It is common for children to develop teeth that are not perfectly straight, a frequent concern for many parents. This natural variation in tooth alignment stems from a combination of factors. Understanding these influences can clarify why a child’s teeth might grow in a crooked manner.
Hereditary Influences
Genetics play a significant role in determining tooth alignment. Just as children inherit traits like hair or eye color, they can also inherit oral characteristics. These inherited traits include jawbone size, tooth size and shape, and natural spacing or crowding.
For instance, a child might inherit a smaller jaw from one parent and larger teeth from the other. This combination can lead to a mismatch where there is insufficient space for permanent teeth to align properly, resulting in crowding. Conversely, inheriting a larger jaw and smaller teeth can lead to excessive spacing or gaps between teeth. These genetic predispositions also influence bite patterns, such as overbites or underbites, which are often observed across family generations.
Oral Habits
Prolonged or intense oral habits during childhood can influence tooth alignment. Habits like thumb sucking, pacifier use, and tongue thrusting apply pressure to developing teeth and jaws. The duration and intensity of these habits determine their impact.
For example, persistent thumb sucking or pacifier use, especially beyond ages two or three, can push the upper front teeth forward and the lower front teeth inward. This constant pressure can lead to an “open bite,” where the front upper and lower teeth do not meet, or a “crossbite,” where upper teeth fit inside lower teeth. Similarly, tongue thrusting, where the tongue pushes against the front teeth during swallowing or at rest, can shift teeth out of alignment or create gaps.
Developmental and Environmental Factors
Beyond genetics and oral habits, several developmental and environmental factors contribute to crooked teeth. The timing of baby tooth loss is a factor; if a baby tooth is lost too early due to decay or injury, adjacent teeth may shift into the empty space. This shifting can block the permanent tooth’s path, causing it to erupt out of alignment or become crowded. Conversely, if a baby tooth remains in place too long, it can prevent the permanent tooth from erupting correctly, forcing it to emerge crookedly or behind the baby tooth.
Discrepancies in jaw growth lead to alignment issues. If the upper or lower jaw develops disproportionately, it can result in an overbite, underbite, or crossbite, affecting how teeth fit. Dental trauma, such as mouth injury, can impact a tooth’s position or damage the developing permanent tooth. Chronic mouth breathing, often linked to enlarged adenoids or tonsils, can influence jaw development by altering the resting position of the tongue and facial muscles, potentially leading to a narrower upper jaw and misaligned teeth.
When to Consult a Professional
Parents often wonder when to seek professional advice regarding tooth alignment. The American Association of Orthodontists recommends a first orthodontic evaluation by age seven. At this age, children typically have a mix of baby and permanent teeth, allowing assessment of jaw growth and tooth eruption patterns.
An early assessment can identify problems before they become complex, even if immediate treatment is not necessary. Signs that might warrant an earlier visit include:
Visible crowding
Gaps
Difficulty chewing
An uneven bite
Detecting issues during these formative years can guide jaw growth and help permanent teeth emerge into better positions, potentially leading to simpler interventions later.