The influence of orthodontic non-extraction treatment on the change in the inclination and position of incisors in the Europoid race.

AIM: To detect post-treatment change in the inclination and position of incisors in cases treated with orthodontic non- extraction therapy.

MATERIALS AND METHODS: The group consisted of 102 patients without extractions in lower and upper dental arch during orthodontic treatment. Cephalogram examination evaluated the position of the lower incisor to point A by Downs-pogonion line (-1 to APo) and inclination of the lower incisor to mandibular line (-1 to ML), position of the upper incisor to nasion-pogonion line (+1 to NPo), inclination of the upper incisor to nasion-sella line (+1 to NS) and the size of the inter-incisival angle between upper and central lower incisor (-1 to +1).

RESULTS: In 58 % of cases, the difference in post-treatment and pre-treatment changes in the position of the (-1 to Apo) was within ± 2 mm, which we considered stable. Statistically significantly higher values after treatment were in unstable rather than in stable cases with values (-1 to Apo), (-1 to ML), (+1 to NPo). Statistically significantly lower value after the treatment was measured in unstable cases rather than in stable cases with a value (-1 to +1). There was no statistically significantly different value in stable and unstable cases after treatment in values (+1 to NS).

CONCLUSION: The number of stable post-treatment cases was only 16 % higher than the number of unstable cases. With the increasing value (-1 to Apo), the value (-1 to ML) and (+1 to NPo) increased, the value (+1 to -1) decreased. The value (-1 to NS) not after treatment was not statistically significantly different in stable and unstable cases (Tab. 6, Fig. 4, Ref. 27).