CBCT Evaluation Before and After Maxillary Expansion
Maxillary expansion, particularly Rapid Maxillary Expansion (RME), is a common orthodontic procedure used to widen a narrow upper jaw (maxilla). This technique is essential for improving dental arch spacing, but it also has a significant impact on the patient’s airway and breathing. For children and adolescents, whose bones are still growing, RME can correct maxillary constriction, leading to better breathing, nasal airflow, and even improved sleep quality, especially in those with conditions like pediatric obstructive sleep apnea (OSA).
In recent years, Cone Beam Computed Tomography (CBCT) has become a valuable tool for assessing the structural changes in the maxilla and airway before and after maxillary expansion. In this blog, we’ll explore how CBCT helps evaluate the maxilla and surrounding structures during this process and why it’s a critical part of modern orthodontic care.
1. Pre-Treatment CBCT: Understanding the Starting Point
Before maxillary expansion begins, CBCT imaging provides a highly detailed three-dimensional (3D) view of the patient’s craniofacial structures. This pre-treatment scan offers orthodontists and surgeons valuable insights into the current state of the maxilla, nasal cavity, and upper airway.
What Can Be Evaluated with Pre-Treatment CBCT?
Maxillary Width: The CBCT scan precisely measures the transverse dimension of the upper jaw, determining the extent of maxillary constriction and the degree of expansion needed.
Airway Volume: In cases where breathing issues are suspected, CBCT can measure the volume of the upper airway, providing a clear picture of any obstructions or areas of reduced airflow.
Nasal Cavity Anatomy: CBCT reveals the nasal cavity structure, identifying any deviations or blockages, such as a deviated septum, which may contribute to breathing difficulties.
Dental and Skeletal Relationships: The position of the teeth in relation to the upper and lower jaws, as well as the relationship between the maxilla and mandible, can be evaluated. This helps identify any existing malocclusions that could benefit from expansion.
CBCT is especially useful in complex cases, as it allows clinicians to develop a personalized treatment plan based on an accurate understanding of both dental and airway-related concerns.
2. Post-Treatment CBCT: Measuring the Impact of Maxillary Expansion
After the maxillary expansion is complete, a follow-up CBCT scan is performed to assess the changes that have occurred. This post-treatment evaluation is crucial for determining the success of the procedure and ensuring that the desired results have been achieved.
What Does Post-Treatment CBCT Reveal?
Increase in Maxillary Width: The primary goal of maxillary expansion is to widen the upper jaw. CBCT provides a direct comparison between the pre- and post-expansion scans, allowing clinicians to measure the precise increase in width.
Improved Airway Volume: Maxillary expansion often leads to increased nasal airway volume, which can improve breathing. CBCT helps visualize changes in the nasopharynx and oropharynx, confirming that the expansion has successfully opened up the airway.
Changes in Sinus and Nasal Structure: The expansion process can also affect the nasal cavity and sinuses, improving nasal airflow. Post-expansion CBCT scans can show how these structures have shifted and whether the patient’s nasal breathing has improved.
Dental and Occlusal Changes: As the maxilla expands, the teeth shift into new positions. CBCT helps assess how the expansion has impacted dental alignment, ensuring that the teeth are now better positioned and that any previous issues like crowding or crossbite have been addressed.
3. Airway Benefits of Maxillary Expansion: What CBCT Reveals
Maxillary expansion doesn’t just benefit dental health—it also has a profound effect on the airway, especially in children who suffer from conditions like OSA or chronic nasal congestion. CBCT is instrumental in visualizing these changes and confirming improvements in airway function.
Key Airway Benefits Documented with CBCT:
Increased Nasal Airway Space: A narrow maxilla often restricts airflow through the nasal passages, leading to mouth breathing or snoring. CBCT scans taken after expansion show a wider nasal cavity, which typically results in improved airflow and easier nasal breathing.
Relief from Obstructive Sleep Apnoea (OSA) Symptoms: For children with OSA, CBCT can demonstrate increased upper airway volume, which reduces airway resistance and lowers the frequency of apnoea episodes during sleep.
Reduction of Breathing Issues: Improved nasal airflow can alleviate other breathing problems, such as chronic mouth breathing, which can lead to dental issues and disturbed sleep.
4. Why CBCT Is the Preferred Imaging Tool for Maxillary Expansion
CBCT has become the gold standard for evaluating maxillary expansion for several reasons. Unlike traditional 2D X-rays, CBCT provides detailed 3D images that capture both bone and soft tissue structures. This level of detail is essential for accurately assessing the changes brought about by expansion and for planning any necessary adjustments.
Key Advantages of CBCT:
Precise 3D Visualization: CBCT offers a full 3D view of the entire craniofacial complex, allowing for a comprehensive assessment of the maxilla, airway, and nasal cavity.
Accurate Measurements: Orthodontists can measure the exact amount of expansion achieved and compare it with the initial scan, ensuring that the treatment has progressed as planned.
Airway and Sinus Evaluation: CBCT is not just limited to dental structures—it also provides critical information about the airway, sinuses, and nasal passages, making it a multi-functional tool in orthodontic treatment planning.
5. Monitoring Long-Term Stability
Maxillary expansion is typically a stable procedure, especially in younger patients whose bones are still developing. However, follow-up CBCT scans can help monitor long-term stability, ensuring that the maxilla remains in its expanded position. Additionally, CBCT can track whether the positive effects on the airway and nasal breathing are maintained over time, offering valuable insights for future treatment adjustments if necessary.
Conclusion
CBCT is an essential tool in the evaluation of maxillary expansion, providing unparalleled detail in both pre-treatment planning and post-treatment assessment. By offering precise 3D imaging of the maxilla, nasal cavity, and airway, CBCT ensures that orthodontists can plan and monitor the expansion process effectively, leading to improved dental and respiratory outcomes. For children and adolescents, maxillary expansion has the potential to not only improve dental alignment but also significantly enhance breathing and sleep quality, particularly in those suffering from OSA or chronic nasal obstruction. CBCT ensures that these benefits are realized and maintained, making it an indispensable part of modern orthodontic care.