Cephalometrics in distraction osteogenesis

ROLE OF CEPHALOMETRICS IN PLANNING
DISTRACTION PROCEDURES
www.indiandentalacademy.com

Treatment Planning- Consideration of size,
placement, orientation.
Cephalometry – not a perfect science but a
great tool if used properly (also could
totally mislead if used without proper
understanding)

How to judge the amount of distraction
needed?
1. Use of normative values ?
Not very appropriate, since they cannot be
accurately applied to different ethnic
groups,males and females, persons with
varying builds etc.

2. Norms based on hard tissues alone?
Not appropriate because variable thickness of
soft tissues can compensate for/or
aggravate the hard tissue relations.

3. Instead of absolute linear measurements,
their projected values are more meaningful
to judge their true contribution to the
skeletal dysplasia in a horizontal or vertical
direction

The best known analysis employing the
co-ordinate reference is the COGS of
Burstone and Legan.

COGS of Burstone and Legan.
The drawbacks, however, are
1. Small sample
2. Unreliable ‘surrogate’ horizontal plane.

4.The best option would be probably the True
horizontal or the True vertical references
as applied to the ‘ Natural Head Position’.
The values for Indian population are currently
being established.

5.Ratios are more reliable than individual
linear measurements, because they
overcome the differences in the individual
size.

Certain useful ratios are
a) For sagittal measurements
i. Antr. Cranial base/ Max./Mand
= 20/ 14 /21
ii.. Mandibular components
Corpus/ Ramus
= 7 / 5

b. For vertical dimension
Post. Face height/Ant.Face height(Jarabak
ratio)
= 62-64%

6. These help to customize the ‘normal’ values
for maxillary and mandibular sizes in
proportion to the cranial base. Thus,
individual specific norms (as against
population specific) can be derived.

7. Placement of the maxilla and mandible with
respect to the cranial base (sella) can
compensate or aggravate the size
abnormality

8. Orientation of the maxillary base or the
mandibular corpus would affect the final
position of the anterior limits of maxilla and
mandible.

9. These are assessed in relation to the
thickness of the soft tissue drape to arrive
at the final estimate of maxillary and
mandibular alterations needed.

10. As of now, there is some uncertainty about
the exact quantum of soft tissue
displacement which follows hard tissue
changes.

THANK YOUTHANK YOU

Cephalometrics in distraction osteogenesis

Recommended

Recommended

More Related Content

Similar to Cephalometrics in distraction osteogenesis

Similar to Cephalometrics in distraction osteogenesis (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Cephalometrics in distraction osteogenesis