Yonsei Goodday Dental Clinic: Orthodontic Treatment Considering CO-CR Discrepancy

Hello.

This is Goodday,

sharing stories about dentistry with sincerity.

Although it may be somewhat unfamiliar to the general public,

we would like to explain in depth the concept of CO-CR Discrepancy,

which is carefully checked in actual clinical practice, especially in orthodontics and oral surgery.

A person’s jaw may have different positions

where the teeth come together and

where the temporomandibular joints are most stable.

The difference between these two positions

is called CO-CR Discrepancy.

What is CO-CR Discrepancy?

It is easier to understand after first learning about the two concepts.

CR (Centric Relation) refers to

the state in which the temporomandibular joints (condyles)

are positioned most stably,

regardless of the position of the teeth.

You can think of it as a reference point

where the temporomandibular joints are positioned comfortably

without unnecessary tension.

By contrast, CO (Centric Occlusion)

refers to the position where the teeth come together

when the patient naturally bites down firmly.

Movement of the mandible from CR to CO

Ideally, these two positions are the same,

but in some patients, tooth interference causes the jaw

to move forward or be pushed to the side

before finally coming together.

In other words, the temporomandibular joints may seek one position,

while the teeth cause occlusion to occur in another position.

This difference is called CO-CR Discrepancy.

Causes of CO-CR Discrepancy

Having CO-CR Discrepancy does not necessarily mean

that a temporomandibular joint disorder will develop.

However, when this difference is significant,

it may be an important factor that must be considered

when planning orthodontic treatment.

Yonsei Goodday Dental Clinic always checks

for CO-CR Discrepancy when treating patients with temporomandibular joint conditions

and provides splint or traction appliance treatment

according to each patient’s condition.

A splint helps reduce the load on the temporomandibular joints and masticatory muscles

and find a stable jaw position.

It can also help protect the temporomandibular joints

when symptoms such as teeth grinding or clenching worsen

due to stress, fatigue, or changes in sleep patterns.

Traction appliances are custom-made after consultation and detailed examinations.

The position and strength of the elastics are adjusted

while monitoring progress at intervals of approximately two to three months.

Therefore, when appropriately managed,

it is very rare for them to place excessive strain on the temporomandibular joints.

Both splints and traction appliances

can be made on the day of consultation and examination,

and treatment can begin after receiving the appliance

approximately one week later.

Traction appliance

Splint appliance

In the early stages of splint treatment,

some awkwardness, discomfort, or pain may occur

while adapting to the appliance.

However, most patients gradually adjust

with consistent use,

and symptoms other than discomfort when chewing food

often improve over approximately two to three months.

If orthodontic treatment is started

before the temporomandibular joints have become sufficiently stable,

symptoms involving the joints or changes in occlusion

may potentially worsen.

Therefore, Yonsei Goodday Dental Clinic proceeds with orthodontic treatment

after confirming that the temporomandibular joints and occlusion

have recovered stably.

We carefully monitor the progress

and determine the appropriate time to begin treatment.

To achieve stable long-term results,

before beginning orthodontic treatment,

it is essential to make a diagnosis that considers the balance of

the teeth, temporomandibular joints, and masticatory muscles together.

Yonsei Goodday Dental Clinic does not focus solely

on aligning the teeth.

To help patients chew comfortably even after orthodontic treatment

and maintain a functionally stable occlusion,

we carefully evaluate CO-CR Discrepancy as well

and aim to stabilize both the teeth and the temporomandibular joints through treatment.

We will continue striving to provide high-quality treatment

by carefully evaluating and diagnosing each individual’s condition,

rather than providing standardized care. ^^