This document discusses the progressive slenderizing technique in orthodontic treatment. It involves mechanically reducing the dental interproximal enamel to reshape tooth contacts and decrease tooth width. This helps correct crowding, tooth size discrepancies, and asymmetries. It has advantages over extraction by minimizing tooth movement and relapse risk. Contraindications include high caries risk, poor oral hygiene, and rectangular tooth shapes. When performed correctly, it can remove up to 0.5mm of enamel while avoiding damage to tooth structure or sensitivity. A variety of instruments are used to precisely carry out the slenderizing.

1. PROGRESSIVE
SLENDERIZING
TECHNIQUE
Presenter : Zia Ul Islam

2. Definition
 Mechanical reduction of the dental
interproximal enamel layer, which is
carried out in order to re-shape the
contact area and decrease the
mesiodistal diameter of the teeth to
facilitate alignment.

3. The objectives of slenderizing
include:
• Correction of dentoalveolar discrepancies
• Treatment of tooth size discrepancy (Bolton
discrepancy)
• Adjustment of interdental contact point to the papilla
shape
• Increasing the interdental contact surface in order to
contribute to better stability of corrected rotations
• Correction of asymmetries in order to improve
aesthetics.

4. Indications
1. Crowding
Slenderizing is a technique for the treatment
of minor crowding, but an
experienced orthodontist also can treat
moderate crowding cases.
2. Bolton discrepancies
The upper and lower canine-to-canine and
upper and lower molar-to-molar Bolton
indices indicate where slenderizing might be
undertaken to improve the occlusion.

5. The relation between the lower molar-to-molar tooth
size is 91.3 ± 1.91
The canine-to-canine relation is 77.2 ± 1.65

6. If a ‘12’ Bolton index is achieved, a
molar Class I relationship is obtained
and
if the ‘6’ Bolton index is achieved, a
canine Class I relationship is obtained.

7. 3. Triangular and ‘barrel’
tooth shapes
 According to Bennett and
McLaughlin
 three main tooth shapes:
 rectangular
 triangular
 and a barrel-shaped teeth

8. Tooth shape has great importance in
orthodontic treatment.
The rectangular shape allows a wide and stable
contact point without visible interdental spaces.
The triangular shape allows a reduced and very
occlusal or incisal contact point with BLACK
GINGIVAL TRIANGLES.
Barrel shaped teeth have a reduced contact point in
the middle with apparent embrasures at the incisal
level.

9. If the crown has a triangular shape, the
distance between the bone crest and the
contact point is relatively large. In these
cases, the interproximal papilla tends to
be absent.

10.  4. Macrodontia
 Dental shape does not have any influence
on the enamel thickness but it is
aesthetically more advisable to perform
slenderizing on macrodontic rather than
on microdontic teeth.

11. 5. Over-extended crowns and
fillings
 In such cases, slenderizing is indicated
to obtain normal tooth shape and
dimensions

12. 6. Bilateral dental asymmetries
 Slenderizing, veneers or crowns are often
indicated in order to compensate for
dental asymmetries, upper anterior
region.
7. Adult patient (narrowed pulp chambers)
 Adults have narrower pulp chambers, so
slenderizing can be carried out with less
risk of compromising dental sensibility
than in young patients.

13. 8. Low caries index
 Slenderizing should only be carried out in
patients with a low caries index, in order to
avoid increase in susceptibility.
9. Multiple rotations, in order to achieve
better stability
 In patients who present with multiple
rotations, slenderizing can result in wider
interproximal contact areas, which makes
the tooth position more stable with respect
to the risk of relapse

14. Contraindications
• Patients who do not consent to slenderizing..
• High caries index
• Poor oral hygiene: high bacterial plaque
index
• Rectangular-shaped teeth
• Young patient (large pulpal chambers)
• Enamel hypoplasia, dentine hypoplasia, etc.
• Interproximally abraded teeth

15. Advantages of slenderizing
--Minimizing the need for extractions and
their consequences
The consequences of extraction
orthodontic therapy are:
• Difficulties in extraction space closure due
to loss of archwire control
• Difficulties in root paralleling next to
extraction sites
• Possibility of the space re-opening
(relapse), especially in adult patients.

16. --Less loss of tooth material
Slenderizing causes less tooth volume loss than
extractions.
--Smaller tooth movements
With the progressive slenderizing technique, tooth
movements required are smaller than in extraction
cases.
--Less root resorption risk
With smaller tooth movements and shorter
treatment times, the risk of root resorption is
reduced.

17. -- Better aesthetics
By using the ‘artistic grinding’ slenderizing,
black gingival triangles are avoided,
positioning the contact point at 5 mm from the
bone crest; tooth asymmetries can be
compensatand at the same time tooth shape
can be improved.
• In the anterior group, incisors and canines,
asymmetries should be compensated and
midlines should be centred

18.  • In premolars and molars, the cusps should remain
untouched for intercuspation
 • Slenderizing should be carried out in such a way that
the interproximal contact point remains at the
distance of 4.5–5 mm from the tip of the alveolar crest
to assure black gingival triangles will not be visible due
to the presence of the dental papilla.

19. How much enamel can be
stripped?
The enamel layer at the level of the
contact points has a minimum 1 mm
thickness, except the lower incisors,
where it is 0.6 mm. This allows the
orthodontist to grind half layer: 0.5 mm
on mesial or distal surface of all teeth,
except of the the lower incisors where
0.3 mm can be removed.

20. Instrumentation for
slenderizing  The following instruments may be used:
 Stainless steel strips
 Burs

21.  Discs
 Intensive system for slenderizing

22.  Dentacare system

23.  Measuring instruments and gauges

24. THANK YOU