2nd Molar Extraction: What You Need to Know

Introduction

Second molar extraction is a less common but potentially effective orthodontic treatment option in certain cases. While not as frequently employed as premolar extractions, removing second molars can provide unique benefits in specific clinical scenarios. This article will explore the indications, considerations, and outcomes of second molar extraction to help you understand this treatment modality better.

When is Second Molar Extraction Considered?

Orthodontists may consider second molar extraction in several situations:

• Severe crowding in the posterior region
• Class II malocclusions with deep overbites
• To create space for third molar eruption
• In cases where premolar extraction may negatively impact facial aesthetics

According to a study by Waters et al. (2001), second molar extraction can be particularly effective in treating Class II, deep-bite, low-angle malocclusions.

Effects on Third Molar Eruption

One of the primary considerations in second molar extraction is its impact on third molar eruption. Bishara et al. (1986) found that second molar extraction can lead to faster eruption of third molars and reduce the number of impacted third molars. However, they also noted that the erupted third molars may have poor angulation or contact with first molars.

Orthodontic Outcomes

Second molar extraction can have significant effects on orthodontic treatment outcomes:

• Distal movement of first molars: Waters et al. (2001) observed an average of 1.2 mm distal movement of maxillary first molars in second molar extraction cases.
• Overbite reduction: Stellzig et al. (1996) reported an average overbite reduction from 4.7 mm to 2.7 mm in their study.
• Class II correction: The same study found that 92% of patients achieved Class I occlusion despite initial Class II relationships.

Timing of Extraction

The timing of second molar extraction is crucial for optimal results. Ruiken et al. (1992) suggest that extraction should be carried out when third molars have reached their full crown stage but before radiographic evidence of root formation. They also noted that upper third molars with an angulation of less than 30 degrees and lower third molars with an angulation of 30-60 degrees to the occlusal plane are likely to erupt satisfactorily.

Potential Risks and Complications

While second molar extraction can be beneficial, it's not without risks:

• Poor third molar positioning: As mentioned earlier, third molars may erupt with unfavorable angulation.
• Incomplete space closure: In some cases, the space created by extraction may not fully close.
• Periodontal issues: There's a potential for periodontal problems if the third molar doesn't erupt properly.

Alternative Approaches

In cases where second molar extraction is considered but not ideal, alternative approaches may be used:

• Premolar extractions: More common and may be preferred in certain cases.
• Molar distalization: Using devices like miniscrews to move molars distally without extraction.
• Expansion: In some cases, arch expansion may provide the necessary space.

Conclusion

Second molar extraction can be an effective orthodontic treatment option in carefully selected cases. It offers unique advantages in managing certain malocclusions and can positively influence third molar eruption. However, the decision to extract second molars should be made after thorough consideration of individual patient factors, potential risks, and alternative treatment options. As with any orthodontic procedure, careful planning and execution are key to achieving optimal outcomes.