We often get calls to our office from parents concerned that their child's adult teeth are coming in behind or in front of the corresponding primary tooth. This can create a "shark tooth" appearance that looks to be preventing the permanent tooth from coming in straight. On the contrary, a retained primary tooth is usually not a problem and will come out on it's own. The permanent tooth should "push" the baby tooth out enough that it becomes loose. If the permanent tooth is fully erupted and the baby tooth still isn't loose, a dentist will usually extract the primary tooth before a problem arises.
Retained teeth are usually a problem localized to the mandibular and maxillary incisors (four front teeth). The two mandibular primary central incisors are the first teeth to erupt at about six months. Subsequently, they are the first baby teeth lost at five to six years. They make way for the mandibular permanent central incisors, which typically erupt at ages six to seven. You can definitely see how a small overlap in timing can create the "double tooth" problem.
Overall, any concerns with your child's dentition should be brought up at their yearly checkup. We pride ourselves in being an educational and informative office and want you to leave with peace-of-mind. If you have any concerns with your family's oral health, please call our office!