A 19 year old female patient with the chief complaint of crooked teeth, wants to undergo orthodontic treatment without undergoing extractions. On examination, mild lower incisor crowding was noted. Which of the following model analysis must be done before deciding a treatment plan for this patient?

Interproximal reduction of enamel to accommodate minor crowding is a viable treatment option. The treatment with proximal re-contouring of the teeth can be extended from incisors to premolars and allows some of the cases to be treated with a non-extraction approach. The amount of proximal reduction on lower incisors can be calculated by Peck and Peck analysis, which essentially reconfirms the large mesiodistal width of incisors in proportion to their labiolingual thickness. Peck and Peck suggested a range of 88%–92% for mandibular central incisors and 90%–95% for mandibular lateral incisors. A large ratio suggests need for proximal recontouring. Orthodontics- diagnosis and management of malocclusion, O.P. Kharbanda, 3rd edition