- Alveolar crest is the section of interproximal alveolar bone which includes the free edge of the alveolar process. An increase of the normal forces within limits of tolerance leads to deposition of new bone. If forces are beyond the limits of tolerance, resorption of bone will result whether the force produces pressure or tension.
- This study was designed to evaluate changes of alveolar bone levels in mesial and distal surface of the left, right first molar, by using pre-treatment, post-treatment panorama films.
- Two hundreds sixteen subjects were divided into adolescent group of 104 subjects and adult group of 112 subjects, to which orthodontic treatment with a biscuspid extraction (adolescent group-50 subjects, adult group-50 subjects) or without a non-extraction(adolescent group-54 subjects, adult group-62 subjects) was applied by fixed appliances.
- Pre-and post-treatment panorama films were traced, and alveolar crest height was measured. Amounts of changes in alveolar crest height by treatment were calculated and compared in terms of side of tooth, extraction, age .
- Results were as follows :