Deep Bite Correction Strategies

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Managing Deep Bite and Torque in Clear Aligner Therapy

This article addresses a clinical case involving the correction of a deep bite and torque issues in a patient undergoing clear aligner therapy. Due to the case being over 90 days old, some original communication through Slack was unavailable, but essential questions and treatment considerations have been retained and expanded upon here.

Clinical Background

The patient initially presented with a pronounced deep bite and noticeable wear on the anterior teeth. The treatment plan involved intruding the lower incisors and correcting the torque of the upper teeth. Importantly, the problem was not related to a poor smile arc but rather a lingual inclination of the upper anterior teeth.

At a later point in treatment, the patient had reached their 13th aligner in a previous round, showing some progress. However, further torque and deep bite correction were still necessary.

Refinement Challenges and Treatment Strategy

A primary concern in this case was how to continue progressing after multiple batches of aligners. A refinement had been created based on the current aligner in use at that time, rather than initiating a new set from a better-defined starting point. This may have limited the effectiveness of the movements planned.

The aligners were reportedly fitting well enough based on dental monitoring assessments, with no issues in tray seating or engagement. Nevertheless, the clinical concern was that the changes were insufficient in magnitude. The treatment outcomes appeared too polished and idealized; in reality, successful correction would require a more aggressive or “messier” approach to achieve the intended biomechanical effects.

The primary recommendation was to significantly over-treat both the torque and the intrusion. The treatment up to that point had achieved only a fraction of the intended movements—perhaps one-quarter. To address this, the movements needed to be exaggerated far beyond the desired endpoint to achieve a clinically effective result.

Smile Arc and Curve of Spee Considerations

While the curve of Spee appeared close to flat, the deeper issue lay in insufficient lingual crown torque. A common strategy in such cases is to avoid performing multiple demanding movements simultaneously. Rather than attempting to achieve palatal root torque and intrusion concurrently, the preferred approach is a sequenced strategy:

  1. Proclination of the anterior teeth – This reorients the teeth and creates space for intrusion.

  2. Intrusion along the long axis – Once the teeth are proclined, intrusion can be performed more predictably.

  3. Retraction – After sufficient space is gained, the teeth can be retracted to their final position.

Space may need to be created distal to the canines to facilitate this sequence. This strategic ordering of movements prevents the teeth from pushing into the cortical plate of the maxilla, which can act as a barrier to intrusion.

Anatomical Limitations

Using CBCT imaging, it is possible to identify when tooth roots are impinging on the dense cortical plate. If roots contact the cortical boundary, intrusion becomes mechanically constrained. In such cases, applying intrusion forces directly may be ineffective, as the anatomical resistance of the bone halts movement.

When this occurs, clinicians may consider two main approaches:

  1. Overtreating torque with significant palatal changes, ensuring robust attachments—especially on the premolars and molars—to anchor movements.

  2. Employing a three-phase movement plan: proclination, intrusion, and retraction.

Additional Techniques and Considerations

A third strategy involves the use of temporary anchorage devices (TADs) to facilitate maxillary intrusion. While this is more invasive, it can provide direct and powerful vertical control when conventional aligners fall short.

For mandibular teeth, over-treatment of the curve of Spee and strong patient compliance are essential. Additional measures include using lingual attachments. When a patient bites into the trays with lingual attachments in place, those attachments engage actively, helping to manage vertical forces and support the intrusion effort.

Summary

This case underscores the importance of overtreatment and sequencing in managing complex torque and deep bite issues with aligners. Strategies such as proclination before intrusion, anchorage via molars and premolars, and possible use of TADs or lingual attachments can all contribute to improved outcomes. Compliance and clear communication with the patient remain critical throughout the process. In challenging cases like this one, success often hinges not on doing less, but on overdoing key movements to overcome anatomical and biomechanical limitations.