Effect of single impression technique versus split cast impression technique on speech outcome in maxillary obturators - A randomized clinical trial

Background: The main problem in patients who undergone maxillectomy is the impairment of speech particularly those with hard and soft palatal resection. The defect of the soft palate results in velopharyngeal insufficiency. Aim: This study was conducted to evaluate the effect of using single impression technique versus split cast impression technique for maxillary obturator construction on the speech outcome using spectrogram, nasometer, and patient satisfaction questionnaire. Materials and Methods: Six patients with unilateral hard and soft palatal defects were selected and randomly distributed into two equal groups: For group I, the patients received first definitive skeleton obturator constructed according to the single impression technique and speech outcome, and patient satisfaction outcomes were recorded. The prosthesis was then taken off from the patient for another 1 week, the obturator bulb was modified with split cast impression technique, and the same records were reported. However, in the second group, the steps were reversed that is to say split cast impression technique started first then changed into single impression technique. Results: A statistically significant increase in speech outcome and patient satisfaction outcomes was observed with the use of the definitive obturator constructed with the split cast impression technique as compared to the single impression technique. Conclusion: The use of the split cast impression technique significantly improved the speech and patient satisfaction outcomes. Clinical Significance: Split cast impression technique for maxillary obturator construction improved an intimate contact between the obturator bulb with the posterior and lateral pharyngeal walls, and hence, improved the speech and patient satisfaction outcomes.