Solitary median maxillary central incisor

Dr Tim Luijkx and Radswiki et al.

Solitary median maxillary central incisor (SMMCI) is a rare dental anomaly. It is usually considered as a minor manifestation (variant) of holoprosencephaly (HPE).


It is estimated to occur in 1:50,000 live births.


It is a complex disorder consisting of multiple, mainly midline defects of development resulting from unknown factor(s) operating in utero about the 35-38th day from conception. The etiology is uncertain.


A missense mutation in the SHH gene (I111F) at 7q36 may be associated with SMMCI 2.


Up to 90% have choanal atresia,midnasal stenosis or pyriform aperture stenosis

Radiographic features

  • single,midline central maxillary incisor
  • midpalatal vomerine ridge
  • v-shaped palate
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Article information

rID: 15288
System: Head & Neck
Synonyms or Alternate Spellings:
  • Central incisor syndrome
  • Solitary median maxillary central incisor syndrome
  • solitary median maxillary central incisor (SMMCI)
  • Central megaincisor

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Cases and figures

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