Table 1 Grading of clear aligner treatment difficulty
From: Expert consensus on the clinical strategies for orthodontic treatment with clear aligners
Difficulty level | Skeletal discrepancy | Crowding | Anterior overjet/overbite | Amount of molar movement | Associated manifestations | Treatment approach | CAT-CAT score |
|---|---|---|---|---|---|---|---|
Easy | None | Mild crowding or spacing | Normal or slight abnormal | Molar distalization: <2 mm; mesial movement: 0 mm | None | Non-extraction; Arch expansion, IPR, or Mild incisor proclination | <20 |
Moderate | Mild | Moderate crowding | Deep overbite/overjet | Molar distalization: 2–3 mm; Mesial movement ≤2 mm | None | Molar distalization, Bite jumping, or Extraction of premolars | 21–40 |
Difficult | Moderate to severe | Severe crowding | Severe deep overbite/overjet | Molar distalization >3 mm; Mesial movement >2 mm | Anterior open/crossbite; Posterior open/crossbite/scissor bite; Horizontal and/or vertical discrepancies | Extraction; Implant anchorage/elastics; orthognathic surgery | 41–60 |
Challenging | Difficult cases with periodontal diseases, Temporomandibular Joint Disorders, missing molars, impacted teeth, molar protraction | >60 | |||||
