basal view, the nares and position of the columella are assessed. In Caucasians, the nares are ovoid in shape whilst, in African-Americans, a more circular appearance prevails. The nostrils should be symmetrical in shape and their width approximately three-quarters of the alar base distance. Lastly, the columella should lie in the midline on basal view analysis.
45° nasal analysis
The 45° view provides an excellent view of nasal anatomy. It is considered by some individuals as the best view of facial aesthetics. The shape of the dorsum, supratip appearance and contour of the nasal cartilage are well illustrated in this view (Figure 3).3 The supratip is the nasal region where the inferior aspect of the nasal dorsum meets the tip of the nose.3
Figure 3. 45° nasal analysis.
Nasal changes following Le Fort I osteotomy
A Le Fort I osteotomy inevitably leads to changes in nasal morphology.2 An increase in alar base width is seen following both maxillary advancement and superior maxillary impaction.1,6,7 This results from elevation of the periosteum from the maxilla and subsequent retraction of the zygomaticus major, levator labii superiorus, levator labii superiorus alaeque nasi and nasalis from their points of insertion. It is crucial that the alar base width is carefully evaluated prior to maxillary surgery so as to prevent any adverse effects to facial aesthetics post-surgery.
A rise in the nasal tip is seen following both maxillary advancement and impaction.8,9 This is associated with increased nostril show and the characteristic ‘Miss Piggy’ appearance. Nasal tip elevation results from disruption to the nasal septum and the upper and lower lateral cartilages, as well as the attachment of the medial crural footplates to the septum during maxillary surgery. This will lead to undesirable deepening of a supratip depression, however, in some cases may have the desirable effect of camouflaging a small dorsal hump.1,10
Nasal soft tissue changes seen following inferior maxillary movement differ from those seen in maxillary advancement and superior impaction. Here, there is downward movement of the alae, columella and nasal tip.7 Nasal features should be carefully evaluated pre-surgery as downward movement of an already inadequate nasal tip rotation may lead to the loss of any supratip break.10
In summary, despite these reported changes, it is important to appreciate that, owing to the great variation in nasal morphology, accurate prediction of nasal changes following a Le Fort I osteotomy is difficult. Careful pre-surgical planning on an individual basis is paramount to achieving the best post-operative results.
Risk factors
It is crucial that cases at high risk of undesirable nasal changes are identified prior to the commencement of orthognathic surgery. Various factors have been reported in the literature to be associated with undesirable nasal changes. These include:
The DRI, as described by McFarlane,11 reflects the tissue bulk of the nasal tip in relation to the horizontal size of the nose. A low DRI index score signifies increased tissue bulk. With greater tissue bulk, the nose becomes more susceptible to undesirable tip deflections following surgery. The larger nasal tip, which has an increased development of the lateral crus of the alar cartilages, transmits a greater force to the upper lateral cartilage, which in turn leads to an upward tip rotation. The magnitude of maxillary advancement has been shown to be the greatest contributor to nasal tip deflection.2,12 However, accurate prediction of the extent of nasal tip deflection has not been determined. Factors such as soft tissue lip variations, extent of oedema, radiographic and surgical technique variations, and methodical differences in study designs have accounted for this.13 Alar base widening, in contrast, is affected more by the extent of sub-periosteal dissection than the magnitude of skeletal movement. This is due to freeing the facial muscles from the nasolabial region and anterior nasal spine. Muscle resuturing, as described later, can be employed to limit this adverse change. The pre-operative columella angle (angle formed by the intersection of nasion vertical to the columellar tangent) can also contribute to undesirable nasal changes post-surgery. As the columella angle becomes more obtuse, the likelihood of tip deflection at the anterior nasal tip increases.11 This in turn leads to an increase in nostril show which further worsens nasal aesthetics.
Management strategies
Strategies in mitigating against adverse soft tissue nasal changes are as follows:
Avoiding maxillary surgery;
Pyriform aperture recontouring;
The alar base cinch suture;
The V-Y closure;
The subnasal modified Le Fort I osteotomy;
Anterior Nasal Spine (ANS) resection.
Avoiding maxillary surgery
Anticlockwise rotation of the mandible alone to close an anterior open bite can be considered in circumstances where a bimaxillary procedure is likely to cause adverse aesthetic nasal effects. This clinical practice is gaining increased interest, especially in situations where the anteroposterior and vertical position of the maxilla is within normal limits, the mandibular ramus is short and the condyles show no evidence of resorption.14 However, mandibular surgery alone is not possible where vertical maxillary excess or maxillary hypoplasia are the presenting features.
Pyriform aperture recontouring
The pyriform aperture represents the anterior end of the bony nasal opening. During maxillary surgery, the pyriform aperture is frequently recontoured to accommodate the soft tissues at the base of the nose. This technique is of particular importance in superior and anterior repositioning of the maxilla. Studies in the literature have suggested that alteration to the lateral aspects of the pyriform aperture during surgery is likely to have the most profound impact on nasal changes.15,16 Mommarts et al concluded that it is the pyriform aperture pushing on the alae and not the nasal spine that is responsible for the nasal tip changes. Failure to recontour the pyriform rim sufficiently may lead to alar base flaring, nasal tip elevation and even asymmetry of the nose.16 Recontouring of the pyriform rims is necessary to allow the alar bases to sit within the pyriform rims and so resist nasal widening.16
The alar base cinch suture
The alar base cinch suture (Figure 4) was initially described by Millard in cleft lip patients.17 It was later described by Collins and Epker in non-cleft patients18 and modified by others.19,20 It is a surgical technique employed to minimize widening of the alar base. This is achieved by placing a non-resorbable suture bilaterally through the periosteum in the alar region, thereby anchoring the fibro-areolar tissues and the transverse nasalis muscle. The cinch suture is indicated in osteotomies involving anterior or superior repositioning of the maxilla, where the alar base width is normal pre-surgery. The effectiveness of the alar base suture has been reported in many studies.18,19,21 Collins and Epker18 as well as others19,21 observed continued flaring despite interalar base sutures. The classic cinch technique was subsequently modified, demonstrating improved results.22 In addition to minimizing alar base widening, the alar base suture has the secondary effect of increasing the NLA, which results from the suture crossing the midline and compressing the tissues in this region. This effect could be reduced by suturing the alar base to the bony rim of the pyriform aperture.20 Nasal tip projection is reported to be unaffected by the cinch suture.20 The alar base suture is not indicated in all cases. The alar base width is often narrow in vertical maxillary excess cases, and the subsequent widening that results following surgery helps produce a more harmonious facial balance.
Figure 4. Cinch suture.
The V-Y closure
The V-Y closure (Figure 5) is performed to minimize alar base widening. Using an absorbable suture, the superior aspect of the vestibular incision is pulled anteriorly, in a horizontal mattress fashion, by engaging smaller fragments of the superior margin and larger fragments of the inferior margin. The lip is then retracted and the superior tissue is advanced the desired amount and closed on both sides, with approximately 0.5−1 mm of excess tissue persisting in the midline. The excess tissue is subsequently approximated. The V-Y closure technique thereby restricts lateral retraction of the perioral muscles by suturing them to the superior aspect of the vestibular incision. Advancement of muscle, mucosa and periosteum occurs in union. This technique can be performed in conjunction with the cinch suture or alone. Whilst Rosen concluded that the results from V-Y closure are unpredictable,2 others have found the V-Y closure to be effective at minimizing alar base widening.15 The V-Y closure, however, has been reported to have little effect on vertical changes of the nasal tip.23
Figure 5. V-Y suture.
The subnasal modified Le Fort I osteotomy
The subspinal osteotomy is performed to reduce nasal tip change and produce a more acute NLA than seen in conventional Le Fort I osteotomies. With this technique, the cartilaginous septum, median nasal support, attachments of the footplates to the caudal aspect of the nasal septum and nasal spine are all left intact (Figure 6). It has been postulated that the Le Fort I subspinal osteotomy is more conservative to the perinasal muscular attachments than the traditional Le Fort I osteotomy. Both Becelli et al24 and Mommaerts et al25 in a preliminary study, observed superior results with this technique, protecting against both alar base widening and nasal tip upturning. In a subsequent study, however, Mommaerts et al demonstrated no difference in nasal tip elevation or nasal tip projection in matched groups undergoing maxillary advancement/impaction with and without subspinal osteotomy.16 It was concluded that recontouring of the pyriform aperture during surgery played a more important role in resisting nasal tip changes than the type of surgery performed.
Figure 6. Subspinal osteotomy.
Anterior Nasal Spine (ANS) resection
The precise contribution of the ANS to nasal tip projection is unknown. The ANS is often resected, either partially or completely, in individuals undergoing maxillary advancement or impaction surgery, with a prominent nasal spine or obtuse subnasale contour. The soft tissues attached to the base of the nose should not be disrupted during this procedure. It has been suggested that ANS resection has the favourable effect of reducing nasal tip rise and excess nostril show.1 However, ANS resection is not indicated in all cases. Nasal tip elevation is beneficial in patients undergoing inferior maxillary repositioning, or in those with pre-existing nasal tip droop undergoing maxillary advancement or impaction osteotomies. In addition, an ANS resection is contra-indicated in those with a retracted columella, irrespective of the maxillary surgical move.1 Careful case selection is therefore imperative prior to performing this procedure.
Conclusion
Nasal soft tissue morphology should be carefully considered at diagnosis and incorporated into treatment planning for patients undergoing a Le Fort I osteotomy. Patients should be informed of, and understand the aesthetic significance of, possible adverse nasal changes associated with this procedure. It is key that clinicians are aware of the risk factors to these adverse changes and the various techniques available to minimize deleterious outcomes.
