Influence of orofacial functions on development of face and occlusion

1. Influence of orofacial functions on
development of face and occlusion
Prepared by :Mohammed Al-Awdi
Under supervision :Prof. Maher Fouda

2. In this presentation we will talk about :
Orofacial functions and development of face
Pathophysiology of habits
Classification of orofacial habits
Prevalence of habits
Thumb sucking habit
Tongue thrusting swallowing habit
Mouth breathing habit
Bruxism

3. Introduction:
The orofacial skeletal and dental
development are inextricably linked with the
development of orofacial functions.
The orofacial neuromuscular components in
a newborn primarily function for fulfillment
of the most basic needs of feeding,
maintenance of the airway and gratification
of emotional needs. At this stage of life, an
infant tries to communicate with the world
through the sensory pathways present in
the oral structures of lips and tongue.

4. The lip and tongue act in unison with an intact palate to perform
the act of feeding. The suckling reflex is the most primitive of all
reflexes and yet it is the most well-developed reflex at this
stage. The tongue of the infant is so closely placed next to the
lips and tunnelled so as to cause the milk to flow into the
pharynx and oesophagus. This phenomenon is called infantile
swallow

5. Characteristics of an infantile swallow are:
During the act of swallowing, the
jaws remain apart with the
tongue tip interposed between
the gum pads.
The lower jaw is held and
stabilized primarily by contraction
of the muscles of facial nerve and
the interposed tongue.
The swallow is guided and largely
controlled by the sensory
interchange between the lips and
the tongue.

6. The sucking reflex and infantile swallowing
pattern normally remain for about a year and
slowly diminish as the child grows and start
intake of semisolid food life.
As the child grows, it develops a mature
swallowing pattern that is conducive to
chewing solid food and also helps in
developing speech abilities.

7. This graduation from unfocused
functions to multitasked functions
requires a coordinated development
of the neuromuscular apparatus
around face, jaws, oral cavity and
structures involved in deglutition.
Any deviation from this normal
course of events such as prolonged
retention of primitive functions or
development of an abnormal
function, adversely affects the growth
of the jaw and teeth.

8. While in an infant, the VII cranial nerve (facial nerve) has predominant
control over the muscles stabilizing the mandible, during first year with
the eruption of deciduous teeth, this role is overtaken by the structures
supplied by trigeminal nerve (muscles of mastication).
The tongue no longer thrusts into the space between the gum pads or
incisal surfaces of the teeth, which actually contact momentarily during
the swallowing act. The muscles of mastication take over the role of
stabilizing the mandible as the cheek and lip muscles reduce the
strength of their contraction.
Transition from infantile swallow to mature swallow

9. Normally the tip of the tongue rests near the incisor foramen during
the act of deglutition rather than moving in and out of the mouth.
Minimal contractions of the lips occur during the mature swallow.
Fletcher points out that a change from infantile swallow to mature
swallow may be due to morphologic compulsions of growth.
Whereas the general body dimensions change in the neonate at the
ratio of five to one, the infant tongue only doubles in size. Mature
swallow is normally well developed by 18 months.

10. Speech
Development of speech is another
important function that occurs in a gradual
manner pattern of maturation like the
swallowing pattern.
First the bilabial sounds (produced with
the lips close together or touching) like /b/
and /p/ are produced. Later on, tongue tip
consonants /t/, /d/, and sibilant( hissing )
sounds like /s/ and /z/ are produced. /r/
sound which is produced by a posterior
positioning of the tongue develops very
late.

11. Pathophysiology of habits
Habit has been defined simply as any task or function that is done
repeatedly, and is a part of the subconscious.
Orofacial habits influence the form of the orofacial structures because of
their repetitive nature and longer duration.
The effect of any pressure habit is dependent upon the
trident of habit factors:
1. Duration 2. Frequency 3. Intensity

12. Non-nutritive sucking habits like finger, thumb or pacifier sucking are seen
in many children at this age and these may continue till 2 years of age.
These habits normally stop with transition to mature swallow but some
times these may be seen till the age of 4 years.
Sucking habits

13. Sucking habits
Continuation of non-nutritive sucking habit beyond 4-5 years
greatly hinders the development of normal orofacial function.
During finger sucking, mouth remains open, tongue is positioned
forward and low in the mouth, and an abnormal pressure is generated
by the contraction of the cheek muscles which causes imbalance in
the intraoral force system.
The unfavourable consequences are narrowing of the maxillary arch,
proclined upper incisors, incompetent anterior lip seal and forwardly
placed tongue that moves forward to achieve a complete lip seal.

14. The lower lip becomes trapped under the proclined upper incisors and
this becomes a self-perpetuating problem where the lower lip keep
exerting an outward force on the upper teeth. An open bite like situation
may also be created due to persistent finger sucking. Thus typical Class
II division 1 malocclusion features are precipitated, because of the
cushioning effect of lower lips, and upper lip becoming
redundant(unnecessary).
The habitual lowering of the mandible further prevents natural lip seal
and the patient has to activate his/her lips in order to achieve anterior lip
seal.

15. Tongue thrusting
The repeated anterior positioning of the tongue, anterior openbite,
protruded and spaced anterior teeth and an incompetent anterior lip
seal, all lead to a tongue thrusting like situation. Tongue thrusting could
be the cause and consequence of anterior open bite.

16. Mouth breathing
If a child suffers nasorespiratory blockage due any reason, common ones
being enlarged tonsils, recurrent throat infections, he/she tends to keep
his/her tongue low and forward and is unable to maintain an anterior lip
seal. Such patients develop a mouth breathing habit with consequent
open mouth posture.

17. Classification of orofacial habits
Klein (1952) believed that the habits fall into broad category of :-
1. Unintentional pressure
2. Intentional pressure: those from
orthodontic appliances.

18. 1. Intrinsic pressures :
a. Thumb sucking b. Finger sucking c. Tongue thrust swallow
d. Mouth breathing e. Tongue, lip, cheek, blanket-sucking
f. Nail, lip, tongue bitingg. Macroglossia, overgrowth of the tongue
h. Incorrect swallowing, anaesthesia throat.
Within this broad category of unintentional pressure, he further divided habits into :
2. Extrinsic pressures: example incorrect pillowing
3. Functional pressures: malocclusion seen in musicians.

19. Prevalence of orofacial habits
A number of studies have been carried out around the world to gauge
the problem of thumb sucking and pacifier sucking habits in children. In
Delhi, the prevalence of oral habits in school going children (5-13 years)
was found 25.5%.4 Tongue thrusting was seen in 18.1% followed by
mouth breathing seen in 6.6% children
No habits,
74.5
Lip
biting,
0.04
Tongue
thrust ,
18.1
Mouth
breathing,
6.6
Thumb
sucking,
0.7 Others,
0.1

20. Non-nutritive sucking habits
Non-nutritive sucking habits include thumb sucking, finger sucking, lip
sucking and rarely the cheek. Thumb sucking refers to placing the thumb
or fingers into the mouth many times every day and night, exerting a
definite sucking pressure.
The habit can be repetitive and forceful associated with strong cheek and
lip contractions.

21. Pathophysiology of thumb sucking induced class II div 1 malocclusion and tongue thrust swallow

22. Several theories have been put forward to explain thumb sucking habit
Freudian theory of psychoanalysis is linked to psychosexual development of human. This
theory regards thumb sucking as a symptom of a deeper emotional disturbance or
neurosis(Depression, anxiety).
Eysenck’s learning theory regards it as a form of neurotic symptom itself and not caused by
underlying neurosis. If the symptom (habit) is eliminated, the neurosis will also be
eliminated. Most of the habit breaking appliances work on the learning theory.

23. Several theories have been put forward to explain thumb sucking habit
Palermo theory regards thumb sucking arising out of a progressive stimulus and reward reaction
which would spontaneously disappear unless it becomes an attention getting mechanism.
Sear’s oral drive theory believes that the thumb sucking habit is intimately related to the
prolongation of breastfeeding. The longer the baby is breastfed, stronger will be its oral drive
and more prone it is to thumb sucking

24. Types of thumb sucking
How children place the thumb has been studied using by Subtelny who grouped them A-D.
1. Group A (50%). Thumb was
inserted in the mouth considerably
beyond the first joint or the knuckle.
The thumb occupied a large portion
of the palate pressing against the
palatal mucosa and alveolar tissue.
The lower incisor pressed and
contacted the thumb in the region of
first joint.
2. Group B (24%). The thumb did
not go completely into the vault area
of the hard palate, however. It
entered the mouth up to and around
the first joint or just anterior to it.

25. Types of thumb sucking
4. Group D (6%). The thumb did not
progress appreciably into the mouth. The
lower incisor contacted at a level near the
thumb nail
3. Group C (20%). The thumb passed fully into
the oral cavity and approximated the vault of
the hard palate as in group A. However, the
lower incisor did not touch or contact the
thumb.

26. Effects of digit sucking on oral structures
Digit sucking results in development of features of class II malocclusion.
Proclination of the upper incisors is the first and the most common sign of
persistent thumb sucking. The proclination is self-maintaining because of the
cushioning effect of lower lips, and upper lip becoming redundant. These
proclined incisors are prone to accidental trauma

27. 1. Exaggerated mentalis activity may be seen because
of the effort of the lower lip to attain a lip seal
anteriorly.
2. Maxillary arch shows constriction due to unopposed
pressure from the buccal musculature. Posterior crossbite
tendency may occur.
3. Mandibular incisors may be retroclined or upright.
Effects of digit sucking on oral structures

28. 4. Mandible experiences downward and backward rotation
due to lowered position while sucking.
5. An increase in the ANB angle is seen due to both maxillary
prognathism and mandibular retrognathism.
6. Patient may develop tongue thrusting due to appearance
of spaces in the anterior region.

29. Interception of habit
An initial consultation with the paediatric dentist or the orthodontist will help in
formulating a line of treatment which is dependent upon the age of the patient and
severity of the condition.
• It is suggested that for children below 2 years non-nutritive sucking habit is very
common.
But parents must be alerted towards any possible deficit in attention or inadequate
feeding for the child. If there is no obvious cause then, this habit should
self-correct with time.

30. • For the habits persisting beyond 2 years, i.e. up to 4 years of age, attention must be
given towards the child in terms of love and care. With both parents working, the child
may suffer from attention deficit which should be taken care of.
• In children older than 4 years, signs of malocclusion
should be treated with a reminder therapy.
Mocking and scolding should be avoided at all times.
Attention diverting activities such as outdoor sports
could help.
• In older patients (> 7 yreas) with moderate to severe
form of malocclusion like anterior open bite or posterior
crossbite, definitive appliance therapy should be initiated.

31. Methods used for interception of the thumb sucking habit
ModalitiesIndication
Chemical method
Application of a bitter and a
malodorous chemical like quinine,
asafetida. Cayenne pepper
dissolved in a volatile liquid may
also be used
In an older child of at least 6-7
years who wants to break the
habit but is unable to do soReminder therapy
Restrictive methods
Application of bandages to thumb,
finger, elbow may be done.
Bandages on the thumb will take
away the pleasure from the act.
Bandaging the elbow will prevent
bending the elbow to suck thumb
Intraoral appliances
Palatal cribs, spurs (Graber, ref)
These appliances should be
used in age group of 31/2 to 41/2
years
Expansion appliance like quad-helix
with spurs
In late mixed or permanent
dentition when the malocclusion
has set in
Corrective therapy

32. Tongue thrusting, swallowing habit or retained infantile swallow
The tongue is a powerful muscular organ which exerts tremendous
(powerful) pressure during swallowing at frequent intervals,24 hours a
day.
In tongue thrusting habits, a normal-sized tongue or one that is
overdeveloped thrusts between the upper and lower teeth each time
the patient swallows, producing an open bite.
Sometimes, the patient allows the tongue to rest in the open bite
space between the act of deglutition, preventing the bite from closing.
Tongue thrusting also permits the molars to supraerupt, a condition
which further complicates the problem of correcting open bite cases.

33. Causes of tongue thrusting
 Tongue thrusting may develop as a sequela of prolonged thumb sucking and
retained infantile swallow.
A transitional period from infantile swallow to mature swallow also exhibits
tongue thrusting.
Maturational factors

34. Causes of tongue thrusting
Maturational factors
Anatomic factors
 In macroglossia, there is overgrowth of the tongue. Pressure is exerted against the
lingual surfaces of the teeth, causing them to become spaced. Indentations on the tongue
often appear where the tongue pushes against the teeth.
 Adenoids and tonsils cause the tongue to be positioned anteriorly to prevent blocking of
the oropharynx.
 Tongue thrusting is also called an adaptive behavior. If large spaces are present
anteriorly in the upper and lower teeth, then the tongue will try to move into these spaces
to achieve the anterior seal.
Anatomic factors

35. Causes of tongue thrusting
 Hypersensitive palate causes the tongue to be pushed forward..
Neurogenic factors

36. Types of tongue thrusting
1. Simple tongue thrust: Characterized by teeth
together swallow.
Moyers classified tongue thrusting into three types:
Anatomic factorsAnatomic factors
2. Complex tongue thrust: Characterized by teeth apart
swallow.
3. Retained infantile swallow.

37. Clinical features of tongue thrusting swallow
1. The simple tongue thrusting
o Generalized spacing and proclination may be seen in the upper and lower anterior
teeth.
o Increased overjet, reduced overbite or presence of an anterior open bite may be
seen.
o Exaggerated perioral musculature during the swallowing action
The clinical features seen in the tongue thrusting condition are dependent on the
type of tongue thrusting:

38. 2. The complex tongue thrusting
o The teeth are apart during the swallowing process.
o The tongue spreads laterally in between the upper and lower teeth.
o Lateral tongue thrusting is seen in such cases.
o Unilateral crossbite may also be seen.

40. Diagnosis of tongue thrusting swallow
1. Extraoral examination shows an exaggerated perioral contraction during
swallowing. Increased vertical dimension of face due to over eruption of the
molars into the freeway space is evident

41. Diagnosis of tongue thrusting swallow
2. Intraoral examination shows appearance of open bite, and spacing between
teeth. A forced tongue may cause gushing of saliva through the spaced dentition

42. Reminder therapy Palatal appliances
Palatal cribs, spurs, palatal rolling ball
Corrective therapy Removal of obstruction
Surgery for adenoids, macroglossia
Closure of anterior open bite, posterior open bite
and/or anterior spaces with either a fixed or removable
orthodontic appliance
Treatment of tongue thrusting

43. Tongue exercises
■ Elastic band swallow
The elastic band is kept on the tip of the tongue and
the palate and swallowing is practiced
•■ Water swallow
To keep water in mouth and a mirror in hand, and
swallowing is practiced daily
•■ Candy swallow
A candy is placed between the tongue and palate
and swallowing is practiced
Speech exercises
Patient practices syllables like c , g , h , k while
keeping an elastic band between the tongue and the
palate
Lip exercises
Patient practices stretching of lips so as to achieve
anterior lip seal
Treatment of tongue thrusting

44. Treatment considerations :
 Self correcting by 8-9 years by the time permanent teeth erupt.
 If associated with other habits ,associated should treated first
prognosis:
 Simple tongue thrust Excellent
 Complex tongue thrust Good
 Retained infantile swallow Very poor

45. Mouth breathing habit
Altered mode of breathing through mouth is an adaptation to obstruction in nasal
passages.
The obstruction may be temporary and recurrent. While more often it is partial
than complete.
The airway resistance may be enough to force the subject breathe through mouth
Causes of obstruction to nasal passages are:
1. Allergenic rhinitis
2. Enlarged tonsils or adenoids
3. Deviated nasal septum
4. Nasal polyps
5. Enlarged nasal turbinates'

46. Oral respiration leads to excessive vertical eruption of the posterior molars, in
response to a lack of occlusal contact. These overerupted teeth exert a downward
vector of force on the mandible, causing the lower jaw to rotate downward and
backward in a ‘clockwise’ direction.
According to the ‘compression theory’, given by Norland (1918) constriction of
the maxillary arch is related to lowered posture of tongue which happens due to
nasal obstruction in order to facilitate breathing.
A lowered tongue is less capable of balancing the lateral pressures of the cheek on
the maxillary arch.
Effects of oral breathing

47. Solow and Kreiborg (1977) put forward the soft tissue stretch theory in which they suggested
that the obstruction to the airway is a major causative factor in determining the facial
morphology.
According to Cheng ,impact of the severity of nasal obstruction may have a varying effect on
the adverse facial development and this may vary in different facial types. A brachycephalic
or broad faced pattern with strong facial musculature and a deep bite may be less affected by
nasal obstruction, whereas dolichocephalic faces with a narrow, more elongated pattern may
be more susceptible to these changes.

48. Frequent respiratory
infections
Lowered mandibular posture
Swollen nasal mucosa
Reduced nasal breathingEnlarged tonsils and
adenoids
Deviated nasal septum
Decreased nasal width
Constricted maxilla
Downward anterior
tongue positioning
Mouth breathing Extended head posture
Pathophysiology of mouth breathing following reduced nasal breathing

49.  Excessive lower anterior face
height
 Incompetent lip posture
 Excessive appearance of
maxillary anterior teeth, ‘GUMMY
SMILE’
 A nose that appears to be
flattened, nostrils that are small
and poorly developed.
Clinical features

50.  Steep mandibular plane
 Posterior crossbite
 Open-mouth posture
 A short upper lip and a fuller lower lip
 A class II skeletal relationship
 Gingivitis of upper anterior teeth
 A narrow V-shaped upper jaw with a high narrow
palatal vault
Clinical features

51. Diagnosis of mouth breathing
 History
 Clinical features
 Assessment of mode of respiration
1. Water holding test. Patient is asked to hold
water in his mouth. Inability to keep the mouth
closed for > 2 min confirms nasal obstructions
and therefore mouth breathing habit.

52. Diagnosis of mouth breathing
2. Mirror condensation test. A two-surface
mirror is placed under the nose. If the upper
surface condenses, then breathing is through the
nose, but if the condensation occurs on the lower
surface then the breathing is through the mouth.
3. Cotton wisp test. A small wisp of cotton
(butterfly shaped) is placed below the nostrils in a
butterfly shape. If the upper fibres are displaced
then the breathing is through the nose. If the lower
fibers are displaced then it is mouth breathing
habit.

53. Cephalometric analysis
• Lateral view may show presence of enlarged adenoids
and tonsils
• Cephalometric analysis for nasopharyngeal airway show
altered parameters.

54. Rhinomanometric analysis
• Nasal resistance and airflow are
measured with the help of a
rhinomanometer.
• SNORT (Simultaneous nasal and
oral respiratory technique).
This is a highly accurate technique for
quantifying respiratory mode, where in
both nasal and oral respiration are
simultaneously recorded and
calibrated.
The readings of both oral and nasal
respiration are recorded in waveforms
which can be later converted into a
digital format.

55. Diagnosis of mouth breathing
Effective orthodontic therapy necessitates elimination of the nasal
obstruction to allow for normalization of the function of facial musculature
surrounding the dentition and normal development of the facial bones.
An orthodontist must communicate to an otolaryngologist if he/she finds
mouth breathing habit and seek his/her opinion prior to considering any
orthodontic or habit breaking treatment.

56. Diagnosis of mouth breathing
The cause and effect relationship between nasal obstruction and orofacial
development has now been clearly documented although genetic
predisposition is now well understood.
Early intervention to enhance nasal breathing is now an accepted mode of
therapy in cases of established cause of obstruction.
If instituted early during childhood much of the adverse effects of
craniofacial growth are reversed. Various orthodontic appliances have
been designed to discourage mouth breathing and encourage nasal
breathing. Oral screens have been used previously for this purpose.

57. ENT perspective
Adenoidectomy with or without tonsillectomy is most common treatment for
nasal obstruction in children in established cases.
Allergic rhinitis with turbinate hypertrophy should be treated .
maxillary expansion without extrusive mechanism is the answer to expand
the narrow maxilla.
Rapid maxillary expansion (RME) has been reported to reduce nasal
resistance and promote nasal respiration.

58. Bruxism
Bruxism in the simplest terms refers to the clenching and gnashing of the teeth
against each other. Ramfjord and Ash described it as nocturnal, subconscious
activity but can occur in the day or night and may be performed consciously or
subconsciously.
Sleep bruxism is an entity that is very common with children. The adults may
bruxize in either day or night.

59. • Emotional tension seems to be the major cause of
bruxism.
• Occlusal interferences can initiate bruxism.
• Childhood bruxism may be related to other oral
habits, such as chronic biting and chewing of toys and
pencils, thumb-and finger-sucking, tongue thrusting.
• Endocrine disorders, particularly those relating to
hyperthyroidism, may lead to bruxism.
• Gastrointestinal disturbances from food allergy, enzyme
imbalances in digestion cause chronic abdominal
distress.
• Persistent, recurrent urologic dysfunction may be
responsible for nocturnal bruxism.
Etiology

60. • Nutritional and vitamin deficiencies as possible
factors for inducing tooth grinding. Bruxism in
allergic children is known.
• Athletes indulge in bruxism due to increased
muscular activity.
• Allergy plays a definite role in nocturnal bruxism
asthma attacks, upper respiratory tract infections.
• Neurological disturbances like epilepsy .
Etiology

61. The clinical features
• Teeth that are worn down, flattened or chipped
• Atypical occlusal facets — worn tooth enamel, exposing the dentine of the
tooth.
• Increased tooth sensitivity
• Jaw pain or tightness in the jaw muscles

62. The clinical features
• Ear-ache because of severe jaw muscle contractions
• Headache and chronic facial pain
• Chewed tissue on the inside of the cheek
• Hypertrophy of masseter muscle
• Teeth grinding and clenching, this may be loud enough to wake the sleep partner.

63. 1-Psychological counselling to identify and treat any psychological stress, tension
or emotional upset.
2-Correction of any occlusal interference by coronoplasty.
3. Temporary relief can be brought about by occlusal splints or bite plates that will
help in relieving the pain in the muscles by passively stretching them. On relief of
symptoms, the occlusion is equilibrated to correct centric relation.
4. Prosthetic replacement of any missing posterior teeth that could have led to loss
of vertical dimension leading to overcontraction of the closing muscles.
Treatment

64. 5. Oral analgesics for muscular pain.
6. Physiotherapy has proven useful in relieving the symptoms of bruxism.
• Low intensity ultrasonic radiation therapy: Used commonly in orthopaedics for
relieving painful muscular symptoms. It has been useful in bruxism.
• Acupressure/acupuncture treatment for muscular pain.
• Transcutaneous electrical nerve stimulation (TENS) has an analgesic effect over
sensory nerves.
7. Treatment of allergies which may be required in children.
Treatment