Parafunctional Habits: What You Need to Know
A parafunctional habit, like grinding, thumb sucking, or tongue thrusting, is the repeated use of oral structures for things other than eating, swallowing, speaking, or breathing. Why are they so bad? The mouth is like a piece of precision machinery. When something goes wrong, it causes a chain reaction of failures. Parafunctional habits are like a monkey wrench in the machine.
Bruxism (Grinding)
Bruxism, or grinding, is the ultimate monkey wrench. It happens during sleep and comes in episodes where the jaws exert large amounts of force and grind against each other. Over time, bruxism leads to breakdown of the teeth and can cause damage to the temporomandibular joint (TMJ).
Bruxism can be caused by a bad bite, obstructive sleep apnea, or stress. Many people don’t realize they grind until their dentist sees signs or a spouse/roommate notices the grinding.
Symptoms of Bruxism
- Sore or stiff jaw muscles
- Headaches, especially upon waking
- Sore back or neck
- Sensitive teeth
- Painful salivation when first eating
- Jaw pain
- Snoring (grinding can be caused by sleep apnea)
Signs Your Dentist Will Look For
- Scalloped tongue
- Ridges along the inside of the cheek
- Worn teeth
- Notching at the gumline
- Broken or chipped teeth
- Worn or broken fillings
- Narrow airway, large tonsils, small chin, or large tongue
Treatment for Bruxism
If sleep apnea is the cause: Your dentist will refer you to a sleep specialist. Treatments for sleep apnea usually resolve grinding.
Occlusal Guard: A hard acrylic guard custom-made for your teeth, worn at night. It protects teeth and provides relief for the jaw joint and muscles.
Bite Correction: If you have a bite problem, corrections can reduce grinding. Options include:
- Orthodontics (braces)
- Equilibration (small adjustments to teeth)
- Restoring the bite with crowns
Thumb Sucking
Thumb, finger, or pacifier sucking (non-nutritive sucking) is a parafunctional habit. Sucking is a reflex important for self-soothing in infancy. Infants suck for comfort, and for some, it becomes a habit. Most children outgrow it early, but those who don’t face a destructive habit.
What Thumb Sucking Does
Because the thumb exerts pressure against the roof of the mouth and front teeth, it actually reshapes the bones of the upper jaw. The result is:
- Protruding front teeth
- High, narrow palate
- "Reverse smile line" where upper teeth form a rainbow shape (Anterior Open Bite)
This can contribute to tongue thrust and affect speech. Finger sucking can cause an open bite on one side, depending on finger placement.
How to Treat Thumb Sucking
Prevention is key. If babies are given a pacifier to suck rather than thumbs, it can be removed between 4–6 months fairly easily. If the habit is already established, treatments include:
- Thumbuddy (a thumb puppet character)
- Limiting thumb sucking to specific times
- Talking to your child about quitting
Tongue Thrust
All babies are born with tongue thrust—it’s how infants eat. As you grow, the swallowing pattern changes and tongue thrust should disappear by age 7. If it lingers after age 4, it’s a parafunctional habit.
What is Tongue Thrust?
When you swallow normally, your tongue is positioned on the hard palate behind upper front teeth and moves food toward your throat. With tongue thrust, the tongue positions on the backs of front teeth and protrudes through them.
Consider this: the average person swallows 1,200–2,400 times a day, exerting 4 pounds of pressure with each swallow. Tongue thrust pushes the tongue where it shouldn’t be, quickly causing changes.
Causes of Tongue Thrust
- Anything preventing nose breathing
- Thumb sucking
- Difficulty swallowing
- Large tongue
- Angle of jaw line
- Genetics
- Muscular or neurological abnormalities
- Short tongue or being tongue-tied
Signs of Tongue Thrust
- Mouth breathing
- Puckered lips when swallowing
- Open bite
- Gum problems
- Drooling
Types of Tongue Thrust
Tongue can thrust in different directions, causing different teeth malformations:
- Anterior Open Bite: Most common; lips close improperly, tongue protrudes
- Anterior Thrust: Lower lip pulls on lower teeth; upper teeth protrude
- Unilateral Thrust: Tongue postures to one side; open bite on one side
- Bilateral Thrust: Tongue thrusts to mouth sides; teeth on sides open
- Bilateral Anterior Open Bite: Large tongue; only molars touch
- Closed Bite Thrust: Teeth meet, but both top and bottom are flared
- Mandibular Thrust: Inherited pattern; tongue held low and forward; lower jaw protrudes
Treatment for Tongue Thrust
Treating tongue thrust can be difficult but is successful about 75% of the time. Even if you correct teeth alignment with orthodontics, unless you treat the tongue thrust, orthodontics will fail.
Treatment types:
- Myofunctional/Tongue Therapy: Exercises to retrain the tongue
- Appliance Therapy: A crib-type appliance keeps tongue from backs of front teeth
When to Seek Help
If you suspect you or your child has a parafunctional habit, contact Greenspoint Dental. Early intervention prevents serious dental and health problems from developing. We can evaluate your situation and recommend the best treatment approach.