Introduction

Class II malocclusions and anterior open bites represent two of the most frequent challenges in orthodontic practice. Traditionally, they have been considered difficult-to-treat malocclusions, often leading to more invasive therapeutic approaches such as dental extractions or even orthognathic surgery in certain cases. However, recent evidence shows that, in the absence of significant facial discrepancies, satisfactory outcomes can be achieved through less invasive approaches.

In this context, clear aligners combined with temporary anchorage devices (TADs) have proven to be an effective and esthetic alternative, offering comfortable treatments for patients, reduced treatment times, and high predictability of results. These techniques allow not only the correction of dental discrepancies but also the modification of occlusal planes, making it possible to address complex malocclusions such as Class II and open bites with long-term stability.

Etiology and Diagnosis

We present the clinical case of a 36-year-old female patient whose main concern was to improve function and esthetics. The patient had no relevant medical history.

On extraoral examination, the patient presented with a dolichofacial pattern characterized by an increased lower facial third, a mandibular deviation to the right side, a gummy smile, and a convex Class II profile. Intraoral analysis revealed a Class II molar and canine relationship, complete on the right side and partial on the left, accompanied by an anterior open bite extending from premolar to premolar. The lower dental midline was deviated 4 mm to the right, and both arches exhibited bimaxillary constriction with negative posterior inclinations, more pronounced in the second and fourth quadrants as a result of compensatory adaptations to the mandibular deviation. Additionally, anterior crowding was observed, further complicating the occlusal relationships.

Treatment Plan and Progress

Treatment Objectives

The treatment objectives focused on both dental and skeletal corrections. Dentally, the plan aimed to expand both arches, correct compensatory negative posterior inclinations, partially distalize the first quadrant while maintaining a partial Class II relationship to facilitate mandibular anterior rotation, achieve posterior intrusion, slightly extrude the lower incisors, and level and align both arches. Skeletally, the objectives included correcting the anterior open bite by addressing the divergence of the upper and lower occlusal planes, eliminating maxillary canting, and promoting mandibular anterior rotation. Virtual planning involved derotation of tooth 1.6 followed by sequential distalization of one-third of the first quadrant, performed simultaneously with leveling of the upper incisors. The upper arch was expanded and the incisors retracted with overcorrection of radiculo-palatal torque in the anterior segment, while greater posterior intrusion was programmed in the second quadrant to correct canting.

The lower arch was expanded coronally, and the lower incisors were leveled with interproximal reduction (IPR) to resolve the Bolton discrepancy. A virtual jump was incorporated to achieve mandibular anterior rotation and midline centering. In terms of anchorage, in addition to intra-arch support, a temporary anchorage device (TAD) was placed on the distal occlusal surface of tooth 1.6 and connected with a power chain to enhance the predictability of distalization and intrusion in the first quadrant, allowing a faster sequence. Two additional TADs were placed in the second quadrant, one buccally between teeth 2.5 and 2.6, and another palatally between teeth 2.6 and 2.7, enabling the patient to use an elastic over the aligner to reinforce posterior intrusion. Finally, Class II elastics anchored to integrated hooks were prescribed to promote mandibular anterior rotation and midline correction.