Associations between lateral cephalometric dimensions and misarticulations of Finnish dental consonants in cleft lip/palate children

The purpose of this study was to examine the associations between lateral cephalometric variables and the misarticulation of /r/, /s/ and /l/ sound in cleft lip/palate children. The subjects were 134 Finnish-speaking 6-year-old boys with isolated cleft palate (CP, n = 33), unilateral (n = 44), bilateral (BCLP, n = 19) cleft lip and cleft lip/alveolus (n = 38); /r/, /s/ and /l/ distortions were obtained from original hospital records which were based on perceptual speech follow-ups performed by experienced speech pathologists. Cephalometric measurement points were determined from standardized lateral roentgen cephalograms and traced twice by a computer-connected digitizer. The data were entered into a microcomputer and analysed by NCSS 6.0 for Windows using appropriate tests. The results revealed new significant associations between cephalometric measurements and misarticulations, especially that of the /r/ sound in CP and BCLP groups. Children with /r/ distortion had upward rotation of the mandible, maxillary protrusion and a higher position of the hyoid bone in the CP group. In the BLCP group, on the contrary, the mandible had downward rotation, mandibular retrusion and narrower nasopharyngeal port. The /s/ and /l/ sounds were less clearly associated with craniofacial morphology. The anteroposterior relationship of the maxilla and the mandible did not have any association with dentoalveolar misarticulations, instead, the systematic vertical, particularly posterior relationship of the jaws seems to be associated with /r/ sound production in CP and BCLP boys.