The gap between the teeth is usually referred to Diastema. It is usually nothing to worry about except when it affects your speech or aesthetic look.
A diastema is a gap between teeth that is wider than 0.5 millimeters. It can develop between any teeth.
While ‘gapped’ teeth are normal in most cases, there can be identifiable causes. The following are the major causes of diastema:
1. The size of the teeth in relation to the jawbone
If a person’s teeth are too small, relative to the size of their jawbone, gaps may develop between the teeth.
Jawbone and tooth sizes can be genetic, which is one reason that diastemas can run in families.
2. Missing or undersized teeth
If some teeth are missing or smaller than others, a diastema can develop.
This often involves the upper lateral incisors — the teeth to either side of the two upper front teeth. If the upper lateral incisors are missing or relatively small, a gap can develop between the two front teeth.
3. Oversized labial frenum
If this tissue is especially large, it can cause a gap to form between these teeth.
4. Gum disease
Tooth migration is a typical sign of advanced gum disease.
In people with gum disease, inflammation results in damage to the bone that supports the teeth.
Eventually, the teeth may become loose, and gaps can appear.
5. Incorrect swallowing reflex
When the swallowing reflex happens correctly, the tongue presses against the roof of the mouth.
A person may instead push their tongue against their front teeth when they swallow. Over time, this repetitive pressure against the front teeth pushes them forward, causing a gap to form.
Thumb sucking, lip sucking, tongue thrusting, and similar habits can put pressure on the front teeth, pushing them forward.
This can lead to diastemas.
7. Loss of primary teeth
This type of gap is common enough that dentists consider it to be a normal developmental phenomenon in children. No treatment is usually necessary.
A 2012 study reports older findings that these diastemas may be present in approximately two-thirds of children in whom only the central incisors have erupted. The central incisors are the two flat teeth at the front of the upper jaw.