Salivary alpha amylase and cortisol levels in children with global developmental delay and their relation with the expectation of dental care and behavior during the intervention.
Kids with GDD show a silent alarm—high alpha-amylase but normal cortisol—before dental work, so treat the visible anxiety even when lab numbers look fine.
01Research in Context
What this study did
The team collected spit from children with global developmental delay before and after a dentist visit.
They tested two stress markers: salivary alpha-amylase (the fight-or-flight enzyme) and cortisol (the stress hormone).
No control group, just the same kids compared to themselves.
What they found
Alpha-amylase shot up before the drill, especially in kids who later fought or cried.
Cortisol stayed flat, even in the most anxious children.
The body was yelling “danger,” but the classic stress hormone stayed quiet.
How this fits with other research
Gayle et al. (2023) later showed you can calm that same fight-or-flight surge by pairing tiny dental steps with praise and breaks.
Taylor et al. (2018) saw the opposite cortisol pattern: adults with autism did get a cortisol rise before social stress.
The difference is age and diagnosis—grown-ups with autism, not kids with GDD.
Duerden et al. (2012) also found high cortisol in autistic children, but only after an actual blood stick, not before a dental look.
Together the papers say: check alpha-amylase for anticipatory dread; cortisol may stay mute until the poke really happens.
Why it matters
You can spot dental dread before the drill spins—watch for wide eyes, stiff muscles, or offer a quick spit test if medical staff agree.
Start graduated exposure sooner, reward every tiny step, and keep visits short.
Less surprise, less sympathetic fire, fewer canceled appointments and emergency sedations.
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02At a glance
03Original abstract
The purpose of this study was to analyze the alpha-amylase (sAA) and cortisol levels in children with Global developmental delay (GDD) before and after dental treatment and its association with the children's behavior during treatment. The morning salivary cortisol levels and activity of sAA of 33 children with GDD were evaluated before and after dental treatment and were compared to 19 healthy children. The behavior of children with GDD during dental care was assessed by the Frankl scale. Children with GDD showed lower levels of sAA activity than healthy children, but this result was not significant. The salivary cortisol levels were similar between GDD and healthy children. GDD children showed increased levels of sAA (but not cortisol) prior to the dental treatment as compared to the post-treatment phase. GDD children who showed less favorable behavior during dental care had higher levels of sAA and salivary cortisol than GDD children with more favorable behavior, but only the sAA results were significant. In conclusion, GDD children show hyperactivity of the SNS-axis in anticipation of dental treatment which indicates the need for strategies to reduce their anxiety levels before and during dental care.
Research in developmental disabilities, 2012 · doi:10.1016/j.ridd.2011.10.015