Introduction: This research investigated changes in arch width and arch length through a CBCT analysis of patients treated with either Damon or Conventional brackets. Methods: Pre-treatment and post-alignment CBCT files were collected for borderline extraction patients treated through non-extraction therapy (17 Damon, 13 Conventional). Measurements were made for the canine, premolars, and first molars to evaluate dental arch width (inter-occlusal dimension: IOD, inter-apical dimension: IAD), skeletal arch width (inter-buccal/lingual alveolar crests: IBACD, ILACD), angulation, and arch length changes. Results: IOD increased for all teeth, with similar overall expansion in both groups. Damon cases showed tipping of all teeth except the mandibular canine. The arch length increased for both treatment modalities in both jaws. IBACD decreased for teeth, which translated. Conclusion: The claim that moderate to severe crowding can be resolved through translation of the posterior dentition without AP expansion of the dental arch was not supported by this study.