Alternate technique for fabrication of a custom impression tray for definitive obturator construction.

Prosthodontic rehabilitation for an acquired maxillary defect begins immediately at the time of surgical resection. Abrupt alteration of physiologic functions such as speech, mastication, deglutition, and salivary control associated with ablative surgery requires timely prosthetic intervention. Prosthetic rehabilitation begins with a surgical obturator, which is inserted at the time of surgery to help retain the packing, prevent oral contamination of the surgical wound and skin graft, and to allow the patient to speak and swallow during the initial postoperative period. The surgical obturator is commonly converted into an interim obturator with the addition of resilient lining material to adapt to the defect. The interim prosthesis is periodically readapted and relined to capture the dimensional change that accompanies tissue healing within the defect. This process improves patient function and comfort. Definitive obturation is initiated approximately 3 to 4 months after surgery when healing is complete. The impression for a definitive obturator prosthesis should include the skin-graft mucosal junction, lateral aspect of the orbital floor, and the dynamic physiology of the velopharyngeal mechanism during speech and swallowing. The obturator bulb must also be contoured to prevent obstruction of nasal breathing and to maintain nasal resonance during speech. A custom tray is required for the definitive impression procedure due to the extensive nature of the surgical defect. Proper extension and adequate contour of the tray is essential for the success of the impression procedure. The conventional method of custom tray fabrication involves eliminating undercuts on the diagnostic casts for completely edentulous patients, or on the final casts for partially dentate patients, to prevent fracture of the cast during tray removal. Although this procedure preserves the cast, it does introduce errors in the fit of the tray, which may require careful, time-consuming readaptation to the defect. The interim obturator is a tested and proven replica of the intraoral defect. It has adequate extension into the