Association of Neutral Zone Position with Age, Gender, and Period of Edentulism.

PURPOSE: The changing dynamics of an aging mouth influence the position of the neutral zone (NZ). While the advantage of the NZ concept in complete denture treatment is quite established, what is not clearly understood is its position in relation to the crest of the residual ridge due to conflicting reports from previous studies. The purpose of this study was to investigate the distance and direction of NZ position in relation to crest of the residual ridge in edentulous patients and its association with age, gender, and period of edentulism. MATERIALS AND METHODS: A cross-sectional study was conducted in 133 patients (70 males, 63 females) with a mean age of 58.81 +/- 11.78 years. NZ recording was done using admix material by following standard procedures. Two metallic wires were adapted, one on the ridge and another on the center of the occlusal rims, and standardized digital radiographs were made. The position of NZ in relation to the crest of the residual ridge was recorded by noting the direction and measuring the distance between the adapted wires digitally at five locations (right molar, right premolar, incisor, left molar, left premolar regions). RESULTS: Age, gender, and period of edentulism had no significant association with the position of NZ. No specific trend was observed in the in NZ position with a non-significant correlation. CONCLUSIONS: Distance and the direction of neutral zone position in relation to crest of the residual ridge in edentulous patients bear no significant relationship with factors such as age, gender, and period of edentulism.