Functional Risk Part 1 – What Causes It?

June 20, 2022 Lee Ann Brady DMD

I like to think that I have three things I provide to my dental patients:

  1. Risk assessment – helping them understand and fully own risk factors for their long-term dental health
  2. Risk management – helping them understand what they could do to manage that risk
  3. Damage repair – definitively treating a risk that was not completely managed

Many dentists do not pay attention to occlusion unless it is a problem for the patient or unless it becomes an issue in treating the patient. As I tell dentists in Essentials 1: Aesthetic& Functional Treatment Planning, assessing functional risk is as important to me as assessing other risks, such as caries or periodontal disease. I want to find the signs of functional risk, so if a patient has higher risk of damaging teeth from excessive loading, I can help the patient understand that risk and the options for managing it.

Functional Risk Assessment

In a previous blog, Occlusal Wear Part 1: Is it advancing? How fast?, I shared the mental game I play with every patient and the ways in which I document wear changes. With every patient, I ask myself, “Is the wear I see on the teeth normal for the patient’s age? Is it advancing at a pathological rate?”

I categorize patients in one of three functional risk categories:

  • Mild
  • Moderate
  • High

The patients I place in the high-risk category are those whose functional wear and tear is more than it should be for their age. Their teeth are breaking down noticeably faster than the average rate.

In my practice, we measure from the CEJ to the incisal edge of several teeth with wear. We take the measurement on the mid-facial and record it on the patient’s perio chart. At subsequent appointments, we can now repeat these measurements and have clear data showing that the process is continuing. Other great ways to document tooth wear are with photography and digital impressions. We compare scans months later and get a precise measurement of the change.

What causes someone to be at higher functional risk?

A lot of our patients have true TMD. What causes them to become symptomatic–where they have muscle issues, limited range of motion, jaw fatigue or joints trauma, myofascial pain, and they are breaking down their teeth? There are two primary causes: macro trauma and micro trauma.

  1. Macro trauma can cause a temporary injury to the temporomandibular system that then sets up chronic problems in the joints and muscles. This could be due to a car accident or sports incident. I have a macro-trauma patient who was hit was a lacrosse stick, another that was elbowed in the jaw during a basketball game, and a cheerleader who fell off a human tower.
  2. Micro trauma is what dentists call parafunction. This occurs when people put their teeth together outside the normal ways teeth touch when eating, speaking, and swallowing. We think of clenching (both static clenching and power wiggling), grinding, and tapping teeth together. We think of patients who bite their fingernails or chew on the inside of their cheeks or lips. There are lots of types of parafunctional activities. The force generated by the elevator muscles and how much of the time the muscles are overloaded leads to muscle symptoms. Accumulative force causes the excessive wear we see on teeth and damage to jaw joints.

To dentists, I say:

There are many people who have textbook malocclusions, and yet they have healthy teeth and joints. They don’t touch their teeth together outside of eating, speaking, and swallowing. There are many people with perfect occlusions who have TMD symptoms. Malocclusions don’t cause functional risk. Malocclusions don’t cause TMD. The essence of the problem is not how the teeth touch but how much they touch.

To patients with micro trauma, I say:

“You are tougher on your teeth than most of my other patients.” Staying away from psychologically negative words like clenching, grinding, and parafunction, I give them the word tougher. And I say, “You are missing more tooth structure than most people of your age.”

It is helpful for them to have this explanation before I recommend risk management strategies and pre-emptive restoration of teeth before they break.

An analogy I use with patients is the human knee. Knees don’t commonly wear out until someone is 60 to 70 years old, but long-distance runners can wear them out much earlier in life with the repetitive force of running. Our patients with parafunction put a lifetime’s worth of wear and tear on their teeth and their muscles and jaw joints in a compressed amount of time. Like a long-distance runner, their masticatory system suffers micro trauma.

It’s helpful to give patients words and analogies (like knees and car engines that wear out due to faster than normal wear and tear). I’ve had patients say to me, “I don’t like having to replace this crown, but as you said, I am tougher on my teeth than most people.”

Related Course

E2: Occlusal Appliances & Equilibration

DATE: August 10 2025 @ 8:00 am - August 14 2025 @ 2:30 pm

Location: The Pankey Institute

CE HOURS: 44

Dentist Tuition: $ 7400

Single Occupancy with Ensuite Private Bath (per night): $ 345

What if you had one tool that increased comprehensive case acceptance, managed patients with moderate to high functional risk, verified centric relation and treated signs and symptoms of TMD? Appliance…

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About Author

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Lee Ann Brady DMD

Dr. Lee Ann Brady is passionate about dentistry, her family and making a difference. She is a general dentist and owns a practice in Glendale, AZ limited to restorative dentistry. Lee’s passion for dental education began as a CE junkie herself, pursuing lots of advanced continuing education focused on Restorative and Occlusion. In 2005, she became a full time resident faculty member for The Pankey Institute, and was promoted to Clinical Director in 2006. Lee joined Spear Education as Executive VP of Education in the fall of 2008 to teach and coordinate the educational curriculum. In June of 2011, she left Spear Education, founded leeannbrady.com and joined the dental practice she now owns as an associate. Today, she teaches at dental meetings and study clubs both nationally and internationally, continues to write for dental journals and her website, sits on the editorial board of the Journal of Cosmetic Dentistry, Inside Dentistry and DentalTown Magazines and is the Director of Education for The Pankey Institute.

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When Your Occlusal Clearance Disappears

April 19, 2019 Lee Ann Brady DMD

It can be an incredibly frustrating clinical situation, when you have been meticulous about preparing a posterior tooth, (most commonly a molar) for a crown and things aren’t predictable. Using your burs you created depth cuts to ensure adequate occlusal clearance. After the impression you allow your assistant to fabricate the temporary only to have them come get you. Why? Because the temp is thin or perforated on the occlusal. When you go back to check, and have the patient bite, sure enough the opposing tooth is touching your prep.

A common reason that this happens is because we just prepared away the patient’s first point of contact in centric relation. The lateral pterygoid muscle in coordination with the elevator muscles has a learned pattern of firing that bring the mandibular teeth into maximum intercuspal position. This “learned” position is programmed by the patient’s first point of contact when the condyles are seated. For some patients when we remove this contact, and therefore the message that was programming the muscles to locate MIP, they release quickly. When the muscles release and the condyles seat, the occlusion is now totally different than MIP was moments before.

Leaf Gauge
Finding First Point of Contact

One solution that I considered briefly was to no longer work on molars! Alas, not a great business strategy.

Removing this frustration is about understanding which patients are at risk. Identifying risk begins with the exam, whether we are discussing caries or occlusion. There are several key factors that alert me to this potential issue. I start by identifying the patient’s first point of contact and clarifying if it is on the tooth we are about to prepare. If I am going to prepare FPC away, then I look at the magnitude and direction of the patient’s slide, or the difference between this position and MIP. If the difference is small (1-2mm), then even if their condyle does seat the occlusal difference will not cause an issue for clearance. So large slides (3mm or greater) could cost approximately 1mm of clearance on the prepared tooth. Other factors include whether they have a history of occlusal changes or more than one MIP they can find.

Understanding the risk, still leaves us with the question of how to proceed. That is a longer conversation for another post. However, if we proceed as we would before, at least knowing the risk we can explain this to the patient ahead of time, and help them understand how we would manage it if it happens.

Related Course

Functional Esthetic Excellence – Utilizing 100% Digital Workflow

DATE: May 8 2025 @ 8:00 am - May 10 2025 @ 2:00 pm

Location: The Pankey Institute

CE HOURS: 25

Dentist Tuition: $ 3195

Single Occupancy with Ensuite Private Bath (per night): $ 345

Embracing Digital Dentistry This course will introduce each participant to the possibilities of complex case planning utilizing 100% digital workflows. Special emphasis will be placed on understanding how software can…

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About Author

User Image
Lee Ann Brady DMD

Dr. Lee Ann Brady is passionate about dentistry, her family and making a difference. She is a general dentist and owns a practice in Glendale, AZ limited to restorative dentistry. Lee’s passion for dental education began as a CE junkie herself, pursuing lots of advanced continuing education focused on Restorative and Occlusion. In 2005, she became a full time resident faculty member for The Pankey Institute, and was promoted to Clinical Director in 2006. Lee joined Spear Education as Executive VP of Education in the fall of 2008 to teach and coordinate the educational curriculum. In June of 2011, she left Spear Education, founded leeannbrady.com and joined the dental practice she now owns as an associate. Today, she teaches at dental meetings and study clubs both nationally and internationally, continues to write for dental journals and her website, sits on the editorial board of the Journal of Cosmetic Dentistry, Inside Dentistry and DentalTown Magazines and is the Director of Education for The Pankey Institute.

FIND A PANKEY DENTIST OR TECHNICIAN

I AM A
I AM INTERESTED IN

VIEW COURSE CALENDAR