RESUMO
The estimation of tooth size arch length [TSALD] is an important part of treatment planning in orthodontics. This procedure involves considerable time and efforts on the part of a busy clinician. The purpose of this study was to device a new method of predicting the tooth size arch length discrepancy of dental arches at chair without thorough and cumbersome procedure of measuring all teeth from mesial of the first molar to mesial of the contra lateral. Lower incisors were chosen as a standard to assess arch length discrepancy. The study was carried out on 100 patient's casts comprising of 43 males and 57 females. Mean age of patients was 21 years. All sample selected had a permanent set of dentition with a class one molar relation and incisor crowding. The correlation between lower incisor crowding and arch length discrepancy was calculated. The results indicated that there was a moderate correlation between TSALD in lower arch. The correlation coefficient was calculated as 0.673. There was no correlation between lower incisor crowding and upper arch length discrepancy shown by a value of 0.264. Further, chi square test was applied to find an association between the two values [LIC and lower ALD] which showed a p value of 0.00, indicative of strong association. The study suggests that there is a correlation LIC and ALD which further necessitates research in this area to quantify the correlation