Dimensional changes of dental arch following non-extraction orthodontic treatment

Since the emergence of normal occlusion concept, selecting an appropriate treatment plan with or without tooth extraction has been a controversial subject. Nowadays, both methods can be successfully used for treatment of patients. However, some clinicians still believe that non-extraction orthodontic treatments have fewer complications. The purpose of this study was to evaluate dental arch dimensional changes following non-extraction orthodontic treatment.
A total of 200 pre- and post-treatment diagnostic dental casts belonging to 100 patients (non-ext treated by 0.18 roth system) who met the inclusion criteria for this study were collected from the archives of Shahid Beheshti Dental School. Sampling was nonrandomized. A digital caliper with the accuracy of 0.1 mm was used for the measurement of variables such as inter-canine width , inter-premolar width and inter-molar width.
Non-extraction orthodontic treatment increased all the variables, except for the mandibular inter-canine width and incisor-canine distance.
Non-extraction orthodontic treatment causes a significant increase in almost all dental arch parameters. This increase manifests as teeth flaring.