Seminar about Extra oral clinical examination in orthodontics

2. 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


3. 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

4. ANTEROPOSTERIOR ( SAGITTAL ) JAWS RELATIONSHIP
Assessed by one of the following :
A- Facial profile
* Two reference lines

5. Three types of profiles exists based on
these two lines :
* Straight
* Convex
* Concave

6. 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
.

7. 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

8. B- Palpation method
placing Index & Middle fingers
if :* index finger anterior to middle finger ( Cl ll )
* middle finger anterior to index finger
* Even level ( Cl l )
( Cl lll)

9. C – Cephalometric Analysis
Based on :* ANB angle : difference between
SNA angle & SNB angle

10. if
* ANB = 2-4 ……. Skeletal Cl l
* ANB > 4 …….. Skeletal Cl ll
* ANB < 4 …… Skeletal Cl lll

11. 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 )

12. 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

13. Assessment of Transverse law relationship
** facial symmetry
** facial Asymmetry
may be seen in Pt. with
1) hemifacial atropy / hypertrophy ( hemi
hyperplasia)

14. 2) congenital defects
3) Unilateral condylar Hyperplasia
4) unilateral Ankylosis

15. 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.

16. There are many Ways to assess the facial
asymmetry :1/ bird look
2/ composite photograph
3/ Tongue spatula
4/ Radio graphically ( OPG or PA )

17. 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)

18. 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)

19. ** 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.

20. 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.

21. Classification of lips :
 Competent
 Incompetent
 potentially incompetent
 Everted lips

22. **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

23. ** 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

24. 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 subnasale
And tip of the upper lip (labiale superius)>>>
The angle = 110 normally
It reduced in Pt. with proclined upper incisor or
Prognathic maxilla