First teeth: Is eruption of back teeth abnormal?
I am concerned about my daughter's teeth. She is only four months old and her back teeth are the first to appear. All of my friends' children had front teeth first. Is this unusual? Should I have her see a dentist?Question:
It is unusual for the posterior teeth to appear first when the primary teeth are erupting. You should consult with your dentist to determine the cause of this unusual eruption pattern.
The typical eruption pattern of primary teeth is as follows. The lower central incisors (the two front teeth) usually erupt first at about six to nine months of age. The upper central incisors follow shortly after the lower ones. The upper and lower lateral incisors (teeth on either side of the central incisors) will usually erupt at about seven to ten months of age. Occasionally, the lower lateral incisors will erupt before any of the upper incisors erupt. The primary first molars usually erupt about 16 to 20 months. The primary canines may appear at about 16 to 20 months old. The primary second molars come in about 23 to 30 months. These are average ages and there are some variations in eruption times. The eruption sequence is more important than the ages of eruption.
If the eruption pattern is out of sequence or the pattern varies on different sides of the mouth, further investigation is needed to determine if teeth are missing or blocked from erupting properly. Cysts may impede the front teeth from erupting. These teeth may also be completely abscent. These possibilities may indicate systemic conditions or syndromes which should be addressed. For example, syndromes which involve formation of dental cysts include Gardner syndrome or Gorlin syndrome. Syndromes which may cause missing teeth include ectodermal dysplasia, cleidocranial dysostosis, cleft lip/cleft palate, Crouzon syndrome, Down syndrome and Ehlers-Danlos syndrome. Many of these syndromes display other medical conditions.
I do not want to worry you unnecessarily, but it is important to have your infant assessed for any of these medical conditions. Early intervention and treatment are important.Answer: