CASE STUDY “She was bracketed for an open bite since her SN-GoGn was 41 and her overbite was 1mm. The initial archwires were 014 NiTi. The following week second molar bands were placed as well as the NiTanium Palatal Expander.” Fig. 8b Fig. 8a slightly shortened roots. There are no other findings radiographically. The cephalometric radiograph (Fig. 3) was traced using the modified Steiner analysis. J.B. had a Class II skeletal pattern with an ANB measurement of 6 degrees. Her mandibular plane angle was 41 degrees and her Y-axis was 70 indicating a dolichocephalic growth pattern. Her facial profile is convex. At 11.11 years old, I expect 1-2mm of growth of Po.Her NB-T is 12mm and NB-Po is -3mm, which would indicate that the lower incisors cannot move forward. Being African American, I would consider a higher NB-T to NB-Po ratio to be normal, but even with 1-2mm of Po growth, this ratio is undesirable. With an inter-incisal angle of 110, there is room to bring the lower incisors back a little bit which will help both the inter-incisal angle and the NB-T to NB-Po ratio.(Fig. 4) Fig. 8c Treatment Plan ᕡ Opti-mim brackets (.022 slots) on all premolars and anterior teeth. Full bands on all erupted molars ᕢ Archwire sequence ᕣ NiTanium Palatal Expander (NPE) to correct crossbite ᕤ Finish to a Class I occlusion ᕥ Bonded lingual retainers upper and lower (3-3) Estimated Treatment Time: 20-24 months Case Summary J.B.’s treatment began with the placement of Opti-mim brackets premolar to premolar. Bands were placed on all first molars. She was bracketed for an open bite since her SN-GoGn was 41 and her overbite was 1mm. The initial archwires were 014 NiTi. The following week second molar bands were placed as well as the NiTa-nium Palatal Expander. (Fig. 5) The archwire sequence was being done while the NPE was correcting the cross-bite. (Figs. 6A,B) After 9 months of treatment the NPE was removed and the AWS was complete. (Fig. 7) The NPE over-expanded the upper molars by approximately 4mm. Upper and lower inter-arch spaces were closed slowly on an 018x025 stainless steel wire to avoid www.orthodontics.com Treatment Objectives ᕡ Correct bilateral crossbite. ᕢ Be careful not to open bite due to high mandibu-lar plane angle ᕣ Correct inter-incisal angle and improve esthetics by closing spaces ᕤ Obtain a Class I occlusion Spring 2016 29
Journal of the American Orthodontic Society Spring 2016: Page 29
