2. It is very well known that normal function of the stomatognatic system
promotes normal growth and development of the oro-facial complex.
Improper functioning of the stomatognatic system can result in various
malocclusions.
Orthodontic diagnosis cannot be restricted to static evaluation of the teeth
alone, along with their supporting structures, but has to include the
examination of the various functional units of the stomatognatic system
(Eschler,1952).
3. FUNCTIONAL EXAMINATION SHOULD INCLUDE:
Examination of postural rest position and
maximum intercuspation
Examination of TMJ.
Examination of orofacial dysfunction
4. Examination of postural rest position and
maximum intercuspation
Determination of postural rest position
Registration of postural rest position
Evaluation of the relationship: postural rest
position-habitual occlusion in three planes of space
5. Postural rest position is the position of the
mandible at which the muscles that close the
jaws and those that open them are, in a state
of minimal contraction, so as to maintain the
posture of the mandible.
At the postural rest position, a space exists
between the upper and lower jaws. This space
is called the inter-occlusal clearance or the
‘freeway Space’.
7. IRRESPECTIVE OF THE METHOD USED, THE PATIENT SHOULD
BE SEATED UPRIGHT, WITH THE BACK UNSUPPORTED &
ASKED TO LOOK STRAIGHT AHEAD.
Phonetic method.
Command method.
Non-command method.
Combined method
8. The patient is asked to repeat some
consonants like ‘M’ or ‘C’ or repeat a
word like ‘Mississippi’.
The mandible returns to the postural
rest position 1-2 seconds after the
exercise.
The patient is asked not to change the
jaw, lip or tongue position after the
phonation, as the dentist parts the
lips to study the inter-occlusal space.
9. The patient is asked to perform certain functions such as
swallowing.
The mandible tends to return to rest position following this
act.
The patient is asked to perform selected functions.having
the patients lick the lips and swallow reduces the desired
relationship because the mandible returns to the postural
rest within two seconds after the exercise.
10. The patient is observed as he or she speaks or swallows.
The patient is not aware that he or she is being
examined.
This is usually carried out by talking about topics
unrelated to the patient while carefully observing him or
her.
When patient is unaware of the fact that he is being
observed. Careful observations are made as the patient
talks, swallows and turns the head while being
questioned.
11. Combined method
Most suitable for functional analysis in children.
Patient is first observed during swallowing and speaking.
In older children “tapping test”is carried out in order to relax the musculature.
Patient is then distracted,similarly to when using the non-command method.
Regardless of the clinical method in use,the mandible must be checked extraorally to ensure
that it actually has assumed the rest position.
In order to do so,palpate the submental region:relaxed muscles in this area indicate that the rest
position has been attaned.
The lips are then carefully parted with the thumb & forefinger-ensuring that the line of lip
contact is not opened completely-to observe the maxilloandibular relationship in the rest
position.
13. Manual guidance
• Tapping test-chin is placed
between thumb & forefinger.
• The clinician uses this grip to
carry out passive opening &
closing movements of the
mandible in rapid succession
in order to relax the
masticatory muscles prior to
determining the rest position.
• Verify whether the
musculature has been
relaxed by palpating the
submental muscles.
14. Rest position speculum
• A.M.Schwarz
• Placed laterally between the lips in
order to observe the functional jaw
relationship.
• Interfere with lip seal and entire
reflex mechanism of the resting
tonus
• so clinically it is difficult to
determine physiologic rest position
using speculum.
16. THERE ARE VARIOUS METHODS EMPLOYED TO
MEASURE THE INTER-OCCLUSAL CLEARANCE.
Direct intra-oral procedure.
Direct extra-oral procedure.
Indirect extra-oral procedure.
17. Vernier calipers can be used directly in the patients mouth in the
canine or the incisor region to measure the freeway space.
18.
19. Two marks are placed one on the nose, and
another on the chin in the mid-sagittal plane.
The distance between these two points is
measured after instructing the patient to remain
at rest position.
Later the patient is asked to occlude the teeth and
the distance between the two points is again
measured.
The difference between the two readings is the
freeway space.
20. The inter-occlusal space is determined
in a radiograph or by ‘Kinesiography’.
Two lateral cephalograms, at rest
position and other in centric occlusion
can help establish the freeway space.
23. Evaluation of the relationship:postural rest
position-habitual occlusion,in three planes of
space (sagittal,vertical & transverse)
24. Closing movement of mandible
When closing from rest position, the mandible may undergo both rotational and sliding
movement.
The objective of this analysis is to determine the amount and direction of the movement as well
as the proportions of the rotational and sliding components.
The closing movement of mandible can be divided into 2 phases :-
Free Phase-mandibular path from the postural rest to the initial or premature contact position.
Articular phase-mandibular path from the initial contact position to centric or habitual
occlusion. In case of functional equilibrium, the articular phase does not occur (movement
without tooth contact)
25. Metric analysis of the relationship between
rest position and habitual occlusion
Bo=basal plane angle in occlusion
Br=basal plane angle at rest position
MMo=distance between two perpendiculars drawn
to the baseline of the maxilla which pass through
the pogonion and “A”point and are extended
inferiorly.
MMr=same relationship in rest position
Br-Bo=rotational component
MMr-MMo=sliding component
28. Mandibular prognathism-true/pseudo
forced bite
Pseudo forced bite-those true skeletal class III
malocclusion where,due to partial dentoalveolar
compensation of the skeletal dysplasia in the anterior
region (labial tipping of the upper & lingual tipping of the
lower incisors),the mandible occludes at the end of the
closing path by means of an anterior sliding action.
If one reconstructs the tipping of the anterior teeth in a
pseudo-forced bite,these cases have a pronounced
negative overjet.
31. THE PATH OF CLOSURE IS THE MOVEMENT OF THE MANDIBLE
FROM REST POSITION TO HABITUAL OCCLUSION.
ABNORMALITIES OF THE PATH OF CLOSURE ARE SEEN IN SOME
FORMS OF MALOCCLUSION.
Forward path of closure.
Backward path of closure.
Lateral path of closure.
32. A forward path of closure is seen in patients with an edge to edge incisor
contact.
In such patients, the mandible is guided to a more forward position to allow the
mandibular incisors to go labial to the upper incisors.
33. Class II division II cases exhibit premature incisor contact due to retroclined maxillary incisors.
Thus the mandible is guided posteriorly to establish occlusion.
34. Lateral deviation of the mandible to the left or the right side is associated with
occlusal prematurities and a narrow maxillary arch.
36. AUSCULTATION
• carried out with a stethoscope,
• clicking and crepitus in the joint may be diagnosed during
anteroposterior and eccentric movements of the mandible.
• JOINT CLICKING IS DIFFERENTIATED AS FOLLOWS:
1.Initial Clicking: is a sign of retruded condyle in relation to the
disc.
2.Intermediate Clicking: is a sign of unevenness of the condylar
surfaces and of the articular disc, which slide over one another
during movements.
3. Terminal Clicking: occurs most commonly and is an effect of
condyle being moved too far anteriorly, in relation to the disc, on
maximum jaw opening.
4. Reciprocal Clicking: occurs during opening and closing, and
expresses an in coordination between displacement of the condyle
and disc.
• Clicking of the joint is rare in children.
37. PALPATION OF THE
TEMPOROMANDIBULAR JOINT:
During opening maneuvers will reveal possible pain on pressure of the condylar areas. Besides
the right and left condyles can thus be checked for synchrony of action. Palpation – pain on
pressure of the condylar areas. Right & left condyles checked for synchrony of action.
* Lateral palpation of TMJ – Slight pressure on the condyloid process with the index finger.
* Posterior palpation of TMJ – Position the little finger in the external auditory meatus and
palpate the posterior surface of the condyle during opening and closing.
42. Recording of the maximum inter incisal distance
On Maximum jaw opening –
distance between incisal edges of
the upper and lower central
incisors are measured with Boley
gauge.
It is usually 40-45mm.
In over bite cases this amount is
added to the obtained value
whereas in open bite it is
subtracted.
In cases with TMJ dysfunction,
hypermobility is often registered
in the initial stages and limitation
in the later stages.
44. Opening and closing movements of the
mandible:
The opening and closing movements of the mandible as well as its protrusive, retrusive and
lateral excursion are examined as part of the functional analysis. The size and direction of these
actions are recorded during clinical examination. Deviations in speed can only be registered with
electronic devices (Kinesiograph).
The first signs of initial temporomandibular joint problems include deviations of the mandibular
opening and closing paths in the sagittal and frontal planes. In patients with malocclusion and
malaligned teeth, disturbances in mandibular movement are the result of an asynchronic
pattern of muscle contractions. The characteristic movement deviations include incongruency of
the opening and closing curves and uncoordinated zigzag movements. The “C” and “S” types of
deviations are typical signs of functional disturbances.
45.
46. Posselt diagram
A-retruded contact position
A-B-hinge axis movement
B-transition from hinge axis
movement to posterior
opening movement
C-axis of rotation of the
condyle when opening the
mandible from the rest
position
E-maximum jaw opening
F-protruded contact position
G-habitual intercuspation
R-mandibular rest position
47.
48.
49. Radiographic examination of TMJ
Only in limited cases radiographic examinations indicated for patients with functional
disturbances of the temporomandibular joint.
When analyzing the radiographs following findings are registered:
1. Position of the condyle in relation to the fossa.
2. Width of the joint space
3. Changes in shape and structure of the condyle head or the mandibular fossa.
Adolescents with class II, Div. 1 malocclusion and lip dysfunction (lip sucking or sucking) are most
frequently affected by TMJ disorders.
52. Normal infantile swallow
Normal mature swallow
Retained infantile swallow
Deglutition : It is defined as a transit of food
bolus or saliva from oral cavity to the
stomach. we have to examine for
swallowing pattern, 3 types,
53. SWALLOWING
• Normal mature swallowing takes place without contracting the muscles of facial expression. The
teeth are momentarily in contact and the tongue remains inside the mouth.
• Abnormal swallowing is caused by tongue thrust, either as a simple thrusting action or as tongue-
thrust syndrome. The following symptoms distinguish this syndrome:
1. Protrusion of the tip of the tongue
2. No contact of the molars
3. contraction of perioral muscles during deglutitional cycle
During their first few years, infants swallow viscerally. i.e. with the tongue between the teeth. As the
deciduous dentition is completed, the visceral swallowing is gradually replaced by somatic
swallowing.
If visceral swallow persists after fourth years of age, it is considered OROFACIAL DYSFUNCTION.
61. INFANTILE SWALLOWING:
In a new born, the tongue is relatively large and protrudes between the gum
pads and takes part in establishing the lip seal.
It is seen till the age of 1½ to 2 years.
Infantile swallowing pattern is replaced by ‘Mature swallow’, as the buccal
teeth start erupting.
VISCERAL OR INFANTILE SWALLOW • Jaws apart with tongue between gum
pads. • It is triggered off by sensory interchange between the lips and
tongue. • Peristalsis commences in the vestibule • Associated with tongue
and mandibular thrust • The transverse section shows that the tongue is
positioned low in mouth and that the central furrow is depressed.
62.
63. The persistence of the infantile swallowing can be a cause for malocclusion.
Thus the swallowing pattern of the individual should be examined.
64. A PERSISTING INFANTILE SWALLOWING CAN BE IDENTIFIED BY:
• Protrusion of the tip of the tongue.
• Contraction of peri-oral muscles
during swallowing.
• No contact at the molar region during
swallowing.
65. SOMATIC SWALLOW:
• As swallowing is triggered off by contraction of mandibular elevators, the teeth occlude
momentarily during the swallowing act and the tip of the tongue is enclosed in the oral cavity.
• Transverse section shows that the dorsum of the tongue is less concave and approaches the palate
during swallowing
93. Certain malocclusions may cause defects in speech due to interference
with movement of the tongue and lips. This should be observed while
conversing with the patient.
The patient can be asked to read out from a book or asked to count
from 1 – 20 while observing the speech.
Patients having tongue thrust habit tend to lisp, while cleft palate
patients may have a nasal tone.
110. HUMANS MAY EXHIBIT THREE TYPES
OF BREATHING:
Nasal breathing.
Oral breathing.
Oro-nasal breathing.
111. A NUMBER OF SIMPLE TESTS EXIST THAT
CAN BE EMPLOYED TO DIAGNOSE THE
MODE OF RESPIRATION:
Mirror test.
Cotton test.
Water test.
Observation.
112. A double sided mirror is held between the
nose and the mouth.
Fogging on the nasal side of the mirror
indicates nasal breathing.
Fogging towards the oral side indicates oral
breathing.
Fogging on both sides indicates oro-nasal
breathing.
113.
114.
115.
116. A butterfly shaped piece of cotton is placed
over the upper lip, below the nostrils.
If cotton flutters down, it indicates nasal
breathing.
This test can be used to determine unilateral
nasal blockage.
117. The patient is asked to fill his/her
mouth with water and retain it for a
period of time.
While nasal breathers accomplish
this with ease, mouth breathers find
the task difficult.
118. References:-
Graber T.M,Rakosi T,Petrovic A.G;dentofacial orthopedics with functional appliances,2nd edition
Rakosi T,Jonas I,Graber T M;color atlas of dental medicine orthodontic-diagnosis
Xubair,Graber,Vanarsdall,Vig;orthodontics current principles and techniques;5th edition
Okeson J.P;management of temporomandibular disorders & occlusion;6th edition
Rahn A.O,Heartwell C.M;textbook of complete denture;5th edition
The postural rest position is a relatively unchanging neuromuscularly derived relationship of the lower jaw to the upper.
It is the position of the mandible when the elevator and depressor muscles of the mandible are in a state of minimal tonic contraction.
Even though it is a relatively unchanging relationship, it is influenced by head and body posture as it is influenced by gravity.
Thus in order to standardize the rest position measurement the following protocol must be followed.
•The patient is seated upright and relaxed with the back unsupported.
•The head is oriented with the patient looking straight ahead at eye level or looking into his own eyes in the mirror or head can be positioned with the eye ear plane (Frankfort horizontal plane)
Centric relation-maxillomandibular relationship in which the condyle articulates with the thinnest avascular portion of their respective disc with the complex in the anterior superior position against the slope of the articular eminence.(GPT)
This position is independent of tooth contact.This position is clinically discernible when the mandible is directed superior & anteriorly.It is restricted to a purely rotary movement about the transverse horizontal axis.
Centric occlusion-occlusion of opposing teeth when the mandible is in centric relation.This position may or may not coincide with maximum intercuspal position.(GPT)
When the mandible is in the postural resting position,it is usually 2-3 mm below and behind the centric occlusion(recorded in canine area).(Ramjford and Ash,1968).
Recoding unit-a permanent magnet,which is fixed with rapid-setting acrylic to the lower anterior teeth,& A sensor system of 6 magnetometers mounted on spectacle frames.
Every movement of the mandible and the attached magnet out of centric occlusion,alters the strength of the magnetic field.
These changes are recorded by the sensors,processed in the kinesiograph and displayed on a storage oscilloscope.
The mandibular movement & rest position are recorded two-dimensionally on two pre-selectable levels.
The electronic circuitry also allows the rest position to be recorded as three-dimensional coordinates.
Class II malocclusions.
Due to different types of movement of mandible from the rest position to occlusion,the class II malocclusions can be divided into 3 functional types:-
Rotational movement without a sliding component-the neuromuscular and morphologic relationships correspond to each other.
There is no functional disturbance(functional true class II malocclusion)
Rotational movement with posterior sliding movement-The mandible slides backwards and is guided into a posterior occlusal position.
This finding reveals a fuctional class II malocclusion and not a true class II malrelationship.
Rotational movement with anterior sliding movement-Starting from the relatively posterior rest position the mandible slided forwards into habitual occlusion.
The class II malocclusion is actually more pronounced than can be seen in habitual occlusion.
The closing path of the mandible from the rest position in class III malocclusion can be divided into :-
Rotational movement with posterior sliding action-In case with pronounced mandibular prognathism the mandible may slide posteriorly into the position of maximum intercuspation.This masks the true sagittal dysplasia.
Rotational movement without sliding action (pure rotational)-The anatomic/morphologic relationships correspond to the functional relationship (non-functional,true class III malocclusion-unfavourable prognosis)
Rotational movement with anterior sliding action-During the articular phase,the mandible shifts forwards and into a prognathic,foced bite (functional,non-skeletal malocclusion,so-called pseudo-class III-favourable prognosis)
The dentoalveolar compensation of the skeletal dysplasia,which already exists when treatment is started ,greatly restricts the range of orthodontic treatment possibilities and unlike a true forced bite,is indicative of a very unfavourable prognosis.
A-occlusal position
B-Pseudo deep bite-small freeway space.molars have erupted fully.The deepbite is caused by overeruption of the incisors.The prognosis for elevating the bite using functional appliances is unfavourable.If the freeway space is small,extrusion of the molars adversely affects the rest position and may creat TMJ problems or cause a relapse of the deep overbite.
C-True deep bite-large freeway space caused by infraocclusion of the molars.The prognosis for successful therapy with functional method is favourable.As the interocclusal clearance is large,sufficient freeway space will remain after extrusion of the molars.
Freeway space-child4 mm,adult2-3 mm
This analysis is particularly relevant for the differential diagnosis of cases with unilateral cross bite.
Depending on the functional analysis 2 types of skeletal mandibular deviation can be differentiated:-
LATEROGNATHY: The center of the mandible is not aligned with the facial midline in rest and in occlusion. These dysplasias constitutes true neuromuscular or anatomical asymmetry. A lateral cross bite with laterognathy is termed true cross-bite. The prognosis is unfavorable for causal therapy. In figure
• LATEROCLUSION: The skeletal midline shift of the mandible can be observed only in occlusal position; in postural rest position both midlines are well aligned. The deviation is due to tooth guidance (functional non-true malocclusion).
The objective of this aspect of functional examination is to assess whether incipient symptoms of TMJ dysfunction are present.
These symptoms are important for two reasons:
1. Through the early elimination of functional disturbances, some incipient TMJ problems can be prevented or eliminated. This is an indication for early orthodontic treatment.
2. During functional therapy the condyle is displaced or dislocated to achieve a remodeling of the TMJ structures and a change in muscle function. If the temporomandibular structures are abnormal at the start and hypersensitivity is a problem, the possibility of exacerbating the symptoms exist.
Border movement of mandible-sagittal plane ,posselt,1952
Pattern of mandibular movements during opening and closing maneuvers:
Opening and closing paths in sagittal plane.
1. opening and closing arcs cross over inconsistency.
2. The opening movements show greater deviations.
3. The closure pattern is straighter and more constant.
OPENING AND CLOSING ARCS IN HORIZONTAL PLANE:
1. the opening path is pathologically C-shaped At the end of the closing movement, the mandible shifts slightly toward the left.
OPENING AND CLOSING PATHS IN THE FRONTAL PLANE.
The extent of jaw opening is normal and mandible towards left due to occlusal interferences.
Tongue thrust has an important effect on the etiopathogenesis of malocclusion. The thrust may take place in the anterior or lateral regions or can be complex
