Dental arch form and its relationship to speech in unilateral cleft lip and palate subjects; a pilot study

Abstract

Speech therapists and dentists have looked at the influence of dental arch form on speech both in non-cleft subjects and in subjects with clefts of lip and palate. Some authors (Fymbo, 1936; Guay et al., 1978) have implicated inter-canine and intermolar width in speech difficulties, whereas Laine (1987) feels that the risk factors for incorrect sound production appear to be occlusal anomalies. Particular speech sounds consistently singled out as most at risk are is/ and 121. The present study was designed to examine and clarify the relationship between occlusion, maxillary arch form and speech articulation in cleft lip and palate subjects. Subjects comprised 3 1 children aged 5-6 years, 17 with clefts of lip and palate and 14 with clefts of soft palate only. All children were consecutive cases operated on by the same surgeon-lip repair at 3 months and palate repair at 6 months. Speech analysis A phonetic transcription was used to describe each child’s speech. Number and type of articulatory error were noted. Dental analysis Study model casts were measured using a reflex microscope. The features examined were cleft gap, deciduous inter-canine width and the deciduous inter-second molar width, measured in millimetres. Results The soft palate group showed a significantly lower number of speech errors. The incidence of palatalisation and lateralisation of speech sounds were significantly higher in the UCLP group. It suggested that the dento-alveolar components of maxillary arch form had imposed a significant effect upon speech.