RESEARCH ARTICLE PATENCY P This study aims to confirm the nasal airway patency observed in standard dental radiographs through analysis of the anterior nasal cross-sectional area and nasal volume with acoustic rhinometry. articipants for this study were chosen from the patient population under considera-tion for interceptive orthodontic treatment at Tufts University’s Pediatric Dentistry Clinic. A total of 55 Caucasian subjects of both sexes (males=28, females =27) and ranging from age 6-9 years (mean = 7.33) were enrolled. Utilizing the ImageJ program, the subjects’ panoramic and PA cephalometric radiographs were analyzed for radiolucent anterior nasal cross-sectional area. The subjects were then examined with the Eccovision Acoustic Rhinometer (Sleep Group Solutions), which measured anterior nasal cross-sectional area and nasal volume. The data were grouped together, and the areas and volume gathered from the radiographs and rhinome-ter were analyzed for any correla-tion. The statistical analysis was performed using the SPSS program. The data was further divided into right and left nasal side, and a Pear-son Correlation Matrix was created for 8 predictor variables (right and left panoramic area, right and left cephalometric area, right and left rhinometer area, and right and left rhinometer volume). Values in this correlation matrix ranged from 0.712 to 0.988; all were statistically signifi-cant at the 0.01 level (2-tailed test). A very strong correlation was found between the anterior nasal 18 July/August 2010 JAOS cross-sectional area calculated from the radiographs, and the anterior nasal cross-sectional area and nasal volume from the rhinometer. Introduction Dimensional changes of the oromaxillary structures in conjunc-tion with airway obstruction can best be explained by Moss’ functional matrix theory.1 The theory estab-lished that bones grow in response to the functions of the surrounding soft tissue and spaces. Subtelny2 also noted that maxillary intermolar width was narrower in mouth breathers and was associated with a higher prevalence of posterior cross-bite. Muscular pressure exerted during prolonged mouth breathing, resulting from nasal airway obstruc-tion, can affect occlusion and inter-arch relationship by altering growth patterns. Ozbek’s research also described an association between dental malocclusions, vertical growth, and obstruction of the upper airway.3 Throughout Marks’ studies, children with open mouth postures resulting from chronic allergies, demonstrated structural changes including high palatal arches and nasal septum deviance.4 The appearance of nasal septum deviations occurs in 60% of chil-dren and 80% of adults. They can occur from trauma to the nose at an early age or during complicated birth. The deviated septums are key contributors to upper airway obstruction and to malformations of the maxilla.2 In contrast to Moss, yet pertinent to oromaxillary devel-opment, Scott’s Nasal Septal Growth theory states that expansion of the cartilage in the nasal septum provides a source for the physical force that displaces the whole maxilla in an anterior and inferior direction.5 This sets up fields of tension in all the maxillary sutures. The bones then secondarily, but virtually simultaneously enlarge at their sutures in response to the tension created by the displacement process. If we apply Scott’s theory to a patient with a deviated septum, it is justified to correlate the septal deformity with subsequent maxil-lary malformation.6 Chronic obstruction of the nasal cavity is a prevalent problem that presents with multiple causes. The conditions that predispose patients to nasal obstruction can pose chal-lenges to the health care providers in charge of treating the patient. The most common causes of upper airway obstruction include nasal polyps, enlarged lymphoid tissue around Waldeyer’s ring, mucosal swelling, and abnormalities of the septum all commonly associated with hyperplastic adenoids or aller-gic rhinitis.7 Sassouni showed that children with allergic rhinitis had large lower face heights and steep mandibular angles leading to a char-NASAL AIRWAY By Jorge Landa, DMD, Alfred Rich, DMD, and Matthew Finkelman PhD
Journal of the American Orthodontic Society July-August 2010/Buyer's Guide: Page 18
