A 20 year old female patient complains of lower teeth irregularities and wants to undergo orthodontic treatment without undergoing extractions. On examination, moderate lower incisor crowding was noted. Bolton’s analysis reveals an overall mandibular excess of 4 mm and anterior mandibular excess of 2 mm. Which of the following teeth can be selected for interproximal reduction in this patient?

Bolton’s analysis considers the ratio of the tooth material of the maxillary arch to the mandibular arch. The combined and individual widths of maxillary and mandibular teeth have a pre-determined proportion to maintain normal occlusion relationship. An alteration in this balance would lead to unsatisfactory occlusion. If there is a maxillary tooth material excess, then it would lead to a large overjet, whereas if there is a mandibular excess, it will lead to crowding or negative overjet. Clinical Application: Overall excess of 4 mm in the lower arch with a lower anterior excess of 4mm indicates stripping in the lower 3-3 region.  Overall excess of 4 mm in the lower arch with normal ant ratio indicates stripping in the lower posteriors. Overall excess of 4 mm in the lower arch with a lower anterior excess of 2 mm indicates interproximal reduction in all the lower teeth.