The effect of extraction of infrao-ccluded deciduous molars: A longitudinal study.

Department of Pediatric Dentistry
Lutheran Medical Center

Resident’s Name: Craig Elice Date: 4/3/2009
Article title: The effect of extraction of infrao-ccluded deciduous molars: A longitudinal study.
Author(s): Kurol J, Koch G.
Journal: Am. J. Orthod. 87 (1)
Volume (number): 46-53
Date: January 1985
Major topic: Extraction of ankylosed primary molars
Type of Article: Prospective Research article
Main Purpose: This study evaluated the effect of unilateral extractionof submerged mandibular primary molars longitudinally. Comparisons were made between contralateral sides in terms of eruption of permanent successors, alveolar bone level and development of the dental arch.
Materials and Methods: 15 children, mean age of 10.1 years with bilateral infraocclusion and no missing successor teeth were included in the study. Unilateral extractions of the infra-occluded molar were compared to the contralateral side of the same arch. 55 deciduous molars were infra-occluded, 23 pairs in the lower arch. Clinical and radiographic measurements were made as well as photos were taken. The children were examined every 6 months until the permanent successors erupted with an average observation period of 2.6 years. The radiographs were standardized and examined for bone level, eruption pattern of permanent teeth and root resorption of the primary tooth. Casts were measured for infraocclusion and arch perimeter. The extracted teeth were randomly selected and no space maintainer was placed for the duration of the study.
Findings: The degree of infra-occlusion increased in 10 of the 23 molars on the non-extracted side. However the molars exfoliated within the normal time. Alveolar bone height was the same after eruption of successsors on both sides. There was no difference in eruption time between the extraction and non-extraction side, and were within a normal range. Radiographs indicate no difference in root development of successors for either side. Removal of ankylosed teeth resulted in 8 children having 10 residual root fragments left in the bone. In 6 of the 8 children, root fragments were also noted on the contra-lateral side. Most of the root fragments resorbed on the extraction side and all root fragments were still present on the non-extraction side throughout the observation period. Arch length decreased gradually in 14 out of 15 children on the extraction side while arch length increased in 9 out of 15 children and decreased minimally in 6 children. No mesial tipping was noted on either side.
Key points/Summary : No major differences were noted in eruption time of successors, or in marginal alveolar bone height between the extraction and non-extraction sides. The frequency of residual deciduous root fragments was similar between sides. The results indicate that conservative observation rather than extraction of infra-occluded molars is the preferred treatment.
Assessment of article: Good article. Fairly small sample size.