Guided surgical crown lengthening

Surgical crown lengthening is broadly indicated for aesthetic and functional reasons.^{1, 2} Aesthetic indications include altered passive eruption, gingival asymmetry, excess gingival show and correcting the height to width ratio of teeth.³ Functional indications are mostly concerned with increasing the quantity of supragingival tooth tissue for a ferrule.^{4, 5}

When assessing a patient for surgical crown lengthening the clinician must consider the endodontic and prosthodontic status of the teeth, as well as the periodontal factors described elsewhere.^{5, 6} An important periodontal factor to consider when planning a stable, healthy, post-surgery gingival position is the dento-gingval complex. The dento-gingival complex dimension can vary from individual to individual and tooth to tooth, though is widely accepted to be 3 mm on the labial surface.^{7, 8} This dimension includes what was formerly known as the biological width, now replaced with ‘supracrestal tissue attachment’ (STA) following the World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions.⁹ Therefore, to produce a predictable harmonious outcome, the clinician must respect this dimension when considering bone height reduction.⁶