Late teething sign of autism

As a parent, you closely monitor your child’s development and growth. So if their teeth are late emerging, you may wonder if it signifies a problem. Some parents question if delayed teething could indicate autism spectrum disorder (ASD). While each child develops on their own timeline, research shows no direct link between late teething and autism.

That said, a study conducted at the Icahn School of Medicine at Mount Sinai introduced a novel approach to autism detection by analyzing baby teeth. Focusing on the metabolism of metals critical to early neurodevelopment, researchers discovered imbalances linked to autism spectrum disorder (ASD). Daily tooth layer formation acts as a record of chemical exposure, allowing laser testing to reveal altered zinc-copper cycles in children with autism.

The algorithm derived from this data achieved a remarkable 90% accuracy in distinguishing teeth from children with ASD. While not a direct diagnostic tool, the study’s findings pave the way for potential prenatal markers and early intervention strategies.

Late teething sign of autism

Defining Late Teething

First, what exactly constitutes “late” teething? According to the American Dental Association:

  • Most babies get their first tooth between 6 and 12 months.
  • Teeth typically continue erupting until age 3 when all 20 primary teeth have come in.
  • Late teething means no teeth by 12-14 months or the last few emerging after 24 months.

So while not as common, teething up to 6 months later than average is still considered normal variation.

Autism Characteristics

Autism spectrum disorder (ASD) refers to a range of neurodevelopmental conditions characterized by:

  • Social skills deficits
  • Communication difficulties
  • Repetitive behaviors
  • Sensory sensitivity

Signs of autism usually emerge between 12 and 24 months as social and language delays become more apparent. Autism denotes challenges in development, not intellectual disability. Early intervention can greatly improve outcomes.

Teething-Autism Relationship

a. Negative Findings

Parents notice teething and autism developmental stages overlapping in the first few years. But research has not found evidence that late teething causes or predicts autism.

A 2014 study in the Journal of the American Dental Association compared teething timelines for 196 neurotypical infants versus 82 infants later diagnosed with ASD. The study found no statistically significant differences in teething patterns between the groups.

This indicates teething timelines vary normally across all infants, not just those who develop autism. Genetics and other biological factors, not teething, are understood to cause ASD.

However, some speculate missing dental mercury amalgam fillings due to late teething may play a small role in autism risk. But no research proves mercury exposure from fillings causes autism. Modern composites don’t contain mercury either.

Autism is complex, involving brain structure and genetics. While more study on infant development is needed, current evidence doesn’t show delayed teething signals autism later on.

b. Positive Findings

Scientists examining how children metabolize metals, which are critical to neurodevelopment in early life, found that an imbalance in this process could be linked with autism spectrum disorder (ASD).

As children grow, a new layer of tooth is formed each day which shows the chemicals circulating in their body. In a nationwide study of baby teeth from 200 twins in Sweden, the researchers used lasers to test whether zinc-copper cycles were different in those with autism.

The results indicated that zinc-copper cycles in fetuses and children with autism were affected in a number of ways when compared with children without the condition.

They were able to reproduce the same results in studies of children in the U.S and the U.K.

Using this data, the team were able to create an algorithm that was 90% accurate in distinguishing between teeth from children with autism and those without.

Signs of Possible Autism

One of the big challenges in autism is developing a biochemical assay for identifying early in life those who are at risk of autism spectrum disorder later in childhood. At present, the commonly used diagnostic tools are based on clinical assessments and observations, which cannot be used at birth. And the diagnosis is clinically evident by the time that children start to lose their baby teeth.

While teething variation is normal, experts suggest looking for other subtle early signs of autism around 12 months:

  • Not babbling or pointing
  • Poor eye contact
  • Lack of response to name
  • Not smiling socially
  • Poor imitation skills
  • Persistent sensory seeking behaviors

Discuss these red flags with your pediatrician. Early intervention can greatly help development.

Supporting Your Late Teether

If your baby’s teeth are late but they are meeting other milestones, focus on providing teething relief and nutrition. See your pediatric dentist regularly to monitor dental progress. Rely on developmental experts rather than worrying about worst case scenarios.

Autism is complex and not identified by teething timing. If your late teether shows developmental delays, pursue evaluation and appropriate therapies. But avoid assuming teething variation alone equates to problems.

Take comfort that most late teethers catch up without consequence. With love and support, they continue to reach milestones in their own time.



  • Editorial team

    A team comprising oral health care professionals, researchers, and professional Writers, striving to impart you with the knowledge to improve your oral health, and that of your loved ones. 

  • Lilly

    Lilly, aka, Liza Lee, is a passionate community oral health officer and our lead writer. She's not only well-versed in performing a multitude of dental procedures, including preventive, restorative, and cosmetic, but also an avid writer. Driven by the significant oral health burden all around her, Lilly strives to build capacity and promote oral health. She envisions making a lasting impact by advancing research, prevention, and promotion efforts to alleviate oral health disparities. Please share your views and opinions on my posts.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top