Variability of oral-nasal balance characteristics in children with cleft lip and palate over time.

The accurate assessment of oral-nasal balance disorders in children with cleft lip and palate is a perennial problem in Speech-Language Pathology. Nasalance scores obtained with a nasometer can contribute to the diagnosis of oral-nasal balance disorders. The present study investigated how consistent such classifications are over time. Twenty-seven children with cleft lip and palate were recorded six times with a nasometer headset over the course of an orthodontic palatal expansion treatment. Nasalance scores were considered hypernasal when they were higher than 30% for a non-nasal sentence and hyponasal when they were below 50% for a nasal sentence. Based on the nasalance scores, normal nasalance was found in 42.6%, hyponasality in 34.0%, and hypernasality in 23.5% of 162 sound recordings. Only 7/ 27 (25.9%) of the children had the same nasalance-based classification over the six sessions. The others demonstrated variability that straddled two adjacent categories in 15/ 27 (55.6%) of cases and all three categories in 5/ 27 (18.5%) of cases. While clinicians may wish to assign a permanent oral-nasal balance classification to their patients, the study demonstrated that a subset may show unexpected variability over time. More research is needed to establish whether it would be beneficial in some cases to explore this potential for variability before long-term decisions about a patient's clinical management are made.