The 20 Principles of the Alexander Discipline, Volume 3. R.G. "Wick" Alexander
years posttreatment.
Fig 1-6uu Composite tracing.
Fig 1-6vv Cephalometric radiograph 16 years posttreatment.
Fig 1-6ww Panoramic radiograph 16 years posttreatment.
| Table 1-1 | Archwire sequence |
| Archwire | Duration (months) |
|---|---|
| Maxillary | |
| 0.016 nitinol | 7 |
| 0.016 SS | 2 |
| 17 × 25 TMA | 12 |
| 17 × 25 SS | 7 |
| Active treatment time: | 28 months |
| Mandibular | |
| None | 4 |
| 0.016 nitinol | 4 |
| 0.016 SS | 2 |
| 17 × 25 TMA | 3 |
| 0.016 SS | 3 |
| 16 × 22 TMA | 6 |
| 16 × 22 SS | 3 |
| Active treatment time: | 21 months |
| Table 1-2 | Individualized forces |
| Force | Duration |
|---|---|
| Sealed RPE | 6 weeks |
| Removed RPE | 10 weeks |
| Elastics | |
| Lateral box Class III | 6 months |
| Class III buccal box | 2 months |
| Crossbite | 6 months |
| Trapezoid box | 2 months |
| Finishing (W with a tail) | 2 months |
| Table 1-3 | Measurements |
| Initial (mm) | Final (mm) | |
|---|---|---|
| Maxillary intermolar width (6 × 6) | 34.7 | 36.0 |
| Mandibular intercanine width (3 × 3) | 25.8 | 24.9 |
Case 1-2
Overview
A 34-year, 9-month-old man presented with a severe highangle open bite with extreme crowding in the mandibular arch (Figs 1-7a to 1-7j). It was initially apparent that in addition to extraction of the premolars to align the arches, the skeletal problem would require maxillofacial surgery.
Examination and diagnosis
In addition to the vertical skeletal pattern and open bite, the mandibular arch had an extreme arch length discrepancy (more than 8 mm). This discrepancy would necessitate extraction regardless of the final treatment plan. To add to the complications, the molar relationships were Class I on the right side and Class II on the left side. Because of the severe open bite, when the patient smiled, only one-half of the clinical crowns was exposed.
Treatment plan
The decision was made to treat the patient surgically using a three-piece maxillary segmental Le Fort I osteotomy and mandibular advancement. All four first premolars were extracted to create adequate space for correction of the arch length discrepancy.
Note: In my experience, “driftodontics” is not usually successful in adult patients, so in this case, during routine maxillary canine retraction with power chains, mandibular sectional archwires were used to retract the mandibular canines.
Evaluation
Interestingly, as the canines were being retracted, the open bite was spontaneously closing! Figures 1-7k to 1-7dd show the occlusion and arches at various points in the treatment.
As the treatment progressed, both the patient and I began to wonder whether surgery would be necessary. We soon changed the treatment plan to exclude surgery and used typical open bite mechanics (eg, reverse curve of Spee, etc). The final treatment results are shown in Figs 1-7ee to 1-7nn.
Discussion
In retrospect, had we planned to treat the patient nonsurgically from the start, I would have extracted the mandibular left second premolar instead of the first premolar. This would have improved the final left molar relationship.
Long-term stability
Long-term observation (7 years posttreatment) shows that his results are completely stable (Figs 1-7oo to 1-7ww). I wonder if surgery could have improved the final or long-term result.
| Table 1-4 | Archwire sequence |
| Archwire | Duration (months) |
|---|---|
| Maxillary | |
| 0.016 nitinol | 3 |
| 0.016 SS | 6 |
| 17 × 25 TMA closing loop | 7 |
| 17 × 25 TMA | 3 |
| 17 × 25 SS | 6 |
| Active treatment time: | 25 months |
| Mandibular | |
|
None
|