FUNCTIONAL INFLUENCES ON OROFACIAL DEVELOPMENT

FUNCTIONAL INFLUENCES
ON OROFACIAL
DEVELOPMENT
DR SHEHNAZ JAHANGIR
IIND YEAR MDS
DEPT. OF ORTHODONTICS

CONTENTS
 INTRODUCTION
 RESPIRATION
◦ LITERATURE REVIEWS
 BREATHING MODE INFLUENCE IN CRANIOFACIAL
DEVELOPMENT
 INFLUENCE OF MOUTH BREATHING ON
DENTOFACIAL GROWTH OF CHILDREN
 EFFECT OF MOUTH BREATHING ON DENTOFACIAL
MORPHOLOY OF GROWING CHILD
◦ MOUTH BREATHING HABIT
 EFFECTS
 PATHOPHYSIOLOGY
 CLINICAL FEATURES
 DIAGNOSIS

 INFLUENCE OF TONGUE ON DENTOFACIAL GROWTH
◦ TONGUE THRUSTING
 CAUSES
 TYPES
 CLINICAL FEATURES
 DIAGNOSIS
 TREATMENT
◦ LITERATURE REVIEWS
 COMPARISON OF SOFT TISSUE, DENTAL & SKELETAL
CHRACTERISTICS IN CHILDREN WITH & WITHOUT TONGUE
THRUSTING HABIT
 CHEWING, JAW FUNCTION & TMJ DYSFUNCTION
 IMPORTANCE OF MASTICATORY MUSCLE FUNCTION IN
DENTOFACIAL GROWTH
 SWALLOW
◦ INFANTILE SWALLOW
 FEATURES
 TRANSITION FROM INFANTILE SWALLOW TO MATURE
SWALLOW

 SPEECH
 DEVELOPMENT OF ORAL HABITS & MATURATION
OF ORAL FUNCTION
 ORAL MOTOR CONTROL AND OROFACIAL
FUNCTIONS IN INDIVIDUALS WITH DENTOFACIAL
DEFORMITY
 SUCKING HABITS
◦ THUMB SUCKING HABIT
 PATHOPHYSIOLOGY
 TYPES
 EFFECTS
 METHODS OF INTERCEPTION OF HABIT
 CONCLUSION

INTRODUCTION
 Severe malocclusion affects function,
usually not by making it impossible, but
by making it more difficult for the affected
individual to breathe, incise, chew,
swallow and speak normally.
 The reverse also is true: alterations or
adaptations in function can be etiologic
factors for malocclusion, by influencing
the pattern of growth and development.
 The extent to which improved function
justifies orthodontic treatment remains
poorly defined.

Respiration
 There seem to be numerous weak relationships
between respiratory mode and malocclusion, but
the more refined and rigorous the investigations,
the more questionable specific links become.
 The evidence does not support orthodontic
referrals of children for surgery to open the nasal
airway (by removing adenoids, turbinates, or other
presumed obstacles to nasal airflow), because the
effect on the future facial growth pattern is
unpredictable.
 For the same reason, expanding the maxillary
dental arch by opening the midpalatal suture,
which also widens the nasal passages, cannot be
supported as an effective way of changing the
respiratory pattern toward nasal breathing and

 Respiration is one of the body’s vital
functions and under physiological
conditions, breathing takes place
through the nose.
 The mouth-breathing syndrome (MBS)
is when a child has mixed breathing
i.e., the nose is supplemented by the
mouth.

Breathing mode influence in
craniofacial development
Lessa et al BRAZILIAN JOURNAL OF
OTORHINOLARYNGOLOGY 71 (2) PART 1
MARCH/APRIL 2005
 The objective of this study was to
evaluate through cephalometric
analysis the differences in facial
proportion between mouth breathing
children and normal breathing
pediatric patients.

 It was found out that Mouth breathing
children tend to present increased
mandibular inclination, vertical growth
pattern with changes in normal facial
proportions, characterized by
increased anterior lower facial height
and decreased posterior facial height
in mouth breathing children,
 therefore evidencing the influence of
respiratory function in craniofacial
development.

Influence of Mouth Breathing on the
Dentofacial Growth of Children: A
Cephalometric Study
bahija, sundeep et al; J Int Oral Health. 2014 Nov-Dec; 6(6): 50–
55.
 This study was aimed at assessing the
dental and soft tissue abnormalities in
mouth breathing children with and
without adenoid hypertrophy.

 Fifty children aged between 6 and 12
years following otolaryngological
examination were divided into three
groups:
 Group I (MBA): Twenty mouth breathing
children with enlarged adenoids and
60% of nasopharynx obstruction;
 Group II (MB): Twenty mouth breathing
children without any nasal obstruction;
 Group III (nasal breathers [NB]): Ten
nose breathing healthy individuals
(control group).

 Digital lateral cephalograms were
obtained and the dental and soft
tissue parameters were assessed
using the cephalometric software,
Dolphin Imaging 11.5 version.
 Comparison was done using one-way
ANOVA and post-hoc analysis.

Results:
 There was a significant increase in
IMPA, interlabial gap and facial convexity
in both MBA and MB groups when
compared to NB.
 The upper incisor proclination and facial
convexity were significantly higher in
mouth breathers with adenoid
hypertrophy.
 However, upper incisor proclination was
statistically significant only in group MB
when compared to NB.

Conclusion:
 All subjects with mouth-breathing habit
exhibited a significant increase in
lower incisor proclination, lip
incompetency and convex facial
profile.
 The presence of adenoids
accentuated the facial convexity and
mentolabial sulcus depth.

The effect of mouth breathing on
dentofacial morphology of growing child.
S Malhotra, RK Pandey et al; J Indian Soc Pedod
Prev Dent
. Jan-Mar 2012;30(1):27-31
 The oral mode of respiration cause
postural adaptations of structures in
the head and neck region producing
the effect on the positional relationship
of the jaws.
 The aim of this study is to verify the
skeletal relationship of mouth and
nose breathing child.

Materials and Methods
 One hundred children among which
54 were mouth breathers and 46 were
nasal breathers of 6-12 years of age
were submitted to clinical examination
and cephalometric radiographical
analysis.

Result
 The mean values of N-Me, ANS-Me
and SN-GoGn for mouth breathers is
significantly higher.
 ArGo-GoMe (P=0.003) and (P<0.011)
for 6-9 and 9-12 years age group,
respectively, were significantly low in
nasal breathers group.

Conclusions:
 Changed mode of respiration was
associated with increased facial
height, mandibular plane angle and
gonial angle.

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'

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 cheekon the maxillary arch.
Effects of mouth breathing

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.

Frequent respiratory
infections
Lowered mandibular posture
Swollen nasal mucosa
Reduced nasal breathing
Enlarged 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

 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

 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

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 > 1.5 min confirms nasal
obstructions and therefore mouth breathing
habit.

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 thelower
fibers are displaced then it is mouth breathing
habit.

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

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.

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.

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.

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.

The influence of the tongue on
dentofacial growth
 There is much evidence to suggest that unusual
function of the soft tissues in general, and the
tongue in particular, are related to malocclusion.
 Rare cases of aglossia show major collapse of
the dental arches and Harvold’ showed that the
surgical removal of part of a monkey’s tongue
caused a related reduction of arch size.
 Malocclusion is frequently associated with
unusual form or function of the soft tissues which
may range from a simple sucking habit to a ’full
fan’ tongue thrust with only the posterior molars

 It is difficult to measure tongue function
and almost impossible to measure its
posture.
 there is a lot of evidence to suggest that
there is a higher ratio of malocclusion
when the tongue is away from the
palate, especially if it is postured
between-the-teeth or low.
John Mew; Angle Orthodontist, Vol 85, No 4, 2015

Tongue thrusting
• 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.

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

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

 Hypersensitive palate causes the tongue to be pushed forward..
Neurogenic factors

Types of tongue thrusting
1. Simple tongue thrust: Characterized by teeth
together swallow.
Moyers classified tongue thrusting into three types:
2. complex tongue thrust: characterized by teeth apart
swallow.
3. Retained infantile swallow.

Clinical features of tongue thrusting
The clinical features seen in the tongue thrusting condition are dependent onthe
type of tongue thrusting:
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.

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.

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

2. Intraoral examination shows appearance of open bite, and spacing between
teeth. Aforced tongue may cause gushing of saliva through the spaced dentition.

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

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

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

Comparison of soft-tissue, dental, and skeletal
characteristics in children with and without
tongue thrusting habit
Dixit & shetty et al; Contemp Clin Dent. 2013 jan;4(1):2-6
Materials and methods:
 A total of 21 children with tongue
thrusting habit and 21 children without
any habit between age 10 and 14
years were selected for the study.
 Various soft-issue, dental and
cephalometric parameters were
measured and compared statistically.

Results:
 Significantly, higher number of children with
tongue thrusting showed lip incompetency,
mouth-breathing habit, hyperactive mentalis
muscle activity, Open-bite and lisping when
compared to children without tongue thrust.
 Children with tongue thrust showed
increased upper lip thickness and proclination
of maxillary incisors.
 No differences were found in angulation of
mandibular incisors, inter-premolar or inter-
molar widths and all the skeletal parameters
studied.

Conclusion:
 Tongue thrust seemed to affect some
of the soft-tissue and dental
characteristics causing lip
incompetency, mouth-breathing habit,
and hyperactive mentalis muscle
activity, lisping, open-bite, and
proclination of maxillary incisors;
however, no significant skeletal
changes were observed.

Chewing, jaw function, and temporomandibular joint
dysfunction (TMD)-
 It seems obvious that chewing should be
easier and more efficient with good dental
occlusion, but individuals expend the effort
necessary to accomplish important tasks like
chewing, and there is little evidence to
support any impact of malocclusion on
nutritional status.
 Except for the most extreme malocclusions,
the effect appears to be increased work to
prepare a satisfactory bolus for swallowing.
 Masticatory effort is difficult to measure
accurately, so there are no good data for how
much difference it makes to have mild,
moderate, or severe malocclusion.

 It is possible that functional problems
related to malocclusion would appear as
tempero-mandibular dysfunction.
 Little or no data support the idea that
orthodontic treatment is needed at any age
to prevent the development of TMD.
 A recent population-based study in
Germany, with a sample of 7008 individuals
from a population of 212,157 found
essentially no link between malocclusion or
functional occlusion and TMD.
 Some studies have found correlations
between some types of malocclusion and
TMD, but they are not strong enough to
explain even a small fraction of TMD

The Importance of Masticatory
Muscle Function in Dentofacial Growth
 Masticatory muscle function and its influence on
craniofacial growth have been investigated in
animal experiments and clinical studies.
 These investigations commonly show that the
elevator muscles of the mandible influence
transverse and vertical facial dimensions.
 Increased loading of the jaws associated with
masticatory muscle function increases sutural
growth and stimulates bone apposition, resulting
in greater transverse growth of the maxilla and
broader bone bases for the dental arches.
(Semin Orthod 2006;12:110-119.)

 Furthermore, an increase in masticatory
muscle function is often associated with an
anterior growth-rotation pattern and well-
developed angular, coronoid, and condylar
processes in the mandible.
 One interesting point that has not been
thoroughly discussed is that individuals
with strong masticatory muscles have a
more homogeneous facial morphology, in
contrast to individuals with weak
masticatory muscles who show great inter-
individual variation in their vertical facial
dimensions.
(Semin Orthod 2006;12:110-119.)

 Thus, individuals with strong
masticatory muscles usually have a
hypo-divergent facial type, although not
all individuals with hypo-divergent facial
form have strong masticatory muscles.
 The literature supports the hypothesis
that a certain level of masticatory
muscle strength may be sufficient for
normal vertical craniofacial growth,
though it is not a prerequisite.
(Semin Orthod 2006;12:110-119.)

Swallowing/speech
 Both the pattern of activity in swallowing and tongue-lip
function during speech are affected by the presence of
the teeth.
 The most effective way to eliminate a "tongue thrust
swallow" is to retract protruding incisors and close an
open bite, so orthodontics can have an effect on
swallowing, but rarely is this a reason for treatment.
 Normal speech is possible in the presence of extreme
anatomic deviations.
 Certain types of malocclusion are related to difficulty
with specific sounds, and occasionally a reason for
orthodontic treatment is that it would facilitate speech
therapy.
 Usually, however, speech problems are not a reason for
orthodontics.

infantile swallow
 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

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.

 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.

 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.

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

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.

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.

 The development of oral habit is divided
into three periods:
 1. Sucking period
 2. Biting period
 3. Multiple transfer period
Development of oral habits and
maturation of oral functions.
Babita A, Ashok K, Navdha C. Development of oral
habits and maturation of oral functions. J Pharm
Biomed Sci 2015;05(12):932–935.

 The sucking period develops while the
baby is still in the third trimester in its
mother’s womb.
 This habit is developed to train the
neuromuscular system.
 This system is the most perfectly
developed system found at the time of
the birth so that the oral phase of a new
born is well fulfilled.

 The transition from sucking period to biting
period happens in a short period called the
transition period.
 The biting period develops during the pre-
school age (4–5 years old) and reaches a peak
in school age (6–12 years old).
 Biting habit especially nail biting may become
the sign of the transition period in a child from
the thumb sucking habit previously.
 The transition period in girls appears when they
experience puberty and adolescent phase.
 This is different from boys who tend to fight
back the demands that lead to a longer biting
period than the girls.

MATURATION OF ORAL
FUNCTION
 The important physiologic functions of
the oral cavity are respiration,
swallowing, mastication and speech.
 The infant exhibits two reflexes at birth
that are related to sucking.
 They are the rooting reflex and the
suckling reflex.

The rooting reflex
 which lasts until the child is
approximately 7 months of age, is the
movement of an infant’s head and
tongue towards a stimulus touching an
infant’s cheek.

suckling reflex
 active movements of the infant’s
circumoral musculature, expresses
milk from the nipple and it lasts for
approximately 12 months.
 To obtain milk from the mother’s
breast, the infant stimulates the
smooth muscle in the breast to
contract and express milk onto the
tongue; this is suckling.

 The suckling reflex and the infantile
swallow normally disappear during the
first year of life.
 The mandibular elevators, which play a
prominent role in normal mature
swallows, show minimal activity.
 The buccinator muscle is particularly
strong in the infantile swallow as it is
during nursing.
 As the child grows and motor skills
develop, there is improved motor control
of the tongue and oral musculature.
 There appears to be a gradient of oral
function maturation from anterior to

Non-nutritive sucking
 Non-nutritive sucking is considered
normal for children during infancy.
 The most common form is thumb or
finger-sucking.
 Since the mouth is the initial avenue of
communication with the outside world,
and since the orofacial musculature is
relatively well developed, this non-
nutritive sucking apparently gives the
infant a feeling of warmth, a glow, a
sense of satisfaction or euphoria that is
closely linked to the infantile or visceral
swallowing mechanism.

 According to Christensen et al. (2005)
the oral habits detected at the age of
3–6 years old are an important issue
because after this age, the oral habits
are considered as abnormal.

 O’Brien et al (1996) reviewed the literature and
concluded that there are essentially two forms of
sucking:
 The nutritive form (breastfeeding and bottle
feeding) which provides essential nutrients and
 the non-nutritive form which ensures a feeling of
well-being, warmth and sense of security.
 Non-nutritive sucking is probably the earliest
sucking habit adopted by infants in response to
frustration and to satisfy their urge and need for
contact.
 Children who neither receive unrestricted
breastfeeding nor have access to a pacifier may
satisfy their need with alternative habits such as
finger sucking or sucking of other objects (a

Oral motor control and orofacial functions in
individuals with dentofacial deformity.
 Purpose
 To determine the correlation between
oral motor control and orofacial
functions in individuals with
dentofacial deformity (DFD).
PRADO, Daniela Galvão de Almeida et al. Oral motor control and orofacial
functions in individuals with dentofacial deformity. Audiol., Commun.
Res. [online]. 2015, vol.20, n.1, pp.76-83.

Methods
 Sixteen individuals from 18 to 40
years, (average 28.37 years)
participated. Seven individuals were
class II (three women and four men)
and nine were class III (five women
and four men). They were evaluated
for diadochokinesis (DDK).
 The chewing, swallowing, and speech
functions were filmed and analyzed by
three speech specialists.

It was concluded that
 The oral motor control was related to
the severity of the change in chewing
and swallowing functions regarding
the DDK speed and instability
parameters.

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

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.

• 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.

• 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.
THUMB SUCKING HABIT

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

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.

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

Types of thumb sucking
How children place the thumb has been studied using by Subtelny who grouped themA-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.

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.

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

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

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.

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.

•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 years) with moderate to severe
form of malocclusion like anterior open bite or posterior
crossbite, definitive appliance therapy should be initiated.

Methods used for interception of the thumb sucking habit
Indication Modalities
Reminder therapy
In an older child of at least 6-7
years who wants to break the
habit but is unable to do so
Chemical method
Application of a bitter and a
malodorous chemical like quinine,
asafetida. Cayenne pepper
dissolved in a volatile liquid may
also be used
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
These appliances should be
used in age group of 31/2 to 41/2
years
Intraoral appliances
Palatal cribs, spurs (Graber, ref)
Corrective therapy
In late mixed or permanent
dentition when the malocclusion
has set in
Expansion appliance like quad-helix
with spurs

CONCLUSION
 The effect of muscle force is three dimensional. Whenever
there is struggle between bone and muscle, bone yields.
 Muscle function can be adaptive to morphogenetic pattern
or a change in the muscle function itself can initiate
morphological variation in the normal configuration of the
teeth and the supporting bone or it can enhance the
already existing malocclusion.
 Sometimes the structural abnormality is increased by
compensatory muscle activity to the extent that a balance
is reached between pattern, environment and physiology
and so at times it is impossible to assign a specific cause
and effect role to any one factor.
 So for an orthodontist it is necessary to conduct
orthodontic treatment in such a manner that the finished
result reflects a balance between the structural changes
obtained and functional forces acting on the teeth and

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