Eruption cysts also known as eruption hematomas may develop with erupting primary and permanent teeth. They appear as bluish and translucent dome-shaped soft tissue lesions overlying an erupting tooth. An eruption cyst results from fluid accumulation within the space surrounding the erupting tooth. When the fluid in the cyst is mixed with blood, the cyst is referred to as an eruption hematoma. No treatment is typically needed, because the tooth erupts through the lesion, which disappears spontaneous.  As a tooth erupts an eruption cyst  or hematoma may develop. The tooth will eventually rupture this watery sac as it pushes through the gums. Eruption cysts are usually harmless and should be left alone.

 

reference-http://www.mchoralhealth.org/pediatricoh/mod3_6_2.htm

Pediatric Dental Center
Warren, MI
Dr. Shah, Dr. O’Riordan