RICKETT’S: VISUAL TREATMENT OBJECTIVE (V.T.
O)
The Visual treatment objective was first proposed by Holdaway and later by Ricketts. It forecasts
the treatment objectives as influenced by the growth as well as the mechanics.
USES OF V.T.O
1. It predicts growth over an extended treatment time, based on patients morphologic pattern.
2. Analysis soft tissue profile.
3. It graphically planes the best soft tissue profile for the particular patient.
4 Determines favourable incisor positioning based on an ideal projected soft tissue profile.
5. Assists in planning treatment mechanics.
6 The V.T.O forecast is valuable for the orthodontists self improvement in that, it permits him to
set his goals in advance and compare them with the result at the end of treatment. Identification
of the discrepancies between the goals and the result provide him with an objective picture of the
areas in which his treatment could be improved.
THE V.T.O CONSTRUCTION IS DONE TO THE FOLLOWING
SEQUENCE
1. Cranial, base prediction.
2. Mandibular growth prediction.
3. Maxillary growth prediction.
4 Occlusal, plane position.
5. The location of dentition.
6. Soft tissue of the face.
I. CRANIAL BASE PREDICTION
Trace the Basion -Nasion plane
The Basion and Nasion grow I mm per year.
Slide tracing back and trace Nasion area.
Slide tracing front and trace Basion area.
II MANDIBULAR GROWTH PREDICTION:
A. MANDIBULAR ROTATION PREDICTION:
The mandible rotates open or close due to effect of mechanics and inherent facial pattern.
1. Convexity reduction
Facial axis opens 1°/5 mm
2. Molar correction:
Facial axis opens 1°/3 mm
3. Overbite correction:
Facial axis opens / 4mm
4. Dolicofacial pattern
Tendency for facial axis to open 1°
5. Branchyfacial pattern:
Tendency for facial axis to close 1°.
Superimpose Basion along the Basion nation plane and rotate up at Nasion to open the bite and
down at Nasion to close the bite using point dc as fulcrum.
B. CONDYLARAXIS AND CORPUS AXIS GROWTH:
This extends between dc (point in the center of condyle neck along the Basion- Nasion plane and
Xi point (Geometric center of ramus).
CORPUS AXIS:
This extends between Xi point and Pm (protuberance menti the point at which the shape of the
symphysis changes from convex to concave).
The Pm moves forward l mm per year in normal growth. The Xi point shifts up 1 mm per year.
MAXILLARY GROWTH PREDICTION:
To outline new maxilla the distance between original and Menton is divided into thirds by
drawing 2 marks.
Step 1:
Superior mark.
Step 2:
Inferior mark.
To outline body of maxilla super-impose mark not on Menton along facial plane an trace palate:
Point A CHANGES:
The point A changes with various mechanics is as follows:
MECHANICS MAX RANGE
a) 8 mm
b) Class II Elastics 3 mm.
c) Activator 2 mm.
d) Torque 1-2mm.
e) Class III Elastics +2-3 mm.
f) Face Mask +2-4 mm.
FOR EACH 1 MM OF DISTAL MOVEMENT POINT A WILL DROP DOWN 1/2 mm:
Using above parameters construct new point A.
OCCLUSAL PLANE POSITION:
Super impose mark no. 2 on original Menton. Parallel the mandible planes. Construct the new
occlusal plane. (It will tip unto 30° either way depending on class II or III treatments).
UPPER AND LOWER MOLARS:
In case molar is to be moved to change molar relation, then redraw the lower molar forward or
back-ward based on how much it is to be moved.
The upper molar is drawn in good class I position to lower molar.
LOWER INCISORS:
After new point A is traced draw a new A-Pog line.
Super imposes on corpus axis at pm. Place a dot representing the tip of lower incisor in
ideal position i.e., -Imm. Above occlusal plane and I mm ahead of A-Pog plane.
Trace new lower incisor position.
Now trace upper incisor in good overjet over bite relation to lower incisor.
