Influence of orofacial functions ondevelopment of face and occlusion

Prepared by :Mohammed Al-AwdiUnder supervision :Prof. Maher Fouda

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

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.

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 .

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

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 yearsgreatly 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 .

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.

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 .

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.

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.

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 bit-ing; 0.0400000000000001

Tongue thrust ; 18.1

Mouth breathing; 6.6

Thumb sucking; 0.700000000000

001 Others; 0.1

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.

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 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.

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 andseverity 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 yreas) 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

Modalities Indication

Chemical methodApplication 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 so Reminder therapy

Restrictive methodsApplication 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 appliancesPalatal 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

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.

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

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

Causes of tongue thrusting

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:

Anatomic factorsAnatomic factors2. Complex tongue thrust: Characterized by teeth apart swallow.

3. Retained infantile swallow.

Clinical features of tongue thrusting swallow

1. The simple tongue thrustingo 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:

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 of the molars into the freeway space is evident

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

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

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 rhinitis2 .Enlarged tonsils or adenoids

3 .Deviated nasal septum4 .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 cheek on

the maxillary arch .

Effects of oral 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 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

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 respiration1. 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.

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.

Cephalometric analysis

• Lateral view may show presence of enlarged adenoidsand tonsils• Cephalometric analysis for nasopharyngeal airway showaltered 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.

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.

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.

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.

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.

• 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

• 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

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

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.

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

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