In 21 individuals, edentulous in the upper jaw, the speech function was evaluated. In an earlier study, registrations were made when the patients wore complete dentures in the upper jaw and 3-6 months after they had been treated with fixed prostheses on osseointegrated implants in the maxilla. These patients were re-examined after 3 years, as reported in this follow-up study. An expert group as well as a non-expert group participated in a perceptual analysis. Acoustic, audiological and cast analyses were performed. In addition, a questionnaire was filled in. The results indicated that, after initial phonetic problems, 94% of the individuals considered themselves free from speech problems at the 3-year follow-up. The patients' experience of the change of the s-sound corresponded well with the judgement of both the expert and the non-expert groups. Difficulties with pronouncing the s-sound were associated with decreased bite force, the number of occluding contacts, the frontal width of the fixed prosthesis and tenderness at palpation of the masticatory muscles. These oral functional factors will contribute to the s-sound production.