The 20 Principles of the Alexander Discipline, Volume 3. R.G. "Wick" Alexander
show the pretreatment cephalometric tracing and panoramic radiograph. Because she was near adulthood, maxillofacial surgery was considered, but because it was a borderline case, the treatment objectives would have a chance to be successful without surgery.
Examination and diagnosis
This 16-year-old girl had an extremely vertical skeletal pattern (SN-MP of 49 degrees), a transversely constricted maxilla, a dental open bite (4 mm), and a tongue thrust. Skeletal surgery (three-piece maxillary osteotomy) was discussed, but we agreed to attempt nonsurgical and nonextraction treatment first.
Treatment plan
Initially, a fixed palatal expander was used. The patient was instructed to turn the appliance every other day because of potential discomfort. She was also asked to squeeze her teeth together as often as possible. Rather than wear a face mask, she would wear Class III vectored elastics.
Evaluation
Unexpectedly, the rapid palatal expander (RPE) created a 3-mm diastema between the central incisors and increased the open bite by another 5 mm (Figs 1-6k to 1-6m). The buccal tipping of the molars caused premature cusp contacts, thus creating a larger open bite. The good news was that this situation was temporary.
Discussion
After transverse expansion, the next goal was to create a normal occlusion. This was accomplished with Class III vectored box elastics (Figs 1-6n to 1-6r), squeezing exercises, and tongue control. Significant interproximal enamel reduction was performed on the mandibular anterior teeth. The combination of these factors controlled IMPA. Finishing wires (17 × 25 SS) were then placed on both arches (Figs 1-6s to 1-6w), followed by finishing elastics 7 months later (Figs 1-6x to 1-6bb). Figures 1-6cc to 1-6ll show the posttreatment results.
Long-term stability
Open bite malocclusions are difficult enough to maintain in the long term, but when a Class III nongrowing skeletal pattern is added to the mix, the challenge is even greater. The patient continues with her tongue exercises and sleeps in a wraparound retainer (which has a small hole in the anterior part of the acrylic for her tongue).
Interestingly, the occlusion improved with time (Figs 1-6mm to 1-6ww). My assumption as to why is that the final occlusion is in a stable position and the oral and intraoral muscular tissues are functioning normally.
Case 1-1
Figs 1-6a to 1-6c Pretreatment facial views showing a Class III tendency profile.
Figs 1-6d to 1-6f Pretreatment intraoral views. The patient has a 4-mm open bite and Class III molar relationships.
Figs 1-6g and 1-6h Pretreatment occlusal views.
Fig 1-6i Pretreatment cephalometric tracing.
Fig 1-6j Pretreatment panoramic radiograph.
Fig 1-6k Frontal intraoral view after expansion with an RPE.
Figs 1-6l and 1-6m Occlusal views after expansion.
Figs 1-6n to 1-6p Intraoral views 14 months into treatment: maxillary and mandibular 17 × 25 TMA archwires; lateral box Class III elastics are begun.
Figs 1-6q and 1-6r Occlusal views 14 months into treatment.
Figs 1-6s to 1-6u Intraoral views 19 months into treatment: maxillary and mandibular 17 × 25 SS archwires.
Figs 1-6v and 1-6w Occlusal views 19 months into treatment.
Figs 1-6x to 1-6z Intraoral views 26 months into treatment. The mandibular archwire is sectioned, and finishing elastics are placed.
Figs 1-6aa and 1-6bb Occlusal views 26 months into treatment.
Figs 1-6cc to 1-6ee Final facial views after 28 months of treatment.
Figs 1-6ff to 1-6hh Final intraoral views.
Figs 1-6ii and 1-6jj Final occlusal views.
Fig 1-6kk Posttreatment cephalometric tracing.
Fig 1-6ll Posttreatment panoramic radiograph.
Figs 1-6mm to 1-6oo Facial views 16 years posttreatment.
Figs 1-6pp to 1-6rr Intraoral views 16 years posttreatment.
Figs 1-6ss and 1-6tt Occlusal