A gap between a baby’s front teeth, known clinically as a diastema, is a frequent observation for parents and generally represents a normal stage of early dental development. This spacing is so common that it is often considered a sign of a healthy, growing mouth. This gap is usually a beneficial feature that helps prepare the mouth for the much larger set of permanent teeth that will eventually erupt.
The Normality of Spacing in Primary Teeth
The presence of spacing in the primary dentition is not only normal but is actually desirable for future oral health. Primary teeth are smaller than the permanent teeth that will replace them, and they are set within a jaw that is continually growing. This natural spacing provides the necessary room for the larger permanent teeth to emerge without becoming crowded later in childhood.
Dental professionals even have a term for specific, naturally occurring gaps: “primate spaces.” These are typically found between the upper lateral incisor and the canine, and between the lower canine and the first molar. The existence of these spaces is considered a good predictor of a well-aligned permanent dentition, suggesting sufficient space exists for the incoming teeth.
What Causes Gaps (Diastemas) in Baby Teeth
The primary cause of diastemas in young children is the natural size disparity between the teeth and the jawbone. The primary teeth are fixed in size, but the jaw grows rapidly, creating extra space between the teeth. This proportional mismatch ensures the developing jaw can house the permanent teeth, which are substantially wider than their predecessors.
Hereditary factors also play a significant role in determining a child’s dental spacing. If a child inherits a large jaw size relative to their tooth size, gaps will naturally appear between the teeth. This genetic influence often explains why diastema may appear to run in families. In the vast majority of cases, these gaps are simply a reflection of normal, healthy skeletal growth and genetic makeup.
Monitoring and When to Seek Professional Guidance
While most gaps in baby teeth are developmental and harmless, certain factors can cause a persistent diastema that warrants a dental evaluation. One common anatomical cause is an oversized or low-lying maxillary labial frenum. The frenum is the small band of tissue connecting the inside of the upper lip to the gum tissue between the two upper front teeth.
If this band of tissue is thick or extends too far down the gumline, it can physically prevent the front teeth from coming together, maintaining the gap. Another element is prolonged and forceful oral habits, such as thumb-sucking, finger-sucking, or pacifier use past the toddler years. This constant pressure can push the front teeth forward and outward, creating or widening a gap. A dentist can determine if a gap is caused by a mechanical obstruction or a habit that needs to be addressed, though intervention for a prominent frenum is often delayed until the permanent teeth have erupted.
Gaps in Primary Teeth vs. Permanent Teeth
The transition from primary to permanent teeth is a dynamic period where gaps often reappear or change size. The physiological gap that occurs between the permanent front teeth during this transition is often referred to as the “ugly duckling stage.” This temporary spacing occurs as the erupting permanent canines apply pressure to the roots of the incisors.
This pressure causes the crowns of the central incisors to flare outward, creating a gap, but it is considered a normal, self-correcting part of development. As the canines fully erupt, their movement pushes the incisor crowns back together, which typically closes the midline diastema. If a midline gap is less than two millimeters wide, spontaneous closure is highly likely. If a substantial gap persists after the permanent canines have fully erupted—usually around age 12—an orthodontic assessment may be necessary to identify other causes, such as a prominent frenum or missing teeth.