Toward a More Objective Approach to Obturator Reduction

Abstract

Subjectivity has prevailed in determining the location and the amount that each pharyngeal segment should be reduced in an obturator reduction program. In the past, reductions have been based on impressions derived from radiographic and intraoral observations, neither of which is very precise. To circumvent the overall problems of observing and adjusting pharyngeal segments in obturator patients, several different techniques have been used. Mathewson (4) incorporated barium powder when fabricating the pharyngeal segment of an obturator so that it would be more readily visible on radiograms. Mazaheri (5) wrapped tinfoil around the tailpiece of the obturator making it more observable on radiograms. Gul— likson (2) experimented with a strain gauge attached to the pharyngeal segment of the obturator to record points of lateral and posterior pharyn-geal wall contact. Mazaheri and Millard (6) altered the vertical positions of the pharyngeal segments and compared the different positions with differences in nasal resonance. Harkins at al. (3) suggested painting obtu-rators for display and educational purposes. Olin (7) discussed radi-ographic techniques to study obturator placement. Most of these methods do not and cannot incorporate the total three-dimensional concept of palatopharyngeal physiology; furthermore, they are generally quite arbitrary. Therefore, the need to devise a method for determining the specific points of contact between the lateral and posterior walls of the pharyngeal segment of the obturator is great. This paper suggests a comparatively simple method that has proven to be helpful. Method The initial phase of our obturator program includes fitting the patient with a speech prosthesis; that is, fabricating the appliance so that the patient speaks with normal or slightly hyponasal vocal resonance. After the first phase has been completed, the patient begins a regimen of obtura-tor reductions. The rationale and success of this program have been de— scribed earlier. (1, 8) The second phase of our program is systematic pharyngeal segment reduction among those obturator patients whose speech and vocal resonance can tolerate reductions. Because of the desire to alleviate arbitrariness and subjectivity in this second phase, the following method was devised. 157