Eruption of the primary dentition in human infants: a prospective descriptive study

PURPOSE: This study investigated the clinical process of the emergence phase of eruption of the primary dentition including length of time taken to erupt and the association between soft tissue changes and stages of eruption.
METHODS: Twenty-one children aged 6-24 months at commencement of the study were recruited from three suburban daycare centers in Melbourne, Australia. Daily oral examinations of each child were conducted for seven months.
RESULTS: One hundred twenty-eight teeth were observed during eruption. Swelling very infrequently accompanied tooth eruption and in all cases was mild. Forty-nine percent of observed teeth demonstrated gingival redness during the emergence stages of eruption, but there was no significant relationship between redness and specific stages of eruption. Mean duration of eruption, from palpable enlargement of the gingival tissue to full eruption, was 2.0 months (range 0.9-4.6 months). The average rate of eruption was 0.7 mm per month. Many of the deciduous teeth appeared to demonstrate an "oscillating" pattern of eruption, (emerging and then retreating before emerging again). Timing of oscillation was not specific to stage of eruption or tooth type. This was defined as a "transitional" phase of eruption which appears to be common.
CONCLUSION: The results suggest that eruption of the primary dentition is often accompanied by redness, but not swelling, of the gingival tissues. For some children, there also appears to be a "transitional" eruption phase for primary teeth.