Influence of the major connector in a maxillary denture on phonetic function

The purpose of this study was to investigate the influence of the major connector in a maxillary denture. Eight patients with sound dentition were recruited in this study. The experimental connectors were fabricated with Co–Cr. Two positional designs were used: one was the middle type (M), and the other was the anterior and posterior type (AP). The six sounds, /shi/, /hi/, /chi/, /ki/, /ri/, and /ni/, were chosen as the test sounds. Using a speech recognition system, the intelligibility, change and duration of the test sounds were evaluated under three conditions: without connector (WO·C), with the M-type connector (W·M), and with the AP-type connector (W·AP). The intelligibility in WO·C and W·AP was 86.9±17.4% and 57.1±30.1% for /shi/, 79.2±19.7% and 70.5±27.0% for /hi/, 74.7±14.6% and 43.6±24.3% for /chi/, 54.4±16.5% and 23.2±17.8% for /ki/, 85.2±15.9% and 55.1±30.6% for /ri/, and 76.9±26.9% and 50.2±31.3% for /ni/. Significant differences were recognized between WO·C and W·AP in /shi/, /chi/, /ki/ and /ri/(P