it's an eruption cyst. Normal and harmless.
A dental eruption cyst is an oral soft tissue cyst which appears during childhood, and forms around an erupting primary or permanent tooth. Eruption cysts are not malignant.
Forty-five percent of all children experience eruption cysts. Eruption cysts and eruption hematomas are very similar, and differ only in their color. Both types of cysts are smooth, soft, swellings which appear over the area where a child's tooth is about to come in. They may be as large as 1/4 inch in diameter. They usually are clear, or may have a bluish color. Eruption hematomas are simply eruption cysts which have a very dark color.
WHEN DO ERUPTION CYSTS APPEAR?
- Shortly before the underlying tooth erupts into the mouth.
- They can appear as early as 5 months of age, or as late as 12 years of age.
WHAT CAUSES AN ERUPTION CYST?
- An eruption cyst develops when fluid accumulates between an erupting tooth and the overlying layer of enamel epithelium.
- An eruption cyst is really a dentigerous cyst which appears in oral soft tissue.
WHAT IS THE TREATMENT FOR AN ERUPTION CYST?
- Most eruption cysts disappear spontaneously as soon as the underlying tooth erupts into the mouth.
- No treatment is usually needed, since most of these cysts heal within 5 weeks.
- Giving an infant a cold teething ring may help alleviate some of the discomfort associated with eruption cysts.