This document discusses the use of fixed 2x4 appliances to correct anterior crossbites in the mixed dentition. Key points include: - Bands are placed on upper first molars and brackets bonded to incisors with an initial aligning wire. Crossbites can often be corrected within a few weeks. - Factors like displacement, tooth damage, space issues and developing permanent teeth are considered before treatment. - A quadhelix can be added for minor expansion if needed. Fixed appliances allow for better control of forces compared to removable appliances. - Causes of crossbites include trauma, extractions, retained teeth and supernumeraries. - Advantages of fixed appliances

1. Lectured by Prof
. MAHER
FOUDA

2. The basic 2X4 appliance design is as follows:
 bands cemented on both upper first permanent
molars.
 brackets bonded onto the erupted maxillary
incisors.
 continuous archwires to provide/maintain good
arch form, as well as control of anterior teeth.
 supporting stainless steel tubing placed in the
long archwire spans between the molars and
incisors.

3. Archwire

5. A nine-year-old girl was referred by her
dentist regarding both upper central
incisors, which were in crossbite. She
presented with a Class I incisor
relationship on a Skeletal I base in the
mixed dentition. The upper labial segment
was spaced with the lower being well
aligned. She had a premature contact on
the central incisors with a resultant 2 mm
anterior displacement on full closure.

7. Bands were place on both upper first molars and
brackets were bonded to all the upper incisors
with an initial aligning wire of 0.016 inch nickel
titanium being placed. At the next visit, 5 weeks
later, the overjet had been corrected. A 0.016
inch stainless steel wire was then placed with
power chain for a further 4 weeks to close any
residual space and the patient was debonded
.Total treatment time was 9 weeks. No retainer
was indicated and the result was stable 4
months later.

8. Intra-oral photographs after 6 weeks of treatment.
Incisor relationship is now corrected

13. An 8 year-old boy was referred by his GDP
regarding the delayed eruption of the upper left
central incisor due to the presence of
supernumerary tooth. He presented with a
Class I incisor relationship on a Skeletal I base
with well-aligned upper and lower arches .The
supernumerary was removed and the central
incisor bonded to a gold chain using a closed
technique under a general anaesthetic.

15. Brackets were bonded to the three erupted
incisors and bands were cemented onto both
upper first molars with an initial aligning wire
of 0.016 inch nickel titanium. The wire
sequence progressed through a 0.01860.025
inch nickel titanium to a 0.01960.025 inch
stainless steel working arch wire. This was then
used as a base wire coupled with a piggyback
0.016 inch nickel titanium wire applying
traction to the unerupted central incisor via the
gold chain.

17. Once the incisor was through a bracket was
placed and 0.016 inch nickel titanium
archwire fully engaged. The archwire was
then stepped up to a 0.018 inch stainless
steel wire with powerchain to close any
residual spacing prior to debond. The
incisor was self-retaining. Total active
orthodontic treatment time was 10 months

20. A 7 year-old boy was initially referred by his GDP
for the removal of two supernumerary teeth
present in the upper midline. He presented in
the early mixed dentition. The supernumerary
teeth were removed and the patient reviewed 1
year later when he presented with a very
irregular and rotated upper incisors .A course of
264 appliance therapy was prescribed.

22. Initially, all four incisors were bonded with
bands place on both upper first
permanent molars and an initial aligning
wire of 0.012 inch nickel titanium due to
the severe rotations associated with the
upper incisors. Progression was via a
0.016 inch nickel titanium achwire to a
0.018 × 0.025 inch nickel titanium
archwire with a working archwire of
0.019 × 0.025 inch stainless steel.

23. Powerchain was used for a single visit to
close any remaining anterior spacing.
Once a positive overjet and overbite were
established the appliance was removed,
and a palatally-bonded retainer
cemented. Total active orthodontic
treatment time was thirteen months.

25. Intra-oral photographs after alignment
of incisors

26. Post-treatment photographs.
Palatal bonded retainer

29. An 8 year-old girl was referred by her GDP who was
concerned about both upper central incisors being
in crossbite. She presented with a Class III incisor
relationship on a Skeletal III base in the mixed
dentition with an anterior and displacement to the
left of the mandible after initial contact.

31. All four upper incisors were bonded, the upper first
molars banded with a soldered quadhelix, which
was activated, and an initial aligning wire of 0.016
inch nickel titanium placed .Rapid correction of the
incisor relationship occurred and the patient was
debonded after 5 months of treatment. She was
kept under review with the occlusion remaining
stable 3 years later.

33. Pre- treatment

36. Correction of anterior crossbite
with fixed appliance.

41. The boy, 8 years and 9 months had a crossbite of
all four upper incisors. In case history his
mother stated she had a frontal crossbite as a
young girl, and her cousin was operated for the
mandibular prognathism. There was the
crossbite of central incisors in the boy's
deciduous dentition.

42. Class I in molars and canines, crossbite of 21 +12,
flattened upper frontal segment, spaces in both
upper and lower frontal teeth .The
orthopantomographic radiograph shows the teeth
are present in the range of second permanent
molars.
Patient crossbite befor treatment

43. Cephalogram was assessed: Skeletal Class III
according to WITS, Skeletal Class I according to ANB
angle, neutral growth rotation, interincisal angle of
129°, 1+1 to NS angle is 104°, 1-1 to ML angle is 95°.

44. The treatment started with bands on teeth 6+6, 6-6,
transpalatal arch Burstone of steel 0.032" x 0.032" as
the anchorage, and with attachment of brackets on
teeth 21 +12, and 21 -12. In the maxilla we used an
arch of TMA wire, diameter of 0.016" x 0.022", utility
type; lower arch was of stainless steel, diameter of
0.016". At the same time we made bite blocks for the
teeth V+V of photocomposite to eliminate incisors
from articulation. After a month, Class III elastics
were added. Positive overjet of 21 +12 was reached 6
weeks after the beginning of treatment. At that time
the bite blocks were removed .
Overbite achieved

45. For retention a stainless steel arch, diameter of
0.017" x 0.025" was used. Upper and lower fixed
appliances were removed 4 months after
treatment beginning (Fig. 4a-c). Currently, the
patient is in retention phase already for 19
months, he has upper and lower retainer, incisors
are still in positive overjet.
After removal of fixed appliance

48. A 7-year-old female presented with the upper
four deciduous incisors in crossbite . Glass
ionomer cement was added to the occlusal
surfaces of the mandibular second deciduous
molars. Two months later, with the crossbite
corrected, the cement was removed . The
patient’s profile also improved significantly.

49. Pretreatment

52. A 10-year-old male presented with the upper
central incisors in crossbite .The lower first
permanent molars were built up with glass
ionomer cement .Three months later, the
crossbite was resolved .The upper lateral
incisors erupted in a normal relationship to the
lower arch, while the lower anterior crowding
resolved itself as the occlusion was unlocked .

53. 10-year-old male patient with upper central incisors in
crossbite before treatment.

54. Glass ionomer cement bonded to occlusal surfaces of lower
first permanent molars.

55. Case 2. Correction of crossbite in three months.

56. Case 2. Upper lateral incisors erupting in proper positions as
lower anterior crowding resolves Spontaneously.

57. A 7-year-old male presented with a crossbite of
the upper left central incisor and gingival
recession of the lower left central incisor (Fig.
9). Two months after a glass ionomer build-up
of the lower molars, the crossbite was resolved,
and the perio - dontal condition of the lower
incisor had improved significantly (Fig. 10).
Three months later, the gingival contours of the
lower incisor were almost normal (Fig. 11).

59. Correction of crossbite in two months.

62. Physiological spacing (ugly duckling) stage. A transient
anterior open bite can be associated with eruption of the
incisors as they approach the occlusal plane and this
invariably improves with time. The maxillary central
incisors can also be quite distally inclined when they first
erupt, which produces a midline diastema between them.
This physiological spacing or ‘ugly duckling’ stage is
thought to be due to the combined effect of the maxillary
incisor apices being initially quite close together in the
anterior maxilla as the incisors erupt and lateral pressure
from the erupting maxillary lateral incisors and canines

63. 7 year 9 year 14 year

64. As these teeth erupt this pressure is transferred
from the apical region of the maxillary incisors
more coronally, improving their inclination and
usually closing the diastema.

69. Pretreatment panorex radiogragh
Pretreatment
intraoral
photogragh

70. Pretreatment periapical x-ray of maxillary central
incisors

71. Progress panorex radiogragh

72. Final intraoral photogragh
Final periapical radiogragh of maxillary central
incisors

78. 1- presence or absence of an anterior mandibular
displacement.
2-possible damage that has or might occur to the
dentition through excessive tooth wear, or to the
supporting periodontal structures.
3- prevention of establishment of the developing
Malocclusion.
4-space availability – this may be rectified by the early
removal of both the upper deciduous canines.
5-the position of the developing permanent canines in
relation to the roots of the lateral incisors.
6-the depth of the overbite

79.  The magnitude of the crossbite —does it involve
a single tooth or an entire segment?
 Is there a displacement associated with the
crossbite?
 How significant is the skeletal component and
will it be possible to compensate for this
discrepancy with
 tooth movement only?

80. If expansion is indicated at an early stage, then
this can be carried out easily and
simultaneously by adding a quadhelix to the
2x4 appliance.

82.  previous history of trauma.
 early extraction of deciduous teeth allowing
closure of eruption space or formation of
fibrous gingival tissue.
 retained deciduous teeth.
 supernumerary teeth.
 Odontomes.

83. The major advantages in carrying out this treatment
with a 2x4 appliance are the ease with which space
opening can be controlled with a fixed appliance,
and also that the force magnitude and vector can be
controlled much more precisely than with a
removable appliance.

84.  Minimal discomfort.
 Reduces need for patient co-operation.
 Increase control of tooth movements.
 Movement possible in all three planes of space.

85.  Appliance rarely worn full time.
 Appliance damage/lost appliances.
 Difficulty in speech/eating.
 Gagging.
 Decalcification/caries.
 Gingivitis/palatal hyperplasia/fungal infections.
 Incorrect activation produces unhelpful changes.
 Allow only tipping of teeth.

86. Treatment carried out in this mixed dentition
stage may take as little as a couple of weeks,15
but in the more difficult cases can take longer. In
the majority of cases, however, the end result
can be more effectively and efficiently achieved
than if a removable appliance was used.

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