Spectral analysis of /s/ sound with changing angulation of the maxillary central incisors.

Purpose: The aim of the study was to measure the influence of the maxillary central incisors free from adaptation phenomena using spectral analysis.

Materials And Methods: The maxillary dentures of 18 subjects were duplicated. The central incisors were fixed in a pivoting appliance so that their position could be changed from labial to palatal direction.