Cosmetic

Gum Contouring with Veneers: Crown Lengthening & Biologic Width

When the gum line is uneven or the teeth look 'too short', veneers alone won't fix it. This guide explains crown lengthening, the biologic width, and how gum surgery integrates with veneer design.

Reading time
6–8 min
Medically reviewed
Reviewed by a licensed dentist
Last updated
2026-06-01

Medically reviewed by

Medical Review Board (External Clinical Advisors)

Medical review

Editorial review

Evidence Review Lead

Editorial review

Last reviewed:
2026-06-01
Last updated:
2026-06-01
Reading time:
6–8 min
Version:
1.0

Overview

A beautiful veneer on a poorly framed gum line still looks wrong. Two patterns drive the need for gum surgery alongside veneers: an uneven gum line where each tooth shows a different length of crown, and a 'gummy' smile where too much gum is visible and the teeth look square or short. Both are addressed by repositioning the gum and, where needed, the underlying bone.

Why bone, not just gum, has to move

Around every tooth there is roughly 2 mm of soft-tissue attachment plus 1 mm of sulcus — the so-called "biologic width" or "supracrestal attached tissue". If a crown or veneer margin is placed within this zone, the gum becomes chronically inflamed. When the gum is repositioned coronally, the bone often must follow (osseous crown lengthening) to preserve that biological space.

Approaches to a gummy smile

  • Gingivectomy / gingivoplasty: soft-tissue reshaping where the underlying bone position is correct.
  • Surgical crown lengthening: bone is reshaped to reposition the gum permanently when bone is too close to the enamel edge.
  • Lip repositioning: small surgical procedure to reduce upper lip elevation when the gummy smile is caused by hypermobile lip rather than gum position.
  • Botulinum toxin: non-permanent reduction of upper lip elevation as an alternative or adjunct.
  • Orthognathic surgery: for severe vertical maxillary excess; rarely done for cosmetic veneer cases.

Sequencing with veneers

  1. Digital smile design or wax-up establishes the desired gum line and tooth proportions.
  2. Soft-tissue or osseous crown lengthening performed first.
  3. Healing of 8–12 weeks (longer for osseous procedures) before veneer preparation, so the gum stabilises.
  4. Veneer preparation and bonding at the new gum line.

Frequently asked questions