Reduced lip seal strength and missing teeth are associated with poorer masticatory performance in young adults with intellectual disabilities: a cross-sectional analytical study.
Chewing problems in adults with ID are driven more by weak lip seal and missing teeth than by ID itself—screen and treat these factors.
01Research in Context
What this study did
Vassos et al. (2023) compared how well young adults with intellectual disabilities chew food. They also tested two matched groups: adults the same age and adults twenty years older. A dentist counted missing teeth and measured lip-seal strength with a simple bulb tool. Everyone then chewed a standardized gummy tablet so the team could score masticatory performance.
What they found
Adults with ID chewed markedly worse than both control groups. Weak lip seal and missing teeth predicted the poor scores; the level of intellectual disability did not. In plain words, physical oral factors, not cognitive level, drove the chewing trouble.
How this fits with other research
Wormald et al. (2019) showed that adults with ID lose all their teeth three to four times faster than peers. Vassos et al. (2023) now adds that each lost tooth further weakens chewing.
Harkins et al. (2023) reviewed behavioral chewing lessons for children and found they work. Vassos et al. (2023) shifts the spotlight to adults and says: fix the dental hardware first, then teach the skill.
Capio et al. (2013) used simple prompts to raise chews-per-bite in two kids. The new study implies adults may need dentures or seal-strength exercises before prompting can help.
Why it matters
If your client pockets food or chokes, do not assume it is just a behavioral deficit. Screen lip seal with a cheap mouth-pressure gauge and ask the dentist about missing molars. A one-minute check can tell you whether to start swallow-safe strategies, refer for prosthetics, or both. Treat the mouth first, then shape the chew.
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02At a glance
03Original abstract
BACKGROUND: Alterations in oral health have a negative impact on the quality of life of persons with intellectual disabilities (PwIDs). Chewing is a process that influences and determines optimal oral health. However, little is known about how intellectual disability (ID) affects masticatory performance. This study aimed to analyse the differences in masticatory performance between young adults with IDs, young adults without IDs and older adults without IDs. METHODS: A cross-sectional analytical design was used. The masticatory performance was evaluated with a chewing gum validated instrument. In addition, the labial and tongue strength was assessed with the Iowa Oral Performance Instrument. We compared the masticatory performance between groups using one-way analysis of covariance. Body mass index, muscle mass, missing teeth, lip strength and tongue strength were included as separate covariates. A multivariate regression analysis was performed to identify which independent variables could explain masticatory performance in each group. RESULTS: Thirty-two PwIDs, 31 young adults without IDs and 32 older adults without IDs were recruited. PwIDs showed poorer masticatory performance compared with older adults (mean difference: -3.06, 95% confidence interval: -3.87 to -2.26) and healthy controls (mean difference: -2.38, 95% confidence interval: -3.19 to -1.57). The analysis of covariance showed significant difference between groups in the masticatory performance (F = 47.35, P < 0.001, ηp 2 = 0.507). Missing teeth (P < 0.001), right lip strength (P = 0.025) and tongue strength (P = 0.007) as covariables showed a significant interaction with the model. In the PwID group, lip strength and lack of teeth explained 58% of the variance in masticatory performance (R2 = 0.580, standard error = 1.12, P < 0.001). CONCLUSIONS: Persons with intellectual disabilities have a poorer masticatory performance than adults without IDs. Our findings indicate that the primary determinants of optimal masticatory function in PwIDs are the strength of the lip seal and the number of missing teeth.
Journal of intellectual disability research : JIDR, 2023 · doi:10.1111/jir.13032