Prosthetic rehabilitation of acquired mandibular defects by neutral zone concept

Objectives: The objective of this case report is to use neutral zone concept in a patient with acquired mandibular defect for the fabrication of prosthesis with polish surfaces that harness muscular forces for denture stability.
Methods: A patient with left side marginal mandibular resection defect following radiotherapy (squamous cell carcinoma of the jaw) came to the prosthodontic department of FMH College of Medicine and Dentistry for prosthesis. The surgery resulted in loss of teeth and alveolar bone support from the right lower quadrant to left complete lower quadrant (tooth no 25 to 32). An alginate impression supported by thermoplastic compound in the defect area was taken for the study model. Following surveying of the study cast and mouth preparations done accordingly, a framework was cast with nail head projection occlusally in the defect area to support the molding material. (After framework trial, phonetic and swallowing neutral zone was recorded with a thermoplastic impression compound followed by incremental additions of tissue conditioner). Then putty indexes were made and the tooth setup and polished surfaces were finished in wax according to the indices.
Results: The prosthesis was quite stable at the insertion appointment and restored the facial defects in a way that was esthetically pleasing and acceptable to the patient
Conclusions: This case report depicts a clinical scenario where the loss of alveolar ridge and associated soft tissues is managed prosthodontically utilizing the neutral zone concept. The merit of neutral zone technique remains paramount when socioeconomic and other factors such as post surgical morbidity coincide. By utilizing phonetic and swallowing neutral zone technique, complex prosthesis can be satisfactorily made with improved stability and patient satisfaction.