This document summarizes a journal club presentation on the chromosome arch, a non-invasive anchorage device. It describes the fabrication of the chromosome arch and presents two case reports where it was used for maxillary anterior retraction. In the first case, use of the chromosome arch resulted in no anchorage loss, while the second case using a transpalatal arch showed 2mm of anchorage loss. The chromosome arch provides better control of tooth movement in the sagittal and vertical planes compared to conventional anchorage devices. It is concluded that the chromosome arch is an effective and non-invasive way to reinforce anchorage during orthodontic treatment.

1. DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPAEDICS.
JOURNAL CLUB PRESENTATION.
Chromosome Arch: A Non-invasive Anchorage
Device
Amarnath B.C. , Roopak Mathw David , Shiva Prasad
Gaonkar Sanjay Abraham , Garima Chitkara
Presented by: Guided by:
Dr. Deeksha Bhanotia Dr. Mridula Trehan
M.D.S. First year. Professor & Head
NIMS Dental College and Hospital Department of Orthodontics
and Dentofacial Orthopaedics
1

2. Contents:
1. Introduction.
2. Steps in Fabrication
3. Case Report 1: En-Masse Retraction using
Chromosome Arch for Anchorage Reinforcement.
4. Case Report 2: En- Masse Retraction using
Transpalatal Arch for Anchorage Reinforcement.
5. Discussion.
6. Versatility and Advantages of chromosome arch.
7. Discussion.
8. Conclusion.
2

3. Introduction
Anchorage is defined as the resistance to unwanted
tooth movement . Control of anchorage is one of the most
important aspects of orthodontics.
Conventional methods of reinforcing orthodontic
anchorage like Transpalatal arch , Double Transpalatal
arch, Nance button, Intraoral intermaxillary elastics ,
Headgears etc, have certain practical limitations, including
complicated appliance design, produce unwanted
reciprocal effects, and neccessitates exceptional patient
cooperation.
Newer anchorage devices like microimplants
though provide excellent sites of force delivery without
taxing anchorage, have the disadvantages of invasiveness
and is expensive.
3

4. The chromosome arch is a simple, effective and versatile
means of controlling anchorage.
Fabrication of Chromosome Arch:
Chromosome arch was designed by Dr. Esequiel
Eduardo Rodriguez Yanez.
It is made with 0.036” round stainless steel wire in
an “X” manner and it is cemented to first and second
maxillary molars.
In its basic design the chromosome arch has two
distal palatal bends (one on each side) to aid during canine
and anterior segment retraction, diminishing unwanted
tooth movement.
4

5. Steps in Fabrication:
1. Wire bending with the hollow chopped plier in the
middle of the wire.
2. After the bend is done the wire is adapted to the palatal
vault.
5

6. 3. Once adapted to the palatine vault the center of resistance
of the molars is marked and distal bends are made.
4. The distal bends are made and the end of the wire is
adapted to the palatal aspect of the second molars.
6

7. 5. A second wire is bent in the middle and the ends are
adapted to the palatal aspects of upper first molars. These
two wires are placed together and soldered.
6. Soldered chromosome arch on working model.
(chromosome arch can be either bonded or soldered to the
molar bands).
7

8. Case Report 1: En-Masse Retraction using
Chromosome Arch for Anchorage Reinforcement.
A 15-year-old female patient presented with a chief
complaint of forwardly placed upper front teeth.
Extraoral finding:
a. increase in lower facial proportion,
b. incisor exposure of 4mm
c. incompetent lips
d. convex profile.
8

9. Intraorally:
a. Angle's Class I molar
b. Class I canine relation
c. Proclined anteriors
d. increased overjet and overbite.
9

10. Cephalometric analysis
 Class II skeletal relationship (SNA- 84° SNB- 80°,
and ANB-4°) (prognathic maxilla.).
 mandibular plane angle of (MPA=30°).
 The upper and lower incisors were proclined with an
acute interincisal angle (92°) .
 Soft tissue analysis revealed an acute nasolabial angle
and lip strain.
10

11. DIAGNOSIS:
Angle's class I molar relation on a mild class II
skeletal jaw base with average growth pattern. Class I
canine relation and proclined upper and lower incisors,
with mild crowding in lower anteriors with acute
nasolabial angle and lip strain of 2 mm.
TREATMENT OBJECTIVES:
(1) Maintain Class I molar and canine relationships and
obtain normal overbite and overjet.
(2) Alignment of upper and lower arch.
(3) Correcting the axial inclination of upper and lower
anteriors.
(4) Reduce protrusion of the upper and lower lips and
obtain soft tissue harmony.
11

12. TREATMENT PLAN:
Considering the patient's chief complaint, proclination of
upper and lower incisors, acute nasolabial angle, it was
decided to treat this case with extraction of all the first
premolars with maximum anchorage and utilize this space
for retraction of proclined incisors.
12

13. Considering all the above mentioned, the
treatment plan was formulated as follows:
1. General dental care
2. Extraction therapy: Relieve crowding in lower anteriors.
Upper and lower anterior teeth retraction to relieve lip strain
and correct axial inclination of the anteriors.
3. Anchorage plan: Anchorage was reinforced in the upper
arch using chromosome arch including first and second
molars on both sides. Lingual arch was used in the lower
arch.
13

14. 4. Appliance plan: MBT 0.022” slot PEA.
5. Decrowding and Anterior retraction
6. Finishing & detailing
7. Retention plan: Fixed retainers in lower arch and
removable retainer in the upper arch.
Treatment duration was two years and four months.
14

15. 15

16. TREATMENT RESULTS :
Class I canine and molar relationship were maintained and
normal overbite and overjet was established, with good
interdigitation of the posterior teeth.
No loss of anchorage in upper and lower arch in
sagittal plane .
There is no change in the facial axis angle.
There is retraction of both upper and lower anteriors
with no extrusion of upper and lower molars.
16

17. 17

18. Case Report 2: En- Masse Retraction using Transpalatal
Arch for Anchorage Reinforcement.
A 19-year-old female patient presented with a chief
complaint of forwardly placed upper front teeth.
Extraoral findings
increase in lower facial proportion,
incisor exposure of 4mm,
incompetent lips,
convex profile.
Intraorally
Angle's Class I molar and class I canine relation with
proclined anteriors.
18

19. The cephalometric analysis
Class I skeletal relationship (SNA- 82.50, SNB- 79, and
ANB-2.50)
average mandibular plane angle of (MPA=34°).
The upper and lower incisors were proclined with an
acute interincisal angle (106°).
Soft tissue analysis revealed an acute nasolabial angle
and lip strain.
DIAGNOSIS:
Angle's class I molar relation on a class I skeletal jaw
base with average growth pattern with class I canine
relation and proclined upper and lower incisors with acute
nasolabial angle and lip strain of 4 mm.
19

20. 20

21. TREATMENT OBJECTIVES:
(1) Maintain Class I molar and canine relationships and
obtain normal overbite and overjet.
(2) Alignment of upper and lower arch.
(3) Correcting the axial inclination of upper and lower
anteriors.
(4) Reduce protrusion of the upper and lower lips and
obtain soft tissue harmony.
TREATMENT PLAN:
Considering the patient's chief complaint, proclination
of upper and lower incisors, acute nasolabial angle, it was
decided to treat this case with extraction of all the first
premolars with maximum anchorage and utilize this space
for retraction of proclined incisors.
21

22. Considering all the above mentioned, the treatment
plan was formulated as follows:
1. General dental care
2. Extraction therapy: Upper and lower anterior teeth
retraction to relieve lip strain and correct axial inclination of
the anteriors.
3. Anchorage plan: Anchorage was reinforced in the upper
arch using transpalatal arch. Lingual arch was used in the
lower arch.
22

23. 4. Appliance plan: MBT 0.022” slot PEA.
5. Anterior retraction
6. Finishing & detailing
7. Retention plan: Fixed retainers in lower arch and
removable retainer in the upper arch.
Treatment duration was three years
23

24. 24

25. TREATMENT RESULTS ACHIEVED:
Class I canine and molar relationship were maintained and
normal overbite and overjet was established, with good
interdigitation of the posterior teeth.
The superimposition shows
a. Loss of anchorage in upper and lower arch by 2 mm
mesial movement of upper and lower molars.
b. There is no change in the facial axis angle.
c.There is retraction of both upper anteriors with 2 mm
extrusion of upper molars.
25

26. 26

27. DISCUSSION:
The superimposition using chromosome arch as an
anchorage device showed, no loss of anchorage in upper
arch in sagittal and vertical plane with retraction of upper
anteriors.
The superimposition using transpalatal arch as an
anchorage device showed 2 mm of extrusion
2 mm of mesial movement of
upper molars, suggestive of anchor loss along with
retraction of upper anteriors.
Sliding mechanics with chromosome arch provided
better control in sagittal and vertical plane compared to
transpalatal arch and may provide absolute anchorage and
could control mandibular rotation.
27

28. 28

29. Versatility and Advantages of chromosome
arch:
1. Excellent maximum anchorage appliance that includes
a greater number of teeth to the anchorage unit.
2. This device can be used along with other auxiliaries for
affecting multiple tooth movements without taxing the
anchorage.
3. Provides problem based design for force application.
4. The retraction movement is done in a more bodily
fashion, with no undesired rotations and less time.
29

30. 5. Any four teeth can be used for anchorage, provides
greater control in all three plane
6. It is a non invasive, inexpensive device which is easy to
fabricate.
7. The chromosome arch can be soldered to the molar
bands or directly bonded to the molars.
8. Multiple tooth movement, like individual canine
retraction, disimpaction, decrowding, cross bite
correction can be carried out during initial stages of
treatment itself.
30

31. CONCLUSION:
The maxillary anterior teeth were retracted without any
loss of anchorage in sagittal plane in case 1 with the aid of
chromosome arch and 2mm anchor loss is seen in case 2
using transpalatal arch as an anchorage device. In vertical
plane in case 1 using chromosome arch, no extrusion of
molars was seen while using transpalatal arch as an
anchorage device there was an extrusion of upper molars
by 2mm.
Thus the chromosome arch provides an anchorage
control better than conventional transpalatal arch.
Chromosome arch is an effective, non invasive anchorage
device for reinforcing anchorage with PEA. It provides
excellent anchorage control in sagittal and vertical planes.
31

32. RELATED ARTICLES.
Two-Couple Orthodontic Appliance Systems: Transpalatal
Arches.
Joe Rebellato
The transpalatal arch (TPA) can be activated to deliver a
clinically useful array of forces and couples to move and/or
rotate maxillary molars in all three planes of space. Changing the
palatal arch form can produce expansion or constriction of
intermolar width and activation of the inserts of the TPA will
produce couples at the molar sheaths. Activations of the inserts to
generate couples is possible in all three planes of space in the
form of symmetrical V-bends, asymmetrical V-bends, and step
bends. Although the associated equilibrium forces of a couple can
be the source of clinical surprises, they can also be harnessed to
produce favorable tooth movements.
32

33. Butterfly Arch: A Device for Precise Controlling of the
Upper Molars in Three Planes of Space.
Alireza Nikkerdar.
Abstract:
Intra-oral appliances such as transpalatal arch and Nance
appliance fail to resist against forces that tend to loosen the
anchorage. The infirmity arises due to the long lever arm and the
mesial force that is perpendicular to the long axis of the appliance.
The butterfly arch is presented here as an intra-oral appliance that
withstands the mesially directed forces with a mechanism that
puts strain on a stiff wire along its long axis. The unique shape of
the butterfly arch is advantageous in maximum anchorage cases,
cases in which arch width preservation is critical and cases with a
vertical growth pattern. With the aid of the butterfly arch, clinical
concerns such as patient cooperation, wearing extra-oral
appliances, complicated mechanics in extraction cases and control
of the arch length, arch width and vertical dimension would be
greatly diminished. 33

34. 34