Parents closely track developmental milestones, and any variation from the expected timeline can cause concern. Children develop at different rates across physical growth, motor skills, and neurological functions. Understanding the normal range of this timing is helpful when addressing concerns about a child’s overall development. This article addresses a common concern: the timing of tooth eruption and its relationship to neurological development.
Establishing Normal Teething Timelines
The eruption of a child’s first tooth is a physical milestone that follows a very wide range of normal timing. While the first tooth, typically a lower front incisor, generally appears around six months of age, this can happen as early as three months or as late as 12 months, and still be considered within the typical range. Most children have their full set of 20 primary teeth by the time they are three years old.
The timing of teething is primarily a physical and skeletal developmental marker, not a neurological one. Delayed tooth eruption, or “late teething,” is defined as having no teeth by the age of 12 to 15 months. Genetics often play a large role; if a parent or close relative experienced late teething, the child may follow a similar pattern. Pediatric dentists often recommend a check-up if no teeth have emerged by 18 months.
Other common, non-worrisome causes of delayed eruption include premature birth or low birth weight, as these children often reach all milestones slightly later. Nutritional deficiencies, particularly a lack of Vitamin D or calcium, can also affect the rate of tooth development. In the vast majority of cases, late teething is simply a variation of normal development and does not indicate any underlying health or neurological issue.
The Scientific Consensus on Teething and Autism
Late teething is not a recognized or reliable diagnostic sign for Autism Spectrum Disorder (ASD). The diagnosis of ASD relies exclusively on observed behavioral and communication criteria, not on the timing of physical milestones like tooth eruption. Late teething, on its own, is considered a common developmental variation with no established link to neurological conditions.
Some researchers have explored connections between dental development and ASD, often focusing on the composition of baby teeth rather than the eruption timing itself. Studies have used the layers of baby teeth to analyze prenatal and early-life exposure to certain nutrients and toxic elements, finding differences in zinc and copper metabolism in children with ASD. One rare genetic mutation associated with ASD, called ADNP, is linked to a highly accelerated eruption of teeth, not a delay.
While late teething may occasionally coincide with other developmental delays, it is not considered a specific marker for autism. The focus of ASD research and diagnosis remains firmly on differences in social interaction, communication, and the presence of restricted or repetitive behaviors. The presence of late teething should be viewed as a dental timing issue unless it is accompanied by concerning differences in communication or social development.
Recognized Early Indicators of Autism Spectrum Disorder
It is important to understand the actual indicators that healthcare professionals use for screening ASD. ASD is a neurodevelopmental condition characterized by challenges in two core areas: social communication and interaction, and restricted or repetitive behaviors and interests. These signs can appear in children as young as 12 to 24 months.
Social Communication and Interaction
Early indicators in social communication include a limited or absent response to their name by 9 to 12 months of age. A lack of reciprocal social smiling or shared enjoyment with a caregiver by nine months is also a concern. By 12 to 18 months, children with ASD may use few or no gestures, such as pointing to show interest or waving goodbye.
Differences in social interaction may manifest as reduced eye contact or a lack of interest in other children. A child may also have difficulty engaging in simple interactive games like peekaboo by 12 months. Delayed language development, such as not saying single words by 16 months, is another common indicator.
Restricted and Repetitive Behaviors
The second core area involves restricted and repetitive behaviors, which can be observed early in life. This may include repetitive body movements like hand flapping, rocking, or spinning, sometimes referred to as “stimming.” Other signs include an intense focus on parts of objects or an unusual and persistent need for routine.
When to Seek Professional Guidance
Parents should consult a healthcare professional if they have any concerns about their child’s development, regardless of the timing of teething. For dental development specifically, it is advisable to see a pediatric dentist if a child has not erupted any teeth by 18 months of age. This consultation can help rule out rare underlying conditions or nutritional deficiencies that might be the cause of the delay.
If concerns center on developmental milestones, particularly those related to communication and social interaction, parents should speak with their pediatrician immediately. This action is warranted if a child is missing multiple developmental milestones, such as delays in language or motor skills, especially when combined with late teething. The pediatrician can then initiate developmental screening and refer the family to Early Intervention programs, which are designed to provide support for children with developmental differences.