Comparison of speech intelligibility, articulation and oromyofunctional behaviour in subjects with single-tooth implants, fixed implant prosthetics or conventional removable prostheses.

The purpose of this controlled study was to determine the impact of a single-tooth implant, fixed implant prosthesis and completely removable dental prosthesis on intelligibility, articulation and oromyofunctional behaviour. Additionally, the self-perceived overall satisfaction of the dental replacements and the effect on speech was questioned. Objective (acoustic analysis) as well as subjective assessment techniques (perceptual evaluation) were used. The satisfaction of single-tooth implant group was very high (100%) followed by a satisfaction of 87% for the fixed implant prosthesis group and 68% for the removable prosthesis group. The results of the phonetic analyses revealed a normal intelligibility and oromyofunctional behaviour in the three groups of dental replacements. Only one type of articulation disorders was observed in the single-tooth implant group, followed by three types of disorders in the removable prosthesis group and six types of disorders in the fixed implant prosthesis group. In this last group, not only 87% of the subjects showed distortions of one or more consonants but also most consonants of the Dutch language were disturbed in comparison with the single-tooth implant and removable prosthesis users. Special attention must be paid to the fricative /s/ because in more than 50% of all groups, this sound is disturbed.