Non-extraction treatment of skeletal class II malocclusion
A 14-year-old female presented with the chief complain of protruding upper front teeth. Clinical examination showed a convex, retrognathic profile, lip incompetence at rest, and protrusion of the upper lip [Figure –]. The patient had a Class II, division 1 malocclusion with an overjet of 10 mm and an overbite of 7 mm and a pronounced curve of Spee [Figure –].\nCephalometric analysis revealed a convex skeletal profile with ANB angle of 7°, a severely retruded mandible, and a well-positioned maxilla. [, ] Dentoalveolar readings suggested proclined maxillary anterior teeth with mildly retroclined and retruded mandibular anteriors. The mandibular plane angle was normal, suggesting an average growth pattern. Hand X-rays indicated that the patient's growth was not completed.\nTreatment objectives were to:\nObtain a symmetrical Class I occlusion without extractions. Improve facial appearance by inhibiting forward vertical growth of the maxilla and stimulating growth of the mandible. Avoid any backward rotation of the mandible.\nConsidering the finding, non-extraction fixed mechanotherapy was planned using MBT 0.022” slot pre-adjusted appliance. After leveling and alignment, a fixed functional appliance would be given to advance the mandible into a class I relationship. Forsus FRD was the best option, considering age, patient comfort, ease of installation, lack of breakages in clinical use, predictable results, and no need for patient compliance.\nTreatment was started using 0.016” NiTi in both arches, which was followed by 0.018” stainless steel wire with curve of spee, 0.018 × 0.025” and 0.019 × 0.025” NiTi. Finally, a 0.019” × 0.025” stainless steel wire was placed after alignment of 2nd molars. Leveling and alignment was completed in 8 months. At the end of stage I, there was an 8 mm overjet and 6 mm overbite. This was followed by mandibular advancement using Forsus FRD [Figure –]. 29 mm length of push rod was selected. 0.019” × 0.025” SS in the lower arch was given labial root torque in order to prevent the flaring of the lower anteriors due to Forsus. Molar correction was achieved after 7 months of wearing the appliance. This was followed by 3 months of detailing and finishing of occlusion combined with light class II elastics, which were gradually tapered off. The patient was observed for 2-3 months with the appliance in place, without any active forces to check the stability of correction and any occurrence of dual bite. The total active treatment time was 21 months.\nA maxillary removable Begg's wrap around retainer with anterior inclined plane to hold the corrected jaw relation was used for 6 months. This was followed by placement of permanent bonded mandibular cuspid-to-cuspid lingual retainer.