Class II Div I - Using Forsus

Pre-Treatment Photos
Pre-Treatment Records
Archwire Sequence
Highlighting Forsus at 46 Weeks
Treatment Progress - 46 Weeks
Treatment Progress - 64 Weeks
Post-Treatment Photos
Post-Treatment Records
TMJ X-Ray and Final Results
Ceph Tracings - initial vs Final
Profile Comparison & Final Comments
Post-Retention Photos
Post-Retention Records
Ceph Tracings -
initial vs Final vs Post Retention

This case was treated by:
Dr. François Bérubé


Case Type:
Class II Div I (Non-X)

Case Summary:
This patient presented at age 14 years 4 months at the height of his pubescent growth peak, with a complete permanent dentition and lacking 4 wisdom teeth. Skeletally, we noted a moderate to severe retrusive mandible accompanied by a slight transverse deficit in the maxilla. His Class II malocclusion featured a horizontal overjet that varied from 4.8 mm – 5.5 mm, and a vertical overjet of 6.0 mm or 75%. The ectopic positioning of the maxillary canines provides evidence of the severe lack of space (crowding) in the upper arch. A profile analysis indicates a convex facial profile with poor lip support and a retrusive mandible. Hyperactivity of the mentalis is required for this patient to achieve lip closure. The ceph x-ray indicates buccal inclination of the mandibular incisors and sufficient oropharyngeal space for nasal breathing despite the retruded mandible. The panoramic x-ray shows a complete permanent dentition and the presence of 4 developing wisdom teeth, in addition to normal and symmetrical tempo-mandibular articulation. Functionally, we can see a labial incompetence of 4.0 mm at rest and a hyperactive mentalis.

Treatment Objectives:
• Correct Class II molar relationship
• Improve maxillary lip support
• Correct convex profile
• Obtain normal lip competence
• Respect physiologic limits
• Obtain a functional and stable result

Treatment Plan:
I chose to treat this case non-extraction to optimize improvement of maxillary lip support and transverse development in the upper arch. Orthodontic hardware included .022 slot SPEED brackets with Hanson Prescription, modified on the lower incisors to provide torque values of -1˚ (Regular / Roth Prescription), and SPEED Convertible tubes on the upper 1st molars to permit use of Forsus springs for Class II correction.

Initial archwires were light force .014 nickel titanium in both arches, followed in the maxillary with .016 nickel titanium and then .018 stainless steel, and in the mandibular with .018 stainless steel.

This phase consisted of leveling, archform coordination in both arches, and preparation of dental anchorage in the maxillary and mandibular arches. Once dental alignment was achieved using small round archwires working in the "passive zone" of the SPEED brackets, we moved to rectangular archwires using the "active zone" of the SPEED appliance for leveling, archform coordination, and anterior/posterior torque control. Sufficient preparation of dental anchorage required for the use of Forsus Springs, minimized the potential for the undesirable side effects of "detorquing" upper anteriors and/or "flaring" the lower anteriors that can occur with Forsus use. Dentoalveolar decompensation was achieved with an .018 x .025 stainless steel wire followed by a .021 x .025 stainless steel wire with expansion incorporated into the maxillary wire to facilitate transverse archform coordination once Class II correction was obtained.

Class II Correction:
Once dentoalveolar decompensation is achieved, our objective is to use Forsus Springs to correct the Class II molar relationship and retrognathic mandible. 30 weeks after treatment began, a Forsus #29 was engaged, and a horizontal overjet of 7.2 mm was noted. Only 4 months later a Class I molar relationship had been achieved. An overcorrection was required, and as a result, the Forsus springs remained engaged for an additional 4 months. In order to avoid a negative horizontal overjet during this treatment phase, the maxillary archwire was bent 2.0 mm distal to the 2nd molar bracket, and a Class I elastic was placed from the Forsus to the maxillary canine. This permitted a slight Class III overcorrection of the posterior segments, while maintaining a slight horizontal overjet.

Finishing and Detailing:
During this phase a .021 x .025 maxillary archwire, reduced in the posterior using an acid bath, was used for space closure, to correct a slight mid-line deviation, and to avoid "detorquing" the anteriors. In the mandibular arch, light interproximal remodelling were applied to the anterior teeth to correct the Bolton discrepancy, and an .018 x .025 stainless steel archwire was placed in conjunction with chain elastic for final space closure. Once all the spaces were closed in both arches, .018 x .025 stainless steel archwires were used to complete archform coordination and to obtain an ideal functioning occlusion.

Orthodontic retention was facilitated using a fixed lingual retainer wire from the #13 – 23, and from the #34 – 44.