Expansion: how much can the periodontium tolerate?

Arch length discrepancy can be resolved either by extraction or expansion. Normally, the choice of the clinician is founded on evidence-based treatment outcome reports. The adverse effect related to either approach is considered carefully before deciding. In the adult patient, the retraction of soft tissues consequent to extractions may be undesirable. Also, the deep bite may be difficult to correct if incisor proclination is to be avoided. Expansion has been reported to elicit gingival dehiscences. This is a report of a borderline case where the crowding is resolved acceptably through extreme expansion, but without any adverse periodontal effects.