CASE-032 · Fixed Orthodontics

Adult Anterior Crowding with Rotations and Attrition Risk

An adult presenting with moderate upper and lower anterior crowding, rotated lateral incisors, an irregular incisal plane and early wear facets on the lower incisors.

Findings: 05
Options: 03
Stages: 05

Fixed OrthodonticsComplex CasesDigital Planning

Clinical records · drag to compare

Post-treatment frontal intraoral view with aligned anterior segments

Pre-treatment frontal intraoral view showing anterior crowding and rotations

BEFOREAFTER

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Additional records

Progress lateral view during alignment — before

Clinical challenge

Resolving anterior irregularity and protecting the incisal edges without expanding beyond the existing alveolar envelope in a periodontally sensitive adult dentition.

Outcome

Aligned and derotated anterior segments, an even incisal plane, contacts closed without expansion, and marginal tissue maintained.

Diagnostic findings

Upper anterior crowding of 4 mm with bilateral lateral incisor rotations
Lower anterior crowding of 3 mm with an irregular incisal plane
Localised wear facets on the lower incisal edges
Generalised gingival pigmentation with thin marginal tissue in the lower anterior segment
Class I molar relationship, coincident midlines within 0.5 mm

Problem list

Anterior crowding driving rotations and contact point irregularity
Incisal interference producing localised attrition
Limited transverse alveolar tolerance for expansion

Treatment objectives

Resolve crowding through space created by interproximal reduction, not expansion
Derotate the lateral incisors and level the incisal plane
Remove the anterior interference that was generating wear
Preserve marginal gingival architecture

Options weighed

Fixed appliances with IPR
Highest rotation control; more plaque burden on already sensitive tissue.
Aligners with staged IPR
Better tissue hygiene, but rotation control on the laterals was the demanding part of this case.
Extraction of a lower incisor
Resolves crowding decisively; risks black triangles and an unnecessary loss of tooth structure.

The decision

Fixed appliances with staged interproximal reduction and dedicated derotation mechanics — chosen because tissue quality, not space, was the constraint that would decide long-term stability.

Clinical reasoning

The crowding was modest enough to be resolved within the arch. The binding constraint was the thin, pigmented marginal tissue in the lower anterior segment, which made both extraction and buccal expansion poor trades. Fixed appliances gave continuous, direct control of the rotations, with a hygiene protocol written into the review schedule rather than left to compliance.

Strategy

Sequential derotation of the lateral incisors first, then progressive IPR from the canine region inward, with the incisal plane levelled last so that the final edges were finished against a settled occlusion.

Biomechanics

Deliberate bracket positioning with derotation auxiliaries on both lateral incisors, bite turbos on the upper centrals to disengage the interfering lower edges, and reciprocal anchorage distributed across the posterior segments through a continuous archwire.

Treatment sequence

01Digital plan and staged IPR mapping
02Lateral incisor derotation with auxiliaries
03Progressive IPR and anterior alignment
04Incisal plane levelling and edge refinement
05Settling and fixed lingual retention

Digital workflow

Intraoral scans were superimposed at each review to compare achieved to predicted movement; the IPR schedule was released stage by stage rather than front-loaded.

Monitoring, adaptations & reassessment

Six-week reviews with progress checks at the rotated laterals and a hygiene assessment of the lower anterior marginal tissue at every visit.

The upper right lateral was still about 4° short of the planned derotation at month four; the bracket was repositioned and the auxiliary re-activated rather than accepting it and correcting at finishing.

Function was reassessed after settling: the anterior interference that produced the wear facets no longer engaged in protrusive movement.

14 · Clinical takeaway

When the tissue is the fragile part of the case, choose the mechanics that move only what must move — and write the hygiene protocol into the plan.