Bella Smile ↗Case report · Clear aligners (Invisalign)
Teen Class III Crossbite Correction with MARPE
16 year Male Class III malocclusion with concave profile, bilateral posterior crossbite, anterior open bite, edge-to-edge overjet, mild upper and lower crowding, and a 2 mm left mandibular midline shift.
- Patient
- Adolescent (12–17), male
- Classification
- Class III
- Active treatment
- 19 months
- Published
- September 13, 2026
Presentation
Chief complaint. I want to fix my underbite and my back teeth don't fit together
Diagnosis. Skeletal Class III malocclusion with maxillary transverse constriction and bilateral posterior crossbite. The maxillary incisors are proclined and mandibular incisors retroclined, consistent with dental compensation. He presents with an approximately 1 mm anterior open bite and near edge-to-edge anterior relationship with approximately −1 mm overjet. He has Class III molars and Class I canines on the right and Class I molar and canine relationships on the left. The mandibular midline is deviated to the left with a CR-CO functional shift to the left.
Records
Before — Intraoral Photos
After — Intraoral Photos
Before — Lateral Ceph Radiograph
After — Lateral Ceph Radiograph
Before — Panoramic Radiograph
After — Panoramic RadiographMeasurements
| Measure | Norm | Pre | Post |
|---|---|---|---|
| SNA | 82 | 83 | 84 |
| SNB | 80 | 86 | 86 |
| ANB | 2 | -3 | -2 |
| Wits | 0 | -4 | -2 |
| SN-MP | 32 | 22 | 25 |
| U1-SN | 102 | 120 | 119 |
| L1-MP | 90 | 85 | 77 |
| Overjet (mm) | 2–3 | 0 | 2 |
| Overbite (mm) | 2–3 | -2 | 2 |
Treatment
Objectives. Expand the maxillary arch, distalize the mandibular dentition to achieve Class I occlusion, and intrude the posterior teeth to close the open bite.
Plan. Expand the maxilla with MARPE, extract the third molars, then use Invisalign to sequentially distalize the lower dentition and intrude the posterior teeth to close the open bite with class III elastics
Appliances and materials
- MARPE — expander supported with 4 TADS
- Invisalign
- Class III elastics
Progress records
Outcome
Excellent aligner and elastic compliance allowed closure of the open bite and correction to a Class I occlusion. The mandibular incisors were retroclined to help camouflage the skeletal Class III relationship, with adequate thick attached gingiva maintained in the lower anterior region.
Retention
- Fixed U2-2 permanent retainer
- Fixed U3-3 permanent retainer
- Invisalign Vivera retainers to be worn at night
Case reports are shared with patient authorisation. Individual results vary.