The change in the maxillary of inverted impacted supernumerary teeth inversion was observed with the use of radiographs.
The subjects were the 138 panoramic tomograms obtained from 42 children ranging from the deciduous dentition stage to the mixed dentition stage, taken for caries treatment or periodical examination. The existence of the supernumerary teeth had been definitely shown through panoramic tomograms.
The results were as follows:
1) The invertde supernumerary teeth were classified into two groups, “The movement-type” and “The non-move-type”.
2) In “The movement-type”, when supernumerary teeth have shifted into the jaw involved from six to seven years olds.
3) In “The movement-type”, it showed a marked trend while that the formation of the root was in progress, the formation of the root had a tendency to be slow in “The non-movement-type”.
4) In “The movement-type”, it showed a marked trend that the position of the supernumerary teeth when they were found in the beginning existed near the nasal cavity side.
5) In “The movement-form”, the adjoining central incisior on the side with the supernumerary teeth had a tendency to erupt earlier than on the side with the non-supernumerary teeth, and when the supernumerary teeth shifted into the jaw connesponding to the eruption time of the adjoing centralincisior.