Speech and language characteristics in individuals with nonsyndromic submucous cleft palate—A systematic review

Background Up to 80% of individuals with unrepaired submucous cleft palate (SMCP) experience speech difficulties secondary to velopharyngeal insufficiency. Language delays are reported in the broader cleft lip and/or palate population, suggesting that individuals with SMCP may also be at risk. However, contemporary understanding of this population remains limited as there has been no systematic examination of the literature. This review aims to systematically review and document the speech and language characteristics of individuals with nonsyndromic SMCP and, in addition, to identify factors reported to impact speech and language outcomes. Method This review followed the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. Five databases were comprehensively searched using keywords and indexed headings. Included studies had to report speech or language outcomes of individuals with nonsyndromic SMCP. Risk of bias and methodological design quality were examined using tools from the Scottish Intercollegiate Guidelines Network. Relevant data were extracted for analysis. Results Eighteen studies met inclusion criteria, yielding 598 participants. Study results showed that individuals with unrepaired nonsyndromic SMCP may have speech difficulties secondary to velopharyngeal insufficiency including increased nasal resonance and palatalized or glottal articulation. Lower age at primary surgical repair led to better postsurgical speech outcomes. There is a paucity of literature outlining motor or phonological aspects of speech and receptive or expressive language abilities of this population. Conclusion Individuals with nonsyndromic SMCP present with speech difficulties similar to those experienced by individuals with overt cleft palate. Health care professionals should be aware of possible presenting symptoms and consider early SMCP diagnoses where appropriate. Further research is needed to specify the broader communication profile in this population.