Confirming Nasal Airway Patency Observed on Panoramic and Posterior-Anterior Cephalometric Radiographs Using an Acoustic Rhinometer and ImageJ

Tufts University–Pediatric Dentistry

Authors: Jorge Landa, Alfred Rich, and Matthew Finkelman

Rationale: “Currently, dentists and orthodontists rely on subjective visual assessment of the airway extraorally, and by analyzing panoramic radiographs and noting apparent structural and anatomical abnormalities. Once again this current modality of analysis lacks a standardized norm and is subject to human error and thus imprecise. While some recent studies have attempted to bridge this knowledge gap, there is a need to investigate a comprehensive diagnostic tool that is non-invasive and can be coupled with standard dental imaging to formulate the best objective assessment possible. This is where we believe the use of the Acoustic Rhinometer by dentists and orthodontists can serve the greatest benefit to their patients.

“The use of acoustic rhinometry as an adjunct to radiographic examination will provide an objective and non-invasive method to assess the nasal volumetric dimensions. The technique is easy to understand and is not imposing on practitioners or patients. The cross-sectional area and volume of the nasal cavity can be assessed using the acoustic reflections from sound waves emitted from the rhinometer. The computer generated graph of nasal area versus nasal cavity distance plots waves which correspond to particular anatomical landmarks of the nasal cavity. Prior confirmation of the accuracy of these anatomical markers has been confirmed through CT and MRI investigations. The prior studies have provided us with adult norms that can be used for comparison with the readings gathered from the acoustic rhinometer, and a determination can be made as to the patency of the airway. Currently we possess little data on child or adolescent norms, and for this reason continued studies involving the acoustic rhinometer in this age group are indicated.

“It is proposed that using the acoustic rhinometer readings, cephalometric analysis, and ImageJ calculations will yield a correlation between standard dental imaging and examination and airway patency assessment. The need for a definitive and non-invasive evaluation tool conventional to the dental exam can be fulfilled after establishing a relationship between the cephalometric radiographs, panoramic radiographs, and acoustic rhinometer. This comprehensive evaluation method will be instrumental in making multidisciplinary intervention to correct craniofacial abnormalities and nasal airway obstruction.”

Conclusion: “While the acoustic rhinometer is not readily available at most dentists’ office, the technology is becoming more affordable, and the clinician can acquire the skills and technique necessary to operate the equipment through workshops and practice. Furthermore, the ImageJ program is available for free download from the NIH, and scanned or digital radiographic images can easily be traced in the dental setting. The relationship established between the rhinometer and ImageJ in this project confirms the validity of either or both methods in identifying nasal airway obstruction. By noting the nasal health status of the patient in detail before and throughout treatment, the dentist or orthodontist can properly account for the role of the nasal airway in diagnosis, treatment planning, and outcomes assessments, and make a proper referral to the otolaryngologist for treatment if need be.”