Clinical extraoral examination

بسم الله الرحمن الرحيم

” وقل إعملوا فسيرى الله عملكم ورسوله والمؤمنون ”

صدق الله العلي العظيم

ORTHODONTIC DIAGNOSIS

Clinical Examination

Aim Causative factors of mal occlusion

Skeletal factor ( most important ) Soft tissue factor Dental factor Combination of one or more in one

or more than one plane of space

Evaluation of Skeletal relationship The Pt. should sit in upright position

in a comfortable state ( why ? )

Three planes of spaces: Anteroposterior ( Sagittal ) jaws relationship

Vertical jaws relationship Transverse jaws relationship

ANTEROPOSTERIOR ( SAGITTAL ) JAWS RELATIONSHIP

Assessed by one of the following:

A- Facial profile

* Two reference lines

Three types of profiles exists based on these two lines:

* Straight

* Convex

* Concave

Class I — the mandible is 2–3 mm posterior to maxilla. Class II — the mandible is retruded relative to the maxilla. Class III — the mandible is protruded relative to the maxilla.

Note :- this classification only gives the position of the mandible and the maxilla relative to each other and does not indicate where the discrepancy lies.

So we need a lateral cephalograph

.

Facial Divergence •Anterior or posterior inclination of lower face to

forehead determined by a line drawn

• * straight (orthognathic) when the line perpendicular to the floor

• * Anterior or posterior divergence when the line inclined anteriorly or posteriorly

B- Palpation method

placing Index & Middle fingers

if-:

* index finger anterior to middle finger ( Cl ll ) * middle finger anterior to index finger ( Cl lll)

* Even level ( Cl l )

C – Cephalometric Analysis

Based on-:

* ANB angle : difference between

SNA angle & SNB angle

if * ANB = 2-4 ……. Skeletal Cl l

* ANB > 4 …….. Skeletal Cl ll * ANB < 4 …… Skeletal Cl lll

Assessment of Vertical jaws relationship * Normally distance between glabella to sub nasale

and sub nasale to underside of the chin(lower facial height) is equal .

** reduced lower facial height…… deep bite

**increased lower facial height …. Ant. Open bite ***its also can be assessed by studying angle

between

- lower border of mandible

- Frankfort horizontal plane (from auditory meatus to lowest point of infra – orbital margin )

Clinically -:

*** The angle between these lines ranged between 28 – 30 ( normal )

Radiographically :-by measured the angle ** Frankfort horizontal plane between

porion to orbitale

** lower border of mandible between

gonion to menton

Assessment of Transverse law relationship **facial symmetry

**facial Asymmetry

may be seen in Pt. with

1 )hemifacial atropy / hypertrophy ( hemi

hyperplasia)

2 )congenital defects

3 )Unilateral condylar Hyperplasia4 )unilateral Ankylosis

The characteristics of condylar hyperplasia are: 1- Posterior open bite or canting of occlusal plane depending on time when hyperplasia develops.2- Asymmetry of lower facial third.

There are many Ways to assess the facial asymmetry-:

1 /bird look2 /composite photograph

3 /Tongue spatula4 /Radio graphically ( OPG or PA )

Evaluation of facial proportion

**Four horizontal planes : hairline (trichion) , ridge between eyebrows (glabella) , subnasale , chin point (menton)

** upper lip occupies one third of distance

( mouth – nose – chin relationship)

Ideal proportion-: *Upper , lower and middle third should be equal.

* vertical facial measurement is compromised with the width to give normal facial index

if

** facial height > facial width

..…Long face (dolichofacial)** facial height proportional to width

( ..…mesofacial )

** facial width > facial height ……square faces( brachyfacial)

**Width of the nose should be near to the inner inter – canthal distance

** Width of the mouth is equal to the distance between the irises

**facial symmetry : all five segments should be one eye distance in width.

Lips -: The following should be considered:***The form, tonicity, and fullness of the lips. For example, are they full or thin, hyperactive, or with little tone?

***Lip competence. Competent lips meet together at rest without any muscular activity

They should be touch each other or remain apart up to 3-4 mm in relaxing position .

*Normally the upper lip cover the upper incisors except the incisal 2-3 mm , while lower lip cover entire labial surface of lower incisor and the upper incisal 2-3mm.

Classification of lips: Competent Incompetent potentially incompetent Everted lips

**Separated lips at rest

** Closed lips at rest >>>>>> negroid *** The sagittal plane of lips determined entirely by

relationship between basal bone & jaws.

Instances -:

* low lip line >>> Skeletal discrepancy not severe

lip functioning partly behind Upper C incisor>>>>

Cl ll div l * Skeletal discrepancy very severe >>> lip functioning

compeletly behind Upper C incisor >>> no effect

**Ideally the two lips should meet at the center of the upper central crown >>>>> lip line

**in skeletal Cl ll & high lower lip line >>>> lip functioning entirely in front of upper C incisor

>>>>>Retroclination >>>>> CL ll div ll

Ricketts , Esthetic line (E-line) **connect the tip of the nose with soft tissue pogonion

**passes about 4 mm in front of upper lip . about 2 mm in front of lower lip.

**Bimaxillary dentoalveolar protrusion **Nasolabial angle NLA : between lower

Border of the nose and line joining subnasaleAnd tip of the upper lip (labiale superius)>>>

The angle = 110 normally It reduced in Pt. with proclined upper incisor or Prognathic maxilla

Thank you for listening