Orthodontic diagnosis

ORTHODONTIC DIAGNOSIS Dr. Miliya Parveen

Contents
• Introduction
• Overview of Diagnostic Aids
• Case History
• Clinical Examination
• Functional Examination
• Photographic Analysis
• Intraoral Examination
• Recent advances
• Conclusion

• Diagnosis in orthodontics, as in other disciplines of dentistry and
medicine, requires the collection of an adequate database of
information about the patient and the distillation of a comprehensive
but clearly stated list of the patient’s problems from that database .
• This requires a broad overview of the patient’s situation and must
take into consideration both objective and subjective findings.
• The problem-oriented approach to diagnosis and treatment
planning has been widely advocated as a way to overcome the
tendency to concentrate on only one aspect of a patient’s problems.
Introduction

• The goal of the diagnostic process is to produce a complete description
of the patient’s problems and make a problem list.
• To obtain the problem list, a collection of relevant information is
required. This collection is called a database.
• It is obtained from 3 sources.
1. Patient history, & interview data.
2. Clinical (extraoral, functional & intraoral) examination.
3. Analysis of diagnostic records (models, radiographs,
cephalograms, photographs etc.).

Diagnostic Aids
• A comprehensive diagnosis consists of -
Roentgeno-
cephalometric
analysis
Photographic
analysis
Radiographic
analysis
Study casts
analysis
Case history
Clinical
Examination
Functional
analysis

• Diagnostic aids may be classified as essential or supplemental.
• Essential diagnostic aids include –
I. Case history
II. Clinical examination
III. Study models
IV. Certain radiographs -
a) Periapical
b) Bitewing
c) Panoramic
V. Facial photographs

• Supplemental diagnostic aids include –
I. Specialized radiographs (Lateral ceph, Hand-wrist radiograph,
CBCT)
II. Electromyographic examination of muscle activity
III. Endocrine tests
IV. Estimation of basal metabolic rate
V. Xeroradiograhpy
VI. MRI
VII. Digital subtraction radiography
VIII.Laser holograph
IX. Cineradiography
X. Photocephalometry

Case History
• A detailed social, personal, medical and dental history should precede
any clinical examination elicited by the direct questioning of the
patient or parent.
• The process of recording case history starts with recording the
personal details of the patient like name, age, sex, address and
occupation of parents.
• Case history also helps to explore whether the motivation of the
patient is external or internal.

I. Chief complaint :
• The chief complaint of the patient is recorded in the patient's own words
with emphasis on whether the patient is seeking orthodontic care for
functional or aesthetic improvement or both.
• The main objective of chief complaint is to find out what is important to the
patient.

II. Prenatal history:
• Health of mother during pregnancy, history of premature delivery, type
of delivery and drugs used at the time of pregnancy are noted.
• The best known example of such a relationship is the one between viral
infection and cleft formation in newborns.
• Forceps delivery causes trauma to the
condylar region and results in micrognathia.
• Drug use, during this period must
be noted.

III. Postnatal history:
• Duration and frequency of feeding, milestones reached during growth,
presence of habits and history of childhood diseases and injuries are the
important areas in postnatal history.
• Milestones correlate with
development of an individual.
• Chronic medical problems can result in alterations of growth status of
patients.
• Habits can explain some aspects of malocclusion seen in the patient.

IV. Familial History:
• History of a familial disease which may interfere with normal
development of face, teeth and jaws should be elicited.
• Facial forms and malocclusions that have a strong familial tendency are:
− Severe deep bite with class II division 2 pattern
− Skeletal open bite
− Mandibular prognathism
− Bimaxillary protrusion
− Mandibular retrognathism
− Severe crowding/spacing
− Median diastema

• Common problems of familial origin affecting face and jaws:
− Cleft lip and/or palate
− Ectodermal dysplasia
− Cherubism
• Common problems of familial origin affecting the dentition:
− Peg-shaped or missing lateral incisors
− Partial hypodontia of premolars
− Supernumerary teeth
− Macro or microdontia

V. Medical history:
• Allergy to any drugs, latex, nickel-containing alloys, acrylic or impression
materials.
• History of blood dyscrasias requires special management, if extractions are
required.
• History of rheumatic fever or cardiac anomalies requires antibiotic
prophylaxis and should be treated using bonded attachments as bands produce
bacteraemia.
•History of surgical procedures – those done for cleft lip/palate,
tonsillectomy /adenoidectomy, post-trauma.

VI. Drug History:
• In patients under corticosteroid therapy, tooth movement will be impeded
as steroids interfere with prostaglandin synthesis.
• Non-steroidal anti-inflammatory analgesics impede tooth movement.
• History of epilepsy should be controlled before orthodontic treatment and
be treated with fixed appliances. They also take Dilantin – an
anticonvulsant drug that may cause gingival hyperplasia which can impede
tooth movement.
• Patients with osteoporosis take resorption inhibiting drugs (prostaglandin
inhibitors) - bisphosphonates

VII. Dental history:
• Dental history is elicited with focus on history of toothache, sensitivity,
bleeding from gums, pain in the TMJ region, trauma, previous dental
visit, etc.
• Information on the age of eruption and exfoliation of deciduous and
permanent teeth.
• Orthodontic treatment in the presence of periodontal disease is
contraindicated.
• Previous history of orthodontic treatment should be elicited.

Clinical Examination
• Clinical examination consists of – General
examination
Extra-oral
examination
Functional
examination
Intra-oral
examination

1. General Examination:
• Examination of general state of the patient involves recording height,
weight, posture, gait and body build.
• Recording of height and weight is to assess the patient’s growth and
maturation status.
• Posture is a reflection of body’s efficiency to maintain joints in
relationship which require least energy for functions imposed on them.
Abnormal postures can predispose to malocclusion due to alteration in
maxillomandibular relation.
• Gait is the way a person walks and is assessed because it may be affected
by neuromuscular disorders that may have a dental correlation.

• Body build:
May be -
1. Aesthetic: thin physique, usually with narrow dental arches
2. Plethoric: obese with large, square arches
3. Athletic: normally built with normal sized dental arches
Sheldon has classified body build
into three types -
1. Ectomorphic: Tall and thin – late maturers
2. Mesomorphic: Average
3. Endomorphic: Short and obese – early maturers.

2. Extra-oral examination:
During extra-oral examination, patient should be upright with the Frankfort
plane parallel to the floor.
A. Head type: Cephalic index is the ratio of maximum skull width
(biparietal diameter) multiplied by 100 and divided by maximum skull
length (occipitofrontal diameter).
Less than 70 - Hyperdolichocephalic
70 - 74.9 - Dolichocephalic
75 - 79.9 - Mesocephalic
80 - 84.9 - Brachycephalic
85 - 89.9 - Hyperbrachycephalic
More than 90 - Ultrabrachycephalic

B. Facial form: Facial Index is the ratio between morphological facial
height & bizygomatic distance, given by Martin & Saller in 1957.
Hypereuryprosopic x – 78.9
Euryprosopic 79.0 – 83.9
Mesoprosopic 84.0 – 87.9
Leptoprosopic 88.0 – 92.9
Hyperleptoprosopic 93.0 – x

• Usually dolichocephalic head
will have leptoprosopic and
brachycephalic head will have
euryprosopic face.
• Long and narrow faces are
associated with high angle cases,
open bites, class II division 1.
• Broad and short faces are seen in low-angle cases like class II division 2.
• Sometimes head form and facial form will vary. They are called dinaric
individuals.

C. Facial Symmetry: The face is examined in the frontal and lateral
views for symmetry.

• An ideally proportioned face can be
divided into central, medial and lateral
equal fifths.
• The intercanthal distance constitutes the
central fifth and the width of the eyes form
the medial fifths.
• The nose and chin should be centred
within the central fifth.

• Golden proportions of face:
- The mathematical formula for beauty has been defined based on a
simple mathematical ratio of 1:1.618 otherwise known as phi, or the
divine proportion.

D. Facial Profile: The facial profile is examined by viewing the patient
from the side using three landmarks (subnasale, ST nasion and ST
pogonion) and two lines.
• Helps in analysing the anteroposterior positioning of the jaws.

• Bimaxillary protrusion-
− A significant variation of the profile exists among groups from the
southern part of India.
− These ethnic groups have significant protrusion of the upper and
lower dentition, and thereby of midface, upper and lower lips. The chin
may be normal/retrusive.

E. Facial divergence:
• Facial divergence determines the position of lower part of the face
relative to the forehead.
• Divergence was described by Milo Hellmann.
• Divergence can be defined as the inclination of lower face relative to
forehead.
• It uses two soft tissue landmarks, soft tissue nasion and soft tissue
pogonion.
• A line is drawn between the forehead and the chin in the natural head
position.

F. Lip posture and prominence:
• Upper lip is protruded slightly in relation to lower lip in a balanced
face.
• With the lips relaxed, interlabial gap should be in the range of 1 to 5
mm.
• Lip competency can be defined as the ability to approximate the lips
without any strain.
• Lips should be examined for habits like:
 Lip sucking.
 Lip thrust.
 Lip insufficiency.
• Abnormal lip habits can be observed when the patient speaks or
swallows.
• Any lip activity during swallowing is abnormal.

• Lips can be classified as –
1. Competent lips: Lips which are in slight contact
when the musculature is relaxed.
2. Incompetent lips: Anatomically, short lips which
do not contact each other when the musculature is
relaxed.
3. Potentially incompetent lips: The lips are normally
developed but the patient is unable to approximate
the lips at rest due to upper incisor proclination.
4. Everted lips: These are hypertrophied lips with
redundant tissue. They show weak muscular
tonicity.

• Closed lip position –
− Reveals disharmony between
skeletal and soft tissue lengths.
− Increased mentalis contraction
(mentalis strain), lip strain, and alar
base narrowing are observed in
vertical skeletal excess.
− Lip redundancy is seen with vertical maxillary deficiency and
mandibular retrusion with deep bite.
− With balanced lip and skeletal lengths, the lips should ideally close from
a relaxed, separated position without lip, mentalis, or alar base strain.

• The lower lip –
− May be unduly everted, which is usually associated with a large
lower jaw.
− A lower lip which is associated with a small/retropositioned
mandible will be usually trapped in the overjet behind the
protruding upper incisors, which may be falsely interpreted as
upper lip being incompetent.

G. Nasolabial angle (NLA) and incisor protrusion:
• It is the angle formed by tangent to base of the nose and a
tangent to upper lip.
• Normal angulation is 110°.
• NLA is acute or decreases with proclination of upper
incisors.
• NLA is obtuse or increased in retroclination of incisors.

H. Clinical FMA:
• The inclination of mandibular plane angle to the Frankfort
horizontal plane should be noted based on which the vertical facial
proportions between anterior and posterior face are essentially
grouped as neutral, horizontal or vertical face types.
• An angle greater than 30° → vertical grower, signifies that lower
anterior face height could be increased.
• Angle 20° or less → horizontal grower.
• Angle somewhat between 20-30° → neutral grower.

• In a high-angle case, the posterior
ends of the angle meet behind the
auricle or within the occiput. Steep
mandibular plane angle is seen in
patients with long face and open bites.
• In a low-angle case, the two lines are
parallel and meet very far away. Flat
mandibular plane angle is seen in short
faces and skeletal deep bite cases.
• In average FMA cases, it meets behind
the occiput.

I. Slope of forehead:
• May be flat, protruding or steep.
• The esthetic appearance of the nasal profile is influenced by the
curvature of the forehead.
• In cases of a steep forehead, the dental bases are more prognathic
than in cases with a flat forehead.

J. Nasal contour and size:
• Nasal contour may be straight, convex and crooked.
• Variation in size may be microrhinic or macrorhinic.
• Long nose is associated with increased A-P length and
vertical height of maxilla.

K. Chin:
• Chin is examined for height, width and contour.
• Influence on profile -
- Protruding chin with deep mentolabial sulcus → Retrusive lip profile.
-Negative chin formation with absence of sulcus → Protrusive lip profile.
• Chin may be adequaterecessiveexcessive -

L. Mentolabial sulcus:
• Mentolabial sulcus is shallow in bimaxillary protrusion.
• Deep mentolabial sulcus is seen in class II division 1 malocclusion.
• Hyperactive mentalis activity is also seen along with lip habits like lip
sucking and thrusting.
• Puckering of mentalis muscle can be visualized called as golf ball
appearance.

M. Assessment of submental soft tissues:
• Throat form is evaluated in terms of the contour of the
submental tissues.
• Straight throat form is better.
• Chin–throat angle and throat length are assessed.
• The ideal chin–throat angle is 90° and a longer throat is
aesthetically pleasing up to a specific point.

N. Transverse cant of the maxillary occlusal plane:
• Transverse cant can be due to –
- differential eruption and placement of the
anterior teeth
- skeletal asymmetry of the mandible
• Transverse cant is appreciated when a subject is
asked to hold a tongue blade (a long ice-cream
stick) in mouth between the premolars of the
opposite sides while keeping his/her head straight
and observing the parallelism between the tongue
blade and the interpupillary line.

O. Objective evaluation of smile:
• Objective criteria for assessing attributes of a smile –
− Arch form
− Buccal corridors
− Smile arc
− Smile index Ackerman and Ackerman
− Morley’s ratio
− Teeth, their show, shape, size and arrangement
− Gingiva, shape, position, show colour and texture.

(1) Arch form - An arch which is narrow or collapsed may present inadequate
transverse smile characteristics, i.e. large buccal corridors or dark spaces.
Excessive wide arch can obliterate these, resulting in a denture-like smile.
(2) Buccal corridors - the distance between the lateral junction of the upper
and lower lips and the distal points of the canines during smiling. The buccal
corridor is often represented by a ratio of the intercommissural width divided
by the width between first premolars.

(3) Smile arc –
• Formed as a smooth curvature of the lower lip that follows a smooth
consonant relationship of arc formed by maxillary teeth on the vermilion
border of lower lip on posed smile.
• A non-consonant or flat, smile arc is characterized by a flat anterior arc line
than curvature of lower lip on smile. The maxillary arch may be everted such
as in anterior open bite.

(4) Smile index –
• The area within the vermilion borders of the
lips during the social smile.
• Determined by dividing the intercommissure
width by the interlabial gap during smile.
(5) Morley’s ratio –
• The percentage of incisor show on posed smile with respect to the clinical
crown height. Usually it is 75-100%.
• Common causes are:
− Palatal plane tipping downward
− Vertical maxillary excess
− Short lip or greater crown height.

(5) Gingival display –
• Normally, the display of teeth and gums is about 1mm or just above the
cervical margins in posed smile.
• High smile line → show of teeth beyond 2 mm of their gingival lines, can be
caused by anterior vertical maxillary excess, greater muscular capacity to raise
the upper lip, and supplemental factors, such as excessive overjet and overbite.
• Low smile line → teeth are not visible or visible less than normal, may be
due to small incisors, vertical maxillary deficiency or a combination.

Functional Examination
Examination of postural rest position
and maximum intercuspation
Examination of path of closure
Examination of temporo-
mandibular joint (TMJ)
Examination of associated muscles
Examination of orofacial
dysfunctions

Clinical importance of functional analysis :
• To assess how a dysfunction contributes to the creation &/or
aggravation of a malocclusion. Correction of the dysfunction is
integral to the correction of the malocclusion.
• Helps to assess the prognosis of treatment. All functional problems
cannot be corrected and in such cases the orthodontist must realize his
limits and build the occlusion around the existing functional situation.
• Helps in selecting the treatment modality (functional / fixed) e.g.
deep bite correction. If function is abnormal the clinician must
consider whether it should be altered and whether the change in force
produced can be used to help solve orthodontic problems.

1. Examination of postural rest position and interocclusal
clearance :
• Postural rest position is that position of mandible where the synergistic
and antagonistic muscular components are in dynamic equilibrium
with their balance being maintained by basic muscle tonus.
• When the mandible is in the rest
position, it is 2–3 mm below and behind
the centric occlusion recorded in canine
area.
A. Postural rest position -

• Determination of postural rest position is accomplished when the patient’s
musculature is relaxed, sitting upright and looking straight ahead.
• The patient’s musculature can be relaxed by –
1) Phonetic exercises - Patient is made to repeat certain consonants
repeatedly (e.g. ‘M’). Mandible returns to rest position after 1-2 sec.
2) Command methods - Patient is commanded to perform functions like
swallowing
3) Non-command methods - Patient is distracted so that muscles are
relaxed
4) Combined methods - Observed during functions + ‘tapping test’

• The tapping test is done by asking the patient to relax, then by holding
the patient’s chin with the thumb and forefinger, passive opening and
closing movements in rapid succession to relax the masticatory
musculature.

• Once relaxed, the mandible must be checked extra-orally to ensure it is
in rest position by palpating the sub-mental region to check if the muscles
are relaxed.
• The maxillomandibular relationship is then observed by –
1) Parting the lips with the thumb and forefinger, ensuring that the
line of lip contact is not opened completely
2) Using the rest position speculum by A. M. Schwarz.

• The postural rest position is then registered by various methods –
1. Direct intraoral method – plaster core
2. Direct extra-oral method – caliper measurements using the difference
between vertical relation at rest and at occlusion
3. Indirect extra-oral method –cephalometry, electromyography,
kinesiography

• The extra-oral indirect methods are the most reliable.
1. Roentgenocephalometric evaluation -
Two cephalograms, frontal or lateral are taken in centric occlusion
and rest position.

• Kinesiographic registration –
- Allows the mandibular rest position to be recorded three-dimensionally.
- Uses a permanent magnet attached to lower ant teeth with acrylic and a
sensor system of six magnetometers mounted on spectacle frames.
- Change in magnetic field is recorded and displayed on storage
oscilloscope.

• The movement of the mandible from the rest position to full articulation
is analyzed three-dimensionally.
• The closing movement of the mandible can be divided into two phases:
1. Free phase - Mandibular path from the postural rest to the initial or
premature contact position.
2. Articular phase - Mandibular path from the initial contact position to
centric or habitual occlusion.
• Movements of the mandible from the rest position to habitual occlusion
must be differentiated for diagnosis:
1. Pure rotational movement (hinge movement)
2. Rotational movement with an anterior sliding component
3. Rotational movement with a posterior sliding component

• Analysis :
Bo = Angle between maxillary plane and mandibular plane in occlusion
Bn = same in rest position
MMn= Distance between two perpendiculars drawn to the base line of
the maxilla, which pass through the pogonion and "A“ point.
Mmo= same relationship in occlusion
Bn - Bo = rotational component
MMn - MMo = sliding component.

• Clinical significance:
 Increased freeway space is seen in true deep
bite cases where there is infraocclusion of
posteriors. In such conditions, bite opening by
molar extrusion can be attempted.
 Pseudo deep bite with normal freeway space
has normal eruption of posteriors. Bite opening
by intrusion of incisors is recommended.

B. Interocclusal clearance :
• Normally at rest the lower canine should be 3mm below the upper in
comparison with the occlusal position.
• An interocclusal space of upto 4mm is said to be normal.
• The pattern of growth also to be kept in mind.
For e.g. the prognosis is good in a true deep bite problem with a vertical
growth pattern, as the growth is expressed in a vertical direction,
eruption of molars is allowed to occur.

• A true deep bite is one in which there is a large interocclusal space caused
by infraocclusion of the posterior segments.
• It often results from lateral tongue posture or lateral tongue thrust habit.
• Some class II div 2 cases with adequate lip line are good examples of true
deep overbite.
• Treatment in the mixed dentition period
requires the elimination of the
environmental factors inhibiting eruption
of posterior teeth.
• This is a valid and quite attainable
functional appliance treatment objective.

• In conclusion,
True deep overbite with vertical growth - Good
Pseudo deep overbite with horizontal growth - Limited correction
True deep bite with horizontal growth
Pseudo deep bite with vertical growth
Fair
• A pseudo deep overbite with a small interocclusal
space already has normal eruption of the posterior
segment teeth, further eruption is possible only to a
moderate degree . The deep over bite is combined
with over eruption of the incisors. e.g. class II div2
malocclusion with the lip line and a gummy smile.

2. Examination of path of closure :
• Normally the path of closure of the mandible
from the rest position to habitual occlusion is
primarily rotary in functional equilibrium and
normal occlusion .
• The path of closure of mandible from the postural rest position to
maximum intercuspation is evaluated in sagittal, vertical and
transverse planes.
• A patient is examined for presence of functional shifts in the
anterior, posterior or lateral direction.

• Posselt’s Envelope of Motion -
- First described by Dr Ulf Posselt in 1952.
- It is a diagrammatic representation of a
sagittal view of maximum mandibular
movement.
-Posselt postulated that in the first 20mm of
opening and closing, the mandible only
rotates and does not simultaneously move
downward and forward.
- They are also called the border
movements of the mandible.

I) Class II malocclusions –
Three conditions can exist -
(1) Rotational movement without sliding component:
- Neuromuscular and morphologic relationships correspond to each
other.
- Path of closure is straight upwards and forwards with a hinge
movement
- There is no functional disturbance
- Functional true class II
A. Evaluation in sagittal plane –

(2) Rotational movement with posterior
sliding movement
- From initial contact to full occlusion
condylar action is both rotary and
translatory backward and up (posterior
shift).
- This functional type of class II
malocclusion appears more severe
than it actually is and presents a good
prognosis for treatment with
functional appliances.

(3) Rotational movement with anterior
sliding movement
- From initial contact to full occlusion the
mandible translates down and forward.
- This malocclusion is more severe than it
appears with teeth in occlusion.
- This variant is least common and it
represents poor prognosis.

• In functional malocclusions the elimination of functional retrusion or
protrusion leads to an improvement in sagittal relationship.
• This improvement is a change in the spatial interrelationship of the
parts and not caused by growth and development.
• In class II malocclusions with normal paths of closure the
intermaxillary relationships still require alteration but this alteration
requires both a morphologic and a functional change to produce the
desired sagittal correction.

• In conclusion,
 Posterior displacement with horizontal growth direction – Very Good
 Anterior displacement with vertical growth direction – Quite Poor
 Anterior displacement + horizontal growth
 Posterior displacement + vertical growth
Not good but may be
improved depending on
age and facial pattern

(1) Straight path of closure:
- Hinge type condylar function
- Possibility of successful functional appliance
therapy exist only if the magnitude of the sagittal
dysplasia is not too great and therapy is begun
in early mixed dentition.
(2) Rotational movement with posterior
displacement:
- Anterior postural rest position
- Where the path of closure is up and back,
the prognosis is much poorer.
II) Class III malocclusions –
Again, three conditions can exist –

(3) Rotational movement with anterior displacement:
- Posterior rest position → pseudo/postural/habitual Class III
- Path of closure is up and forward
- Prognosis is much better
 But not every Class III with anterior displacement is a mandibular
displacement with a good prognosis. Can be partially compensated by labial
tipping of maxillary and lingual tipping of mandibular incisors.
Because of the extreme tipping, anterior sliding
movement into occlusion. Uprighting the incisors
reveals the severity for which orthognathic surgery
necessary. This is called pseudo-forced bite.

B. Evaluation in transverse plane –
• It consists of observing the path of movement of mandibular
midline as the teeth are brought together from rest position to
habitual occlusion.
• Two types of central shifting of mandibular midline can be
differentiated –
- Laterognathy
- Laterocclusion

I ) Latero-gnathy:
• Centre of mandible does not coincide with facial midline in rest or in
occlusion
• True crossbite
• True neuromuscular or anatomical asymmetry
• Unfavorable prognosis
• Cannot be corrected with functional appliances
• Surgical correction

II) Latero-occlusion:
• Midline shift be observed only in occlusal position.
• In PRP, midlines are well aligned, mandible slides laterally in occlusion.
• Occlusal prematurities; requires eliminating the disturbances in intercuspation.
This can be done by widening the maxillary arch.
• Functional malocclusion.
• Prolonged crossbite relationships can lead to asymmetric jaw growth if
allowed to continue for a number of years during growth period.

C. Evaluation in vertical plane –
The vertical dimension of the freeway space is assesed.
According to Hotz and Muhlemann,
I) True deep overbite –
- Large freeway space caused by infraocclusion of the molars
- Prognosis is favourable with functional therapy with extrusion
of the molars
II) Pseudo-deep overbite –
- Small freeway space with molars fully erupted
- Deep overbite is caused by overeruption of the incisors
- Prognosis with functional appliances is unfavourable
- If freeway space is small, extrusion of molars is unfavourable

3. Examination of temporo-mandibular joint (TMJ) :
A. Importance of evaluation of TMJ and condylar movement –
• Early diagnosis of TMJ dysfunction and its elimination can prevent or
eliminate incipient TMJ structural problems.
• Early elimination of functional disturbances can prevent or eliminate
TMJ problems.
• During functional therapy the condyle is displaced and dislocated to
achieve a remodeling of the TMJ structures. If TMJ structures are
abnormal at the start, the possibilities of exacerbating the symptoms in
the course of functional therapy exists.

• TMJ dysfunctions can arise in the following manner:
1. Malocclusion-parafunction-structural breakdown
2. Trauma
3. Inflammation
4. Infection
• TMJ dysfunctions arising out of malocclusion-parafunction are of
interest to the orthodontist.
• Various researchers have come to the conclusion malocclusion
has no bearing on the severity of TMJ dysfunction. Untreated and
treated subjects have similar prevalence of TMJ symptoms. On the
other hand another set of researchers alleged that malocclusion can
lead to TMJ symptoms.

B. Symptoms of TMJ Disorders :
Initial symptoms may be seen in 8-14 years of age.
I. Tenderness on palpation -
• Most primary characteristic symptom
• Complaints of pain in or in front of the ear.
• Tenderness on palpation of the joint in the area implies inflammation.
II. Joint sounds -
(1) Click → single explosive noise, a sudden distraction of two wet
surfaces, symptomatic of some kind of disc displacement.
(2) Crepitus → It is the continuous noise heard during opening and
closing of joint, often caused by the worn articulatory surfaces of the
joint.

III. Range of motion -
Range of motion is the only truly measurable parameter, since the others
are more subjective. It is important to determine the severity of symptoms.
(1) Incisal opening –
• Measured from the upper incisal tip to the lower,
with the patient opening to his/her maximum,
comfortable, pain free range.
• The maximum (forced) limit is also recorded.
• Limited mouth opening due to pain → muscular
problems whereas due to an obstruction → disc
displacement.
• The normal range of mouth opening is 53-58mm,
less than 40 mm is suggestive of restricted mouth
opening.

(2) Lateral excursions –
• The lateral movement is measured from
midline to midline, when the patient is
moving the mandible to its maximum extent,
from one side to another.
• Less than 8 mm is considered as restricted.
(3) Mandibular deviation –
• When the jaw is opened, the path it follows should be smooth, straight and
consistent.
• Deviations from the norm are either lasting or transient, and are suggestive
of internal derangements of different varieties.

C. Clinical and functional examination of TMJ :
I. Observation –
• The path taken by the midline of the mandible during maximum opening.
• In a healthy masticatory system - no alteration in the straight opening
pathway.
(1) Deviation - shift of the jaw midline during opening that
disappears with continued opening (a return to midline) →
due a disc interference.
(2) Deflection - shift in the midline to one side that becomes
greater with opening and does not disappear at maximum
opening → due to restricted movement in one joint

• 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 movements 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 deviation are typical signs of functional
disturbances.

II. Auscultation –
• The diagnosis of a joint click depends
upon whether the click is -
- present in one joint or both sides
- is associated with pain or not
- is consistent or intermittent.
• On opening, the timings of click and so the intensity is recorded.
• A click heard later in the opening cycle may represent a greater
degree of disc displacement.
• The sounds are rechecked after asking to bite forward into incision
and then open and close, most often they disappear.

- The timing of clicking may be –
a) Initial clicking - retruded condyle in relation to the disc.
b) Intermediate clicking - unevenness of the condylar surfaces and of the
articular disc, which slide over one another during the movements.
c)Terminal clicking - most commonly and is an effect of the condyle
being moved too far anteriorly, in relation to the disc, on maximum jaw
opening.
d) Reciprocal clicking - during opening and closing, and expresses an
incoordination between displacement of the condyle and disc. Clicking
of the joint is rare in children.

III. Palpation of TMJ -
• Pain or tenderness of the TMJ is determined by digitally palpating the joint
in two areas bilaterally.
(1) Preauricular area –
- The pulp of index finger should be placed here,
gently applying pressure medially on the lateral
pole/head of the condyle while the jaw is closed.
- The level of pain and discomfort on each side
should be assessed and compared.
-Synchrony of movement on opening and closure
is checked.

(2) External auditory meatus –
-The little finger with pulp facing the condylar
head should also be gently placed in the external
auditory meatus to evaluate the motion of the
condyles.
- Posterior aspect of the joints are palpated in
this way with force being directed anteriorly.
- Synchrony of movement on opening and
closure is checked.

D. Radiographic examination of the TMJ :
• Indicated only for exceptional cases in children with functional disturbances
as findings are rare at an early age.
• The findings registered are –
- Position of condyle in relation to fossa
- Width of joint space
- Changes in shape and structure of condylar head and mandibular fossa

a) Palpation of the lateral pterygoid muscle
- The pain projection area of the
lateral pterygoid muscle is palpated in close
proximity to the neck of the condyle and the
joint capsule, cranially behind the maxillary
tuberosity.
- The examination is carried out with the mouth open and the mandible
displaced laterally.
- In the initial stages of TW dysfunction, the muscle often hurts upon
palpation on one side only. In the advanced stage the pain is usually bilateral.
4. Examination of associated muscles:

b) Palpation of the temporalis muscle
- The temporalis muscle palpated bilaterally and
extraoraly. The anterior, medial and posterior
portions of the muscle are examined separately
while the muscle is contracted isometrically.
- The temporal tendinous attachment on the
coronoid process, in the posterolateral region of
the upper vestibulum is palpated while patient's
mouth is half open.

c) Palpation of the masseter
- The superficial masseter muscle is palpated
beneath the eye inferior to the zygomatic arch.
The deep portion is palpated on the same level,
approximately 2 finger widths in front of the
tragus.
- During maximum isometric muscle contractions
the width of the superficial masseter and its
direction of pull can be registered around the
gonial angle. This muscle attachment should be
examined for pain on pressure. Occasional
trigger spots may occur which Can be quite
painful.

5. Examination of orofacial dysfunctions:
A. 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:
l) Protrusion of the tip of the tongue
2) No tooth contact of the molars
3) Contraction of the perioral muscles during the 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.
• Should visceral swallowing persist after
the fourth year of age, it is then considered
an orofacial dysfunction.

• Tongue thrust has an important effect on the etiopathogenesis of
malocclusions.
• Tongue thrust can be broadly classified into
TONGUE THRUST
• PRIMARY
• SECONDARY
• ANTERIOR
• LATERAL
• COMPLEX
• ENDOGENOUS
• HABITUAL
• ADAPTIVE
B. Tongue Thrust –

Tongue thrust maybe considered as primary or secondary from the
etiologic point of view.
1. The primary dysfunctions cause malocclusions and the treatment
must concentrate on eliminating the orofacial dysfunction.
2. Secondary dysfunction can be considered an adaptive phenomenon
to an existing skeletal or dento-alveolar deviation in the vertical
development. These secondary abnormalities usually correct
spontaneously while the morphological discrepancies are being
treated.
• Primary-secondary Dysfunctions:

Causes of Dysfunction
• Endogenous factors
• Heredity
• Imitation
Primary Secondary
• Adaptation

• Primary tongue dysfunction in conjucation
with hyperplastic tonsils
- A retracted tongue would touch infected,
swollen tonsils if these were to protrude far
out of the surrounding structures. in order to
avoid painful sensation and to keep the oral
airway open the mandible is dropped and the
tongue postured forward.
• Hyperplastic tonsils
Moderately swollen palatine tonsils which
protrude significantly from the tonsillar
sinus.

• Adaptive tongue dysfunction
After loss of teeth, the tongue is used to fill the
gaps, thus sealing the oral cavity i.e. compensatory
dysfunction.
• Adaptive dysfunction with skeletal malocclusion
Cephalogram of an open bite due to rickets. The
tongue Dysfunction is an adaptation to the skeletal
and dentoalveolar morphology.
• Open bite due to rickets
The skeletal and dentoalveolar open bite is
aggravated by the adaptive tongue dysfunction.

• Configuration of the craniofacial and
dysfunctions :
- The morphology of the facial skeleton and the
effects of tongue thrusting are correlated to a
certain degree.
- Horizontal growth pattern in conjunction with
tongue thrusting usually results in bimaxillary
dental protrusion.

- In vertical growth pattern with tongue thrust the
lower incisors are often are in lingual inclination.
- From the differential point of view it is
important to clarify both the skeletal relationship
and the tongue dysfunction in order to localize
the results of the abnormal tongue functioning.

• Methods Of Examination
- Various methods can be used to examine tongue dysfunctions. The
different types of clinical examinations are : electronic recordings,
electromyographic examinations, recording of the pressure exerted by
the tongue intraorally , roentgenocephalometric anaylsis,
cineradiography, palatographic, neurophysiologic examination.
- The position and size of the tongue in relation to the available space is
assessed by using roentgenographic cephalometrics. However, in most
orthodontic cases, registering the position of tongue is more important
than determining its size.

a) Palatography
- It involves recording the contact surfaces of
the tongue with the palate and teeth while the
patient produces speech sounds or performs
certain tongue functions.
- A thin layer of contrasting precise impression
material is applied on Patients tongue. Once the
consonants are pronounced, Patalogram is
documented photographically.

- Accurate pronunciation of “s”
During articulation the mandible is lowered
and pushed forward. The tongue rests on the
teeth and alveolar processes, and a groove is
formed in the center through which the air
stream is directed.
- Interdental sigmatism (lisping)
During this defective pronunciation of the
“S” sound, the tongue is usually protruded.
- Palatal sigmatism
This abnormal pronounciation is caused by
an unphysiologic friction noise between
tongue and hard palate.

- Lateral sigmatism on the left side
The tongue rest on the anterior teeth. The column of air
escapes on the left side.
- Bilateral sigmatism
Palatogram of this type of defective articulation in a
patient with microglossia.
- Sigmatism due to lateroflexion to the left side
The tip of the tongue is raised too high and rest on upper
incisors. The tip of the tongue deviates to the left.

b) Metric evaluation of tongue posture
Assessment of tongue size from metric analysis requires measurement of the
distance between the superior tongue surface and the roof of the mouth.
This is done along the seven constructed lines. These measurements indicate
the relative size of the tongue.
Is 1- Incisal edge of the lower central incisor
Mc- Cervical distal third of the last erupted molar.
V- The most inferior point of the uvula, respectively
its projection on the reference line.
O- Midpoint on the reference line between Is1 and
V.
A line is drawn through O, perpendicular to the
horizontal baseline and extended to the palate.
Further four lines are drawn at 30 degrees to each
other, resulting in total seven lines.

- Tracing of the analysis on the lateral cephalogram
Marking of the contours of the bony palate and dorsum of the tongue. Horizontal
and vertical reference lines for metric evaluation are illustrated.
The morphologic relationships in
case of retracted, elevated tongue.
Relationship in case of a downward
forward tongue posture.

- Template for metric analysis of tongue position
Transparent plastic template with an inscribed millimeter scale for
analyzing the position of the tongue on the lateral cephalogram. The
template is oriented on the point O.

C. Lip Dysfunctions
-The etiology of lip dysfunction is similar to that of tongue habits and is
assessed in relation to the configuration and functioning of the lips.
-Configuration of lips: The configuration of lips differs a great deal and
can be classified as follows :
1. Competent Lips
The lips are in contact when the
musculature is relaxed.
2. Incompetent Lips
Anatomically short lips with a wide
gap between the upper and lower lip in
relaxed position. Lip seal can only be
closed by increasing contraction of the
orbicularis oris and mentalis muscle

3. Potentially Incompetent Lips
The protruding upper incisors
prevent the lip closure. Otherwise
the lips are developed normally.
4. Everted Lips
These are hypertrophied lips with
redundant tissue but weak
muscular tonicity.

• Lip Habits
- Various habits of lips can be divided into:
1. Lip sucking
2. Lip thrust
3. Lip insufficiency
- Lip dysfunctions can be observed while the patient is speaking and
swallowing. The lower lip often shows variations of dysfunction with
regard to the tip of the tongue. The lower lip and tip of the tongue are
often in contact. In such cases, the lower lip is sucked in and is pressed
against the tip of the tongue. It is a symptom of orofacial dysfunction.
Visual evidence of mentalis muscle activity is also abnormal.

1) Lip Sucking
Lower lip is positioned behind the upper incisors,
this malpositioning of the lips occurs in
conjunction with hyper active mentalis muscle.
Lateral Cephalogram indicates that lower lip
dysfunction causes further protrusion of the upper
incisors and impedes the forward development of
the anterior alveolar process.

2) Lip Thrust
Characteristic profile of the lower third of the
face in a case of hyperactivity of the mentalis
muscle.
This type of lip habit is combined with lingual
inclination of the incisors.

D. Cheek Dysfunction
- In cases of cheek sucking and cheek biting, the
soft tissues are interposed between the teeth,
which promotes the formation of the lateral open
bite or deep over bite.
- Increased lateral pressure by the cheek
musculature impedes the transverse development
of the jaws.
- This type of cheek dysfunction is common in
cases with buccal non-occlusion.

E. Hyperactivity Of Mentalis Muscle
-The deep mentolabial sulcus is characteristic of the hyperactive mentalis
muscle. This muscle behavior impedes the forward development of the
anterior alveolar process in the mandible.
-The abnormal mentalis function often occurs together with lip sucking or
lip thrust.

The Hyperactive mentalis muscle
pulls the lower lip upward and
rearward and presses it against the
lingual surface of upper incisors.
The upper lip remains motionless.
The normal lip seal is disturbed
and the tongue is displaced
downwards.

F. Mouth breathing
- The mode of respiration is examined to establish whether the nasal
breathing is impeded or not.
- Chronically disturbed nasal respiration represents a dysfunction of the
orofacial musculature. It can restrict development of the dentition and
hinders the orthodontic treatment.
The extra oral appearance of
these patients is often
conspicuous and is termed as
‘Adenoid Facies’.

• Clinical findings of patients with oral respiration :
a) High palate
b) Persisting ‘tooth germ position’ of the upper
incisors.
c) Narrowness of upper arch
d) Poor oral hygiene
e) Crossbite
f) Hyperplasia of gingiva

G. Pattern Of Facial Morphology
The configuration of the facial skeleton and oral respiration are correlated to
certain degree. Impeded nasal breathing shows a higher frequency in facial types
with vertical growth tendency. Proliferation of the adenoids is more common
and more pronounced in patients with oro-nasal respiration. The incidence of
hypertrophied tonsils is also increased in this group.
Small sized adenoids Medium sized
adenoids
Large sized
adenoids

H. Tongue Posture
Two different tongue posture are possible in case of oro-nasal respiration.
Type I : The tongue is flat and its tip
is behind the lower incisors. This type
is often encountered on conjunction
with a anterior cross bite.
TYPE II :The tongue is flat and
retracted. This type of abnormal
tongue posture is common in cases
with oral respiration and disto-
occlusion.

I. Examination of Breathing Mode
- The case history and evaluation of tongue and lip posture as well as lip
function provide certain keys concerning the breathing mode.
- Following are the various clinical methods of examination:
1. Cotton pledget test
2. Mirror test
3. Observation of nostrils
- When interpreting the findings, it must be taken into account that the
respiratory mode is controlled by the nasal cycle which changes
approximately every 6 hours. This is a physiologic protective mechanism
which prevents nasal membranes from drying out. Due to the nasal cycle,
one nasal airway is always more constricted than the other.

NASAL RESPIRATION
The size and shape of external nares
of a patient with nasal respiration
during inspiration(left) and
expiration(right). Noticeable changes
in the cross section seen.
ORONASAL RESPIRATION
The alar muscles are inactive and so
the nares do not change their size.

• Differential Diagnosis
- Differential diagnosis must be used to determine whether the problems
in nasal respiration are due to an obstruction of the upper nasal passages
or habitual oral respiration.
- In case of an obstructed nasal passage, an operation by an ENT specialist
is indicated.
- Should the nose not be obstructed, pre-orthodontic therapy should be
carried out to treat restricted nasal breathing. This may include breathing
exercises or incorporation of a perforated oral screen.

Impeded Nasal Respiration
Minimal nasal
obstruction
Habitual oral
respiration
Severe nasal obstruction
Oral respiration - organic
causes
Dentofacial
Orthopedics
Exercises
Oral Screen
Dentofacial
orthopedics
ENT treatment
Wait, later
mechanotherapy

Myofunctional exercises for patients with
habitual oral respiration
Lip exercises with a piece of cardboard to
improve the lip seal are indicated. The
cardboard should be held loosely in a
horizontal position with the lips.
Changing habitual oral respiration
The custom made perforated oral screen is
placed in the vestibule. The airholes are
sealed off one after the other to convert
patients who breathe through their mouth to
nasal respiration.

- For the analysis of the relationship between craniofacial and the soft tissue
facial contours, profile and frontal radiographs are taken under standardized
conditions.
- This is done with the patient sitting upright in habitual occlusion and with
relaxed lips and mentalis muscles.
- Profile and frontal radiographs can be achieved in various ways.
1. Frontal and lateral views can be taken with a single camera as
described by Simon, with the patient in two different positions.
2. The two photographs are taken with a single camera, obtaining
different aspects by the use of mirrors.
3. The frontal and lateral views are taken simultaneously, using two
cameras.
PHOTOGRAPHIC ANALYSIS

A. Profile View
- For the profile exposure the camera is placed parallel to the facial
midsagittal plane. Patients head is oriented in accordance with the Frankfort
Horizontal Plane.
- Patient’s eyes should be looking straight ahead, unstrained and the ears
should be uncovered.
- A.M Schwartz compiled a detailed classification of the variations of the
facial profile. Evaluation is based upon the construction of three reference
planes:
1. Eye - ear plane ( Frankfurt horizontal plane)
2. Skin nasion perpendicular, according to Dreyfuss
3. Orbital perpendicular, according to Simon.
- The perpendiculars delimit the “jaw profile field”.

Straight Average Face
In an ideal average value face the subnasal point
touches the skin nasion perpendicular.
The soft tissue chin point lies in the center of the
‘Jaw profile field’ and the ‘skin gnathion’ lies on
the orbital perpendicular.
N- Skin Nasion
Sn- Subnasale
Gn- Skin Gnathion
Pog- Skin Pogonion
P- Porion(uppermost point of tragus)
Or-Orbitale
H- Frankfurt Horizontal plane
Po- Orbital perpendicular
Pn- Skin nasion perpendicular
JPF- Jaw profile field

- Depending on the location of the subnasal point relative to the skin
nasion perpendicular, there are typical profile variations:
1. Average face - subnasale lying on the skin nasion perpendicular.
2. Anteface - subnasale lying in front of the skin nasion perpendicular
3. Retroface - subnasale lying behind skin nasion perpendicular.

- For each of the profile, two further facial types can be differentiated
depending on the changed location of the soft tissue pogonion relative to
the subnasale - forward slanting or backward slanting faces.
Backward
slanting
profile
Forward
slanting
profile

Lip Profile Analysis
- Lip profile is of great importance for facial expression. The contours of the
lower face are therefore further analyzed by means of the mouth tangent.
- In a straight average face the mouth tangent bisects the vermilion portion of
the upper lip. It touches the border of the lower lip, and it forms a 10 degree
angle with the Pn-perpendicular.
Ls- Labrale superius
Li- Labrale inferius
Sto- Stomion
T- Mouth tangent ( joins
subnasale and soft tissue
pogonion)

Protrusive upper and lower lips
Retrusive lip profile

Facial Divergence
- The inclination between two reference lines are analyzed.
1. The line joining the forehead and the border of upper lip.
2. The line joining the border of the upper lip and soft tissue pogonion.
- Three profile types are differentiated according to the relationship
between these two lines.
1. Straight profile.
2. Convex profile
3. Concave profile

Straight profile: The two lines form a nearly straight line.
Convex profile: The two reference lines form an angle indicating a relative
backward displacement of the chin (posterior divergent)
Concave profile: The two reference lines form an angle indicating a relative
forward displacement of the chin (anterior divergent)

STRAIGHT CONVEX CONCAVE
A convex soft tissue profile suggests a Class II jaw
relationship and a concave profile suggests a Class III relation

Frontal View
- An analysis of the frontal picture is important in assessing major
disproportions and asymmetries of the face in the transverse and vertical
planes.
- Even a slight rotation of the head from the plane of the film can result
in major discrepancies. Therefore it is absolutely essential for the
camera to be placed perpendicular to the facial midline during exposure.
- For clinical analysis mark two orbital points and the skin nasion
perpendicular is constructed.
- A mild degree of physiologic asymmetry between the two sides of the
face exists in nearly all normal individuals.

Facial Symmetry
- Schematic illustration of a symmetric proportioned
face in the frontal plane
- Vertical reference plane – Facial midsagittal plane
(joins the skin nasion to the subnasal point)
- Upper horizontal plane – Bipupillary plane
- Lower horizontal plane – Parallel to the bipupillary
plane through the stomion.

Facial Asymmetry
Patient with marked left-right difference in the development of the mandibular
body and the mandibular angle.
The relative enlargement of the right side is associated with hyperplasia of the
right masseter muscle.

Orthodontic diagnosis

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