Deforming oral habits are learned repetitive behaviors with no functional purpose that can lead to malocclusion. Common harmful oral habits discussed in the document include thumb sucking, mouth breathing, nail biting, and tongue thrusting. These oral habits become unconscious over time and can cause dental issues depending on factors like age and frequency. For example, thumb sucking is normal for young children but considered abnormal past age 3-4 and can result in issues like an open bite and crossbite if persistent. Studies have found correlations between oral habits and malocclusion in both deciduous and permanent dentition.

1. ‫الطبية‬ ‫التقنية‬ ‫كلية‬-‫مصراتة‬
II ‫األسنان‬ ‫تقويم‬ ‫تقنية‬
Orthodontics II
9
‫د‬.‫قندي‬ ‫أمحـمد‬ ‫فتحي‬

2. ‫الضارة‬ ‫الفموية‬ ‫العادات‬
Deleterious Oral Habits

3. Bruxism

4. Mouth breathing

5. Thumb sucking

6. Nail biting

7. Tongue thrusting

8. DONE

10. Deforming oral habits are defined as a form of behavior that is picked-up due to its
frequent repetition. They have no functional use nor are they necessary.
Oral habits are learned patterns of muscular contractions, which are complex in nature
Bad Oral Habits
Habit is defined as an automatic response to a specific situation acquired normally
as the result of repetition and learning
They are conscious at the beginning and become unconscious at some point in the
child’s development.
These harmful oral habits represent the primary cause for maloclusion. They
produce an imbalance between the intra and extra oral musculature. The
repercussions depend on the age of the subject and also the frequency and
intensity with which they occur.

11. • For example, a thumb sucking or tongue thrusting habit in a 3 year old can be
considered normal, while the same habit in an 11 year old is considered abnormal.
Oral habit is normal behavior in infants. Usually temporary and disappear by itself
at the age of about 3-4 years.
There is a correlation between oral habits and malocclusion of deciduous dentition;
40% of the causes of malocclusion were found to be related to oral habits. It has
been reported that the incidence of malocclusion in children with oral habits was
74 %, while the incidence was only 25.1% in children without any oral habit.

12. • Digital sucking (3.6%) and mouth breathing (6.3%) was mostly observed among younger
age group (7 to 9 years).
• However nail biting (4.3%) and lip biting (4.7%) was commonly noticed in older sample.
Basra AS, Kaur N, Singh A, Singh K, Singh KP (2016) Deleterious Oral Habits among School
Going Children - A Cross- Sectional Study. J Interdiscipl Med Dent Sci 16

13. Thumb Sucking
Recent studies have shown that thumb sucking may be practiced even during intra
uterine life. The presence of this habit is considered quite normal till the age of 3-4
years. Persistence of the habit beyond this age can lead to various malocclusions.
The child has the tendency to place his fingers or any other object into the oral
cavity.
Thumb sucking habit can be defined as the repeated forceful sucking of the thumb
with associated strong buccal and lip musculature contraction.
Repeated and forceful sucking of thumb with associated strong buccal and lip
contractions. Starts in I.U life and continues up to first 2 yrs; disappears with
maturation.

14. Thumb sucking is a habit that is common in children. The habit of thumb sucking
that prolonged can cause malocclusion. According to Profit (2000) 6, characteristics
malocclusion related to the combination of pressure directly from the thumb and
change patterns of pressure cheeks and lips. Cheek pressure on the mouth corner is
the highest pressure, the pressure of cheek muscle to the posterior teeth of upper
jaw increased due to the contraction of buccinators muscles during sucking at the
same time so it makes maxilla into shaped V.
Also other non-nutritive habits such as thumb sucking or finger sucking are often
implemented by infants/children to pacify and comfort themselves, as sucking is a
natural instinct for a baby, and it is the baby’s first coordinated muscular activity
Sucking habits inhibit growth of the mandible, produce not only upper protrusion
and spacing but also lingualization of the lower teeth. It also increases the risk for
gastrointestinal disease.

15. Digit or thumb sucking results in various side-effects as follows:
1. Anterior open bite
2. Increased overjet
3. Lingual inclination of lower incisors and the labial inclination of upper incisors
4. Posterior cross bite
5. Compensatory tongue thrust.
The side effects of finger sucking are
• 1. Anterior open bite
• 2. Increased over jet .
• 3. Lingual inclination lower incisor and labial inclination upper incisor.
• 4. Posterior cross bite .
• 5. Compensatory tongue thrust .
• 6. Deep palate.
• 7. Speech defect .
• 8 Finger defects.