How Can A Dentist Determine the Correct Vertical Dimension of Occlusion (VDO) in Complex Cases?

Getting the vertical dimension of occlusion (VDO) right feels like the ultimate test for any restorative dentist. We’ve all seen those cases where the patient presents with severely worn dentition, a collapsed lower third of the face, and perhaps a history of failed single-tooth dentistry. The temptation is to simply open the bite to create room for porcelain, but without a clinical rationale, you’re essentially guessing. Our goal here is to share how we should move away from guesswork and toward a repeatable, biological framework for establishing VDO in even the most daunting full-mouth cases.

Establishing a new VDO isn’t about hitting a specific measurement on a millimeter ruler. Instead, it’s about finding the physiological space where the muscles, joints, and teeth can coexist without conflict. If you’ve struggled with patients complaining that their new restorations feel “too big” or if you’ve seen early porcelain fractures on a beautiful new case, the issue almost always traces back to a mismanagement of the vertical dimension or the envelope of function.

What Is the Vertical Dimension of Occlusion (VDO)?

At its core, VDO is the space between your upper and lower jaws when your teeth come together. Essentially, it’s the height of your face when your mouth is closed. Getting the VDO right is crucial because it impacts everything from how the bite functions to how the face looks. In full-mouth rehabilitation cases, even small adjustments to VDO can make a significant difference in both aesthetics and long-term function.

In more complex cases, like restoring an entire mouth of teeth, determining VDO isn’t just about measuring the space between the teeth. It involves balancing form and function to ensure your patient’s bite is comfortable, natural-looking, and free of complications in the future.

Why Does VDO Matter in Complex Cases?

The vertical dimension of occlusion isn’t just a technical detail—it plays a direct role in the overall health and well-being of your patients. When the VDO is off, it can lead to several issues:

• TMJ discomfort (pain or clicking in the jaw)
• Muscle strain in the face and neck
• Tooth wear or misalignment that could lead to tooth loss
• Aesthetic issues, such as a too-short or too-long smile

For complex cases, especially when you’re restoring multiple teeth or correcting jaw relationships, getting the VDO right ensures that everything works as it should. When it’s off, even the best dental work can feel uncomfortable or unnatural.

How to Determine the Right VDO for Complex Cases

When it comes to determining VDO in complex cases, there’s no one-size-fits-all approach. Every patient is unique, and finding the correct VDO requires careful observation, measurements, and sometimes even a bit of trial and error. Here’s a step-by-step guide I follow to get it right.

1. Start with the Patient’s Current VDO

Before making any changes, it’s important to evaluate the patient’s current VDO. Sometimes, the patient is already used to their current bite, even if it’s not ideal. To start, look for any signs that might indicate a problem with the existing VDO, such as:

• Tooth wear or chipping—especially on the front teeth
• Jaw pain or clicking when opening or closing the mouth
• Muscle soreness in the face, especially after chewing

These signs can help you determine whether the VDO is too high or too low and what adjustments are needed.

2. Assess the Patient’s Facial Proportions

While measuring the VDO is important, you should also consider the patient’s facial appearance. Look at how their lips come together when they’re at rest, and take note of how much tooth is visible when they smile. The goal here is to create a bite that not only functions well but also looks natural.

Additionally, pay attention to the vertical facial height. This can help you determine whether the VDO needs to be increased or decreased. The idea is to find a balance that harmonizes with the patient’s overall facial proportions without making them look “overdone.”

3. Functional Assessment: Is the Bite Balanced?

Once you have a feel for the patient’s current VDO and facial proportions, you need to assess how the bite functions. A properly balanced bite is essential for long-term oral health. Here’s what I focus on:

• Jaw muscle relaxation: Proper VDO should allow the jaw muscles to rest in their most relaxed position, with minimal effort required to keep the mouth closed.
• Tooth contact: The bite should be balanced, with even pressure on all the teeth when the patient bites down.
• Jaw movements: The VDO should support smooth side-to-side and forward-backward jaw movements.

By checking these elements, you can ensure that the VDO isn’t just aesthetically pleasing but also functional.

4. Use Diagnostic Tools to Confirm

To refine your VDO measurements, it’s essential to use a few diagnostic tools to get precise data. Some of the tools I rely on include:

• Facebow transfer: This helps transfer the relationship between the patient’s maxilla and temporomandibular joint (TMJ) to the articulator. It’s useful for duplicating the patient’s bite in a more controlled setting.
• Jaw-tracking devices: These help monitor jaw movements and ensure the VDO adjustment is appropriate for the patient’s natural bite pattern.

Along with these, don’t forget the importance of photographs and radiographs to ensure that both the functional and aesthetic aspects of the patient’s bite are being properly considered.

5. Test and Adjust

Once the VDO is adjusted, it’s time to test the results. I usually begin with temporary restorations or bite splints to simulate the final bite. This phase gives me a chance to see how the VDO performs in normal use and allows me to make any necessary tweaks before finalizing the restoration.

The trial phase also provides an opportunity for patient feedback, which is essential to ensuring the VDO is right for them. After all, they’re the ones who will be living with the results, and their comfort is paramount.

The Importance of Early Evaluation

When dealing with complex occlusion cases, it’s crucial to act early. Evaluating the VDO and addressing any issues before the patient reaches adulthood can lead to faster, more predictable results. In fact, by intervening early in full-mouth rehabilitation cases, you can avoid the need for invasive surgeries or lengthy treatment plans later.

At Clinical Mastery, we offer training to help you learn how to offer predictable Full Mouth Rehabilitation services and handle complex occlusion cases. Our Colleyville campus provides hands-on learning, giving you the tools to master techniques that ensure functional, aesthetic, and comfortable results for your patients.

Why VDO is Key to Success in Full Mouth Rehabilitation

The vertical dimension of occlusion is more than just a measurement; it’s the foundation of a healthy, functional, and aesthetically pleasing smile. Getting it right in complex cases isn’t just about using the right tools—it’s about understanding the patient as a whole. By considering facial proportions and bite balance, and using diagnostic tools, you can help ensure your patients achieve the best possible outcome.

If you’re an aspiring dentist looking to improve your skills in full mouth rehabilitation, mastering VDO is a crucial step. At Clinical Mastery, we offer in-depth training to help you handle complex occlusion cases with confidence.

Interested in taking your skills to the next level? Book an appointment or sign up for our next course today.

People Also Ask

1. How do I know if the VDO is incorrect in my patient?
   Signs of an incorrect VDO include tooth wear, jaw discomfort, or muscle strain. A proper assessment of the bite and facial proportions will help determine if the VDO needs adjustment.
2. Can VDO change over time?
   Yes, VDO can change due to aging, tooth wear, or orthodontic treatments. Periodic assessments are essential to ensure the VDO remains correct.
3. How do I test the VDO before finalizing it?
   Temporary restorations or bite splints can simulate the final bite and give you an opportunity to adjust the VDO before proceeding with permanent restorations.
4. How can I improve my skills in determining VDO for complex cases?
   At Clinical Mastery, we offer specialized training to help you learn how to offer predictable Full Mouth Rehabilitation services. Our Colleyville campus provides practical learning experiences that will improve your confidence in managing complex cases.
5. Does increasing VDO cause long-term TMD issues? 

Actually, when done correctly in harmony with centric relation, increasing VDO rarely causes TMD. Problems typically arise from “interference” in the bite or forcing the jaw into a position that the muscles have to fight against, rather than from the vertical height itself.

6. Is there a specific limit to how much I can open the VDO? 

There is no “hard limit” in millimeters, but there is a biological limit for each patient. Most clinical studies suggest that a 3-5mm increase is well tolerated by most patients, provided the occlusion is balanced, and the change is tested in provisionals first.