The pretreatment images present an 11.9 year old female in the full permanent dentition. She is class II, deep bite dental with 100% over bite. There is no crowding of concern in either arch. Facial images show a balanced face, good profile and a shorter lower face height that could be improved through opening the bite and a class II correction.
Pre treatment models show a half class II dental relationship bilaterally, 100% deep bite dental, random spacing in both arches, good arch form and symmetry. The dental midline is intact and no tooth size discrepency is noted. The panorex is unremarkable with all teeth present and no abnormalities existing. The Cephalometric Analysis indicates a class II skeletal relationship, closed vertical due to the deep bite, good relationship of lower incisor to pogonion and a neutral growth pattern. Her soft tissue profile indicates a slightly convex profile especially with the lower lip, but this too can be contributed to the lip curl and deep bite.
The treatment plan for this young lady was to align the upper and lower anterior teeth with and archwire sequence and make the class II correction in a removable functional appliance. This was for several reasons. She had a history of poor oral hygiene and non compliance. If the patient does not comply with the MDA, the dentition is adversely affected. If she doesn't wear the appliance, we get no results, good or bad. Also, this would give the premolars and upper cuspids more time to erupt for proper bracketing. She will be finished with an archwire sequence after the appliance.
First molars were banded and the upper incisors and lower cuspid to cuspid were bracketed and were leveled, aligned and rotated. Segmental .016 x .022 SS wires were placed to maintain the anteriors during appliance wear. U&L impressions were taken for fabrication of the Orthopedic Corrector I.
The Orthopedic Corrector is a removable functional appliance, similar to a Bionator. The difference being the two additional expansion screws added to the appliance. The addition of these screws eliminates the need for construction of a second appliance (in severely retruded skeletal Class II or TMJ-involved cases). After the third or fourth month of wear (when the patient’s muscles have readjusted to their new position), the screws can be activated and the appliance can be advanced. Turning them in unison moves the anterior cap forward. This allows the mandible to be advanced even further as treatment progresses. The Orthopedic Corrector I is used to increase the vertical in deep overbite cases, while the Orthopedic Corrector II is used to close open bites. Note: Wax bite requirements for this appliance remain the same as for the regular Bionator. The construction bite registration is taken with the mandible forward in an end to end or over-corrected position, as long as the patient is comfortable in the position. If the patient is not comfortable in protrusive, you can move them forward in steps. This patient was completely comfortable in an overcorrected position, slightly class III.
Removable functional appliances will work and are effective as long as there is good patient cooperation and the malocclusion is bilateral, but it is also important to understand the function and force that makes the corrrection. Because of the construction of the appliance, holding the mandible forward, there is also a headgear effect on the maxilla. The correction is reciprocal because of the equal forces to both arches. The maxilla is held stationery or often times retracted while the mandible is advanced. It is imperative that the patient wear the appliance 24 hours a day with the exception of eating and brushing.
The Orthopedic Corrector I is designed to correct Class II malocclusions by maintaining the mandible in an advanced position and guiding the eruption of the posterior teeth. The mandibular anteriors are covered with an acrylic cap which comes in contact with the maxillary anteriors. The midline expansion screw can be used for arch development when it is indicated. If needed, the mandible can be subsequently advanced by the side screws with minor adjustments made to the acrylic.
After wearing the appliance for 9 months, we placed bands and brackets and began an archwire sequence. These images were taken one year into treatment and she is in the .016 x .022 thermal activated nitanium wires. The posterior occlusion on the right side shows an overdistalized super class I to class III relationship. The left side displays a class I occlusion once the cuspid is retracted to close the space and the second premolar is rotated distally. As we anticipated, cooperation was not good and her wearing schedule was sporatic. The bite did not open and the arches did not level with the appliance due to the lack of compliance, but we did manage to get some anteroposterior correction. A "long" chain elastic was placed on the upper arch to consolidate some of the spacing. We will now continue through the SS archwires to level and align the teeth for bite opening.
Posted .018 x .025 SS archwire was placed on the upper arch with Pletcher Springs to close the remaining spaces and retract the anterior teeth. An accentuating curve was placed in the upper archwire for final bite opening and lingual root torque of the anteriors. Buccal root torque was placed in the posterior segments of the archwire. Once all the spaces are closed and we have final bite opening the patient was placed in .019 x .025 braided archwire to allow for settling. These wires are then cut to segmentals, lateral to lateral on the upper and cuspid to cuspid on the lower. After 3 weeks, impressions were taken for an upper hawley retainer and a direct bond lower lingual retainer was placed.
These images were taken about 1 week post retainer delivery. She is in class I relationship with normal overjet and overbite with well developed arches upper and lower. Facial images present a pleasing profile with a marked improvement after establishing the vertical dimension and eliminating the lip curl. Active treatment time for this case was 24 months.