ABSTRACT
ABSTRACT Background: In modern populations, the impaction rate is higher for third molars than for any other tooth. Due to the speculation of third molar role on late incisor crowding, many orthodontists prescribe removal of third molars before, during or just after orthodontic treatment. Objectives: The aim of this study was to compare whether orthodontic extraction of first premolar lead to any angular changes in second and third molars. Material and method: Orthopantograms of 20 patients undergoing orthodontic treatment were collected pre and post treatment. The patients were divided into two groups – nonextraction and extraction group. Each group consisted of 10 patients. The angles were measured between the long axis of 2nd molar and 3rd molar with horizontal plane. Changes in 2nd and 3rd molar angulation from pre-treatment to post treatment for two groups were compared by Mann- Whitney utest. Results: Statistical analysis revealed that maxillary and mandibular 2nd and 3rd molar showed an improvement in angulation but it was statistically non-significant. Conclusion: The findings of the present investigation suggest that premolar extraction therapy has a favourable effect on maxillary second & third molar angulation, while no changes in mandibular second & third molar angulation during treatment were found in patients treated with and without premolar extractions.
ABSTRACT
In the process of evolution the jaw has become smaller, allowing less room for the 3rd molars and causing numerous dental problems. Research now indicates that in many of cases there is complete agenesis of 3rd molars which may be because of environmental influence on human evolutionary process. An objective of this study is to asses genesis and impaction of 3rd molar in adolescents of Ahmedabad city. This study was done in 100 adolescents (age 15-19 years) of Ahmedabad city during January 2013 to July 2013. Genesis or agenesis and impaction of 3rd molar was confirmed by Orthopantomogram (OPG) and data was analyzed using Fisher’s exact test in GraphPad Prism software (6.0.3). Out of 100 adolescents, 66 have presence of tooth-buds of all four 3rd molars, while in 23 cases OPG shows absence of tooth-bud (agenesis) of one of the four 3rd molars, in 6 cases tooth-buds of two out of the four 3rd molar were absent, in 3 cases tooth-buds of three out of four were found to be absent and in 2 cases all the four 3rd molar tooth-buds were absent. Gender difference was not significant. Different pattern of impaction was found in 38 subjects. Agenesis & impaction of 3rd molar may be a part of evolutionary process which has undergone because of changes in food habits from coarse abrasive diet to soft western diet.