Alveolar bone grows with development of tooth germs and roots; bone deposition occurs with tooth eruption. Bone
tion and deposition, and when the balance between them is disrupted, decrease in
components undergoes processes ofre=sorpda lern
alveolar bone height or excessive bone deposition result. It has been known that repositioning of teeth through orthodontic treatment can cause alveolar bone resorption which result in decreased alveolar bone height, and there have been many studies to evaluate such effects. X--ray films that could be rephated and standardized were chosen in clinical studies, and among them, bitewmg films men used for objective evaluation of changes in alveolar bone level. Twenty subjects, 10 to 13-year- old (average 10) children with C31 molar key, healthy oral condition, no congenital missing, no periodontal 4domnttal disease, and pre-and
bitewing films, were randomly selected for comparison of alveolar bone heigh. Amounts of tooth and changes in alveolar bone heights were analyzed. The following results were obtained:
L Amount of tooth mmaneit in canine, premolar, and molar regions, changes in tooth axis, and changes in alveolar bone heights were measured, and the mean and median values were obtained.
Z When pre-and alveolar bone levels were compared, larger changes were noticed in maxilla than mandible. I When mesio-distally compared, larger changes were observed in the distal sides of AM and W& mesa[ sides of 4M3 and
4D3, distal sides of 4D3 and 5NA menial sides of 5M3 and 5-D3, and distal sides of 5D3 and 6M3.
4, When the amounts of tooth movements(TX, Mand changes in tooth axis(A) were compared, 34TX, 34TY, 34A of both sides
in maxilla were greater, and changes in alveolar bone level were greater than any other region.
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