Oral Habits

Thumb and Finger Habits

Thumb and finger habits make up the majority of oral habits. However two thirds of children who engage in thumb and finger habits outgrow them by age five. The dentofacial changes will vary with the intensity, duration and frequency of the habit and the position of the digit in the mouth. The dentofacial changes include:

  • Anterior open bite
  • Facial movement of the maxillary incisors
  • Lingual movement of the mandibular incisors
  • Maxillary constriction

The earlier the habit is discontinued the greater the likelihood of dentofacial changes self correcting. However, the child should be allowed to stop the habit spontaneously. Most habits stop in school due to peer pressure so definitive treatment is not initiated until ages 4-6 years. If the child or the parent does not want to discontinue the habit do not force the issue. The type of treatment prescribed is dependent on the child’s willingness of the child to stop the habit.

Image: Girl sucking thumb
Image: Dental disfiguration due to thumb sucking.

The simplest treatment is counseling the patient. The success of this approach is dependant on the child’s ability to understand the consequences of continuing the habit. This approach is most successful in older children. A second approach is reminder therapy. This is effective in a child who wants to stop the habit but needs additional help. The technique involves placing a cue on the patient’s finger as a reminder not to place their finger in the mouth, especially while sleeping. The cues may be a bandage, a sock or mitten, a bitter substance or a commercially bought appliance. It is important to emphasize to the child that the treatment mechanism is not a punishment but just a reminder.

The reminder therapy can be used in conjunction with a reward system.  A contract is drawn up with the child and parent.  The contract states that the child will discontinue the habit in a specified amount of time and if successful will receive a reward (the type agreed upon by the parent and child).  Placing stickers or marks on a calendar monitors the child’s progress.

Image: Child with thumb covered to deter thumb sucking.
Image: Mavala STOP product
Image: Puoch with quarters to represent the reward contract for not sucking thumb.
If the habit persists after the reminder therapy and the child truly wants to discontinue the habit then intraoral appliance therapy should be considered. The intention of placement of intraoral appliance is to discourage the habit by making it difficult to suck the thumb or finger.

Common Intraoral Appliances

The Quadhelix appliance has a dual function. The appliance acts as reminder to the child not to place the thumb or finger in the mouth and simultaneously expands the constricted arch, if present.

Image: Quadhelix appliance
The Kentucky Bluegrass appliance discourages the digital habit by reducing sucking satisfaction. The acrylic cylinder spins as pressure is exerted by the thumb or finger interfering with placement of the digit. It does not expand constricted arches.
Image: Kentucky Bluegrass appliance
The Palatal Crib mechanically interferes with thumb and finger placement. It does not expand a constricted arch.
Image: Palatal Crib

It should be emphasized to the child that these appliances are not punishments but are aids in discouraging the unwanted habit.


The consequences of extensive use of a pacifier are similar to that of finger and thumb sucking but not as pronounced. The pacifier habit tends to end earlier than digital habits because they are easier to lose intentionally or non-intentionally. Ninety percent are ended before 5 years of age and 100% by age 8. The earlier the pacifier is removed the greater the chance of the dentofacial changes self correcting.

Image: Child with pacifier in mouth.
Image: Pacifier damage to teeth.

Lip Habits

Lip licking is the most common lip habit. The most common clinical effects are inflamed chap lips exhibiting an erythematous wide border encircling the lips with normal skin area just around the vermillion border. Severe lip licking, with the lower lip tucked behind the maxillary incisors, places excessive lingually directed forces on the mandibular teeth and facial forces on the maxillary teeth, resulting in retro-inclination of the mandibular incisors, proclination of the maxillary incisors and increased overjet. There is little that can be done to stop the habit, however, the irritated areas can be controlled with the application of steroids, antibacterial and antifungal ointments.

Image: Lip licking
Image: Lip sucking


Bruxism is the nonfunctional grinding or gnashing of teeth. It occurs most often during sleep, however some children grind their teeth when awake. It results in wear of teeth and can cause masticatory muscle soreness and TMJ pain. Local factors include occlusal interferences or high restorations. Systemic factors include stress, personality disorders, nutritional deficiencies, allergies, endocrine disorders, musculoskeletal disorders and mental retardation. Most children outgrow the habit and treatment is unnecessary. For those that do not, treatment consists of:

  • Equilibration of the occlusal interferences
  • Referral to medical personnel to rule out systemic or psychological problems
  • Fabrication of a night grinding appliance
Image: Bruxism
Image: Night grinding appliance