Study Examines Tooth Decay Rates in Children and Youth with Cerebral Palsy

Motor Impairment and Dental Caries in Cerebral Palsy

Cerebral palsy is a physical condition that affects movement and posture. To classify how severely motor function is impacted, healthcare professionals use a tool called the Gross Motor Function Classification System (GMFCS). Because physical motor impairments can make daily oral hygiene tasks more challenging, researchers have investigated whether individuals with higher degrees of motor impairment face a greater risk of oral health problems, such as dental caries (tooth decay).

To answer this question, a nationwide longitudinal study in Aotearoa New Zealand evaluated dental health records for children and young people with cerebral palsy. The study aimed to assess overall oral health outcomes and determine whether motor impairment levels, as measured by the GMFCS, were directly linked to an increase in tooth decay at 5 and 12 years of age.

Linking Register and Community Health Records

The research team conducted a longitudinal analysis by linking clinical records from the New Zealand Cerebral Palsy Register (NZCPR) with national Community Oral Health Service data collected between 2008 and 2023. The total study group included 1,220 individuals with cerebral palsy aged 21 years or younger.

To evaluate dental health, researchers looked at the dmft and DMFT indices. The lowercase “dmft” index measures the number of decayed, missing, and filled primary (baby) teeth, while the uppercase “DMFT” index measures the same factors in permanent (adult) teeth. Out of the 1,220 total participants in the registry, 981 individuals (80 percent) had at least one recorded dmft or DMFT entry in the dental service database.

Key Findings on Caries Rates and Motor Impairment

When examining overall tooth decay rates, the researchers found that a clear majority of the evaluated children were free of decay at both key age milestones:

• At age 5 years, 306 out of 429 children with recorded data (71 percent) were completely caries-free in their primary teeth.
• At age 12 years, 167 out of 230 children with recorded data (73 percent) were completely caries-free in their permanent teeth.

When the researchers analyzed whether these caries-free rates differed according to the severity of physical motor impairment, they found no variation across GMFCS levels. In other words, having a higher level of motor impairment was not associated with poorer oral health outcomes or increased dental decay in this population.

Ethnic Disparities in Dental Health

While physical motor impairment levels did not correlate with tooth decay, the study identified significant disparities when accounting for demographic background. After adjusting for potential confounding factors, dental decay was found to be notably more common among specific ethnic groups:

• At age 5 years, children of New Zealand Māori ethnicity had 3.60 times higher odds of dental decay compared to European children. Pacific Peoples children had 5.11 times higher odds, and Asian children had 3.06 times higher odds compared to European children.
• At age 12 years, dental decay remained significantly more prevalent among New Zealand Māori children, who had 3.18 times higher odds of decay compared to European children.

Study Limitations

When interpreting these results, several study characteristics and limitations must be considered:

• The study analyzed records specifically from Aotearoa New Zealand, meaning the findings reflect the local population and public oral healthcare system, which may not directly apply to populations in other countries.
• The evaluation relied on existing registry and service database records. Not all 1,220 participants had recorded assessments at both 5 years (429 participants assessed) and 12 years (230 participants assessed).
• As an observational study based on linked health data, the findings identify statistical associations rather than proving a direct cause-and-effect relationship for the observed ethnic disparities.

What This Means for Patients

This nationwide research shows that among children and youth with cerebral palsy, higher levels of physical motor impairment do not automatically correspond to a higher burden of tooth decay. A majority of the children evaluated at ages 5 and 12 were free of dental caries. However, the presence of significant ethnic disparities highlights that broader demographic factors influence oral health outcomes, emphasizing the importance of culturally responsive oral health interventions for all children.