This document discusses different types of growth modification appliances used to treat malocclusions. It begins by explaining that growth modification uses remaining growth potential to alter jaw size and positioning. Key appliances discussed include the Andresen activator, twin block, and various types of headgear. Factors like timing of treatment, force magnitude, and duration of force application are reviewed. Both passive and active functional appliances are indicated, with considerations for skeletal, dental, and vertical discrepancies.

1. Growth modification of different
types of malocclusion
Prof. Maher A. Fouda
Prepared by:- Bilal A.M.
Faculty of dentistry-Mansoura university -
Egypt

2. GROWTH MODIFICATION
Growth modification attempt to change skeletal
relationships by using the patient’s remaining
growth to alter the size or position of the jaws.

3. PATIENTS EXAMINATION
 Patient’s examination.
 1- personal details.
 2- complaints and motivation.
 3- dental history .
 4- medical history .
 5- extraoral examination.
 6- intra oral examination.

4. ORTHODONTIC RECORDS
1- study models
2- x- ray:-
A- cephalometric
B- panoramic
C- prei apical if needed
D- bite wings if needed
E- occlusal if needed
F- hand wrist (imperative).

5. Hand wrist x-ray

6. Growth modification
Three assumptions are made when growth
modification is undertaken:-
1- first and most obvious, the patient must be
growing.
- Females are best treated between the ages of 9 and
11 years.
- males are best treated between the ages of 11 and
13years.

7. Growth modification
-2 The second assumption is that the orthodontist can
diagnose the skeletal discrepancy and design
treatment that will apply the appropriate amount and
direction of force to correct the discrepancy.

8. Growth modification
-3 The third assumption is that the growth
modification is only the first phase of a two-phase
treatment plan.

9. How does Growth modification work??
Three theories are offered:-
1- the first theory suggest that growth modification
appliance change the absolute size of one or both jaws.
2- the second theory is that growth modification may
work by accelerating the desired growth but not
changing the ultimate size or shape of the jaw.

10. 2- the second theory is that growth modification may
work by accelerating the desired growth but not
changing the ultimate size or shape of the jaw.

11. 3- the third possibility is that growth modification
may work by changing the spatial relationship of
the two jaws. The ultimate size of the jaw and its
rate of growth are not changed, but by
modifying the orientation of the jaws to each
other, a more balanced profile may result.

12. Biological age and hand radiograph:
HAND AND WRISTX-RAY:
■ In evaluating any group of normal children of the
same chronolgic age, it is clear that each has his own
characteristic growth time clock, i.e. there is early,
middle and late maturars, so chronolgic age is not an
accurate indicator of the stage of development. In an
effort to determine a child's develompental age,
methods of assessment using skeletal maturation (hone
age) have been devised.

13. Hand wrist x-ray

14.  The hand and wrist have been used most
commonly for assessment of pubertal
maturation. The hand and wrist may be
easily radiographed, with minimal
radiation exposure to the rest of the body.
The union of the epihyses with their
diaphyses occurs in specific order, which
in females is advanced 3-4 years
compared to that in males. (Diaphysis is
the shaft of long bone .

15.  Epiphysis: Portion of a bone which in early life
is distinct from the shaft). Between the ages of
12.5 and 14 years the most active
transformation of the epiphyseal cartilages
occurs concurrently with peak height velocity
and after completion of the permanent
dentition through the second molars. Skeletal
age was found to be more highly correlated
with menarcheal age, and menarche usually
occured soon after the fusion of the epiphyses
of the distal phalanges with their shafts.

16. 1 -Chapman has proposed a radiographic method
using a standardsized dental film to assess the
development the first metacarpophalangeal joint. The
development of the adductor sesamoid is staged
according to ossification. The onset of ossification of
the sesamoid occurs at the beginning of the adolescent
spurt in height and maximum velocity usually occurs
at the "seed” stage.

17.  It gradually increases in circumference over a
period of 2 - 3 years. Immediately after the inital
verification that the adductor sesamoid has
started its calcification statural height and facial
components begin a rapid, and definite spurt in
their developmental growth velocity. A limiting
factor in using this clinical signal is that without
serial records the clinicians may have difficulty
in determining with accuracy when the sesamoid
started its mineralization if it is present at the
time of the first recording .

18.  It a significant percentage of
calcification of the sesamoid has
taken place the individual is beyond
the pubertal phase of accelerated
growth. The converse is also true
without any initial signs of
calcification that is the circum-
pubertal growth spurt may be
reliably assumed to have not yet
begun.

21. Characteristic features of Skeletal class II patients.
Skeletal Class II malecc^sien may be characterized by both
sagittal and vertical discrepancies:
Sagittal discrepancies:
a. Prognathic maxilla and erthcgnathic mandible.
( maxillary protrusion).
b. Retrognathic mandible and crthcgnathic maxilla, (mandibular
retrusion.) or
c. a combination of both.

24. FUNCTIONAL APPLIANCES TO
TREAT CLASS II DIV I
Definition
Removable or fixed orthodontic appliances which use
forces §enerated by the stretching of muscles, fascia
and /or Peridontium to alter skeletal and dental
relationships.

25. Average angle cases
When ????
- Functional appliance treatment should be started before
the pubertal growth spurt
- This is the time when the mandible may exhibit
increased growth which may be influenced
- Duration—10-12 hours a day.
- These appliances should be worn at night-time as this is
when growth takes place

26. Activator

27. Activator

29. Class II div I due to maxillary protrusion I-
Extra oral examination
- Retrognathic profile
- Patient is asked to protrude the mandible, to give a
simulation of how the facial appearance would be if
mandibular growth occurred.

30. Case Report
11 year old male

31. Uncrowded Class II division 1 malocclusion with an
overjet of 11.5 mm, and an upper midline diastema
of 1.5 mm, with a minor left-side crossbite.

32. 2- Impressions
It’s important to ensure a good impression in the
lower lingual sulcus area.

33. 3- Study casts

34. 3- Study casts

35. 4- Intraoral Examination

37. 5- Radiographs

38. CEPHALOMETRIC X-RAY AND
ANALYSIS

39. Assessment of overjet

40. Assessment of ANB angle
 ANB +2 - +6

41. Assessment using Wits appraisal
Wits appraisal
-1mm to + 4.5 mm

42. Activator

43. The andreson activator
 Monoblock design Comprises upper and lower
acrylic fused together and has a solid palate. The
labial bow lies against the upper incisors palatal
wire to minimize palatal tilting of upper incisors and
has no clasps.

44. The Andresen type activator is a tooth-borne passive
appliance that opens the bite and the mandible is
advanced for Class II correction

45. The activator consists of a single block of plastic
constructed so that lingual flanges on lower cause
the mandible to be positioned forward

46. Mandibular incisors are capped so that forward
movement is resisted while the mandibular
posterior teeth are free to erupt.

47. Steps of construction
A piece of wax of approximate 6 x 8 cm
dimensions is warmed in hot water and folded
over to make a soft roll

48. Register the bite with the mandible in a protruded
position

49. Alternatively, bite may be registered by means of
exacto bite.

50. The indentations in the wax form the lower teeth
should be 2 or 3 mm deep.

51. Construction bite registration for TB
appliance taken in edge to edge position with
Exactobite stick.

53. Patient bites with incisors edge to edge
similarily 6mm separation of molars

54. Fold wax lengthwise twice to 1/3
size .Do not flatten

55. Turn folded wax lengthwise and fold once with
spatula in between

56. Crimp lower edge against spatula. Do not
flatten

57. Patient bites with incisors edge to edge

58. Final wax bite

59. The impressions are poured in stone and carefully
mounted on a plane line articulator, ensuring that the
bite is correct.

60. The labial bow of 0.8 mm wire is reinforced with
stainless steel tubing where it will enter the
baseplate

61. The tags of the labial bow are turned down at right
angles to the palate.

62. The softened roll of wax is placed just below the
occlusal surfaces of the teeth and pressed firmly into
the embrassures between the teeth and spread onto
the palate

63. The upper and lower baseplates
are waxed
Incisal edges of mandibular
anteriors are capped with a
thin layer of wax

64. The completed waxed up
activator

65. The appliance embedded in the deep half of the flask

66. The finished appliance

67. Activator■ Stimulation of myotactic reflex activity, causing isometric
muscle contractions.
■ Lose fit of appliance with low vertical dimension
■ Muscle force transmitted onto teeth: uses kinetic energy
■ Increased activity of elevator and protractor muscles with
relaxing and stretching of retractors.

68. Activator
other views:
■ Muscle contraction: superior head ٥۴lateral pterygoid
muscle
-Petrovic (rat studies), McNamara (primate studies)
-variations in the mode and direction of dislocation of
mandible.
■ Condylar unloading: Lysle Johnston

69. For the average angle cases, the acrylic can be left
untrimmed to restrict eruption of the lower molars.

70. In low angle cases, acrylic trimming is done to allow
eruption of posterior teeth.

71. It is possible to grind
grooves into the acrylic
adjacent to upper molars
and premolars, so that they
are guided in a distal and
buccal direction during
eruption, and this can help
to maintain good lateral
arch coordination as the
overjet reduces.

72. Buccal movement of a molar tooth by means of a pad
of rubber pulled into an undercut hole in the
baseplate.

73. Andresen was constructed using a wax bite with the
mandible protruded approximately 8 mm.
- It was worn for 10 months
- The lower molars and second premolars were free to
erupt.

74. 10 months later
The overjet was reduced from 11.5 mm to 3.5 mm
using only the Andresen appliance for 10 months
The molars and premolars were in Class I relationship

76. Class II Treatment
9-year-old female patient with severe overbite and Class II malocclusion
before treatment.

77. Placement of twin block appliance with bite jumping screws.

78. Immediate improvement in soft-tissue profile.

79. Class III Treatment
Bite jumping screws built into anterior acrylic plate of
maxillary Class III bite blocks.

80. 12-year-old female patient before treatment.

81. A. Twin block with initial bite advancement of 3mm.
B. After seven months of treatment, with further bite
advancements made by adding spacers of 3mm, 3mm,
and 2mm bilaterally.

82. After seven months of twin-block therapy.

83. Case report : Start records

84. Modified twin block

85. Post twin block

86. Pre adjusted Edgewise appliances

87. Post treatment records

91. Passive functional appliances
 Frankel

92. Active functional appliances
 Removable active functional appliances
 Bionator

95. Head gear activator

96. Active functional appliances
 Fixed active functional appliances
 Herbst

97. Duration and timing of wear
 Functional appliance treatment should be started
before the pubertal growth spurt
 This is the time when the mandible may exhibit
increased growth which may be influenced
 Functional appliances should be worn for at least
10-12 hours a day
 These appliances should be worn at nighttime as this
is when growth takes place

108. INDICATIONS
1- Growing ages (Mixed dentition and/or early permanent dentition)
2 – Skeletal considerations (Sagital correction ofclassll&lll)
Skeletal Class // with Short mandible.
A- Class II division I
B- Class II division 2 (Convert div 2 to div 1).
1- Vertical Considerations
Normal to low angle cases.
2- Dental Considerations
- Local irregularity and rotation of incisors especially upper incisors
- Crowding or dental compensation (Pre-functional Orthodontics
require
3- Open bite/ deep bite correction
4- Cross bite correction
5- To correct mal-forming dysfunction

109. CONTRAINDICATIONS
1- Children with neuromuscular disorders
a. Poliomyelitis
b. Cerebral palsy
2- Compliance
3- Hyperdivegent faces
4- unfavorable growth
5- Protruded lower incisors
6- Severe crowding
7. Age

111. High pull Face bow
 Van Beek appliance incorporates high pull face
bow and buccal capping. It also incorporates
incisor cappings. It is indicated in the treatment of
anterior open bite.

112. High pull Face bow
 High pull face bow can be attached to maxillary
intrusion splint. The splint incorporates acrylic
coverage of all the teeth in the upper arch .

113. Treatment of class II div I by extra oral
appliance.

118. High pull headgear holds or intrudes posterior teeth.

119. Case 1 before and after treatment.

122. Low pull face bow
Cervical pull face bow exerts
force below the level of
occlusal plane will tend to
extrude the upper molar teeth
and thus cause an increase in
the vertical dimension of the
lower face. While this may be
an advantage in a patient with a
deep overbite and reduced
lower facial height, it is
contraindicated in a patient
with open bite and increased
lower face height .

123. Low pull face bow

125. Cervical pull headgear
•Point of attachment lies below the occlusal plane ,the external
force is directed inferiorly as well as posteriorly.
•With the face bow the cervical attachment permits the creation
of force vector that permits the extrusive and distal movement of
molars.
• Force vector is altered when the angle of the face-bow in
relation to the dental bow and the length of the face-bow are
changed.

129. Spring – Gear with adjustable levels of force

130. Cervical fashion releasable headgear

131. Cervical fashion releasable headgear

132. Cervical fashion releasable headgear

134. High pull headgear

135. - Point of attachment is above the occlusal plane
- The extra oral force is directed superiorly and
posteriorly.
- High attachment permits the force vector to correct
anteroposterior maxillary excess and vertical
maxillary excess.
- Force vector is altered when vertical position of the
outer bow is changed.
High pull headgear

136. High pull headgear

137. High pull headgear

138. Present day

140. straight pull headgear
- External force is directed to more surface area - more
comfort.
- direction of the force vector can be modified.
- If the forces are equal for each attachment the resulting
force vector is usually above the occlusal plane but inferior
to the vector created with the occipital attachment alone.
- Requires more patient CO operation

141. Duration of the force
- At least 12 to 14 hrs per day (Klein 1957, Rickets
1960).
- Recommended in the evenings- growth hormone
release is higher. Growth hormone enhances the new
bone formation at the epiphyseal plates of the long
bones in growing children.

142. Magnitude of the force.
- For dental movements -15 to 400gms per side
depending on the size and tooth movement,
- A minimum force of 250 gm per side (total 500gm)
is enough for to modify skeletal change.
- To maximize the potential for skeletal change,
orthopedic force - 400 to 900 gm per side [ 1 to 2
pounds ] (Graber 1965).

143. Timing of force application
- Orthopedic effect in growing children
- Most active period of growth.
1- Just before the eruption of permanent teeth or in mixed
dentition
2 - during the pubertal growth spurt.

144. Cervical pull headgear
٠Point of attachment lies below the occlusal plane ,the
external force is directed inferiorly as well as posteriorly.
٠With the face bow the cervical attachment permits the
creation of force vector that permits the extrusive and distal
movement of molars
٠Force vector is altered when the angle of the face-bow in
relation to the dental bow and the length of the face-bow
are changed.

145. The sagittal correction of Class II cases may be
brought in several ways:
- Relocating the maxilla backward or inhibiting its growth,
- Moving the upper teeth distally.
- Releasing forward growth of the mandible,
- Moving the lower teeth mesially.
- Inhibiting the vertical growth of the maxilla.
- Inhibiting eruption of upper posterior teeth while
permitting eruption of lower posterior teeth.

146. Low angle cases.
The treatment objectives in cases of this nature are to:
- reposition the maxilla posteriorly.
- permit forward growth of the mandible.
- promote eruption of lower posterior teeth.
- promote extrusion of the upper molars and distal eruption of the
remaining upper posterior teeth.
- restrain the anterior vertical growth and eruption of teeth, and
- prevent mesial drift of lower posterior teeth and buccal tipping
of lower incisors.

147. Extra oral force is mandatory for 2 reasons:
- There is an extensive skeletal discrepancy due
essentially to a protracted maxilla and,
- The lower incisors would not be tipped further
labially, which happens often when activator are used
alone.
- Extraoral appliance of choice Cervical headgear,
since it has both a distal and an inferior force
component.

148. Straight pull headgear

149. Average angle cases
٠ Class II children with ncrmal face height (many of
whom have anterior deep bite because of excessive
eruption of lower incisors) can be treated with either
headgear or a functional appliance.
٠ If molars are moved distally and extruded, the
mandibular plane angle tends to increase.
٠ straight-pull or interlandi headgear is preferred over
cervical headgear, to reduce elongation of maxillary
molars and better control

150. Average angle cases
- It is a combination of the high-pull and cervical headgear.
- Main advantage is pure posterior translatory force as required in
Class II malocclusion with no vertical problems.
- This is accomplished by placing the force vector through the
center of resistance, parallel to the occlusal plane.
-This means bending the outer bow to the same level as CR, and
hooking the elastic to a notch at the same vertical level. This
prevents anterior migration of maxillary teeth, or possibily even
translate them posteriorly.

152. (A), Normal occlusion; (B), Class I
malocclusion;(C), Class II malocc
lusion; (D), Class III malocclusion.
Note the position of the mesial cusp
of the maxillary molar relative to the
mandibular molar in each type of
occlusion.

153. Orthopedic Treatment
The goal of orthopedic treatment is to maximize the
skeletal changes and minimize the dental changes
produced by the orthopedic force. The method and
effect of growth modification by the orthopedic
appliances depend on the initial age of the patient and
their skeletal pattern. Orthopedic treatment should be
limited to children with active growth remaining.
Since more skeletal change is obtained when
orthopedic treatment is started early, it is
recommended to start treatment in the early mixed
dentition stage (eruption stage of the permanent
incisors and first molars).

154. For treatment with a chin cap ,orthopedic treatment
should be continued until growth is complete or when
the growth rate is decreased. Remaining growth
should be evaluated not by chronological age but
skeletal age. Skeletal age may be assessed by either
hand-wrist radiographs, change in height or secondary
sexual characteristics, or using the vertebral
maturation method. Annual cephalometric radiographs
are considered most accurate in evaluating completion
of skeletal growth. Cephalometric analyses can also
help in determining whether the skeletal Class III
problem is due to an underdeveloped maxilla,
overdeveloped mandible, or a combination of both.

155. The choice of orthopedic appliances for growth
modification is usually determined according to the
patient’s skeletal pattern. In general, chin caps are
used in children who have an overdeveloped mandible
while rapid palatal expansion (RPE) and/or maxillary
protraction is used in patients who have a maxillary
deficiency.

156. In addition, to obtain optimal treatment results, it is
important for the patient to wear the orthopedic
appliance for more than 12 hours a day. Therefore
patient cooperation is paramount in orthopedic
treatment of Class III malocclusion patients.

157. Chin Cap
In patients with an overdeveloped mandible, chin caps have
been used in an effort to inhibit mandibular growth. However,
there are limitations in its use since the mandibular condyle is a
growth site rather than a growth center. According to reports by
Mitani and Sugawara,6 chin cap therapy on children with
overdeveloped mandibles was effective during the period of
treatment but lacked long-term stability due to relapse from
catch-up growth of the mandible.

158. Dermaut and Aelbers also stated that chin cap therapy
is best used on mild skeletal Class III patients or as
auxiliary measures in patients wearing functional
appliances.

159. Since the main effect of chin cap therapy is backward
and downward displacement of the mandible with
linguoversion of the lower incisors, its use should be
limited to children with a pseudo (functional) Class III
or a mild Class III malocclusion. For patients who
have an overdeveloped mandible, it is prudent to plan
for orthognathic surgery after growth is complete.

160. Class III malocclusion with mandibular
excess
 There is some evidence that a chin cup is more effective in
young children under age 7 than the same treatment used
later.
 Unfortunately despite efforts to modify excessive
mandibular growth, many of these children ultimately need
surgery, and the chin cup treatment is essentially
camouflage.

161. High pull Chin cup
 Chin cup is used to inhibit or control forward growth
of the mandible in skeletal Class III patients.
Patients with mandibular excess can usually be
recognized in the primary dentition despite the fact
that the mandible appears retrognathic in the early
years of most children .

168. Maxillary retrusion

169. Simultaneous use of Monoblock
and elastics

170. Developing class III treated by Balters
Bionator

171. Reverse twin block

177.  In mixed dentition stage , the face mask is attached to hooks
opposite the laterals . The hooks are soldered to labial arch
which is soldered to first molar bands . The labial arch is at
the level of the gingival third . A palatal arch is also adapted
to the teeth and is soldered to the molar bands from the
palatal aspects of the teeth .

195. DIAGNOSIS AND ETIOLOGY
The patient, an 8-year-old girl, came to the
Kangnung National University Orthodontic
Clinic in Gangneung, South Korea, with a
chief concern of “my bite is not right.”
Clinically, she had a concave facial profile,
and acute nasolabial angle, and a protrusive
mandible.

197. TREATMENT PROGRESS
Phase 1 treatment was started at age 8 years 4 months with
a maxillary removable appliance to regain space lost
from the early loss of the deciduous molars (Fig 4).
After 6 months of observation, a surgical miniplate was
placed. Local infiltration anesthesia was administered to
the maxillary left and right buccalvestibular areas after
surgical disinfection. A vestibular incision around the
canine area was performed. After an atraumatic
subperiosteal dissection to the infrazygomatic crest, a
curvilinear miniplate was adapted, bent to the zygomatic
buttress’s bony surface, and fixated with 3 self-tapping
miniscrews per side.

198. Phase 1 treatment included a maxillary removable
appliance to regain space lost by early loss of the
deciduous molars.

199. Location of the miniplate relative to the zygomaticomaxillary
suture. Note that this figure is only for visualization purposes
as this is a skull of an adult, and the anatomic contour of the
zygomatic process of the maxilla changes with age

200. After atraumatic subperiosteal dissection to the
infrazygomatic crest, a curvilinear miniplate was
adapted, bent to the zygomatic buttress bony surface,
and fixated with 3 self-tapping miniscrews; B, screws
should be placed in a posterior-superior direction to
prevent damage to the premolar tooth follicles. Cha et
al 103 American

201. Maxillary protraction was started 2 weeks after
placement of the miniplates, with a force of 300cN
per side applied 12 to 14 hours per day (Fig 6).
Within 10 months of treatment, a three quarters
premolar width Class II molar relationship was
established. Thereafter, the patient’s wearing of
protraction headgear was limited to nighttime only as
a retainer for 10 months. The plates were removed
after the facemask treatment. A mucoperiosteal
incision and a subperiosteal dissection were
performed to expose the miniplate. The monocortical
screws were removed first, and the miniplate was then
detached because often new bone is deposited next to
the plate. The surgical site was then closed and
sutured.

202. Maxillary protraction was
started 2 weeks after
placement of the miniplates.

203. Progress records taken at age 10 years 7 months
showed favorable growth between the maxilla and
the mandible, and the malocclusion could be
camouflaged by orthodontic treatment. The patient
was treated with fixed appliances for 18 months to
establish a good molar relationship and correct the
midline discrepancy. A maxillary circumferential
retainer and a mandibular lingual fixed retainer were
placed after appliance removal. The patient was
instructed to wear the retainer at night for 10 to 12
hours.

204. TREATMENT RESULTS
After 14 months of protraction headgear treatment the
malocclusion was overcorrected to a Class II molar
relationship to compensate for future excessive mandibular
growth. Superimposition of pretreatment and posttreatment
cephalometric tracings showed 8.1 mm of forward
movement of A-point and 3.3 of counterclockwise tipping
of the palatal plane . The ANB angle changed from –2.2 to
1 6.7. The SNO, or angle between the anterior cranial base
and orbitale, changed from 63 to 70. Labial tipping of the
maxillary incisors and lingual tipping of the mandibular
incisors, which are typically observed after tooth-borne
protraction, were not seen with the miniplates.

205. Progress
photographs
after 14
months of
protraction
headgear
treatment.

206. Intraoral photographs near the end of phase 2
fixed appliance treatment.

207. Postretention photographs 27 months
after appliance removal.

208. Maxillary Protraction
In children with an underdeveloped maxilla, maxillary growth
can be facilitated by means of an orthopedic force with a
protraction device.
To encourage forward and downward growth of the maxilla, it
is most effectively performed when the maxilla is protracted as
one rigid unit. For this reason, labiolingual appliances,
removable appliances, or fixed appliances with strong heavy
wires can be used. However, RPE is considered one of the
most popular and effective appliances.

209. Figure 5. Miniscrews inserted on the palatal or labial side of the
alveolar bone and connected to the RPE by wires and direct resin for
maxillary protraction. (A) Occlusal view; (B) anterior view.
Previous studies have shown that patients protracted
after opening the midpalatal suture with RPE showed
greater forward displacement of A point than patients
protracted with a labiolingual appliance and no
midpalatal suture opening.

210. Recently, miniscrews have been inserted on the palatal or
labial side of the alveolar bone and connected to the RPE to
reinforce the maxilla. For patients with increased lower face
height, a posterior bite blocks on the lower
dentition or bonded RPE appliances can be used
to avoid an increase in
the vertical dimension.

211. Figure . (A) Anterior open bite was created after
maxillary protraction by backward and downward
rotation of the mandible. (B) Miniscrews were
implanted on the palatal slope for intrusion of maxillary
molars for bite closure. (C) Anterior openbite was closed
after the second phase of treatment.

212. There have been numerous reports regarding maxillary
protraction with orthopedic force.However, relapse
following treatment has been seen in certain patients after
growth has been completed. According to Sung and Baik,
the direction of the forward and downward displacement
resulting from the maxillary protraction was similar to
that of a Class I control group while the amount of
forward and downward maxillary displacement measured
at A point was significantly greater than that in the Class I
control group.

213. However, during the observation period of 1 year
following protraction, the amount of maxillary growth
in the protraction group was found to be less than the
control group, indicating the possibility of short-term
relapse. Figure below shows a 14-year 6-month-old
Class III patient with an underdeveloped maxilla and a
fairly long mandibular body length.

214. The patient was treated with an RPE and facemask for 1 year
and6 months and treatment was completed withfixed
appliances. Due to the maxillary protraction, the mandible
rotated backward and downward resulting in an increase in
mandibular plane angle from 42.1° to 43.9° and a 2-mm
anterior open bite.
Figure 9. A 14-year 6-month-old male with a Class III openbite
malocclusion treated with an RPE and facemask (A-F) and fixed
appliance with molar intrusion using miniscrews in the second phase
(G-L).

215. Because of these changes, miniscrews were implanted
between the upper first and second molars for intrusion in
the second phase of treatment. Following treatment,
the openbite was closed and the mandibular
plane angle returned to 42.8°.
Figure 9. A 14-year 6-month-old male with a Class III openbite malocclusion treated with an RPE and
facemask (A-F) and fixed appliance with molar intrusion using miniscrews in the second phase (G-L).

216. Arch expansion
It`s one of means of creating space in dental arches
Expansion can be classified into:
- rapid maxillary expansion devices
- slow expansion devices

220. Rapid maxillary expansion (RME)
can be used to correct unilateral or
bilateral posterior cross-bites and it occurs
when the forces applied to the teeth and
the maxillary alveolar process exceeds the
limit needed for orthodontic tooth
movement and the applied pressure acts as
an orthopedic force that opens the
midpalatal suture.

221. The maxilla articulates with ten other bones of
the face and the cranium.

223. Fig . 3D reconstruction from CT image: occlusal view showing
complete parallel opening of midpalatal suture from median
diastema, 2 parts of maxilla, palatal processes to posterior nasal
spine.

224. •As sutural patency is vital to R.M.E, it is important to know
when does the suture closes by synostosis.
• On an average 5% of suture is closed by age 25 years.
Earliest closure occurs in girls aged 15 yrs. Greater degree of
obliteration occurs posteriorly than anteriorly.
•Ossification comes very late anterior to incisive foramen –
this is important when planning surgical freeing in late
instances of RME

225. We will use a new classification for RPE
appliances as follow:

226. The Hyrax appliance is essentially a non-
spring loaded jackscrew with an all-frame that
is soldered to the bands on the abutment teeth.
This type of appliance causes the least
irritation to the palatal mucosa and it is easier
to maintain good oral hygiene with it.

227. A rapid palatal expander with a habit breaker added.

228. Hygienic Rapid Palatal Expander with
occlusal wires
Hamula developed what the hygenic RPE

229. Haas introduced an appliance
which is a tissue borne fixed
appliance. He believed that his
appliance can cause more parallel
expansion forces on the two
maxillary halves and that the
forces are more evenly
distributed on the teeth and the
alveolar processes.

230. The appliance is attached to the teeth, with bands on
the first molars and first premolars, and to the palate,
by acrylic pads between the first premolar and first
molar.

231. 1. Patients who have lateral discrepancies that result in
either unilateral or bilateral posterior crossbites
involving several teeth are candidates for RME.

232. RPE: Hyrax Design
Bands on 6's & 4's
RPE: Hyrax Design
Bands on 6's

233. RPE: Dishinger Bonded
Design embedded in
acrylic splints Bonded RPE with a wire framework
that has acrylic splints

234. Case report 1 . This case is treated by rapid palatal
expander (RPE), is generally worn for four to six months.
During the first few weeks of wear it is necessary
to expand (activate) the appliance.
Rapid Palatal Expansion

235. Two weeks later, half of expansion is completed
Expansion is completed

236. ACTIVATION OF THE RME
APPLIANCE

237. •The basic principle of the appliance involves the
generation of forces that are capable of splitting the
mid-palatine suture. Hence, the forces should be
definitely more than the usually used orthodontic forces.
•The forces generated are close to 10 to 20 pounds. An
expansion of 0.2 to 0.5-mm should be achieved per
day. The screw is activated at between 0.5 to 1mm per
day and about 1 cm of expansion can be expected in 2
to 3 weeks.

238. •The activation schedules tend to vary depending upon the
age of the patient and form of the appliance. Timms has
suggested an activation of 90°,morning and evening for
patients up to the age of 15 years. In Patient above this age,
he suggests an activation of 45° four tirnes aday.
schedules of activation

239. • Zimring and lsaacson recommended, two turns per day for
initial 4 to 5 days followed by once turn per day in growing
individuals. For adults the recommended two turns each for the
first two days followed by one turn per day for the next 5 to 7
days and then only one turn every alternate day till the desired
expansion is achieved.

240. HOW TO TURN THE
EXPANDER

241. Radiograph showing the
swallowed object in the
stomach.
For rapid maxillary expansion
activation keys, some steps must
be followed. The first is to use
dental floss tied around the key
and then rolled up on the finger to
allow ready recovery in case of
deglutition or aspiration.

242. Pre Expansion
Post Expansion

243. Case report 2
Constricted maxilla and posterior crossbite
treated with (RPE).No spaces for the canines.

244. Unilateral crossbite treated with RPE
Case report 3 5-year-old patient who presented with a
constricted maxilla and a lateral mandibular shift on closure. A
Hyrax type of rapid palatal expansion appliance was used to
correct the posterior crossbite.

245. Pre treatment
Post treatment . Note the midline diastema formed by skeletal
expansion.

247. • A transverse maxillary deficiency in an adult is a
challenging problem, especially when it is combined
with a severe anteroposterior jaw discrepancy. The
demand for nonsurgical maxillary expansion might
increase as patients and clinicians try to avoid a 2-
stage surgical procedure—surgically assisted rapid
palatal expansion followed by orthognathic surgery—
and detrimental periodontal effects and relapse

248. • In this regard, a miniscrew- assisted rapid palatal
expansion was devised and used to treat a 20-year-old
patient who had severe transverse discrepancy and
mandibular prognathism.
• Sufficient maxillary orthopedic expansion with
minimal tipping of the buccal segment was achieved
preoperatively, and orthognathic surgery corrected the
anteroposterior discrepancy.

249. •The periodontal soundness and short-term stability of
the maxillary expansion were confirmed both
clinically and radiologically.
•Effective incorporation of orthodontic miniscrews for
transverse correction might help eliminate the need for
some surgical procedures in patients with complex
craniofacial discrepancies by securing the safety and
stability of the treatment, assuming that the suture is
still patent.

250. Pretreatment facial photographs

251. Pretreatment intraoral views showing severe
transverse and anteroposterior jaw discrepancy

252. Pretreatment casts

253. Fabrication and application of the MARPE: A, fabrication
on the cast; B-D, placement of the appliance and
expansion procedure for 6 weeks; E, after consolidation
and arch alignment at 10 months.

254. Periapical views during maxillary expansion: A, before
expansion; B, after 4 weeks of expansion, with the upper
diastema temporarily closed by resin buildup for esthetic
reasons; C, after consolidation and arch alignment at 6 months.

255. Posttreatment facial photographs

256. Follow-up intraoral photographs18 months after
debonding; F, axial computed tomogram showing the 3-
mm apical level from the cementoenamel junction 12
months after debonding

257. Slow Palatal Expansion
The second category for maxillary expansion is the slow
maxillary expansion group.
These appliances apply slow and continuous forces which do
not attempt, as a main objective, to open the midpalatal
suture.
These appliances include: removable expansion plates , Porter
W arch, and Quad-Helix.
W arch Quad-Helix

259. Case report 4 a patient in the mixed dentition
and has a bilateral posterior crossbite will be treated
with 3D Quad helix
Pre treatment

260. Pre treatment occlusal view
Transverse dimension (49mm
molar width) of the maxilla
before treatment.

261. After 2 months After 4 months
Beginning of Treatment

262. Before and After Quad-Helix 3D expansion – 5
months total time

263. Transverse dimension (57mm molar width) of the
maxilla after expansion (8 mm width addition by
expansion)

264. Case report 5 bilateral posterior crossbite treated
with Quad helix

265. During expansion

266. After expansionPre expansion

267. After treatment is completed

268. Case report 6 a 5-year-old boy who presented with a
unilateral posterior lingual crossbite and a lateral mandibular
shift due to a width discrepancy between the maxillary and
mandibular arches. The discrepancy between the width of the
maxilla and that of the mandible caused the mandible to
deviate to one side to occlude on the posterior teeth.
Unilateral crossbite treated with slow
palatal expansion

269. The preferred treatment is to increase the width of the
maxillary arch by the use of a fixed or removable
appliance. This case is treated using a W-arch
expansion appliance. The W-arch was constructed
with ,036-in stainless steel wire.
Pre treatment Post treatment

270. Case report 7 a case had unilateral crossbite .An
unequal W-arch used to correct a true unilateral maxillary
constriction. The side of the arch to be expanded has
fewer teeth against the lingual wire than the anchorage
unit. Even with this arrangement, both sides can be
expected to show some expansion movement

271. Removable Expanders

273. Transverse Expansion of the Arches
Active plate splitted in the midline will expand constricted
maxillary arch almost totally by tipping the posterior
teeth buccally .Not by opening mid-platal suture.
Therefore this appliance is not indicated for skeletal
crossbites or dental expansion for more than 2 mm per
side.