10: Nasal Airway Considerations in the Evaluation and Treatment of Dentofacial Deformities

Nasal Airway Considerations in the Evaluation and Treatment of Dentofacial Deformities

The efficiency of care for the individual with a dentofacial deformity requires the collaborative management of any presenting upper airway obstruction, facial dysmorphology, and malocclusion or dental rehabilitative needs. At the time of orthognathic surgery, the surgeon has an opportunity to further contribute to the patient’s quality of life by seamlessly addressing any longstanding breathing and sinus drainage difficulties that coexist with the jaw deformity. Breathing difficulties may range from isolated symptomatic nasal airway obstruction to obstructive sleep apnea and should not be overlooked. The impact and frequency of the combined occurrence of nasal obstruction, sinus disease, and maxillary deformity have been recognized and discussed in established literature for well over 100 years:

“The nasal fossae are bounded by the maxillary bones and by bones attached to the maxillae; therefore deformities of maxillary bones are bound to influence the size, shape and patency of the nasal fossae. Nasal obstruction may be due directly to deformity or to lack of development of the maxillae. Any [intranasal] bony [obstructions] are removed [surgically] until ample breathing space is established. If nasal obstruction is due simply to lack of size of the nasal fossae and there are erupted [permanent] molar teeth [on each side], then the treatment consists of placing a jackscrew across the mouth from one upper molar to the other. As the screw is spread, the intermaxillary suture opens, the maxillae separate, and the nasal obstruction is relieved.”10

—VILRAY PAPIN BLAIR, AM, MD, FACS (1914)

Frequent Causes of Chronic Obstructive Nasal Breathing

Nasal septoplasty is a generic descriptor of the surgical correction of septal thickenings and deflections frequently carried out to improve nasal airflow and sinus drainage (Figs. 10-1 and 10-2).3,7,20,30,52,53,57,75,80,88,89,91,93,94 Enlarged inferior turbinates also commonly obstruct nasal breathing and interfere with sinus drainage (Fig. 10-3). Hypertrophic inferior turbinates that are only minimally responsive to medical treatment are best managed by partial (surgical) reduction.8,23,77 A tight nasal inlet or constricted pyriform apertures occur in conjunction with a narrow maxillary arch (Fig. 10-4).58,86,90,95 An elevated floor of the nose is a frequent finding in the presence of anterior vertical maxillary excess (i.e., long face growth pattern) (Fig. 10-5).63,81,112 A scarred nasal vestibule seen with a repaired cleft nasal malformation may be another cause of persistent nasal obstruction (Fig. 10-6). Nasal septal deformities, inferior turbinate enlargement, a tight nasal inlet, and an elevated nasal floor all commonly coexist with maxillary deformities (Figs. 10-7 and 10-8).1,1214 Favorable access to the nasal septum, the inferior turbinates, the pyriform apertures, and the nasal floor to correct these airway obstructions and deformities is possible through the Le Fort I down-fracture osteotomy that is commonly used in orthognathic surgery (Figs. 10-9, 10-10, and 10-11).8285

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Figure 10-4 A woman in her early 20s shown before and after orthognathic surgery for a long face growth pattern (see Fig. 21-5). Reconstruction also included segmental maxillary osteotomies with arch expansion. This approach also widens the nasal cavity to decrease intranasal airway resistance and improve breathing.

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Figure 10-5 A typical teenager with a long face growth pattern demonstrates physical findings that are consistent with a lifelong history of obstructed nasal breathing (see Fig. 7-2). These findings include septal deviations, inferior turbinate hypertrophy, a narrow (tight) nasal aperture, and an elevated nasal floor.

Maxillofacial literature has traditionally addressed aspects of nasal obstruction, nasal anatomy, and sinus drainage in the patient who is undergoing orthognathic surgery, but often only in subjective and limited ways.8,18,24,27,32,33,36,38,55,56,71,73,74,76,103,104,107 Authors traditionally discuss the effects of Le Fort I osteotomies on nasal morphology (i.e., aesthetics) and occasionally recommend adjunctive soft-tissue techniques in the hopes of limiting suboptimal aesthetics (e.g., the alar cinch stitch).37 Little consideration is given to either baseline upper airway findings or how the maxillary surgery may affect long-term nasal breathing. Warren and colleagues discusses issues of nasal airway changes after Le Fort I osteotomy with maxillary impaction, advancement, and transverse widening.108 They used a pressure flow meter to assess nasal airway breathing before and after maxillary osteotomies.21,29 Turvey and colleagues recognized preexisting nasal obstruction in many of their orthognathic patients.103 They suggested methods of avoiding adverse effects on nasal airway resistance that may result from Le Fort I maxillary osteotomy procedures.104 Moses and coworkers reported about a series of patients who were treated for nasal obstruction and sinus drainage difficulties after Le Fort I maxillary procedures were carried out for long face growth patterns (e.g., vertical maxillary excess with anterior open bite).71 They concluded that Le Fort I impaction frequently aggravates preexisting nasal airway obstruction and sinus disease. Williams and colleagues examined the nasal airway function (breathing) in a consecutive series of subjects (n = 50) before and 5 months after undergoing (1) Le Fort I osteotomy with advancement and vertical lengthening (2) maxillary segmentation with transverse expansion (14 of 50 subjects, 28%); and (3) recontouring of the nasal floor and pyriform rims with a rotary drill. Despite these favorable nasal airway surgical maneuvers, when ignoring potential pathology of the septum (e.g., buckling and deviation) and the inferior turbinates (e.g., hypertrophy/enlargement), a full 20% of their study subjects experienced a worsening of their nasal airway function after surgery.113a

Unfortunately, in the individual with a dentofacial deformity, a methodic approach to the evaluation and management of chronic nasal airway obstruction at the time of orthognathic surgery is often not undertaken. We suggest that any upper airway obstructions be assessed by the orthognathic surgeon with the same vigor as the effects of the presenting jaw deformities on malocclusion are evaluated (Figs. 10-12 and 10-13).51,8385,87

The Effects of Respiratory Pattern and Jaw Posture on Maxillofacial Growth

The link between an open mouth or oral breathing pattern and maxillofacial growth has been documented in the literature.4,5,11,17,24,25,28,31,41,

Jan 1, 2015 | Posted by in Orthodontics | Comments Off on 10: Nasal Airway Considerations in the Evaluation and Treatment of Dentofacial Deformities
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