HOW to measure CBCT BEFORE AND AFTER MID PALATAL SUTURE OPENING

HOW TO MEASURE CBCT BEFORE
AND AFTER MID PALATAL SUTURE
OPENING
..

Mid palatal suture
maturation …

MID PALATAL SUTURE CHARACTERS
 The mid palatal suture described as an end-
to-end type of suture with characteristic
changes in its morphology during growth. In
the infantile period, Melsen reported that the
mid palatal suture is broad and Y-shaped in its
frontal sections...

 The ossification process in the mid palatal suture
starts with bone spicules from suture margins
along with “islands” (ie, masses of acellular
tissue and inconsistently calcified tissue) in the
middle of the sutural gap.(23, 24,25,26).

FIVE STAGES OF MATURATION OF THE MID
PALATAL SUTURE
 1. stage A, straight high-density sutural line, with no or
little inter digitation.
 2.stage B, scalloped appearance of the high-density sutural
line.
 3.stage C, 2 parallel, scalloped, high-density lines that
were close to each other, separated in some areas by small
low-density spaces.
 4.stage D, fusion completed in the palatine bone, with no
evidence of a suture.
 5.stage E, fusion anteriorly in the maxilla.

 The formation of spicules occurs in many places
along the suture, with the number of spicules
increasing with maturation…
Fernanda Angelieri,a Lucia H. S. Cevidanes,b Lorenzo Franchi,c Jo~ao R. Gonc¸alves,d
Erika Benavides,e and James A. McNamara Jrf S~ao Paulo and Araraquara, Brazil,
Ann,.Arbor, Mich, and Florence, Italy. November 2013 Vol 144 Issue 5,
American Journal of Orthodontics and Dentofacial Orthopedics..

Stage A of maturation of the midpalatal
suture is
seen in this patient as a relatively
straight high-density
line at the midline.

A, Stage B is observed as
1 scalloped, high density
line at the midline.
B, Stage B . characterized by a
scalloped high-density line in
some areas and, in other areas, as
2 parallel, scalloped, high-density
lines close to each other and
separated by
small low-density spaces.

Stage C is visualized as 2 parallel, scalloped, high
density lines that are close to each other and
separated in some areas by small low-density
spaces. The suture can be arranged in either A, a
straight or B, an irregular pattern

Stage D is visualized as 2 scalloped, high-density
lines at the midline on the maxillary portion of the palate.
The mid palatal suture cannot be visualized in palatine
bone, and the density of the para sutural palatine bone
is higher compared with the para sutural maxillary bone…

stage E, sutural fusion has occurred in the
maxilla. The mid palatal suture cannot be identified,
and the para sutural bone density is the same as in
other regions of the palate…

 Inter digitation increases then fusion occurs
earlier in the posterior area of the suture, with
progression of ossification taking place from
posterior to anterior with resorption of cortical
bone in the sutural ends and formation of
cancellous bone..
For this reason expansion opening of mid
palatal suture occur more in anterior region
than posterior …..

(31). Knaup B, Yildizhan F, Wehrbein H. Age-related changes in the
midpalatal suture. J Orofac Orthop.2004;65:467–74. [PubMed]
(32). Melsen B. Palatal growth studied on human autopsy material. Am J
Orthod. 1975;68:42–54. [PubMed]
(33). Persson M, Thilander B. Palatal suture closure in man from 15 to 35
years of age. Am J Orthod.1977;72:42–52. [PubMed]
(34). Knaup B, Yildizhan F, Wehrbein H. Age-related changes in the
midpalatal suture. J Orofac Orthop.2004;65:467–74. [PubMed]
(35). Cohen MM., Jr Sutural biology and the correlates of
craniosynostosis. Am J Med Gen. 1993;47:581–616. [PubMed]
(36). Sun Z, Lee E, Herring SW. Cranial sutures and bones: growth and
fusion in relation to masticatory strain.Anat Rec A Discov Mol Cell Evol

 A radiographic analysis of bone maturation at the
suture by means of digital images is based on the
detection of differences in density, which represent
alterations in bone mineral content. Density
measurements provide a wider range of gray scale
levels from 0 to 255 (from black to white) while the
human eye can only distinguish 28 to 32 shades.(ref)
Consequently, digital images enable to distinguish
smaller alterations in bone than human eyes when
analyze a conventional film-based occlusal
radiograph.
.(ref) ..Gröndahl HG, Wenzel A, Borg E, Tammisalo E. An image plate system for
digital intra-oral radiography. Dent Update 1996;23:334-
. Pfeiffer P, Schmage P, Nergiz I, Platzer U. Effects of different exposure values on
diagnostic accuracy of digital images. Quintessence Int 2000;31:257-60.

OPENING OF MID
PALATAL SUTURE IN
CONSTRICTED
MAXILLA …

CONSTRICTED MAXILLA …
 The maxillary deficiency in the transverse plane is called
maxillary constriction. The main etiologic factors of this
deficiency are mouth breathing, harmful habits, like
thumb sucking and/or pacifiers, and atypical phonation
and swallowing. The passage of air through the nostrils,
purified and warmed by the nasal hair, and the contact of
the dorsum of the tongue at rest with the palate are the
major stimuli of transverse growth of the maxilla during
the craniofacial developmental period. The poor
positioning of the tongue, the imbalance of perioral
muscles, the lack of lip seal, together with the labial
hypotonicity, contribute to maxillary constriction.

Regina Helena Lourenço BelluzzoI; Kurt Faltin JuniorII; Cícero Ermínio
LascalaIII; Lucas Bacci Renno ViannaIV, Maxillary constriction: are there
differences between anterior and posterior regions , Dental Press J.
Orthod. vol.17 no.4 Maringá July/Aug. 2012

Before and after expansion in
constricted maxilla

A) 6-year-old boy with a narrow upper maxilla.
When the mouth closes, the mandible is aligned
with the upper jaw (blue arrow)

(B) At the end of closing, interference
between the right canines (circle) makes
the mandible shift to the right in a cross
bite….

Posterior cross bite ( PXB) , a common malocclusion in
patients seeking orthodontic treatment, can be a unilateral or
a bilateral malocclusion of the deciduous, mixed, or
permanent dentition. The incidence of posterior cross bite
ranges from 7% to 23%, with unilateral cross bite being
predominant. Unilateral posterior cross bite includes the
teeth on 1 side of the arch and can be defined as either a
functional posterior cross bite or a true unilateral posterior
cross bite. In a functional posterior cross bite, mild bilateral
constriction of the maxillary arch that creates occlusal
interferences leads to a functional shift of the mandible
toward the cross bite side upon closure. In a true unilateral
posterior cross bite from intra-arch or jaw asymmetry, a
cross bite is seen in both centric relation and centric
occlusion without a functional shift of the mandible…

True unilateral posterior cross bite is a less common
malocclusion than functional posterior cross bite…
Baka et al, Cone-beam computed tomography evaluation of dentoskeletal
changes after asymmetric rapid maxillary expansion, American Journal of
Orthodontics and Dentofacial Orthopedics, January 2015 Vol 147 Issue
1…

TREATMENT OF CONSTRICTED MAXILLA
BY EXPANSION ..
 Palatal expansion is the most common method
used to improve the transverse dimensions of the
maxilla. Three types of palatal expansion are :
rapid maxillary expansion, slow maxillary
expansion, and semirapid maxillary expansion ..
Brunetto et al, Three-dimensional assessment of buccal alveolar bone after rapid and
slow maxillary expansion: A clinical trial study, American Journal of Orthodontics and
Dentofacial Orthopedics, May 2013 Vol 143 Issue 5..

. (A) At the end of the expansion treatment, the
maxillary arch is “overcorrected”; there is a lot more
expansion than necessary. The posterior segments are
wider than the lower posterior teeth. The mandible
now deviates to the left, which shows occlusal
instability at that moment. This is more obvious with
an upper occlusal view (B, arrows). This excess in
expansion will disappear once the expander is
removed

This excess in expansion will disappear once the
expander is removed. (C) 2 months after
removing the appliance, the excess in expansion
starts to decrease. (D) After 5 months, the
maxillary arch width is normal, the crossbite is
corrected, the midlines are aligned and the
mandible is centered

WHAT IS AN EXPANDER AND HOW DOES IT
WORK?
 The expander is a custom-made orthodontic appliance which is
bonded (cemented) to the posterior upper teeth and which
allows enlargement of the palate.
 It includes a screw placed in the middle that can be turned to
activate the appliance and generate a force that delicately
separates the two palatal bones where the suture that unites
them in the middle is located.
 The patient (or the parent) must perform 1 or 2 screw
activations per day, never more, until desired enlargement is
obtained.
 The activation period can last from 2 to ± 3 weeks and will
result in activating the screw between 40 and more than 50
times.

 The patient is seen regularly (every 7-15 days) during
the activation period.
 Once necessary expansion is obtained, activations of
the screw are stopped and the appliance stays in place
±3 months to allow the bone tissue to form in the
middle of the palate, in the suture that has been
enlarged...

During maxillary expansion, the opening of the
suture is made rapidly..

(A) Before activation of the appliance; the expansion screw and the
suture are closed. (B) Toward the end of expansion, the screw is open
(blue arrows) and the suture is open by several millimetres. The red
arrows indicate the dark zone which represents the opening of the suture.
(C) Another case showing a very wide opening during maxillary
expansion. The expansion screw was open by 14 mm and the dark zone of
the suture is well visible.

Front (anteroposterior) view, a radiograph clearly shows the opening
of the palatal suture indicated by yellow arrows. A, B and C represent
the same enlarged radiograph. The expansion screw, which reached its
maximum opening, is also visible.

The red arrow in (C) indicates the opening between the central incisors. (D)
Occlusal radiograph where the opening of the suture is clearly visible. The
darker areas on the radiographs are where the maxillary bones were
separated.

MEASURING CBCT BEFORE
AND AFTER MID PALATAL
SUTURE OPENING (MSO)…

 Cone-beam computed tomography (CBCT) was
developed in the 1990s as an evolutionary
process resulting from the demand for 3-
dimensional (3D) information obtained by
conventional computed tomography (CT) scans..
CONE BEAM COMPUTED TOMOGRAPHY
Third Eye in
Diagnosis and
Treatment planning

 A number of diagnostic tasks unique to dentistry are
driving this development. Planning implant placements to
replace teeth, securing dentures, and anchoring orthodontic
appliances are frequent applications for 3D investigations
of the jaws.. Also, upper airway analysis, and orthodontic
and ortho gnathic surgical planning for patients with
significant facial asymmetry has been increasingly
performed based on 3D volumes.. CBCT has also been
used to study the changes of the maxillary dento skeletal
complex with rapid palatal expansion. CBCT technology
for dentistry has some advantages over medical CT, such
as lower cost and radiation dose, shorter acquisition time,
better resolution, and greater detail…

Azeredo et al, Computed gray levels in multislice and cone-beam computed
tomography,American Journal of Orthodontics and Dentofacial
Orthopedics, July 2013 Vol 144 Issue 1 A..

CONE BEAM COMPUTED TOMOGRAPHY .
Three-dimensional cone-beam computed
tomography (CBCT) has attracted considerable
attention as a modern diagnostic tool because it can
accurately visualize and analyze the 3D shape and
position of soft and hard tissues…
CBCT
MACHINE

A, Scanning of CBCT followed immediately by B, the 3D
facial photograph. The patient maintained the same posture
during both scans.

CBCT imaging enables a detailed evaluation of
changes in the dento skeletal complex… changes
in the maxillary and mandibular arch widths were
determined at several levels, along with changes
in the bucco lingual inclinations of the posterior
teeth. Changes at any level of the maxilla or
mandible can be evaluated easily and accurately
using CBCT images...

ADVANTAGES OF CBCT IN
ORTHODONTICS
 Cost: CBCT devices have gained smaller size, thanks to
technological developments. The cost of CBCT imaging
is very low compared to computerized tomography.
Image processing is easier because it is limited to the
head and face. Maintenance cost of CBCT devices is
much less..
 Reduction of radiation dose: Referring to the results of
the different studies, CBCT devices emit up to 98% less
radiation.

 Quick scan: With CBCT devices, all raw data are
obtained in a single turn. In this way, the patient's length
of stay is reduced and the device increases patient
satisfaction
 Dimensional reconstruction feature: The most important
advantage of CBCT is possible to display and arrange
3D data in personal computers
 Image processing: Various comprehensive soft wares for
implant placement and orthodontic measurements are
available.
Eur J Dent. 2014 Jan-Mar; 8(1): 132–
140.

 CBCT provides information about root
inclination and torque, bone thickness and
morphology at the points where mini-screws are
decided to be implanted and osteotomy sites
during surgical planning…

DISADVANTAGES OF CBCT IN ORTHODONTICS
CONE BEAM
 The main factor of weakness in image quality is
image artifacts, such as metal brackets and
restorations.
 The actual color of the skin and soft tissue images
cannot be determined.
 Unwanted patient movement may cause image
disorder.

 Price of these devices is more expensive than
conventional X-ray equipment, and these devices
require more space.
 Radiation scattering may occur preventing of
image monitoring

THREE-DIMENSIONAL SUPERPOSITION
 Images of cranial structures taken at different
times can be superimposed on pre-defined points
using the 3-dimensional software. Measurements
performed on these images are imported to a
computer, and then growth changes and treatment
progress are evaluated. Thus, stability and post-
treatment assessment can be made with the help
of 3D superposition.

CBCT image shows the
three reference planes:
axial, sagittal, and frontal
(coronal), which
correspond to the
reference box that defines
planes relative to superior
(S), inferior (I), and
lateral (L).

•CBCT image orientation using: A, sagittal; B, coronal;
and C, axial slices.

. Maxillary linear and angular measurements on the cross bite and non cross
bite sides of the maxilla: A, nasal and palatal floor measurements, and
external maxillary widths measured relative to the mid sagittal plane at 4
levels: the buccal apex, buccal alveolar crest, most prominent point of the
crown, and buccal cusp tip; B, internal maxillary widths measured relative
to the mid sagittal plane at 2 levels: the palatal apex and palatal alveolar
crest; C, the angle between the long axis of the palatal root and a horizontal
reference line parallel to the palatal plane.

CBCT for the maxillofacial region enables multi
planar imaging and provides 3-dimensional (3D)
information, allowing for measurement of axial
inclinations of the dentition and changes in the
transverse dimensions free from distortion,
magnification, and superimposition. CBCT imaging
provides sub millimeter resolution images (isotropic
resolution, 0.4-0.125 mm) with relatively short
scanning times (10-70 seconds) and a reduced radiation
dose (equivalent to that needed for 4-15 panoramic
radiographs)..

Cone beam computed tomography scans were
taken using the Classic i-CAT® (Imaging Sciences
International, Inc., Hatfield, USA) cone beam CT
scanner. All scans were taken by the same technician
using either the 16 x 13 or the 16 x 22 centimeter field
of view with a voxel size of 0.4 millimeters. Patients
were positioned in a vertical seat with their head
stabilized in the headrest to prevent any unwanted
movement during the 20-second scan, teeth together
in centric occlusion, and the Frankfort Horizontal
plane parallel to the floor, as determined by the external
auditory meatus and soft-tissue orbitale.

Today, it is increasingly applied in dentistry mainly
because it is more affordable and entails lower
radiation exposure…
Nahm et al, Accurate registration of cone-beamcomputed tomography scans to 3-
dimensional facial Photographs, American Journal of Orthodontics and
Dentofacial Orthopedics, February 2014 Vol 145 Issue 2..

. Occlusal view of 4-banded Hyrax
appliance.
Diagram showing M1 furca and respective
C1, P1, and P2 apex reference points with
measurement lines connecting
contralateral sides

. Axial slice depicting measurements with reference
points erased for visualization (white, PMW; red,
BMW)

The use of CBCT to quantitatively evaluate and
compare skeletal expansion and alveolar tipping of
the maxilla at the maxillary canine (C1), first
premolar (P1), second premolar (P2) and first molar
(M1) after RME. Transverse effects to the maxillary
suture, nasal width..

The amount of palatal maxillary expansion (PMW) was the
difference between T1 and T2 widths (PMW2 – PMW1).
The amount of buccal maxillary expansion wasBMW) ..
the difference between T1 and T2 widths (BMW2 -
BMW1) …
Garrett et al,Skeletal effects to the maxilla after rapid maxillary expansion
assessed with cone-beam computed tomographyAmerican Journal of
Orthodontics and Dentofacial Orthopedics July 2008,

Positive PMW and PMW value indicated
expansion..
Three orthogonal views showing triangulation of M1 furca location and
respective C1, P1, and P2 apex reference points with measurement lines
connecting contralateral sides.

T1 coronal image derived from the
openedpolygon cut (white, NW1; green,
NFW1; red, MSW1)
. PAA is formed by the
intersection of best-fit lines
drawn through the palatal
alveolar plates.

Thick slice axial image showing maxillary SE (white).

EFFECTS OF MID PALATAL SUTURE
OPENING ON MAXILLA
Skeletal expansion
The separation in mid palatal suture occur in a
triangular pattern with the wider base at the anterior
portion of the maxilla. a midline suture runs the full
length, anterior to posterior, of the maxilla and the
palatine bones, which should allow for equal or parallel
opening, the proposed lack of opening in the posterior
region is due to the interlocking pyramidal processes of
the palatine bone with the immovable medial and
lateral pterygoid plates of the sphenoid bone..

Diagram of coronal views before and after expansion.

Linear measurement of the maxillary width
(MaxW)

Skeletal expansion is not just limited to the maxilla
during RME. Surrounding skeletal structures such
as the nasal aperture and maxillary sinus are
modified during maxillary expansion treatment…
Garrett et alSkeletal effects to the maxilla after rapid maxillary expansion

Computer tomographic
scan at the molar level
before (a) and after (b)
expansion

Dento alveolar expansion or tipping..
The expansion of palatal and buccal alveolar plates
gives us information about the alveolar process of
bending or tipping. Any additional expansion beyond
that of sutural separation would be derived from tipping
of the alveolar ridges…

Measurements of bone plate thickness of the maxillary right posterior teeth and palatal
maxillary width on the axial section: A, first molar disto buccal bone thickness; B, first molar
mesiobuccal bone thickness; C, first molar palatal bone thickness; D, second premolar buccal
bone thickness; E, second premolar palatal bone thickness; F, first premolar buccal bone thickness;
G, first premolar palatal bone thickness; H, canine buccal bone thickness; I, canine palatal bone
thickness; J, palatal maxillary width.

Buccal cortical plate thickness (BCPT), buccal bone
thickness (BBT), alveolar width (ALW),
lingual bone thickness (LBT), palatal width (PW), and
intermolar width (IMW) measurements

Orthodontic effect, represented by the flaring of the
posterior teeth and alveolar process, is an integral
part of rapid maxillary expansion. It is known to
practitioners who deal with orthopedic expansion
that hand in hand with the gradual opening of the
Mid palatal suture, the force delivered by the expander
causes periodontal ligament compression,
lateral tipping of the alveolar process and subsequent
flaring of the posterior teeth.

The patients who showed the greatest increases in IMW
also showed the greatest increases in lingual bone
thickness and greatest decreases in buccal bone
thickness. The mean decrease in the buccal bone
thickness (1.6 mm) was the same as the mean increase
in lingual bone thickness (1.6 mm).
Garib et al reported similar effects with rapid maxillary
expansion, with buccal bone thickness at the mesio
buccal root of the maxillary first molar decreasing 0.7
mm, and lingual bone thickness increasing 0.8 mm.

T1 and T2 images of a patient with little or no buccal bone thickness adjacent to the
mesiobuccal root of the maxillary first molar after expansion. The axial slice was taken at
the level of the first molar furcation, and the coronal slice was taken through the center of
the left mesiobuccal root, perpendicular to the outer contour of the buccal cortical plate.
The red vertical and green horizontal lines show the axial orientation of the maxilla. The
blue horizontal reference line in the coronal slice represents the
level of the axial slice where the measurements were made.

 1. Early treatment with the quad-helix appliance proved to be
highly effective in increasing inter molar, palatal, and alveolar
widths over the long term.
 2. Molars tended to move both with and through the alveolar
ridge, substantially decreasing buccal bone thickness and
increasing lingual bone thickness.
 3. The relatively light forces produced by the quad helix appear
capable of moving teeth through the cortical plate.
 4. The increase in palatal width corresponded to 50% to 60% of
the overall expansion…

,
Corbridge et al ,Transverse dentoalveolar changes after slow
maxillary expansion, American Journal of Orthodontics and Dentofacial
Orthopedics, September 2011 Vol 140 Issue 3.

Nasal changes
 The effects of RME are not limited to the maxilla
but extend to the surrounding nasal and craniofacial
structures. Haas showed that the nasal aperture could be
significantly widened, thereby increasing nasal respiration..

 RME is known to affect nasal aperture width,
which is consistent with finite element mode line.
Previous CBCT studies reported that RME
produced a 1.6-mm increase in the width of the
nasal floor; this is comparable to 1.3 - 1.4 mm of
expansion for bonded and banded RME . In 9- to
11-year-old patients, the banded appliance
produced,0.5 mm more nasal floor expansion
than the bonded appliance.
Ryuzo Kanomia; Toru Deguchib; Eriko Kakunoa; Teruko Takano-Yamamotoc; W. Eugene
Robertsd, CBCT of skeletal changes following rapid maxillary expansion to increase
arch-length with a development-dependent bonded or banded appliance, Angle
Orthodontist, Vol 83, No 5, 2013,

COMPUTED GRAY LEVELS IN MULTISLICE AND
CONE-BEAM COMPUTED TOMOGRAPHY
 The software programs were reliable and had no
influence on the CT and CBCT gray level
measurements. the gray levels might have
discrepancies when different CT and CBCT scanners
are used. Therefore, caution is essential when
interpreting or evaluating CBCT images because of
the significant differences in gray levels between
different CBCT scanners, and between CBCT and CT
values.
American Journal of Orthodontics and Dentofacial
Orthopedics, July 2013 Vol 144 Issue 1,

MID PALATAL SUTURE MATURATION: CLASSIFICATION
METHOD FOR INDIVIDUAL ASSESSMENT BEFORE RAPID
MAXILLARY EXPANSION
 The classification of mid palatal sutural fusion using
CBCT allows the diagnosis of the overall antero
posterior characteristics of the mid palatal suture without
overlapping of other anatomic structures. This method
might provide reliable parameters for the clinical
decision between conventional and surgically assisted
RME for adolescent.
American Journal of Orthodontics and Dentofacial
OrthopedicsNovember 2013 Vol 144 Issue 5

MID PALATAL SUTURE OPENING DURING
FUNCTIONAL POSTERIOR CROSS-BITE CORRECTION
 The purpose of this study was to determine whether
opening of the mid palatal suture occurs during
treatment of posterior cross-bites by means of a
Porter or W appliance,(deciduous or mixed dentition)
In eight of the ten cases treated there was
radiographic evidence of mid palatal suture opening.
Posterior cross-bite correction with a Porter or W
appliance may occur either by a combination of mid
palatal suture opening and buccal tipping of posterior
teeth or by buccal tipping alone.
Van A. Harberson, D.M.D., and David FL Myers, D.D.S., MS.*
Am. J. Orthod. Seprember 1978

MINERALIZATION IN THE MID PALATAL
SUTURE AFTER ORTHODONTIC EXPANSION
 The measurements showed that the mineral content
within the suture rose rapidly during the first month after
the completion of suture opening. In the bone beside the
suture, the mineral content decreased sharply during the
first month of measurement; later it returned to the initial
level.
Christer EkstrSm, D.D.S.,* Carl 0. Henrikson,** and Rolf Jensen***
Stockholm, Sweden Am. J. Orthod. April 1977

MODIFICATIONS OF MID PALATAL SUTURAL
DENSITY INDUCED BY RAPID MAXILLARY
EXPANSION: A LOW-DOSE COMPUTED-
TOMOGRAPHY EVALUATION

1. In pre pubertal subjects, the density of the mid
palatal suture is less than the density measured in the
maxillary bone.
2. The reduced sutural density after expansion indicates
that RME therapy before puberty produces effective
opening of the mid palatal suture.
3. Six months of retention after RME allows
reorganization of the mid palatal suture with density
values similar to the pretreatment ones.
Franchi et al,American Journal of Orthodontics and
Dentofacial Orthopedics April 2010 Volume 137, Number 4

INFLUENCE OF THE EXPANSION SCREW
HEIGHT ON THE DENTAL EFFECTS OF THE
HYRAX EXPANDER
Hyrax expander closely fit to the molars and premolars,
simulating the horizontal restriction of the movement that
would be imposed by bands on the first molars.

Expander apparatus: A, lowest
position, screw simulated in a plane
parallel to the occlusal plane at the
center of the maxillary teeth and 10
mm below the maxillary first
molars’ center of resistance; B,
intermediate position, screw parallel
to the occlusal plane at the same
level as the maxillary first molars’
center of resistance; C, the highest
position, with the screw closest to
the palate, 10 mm above the
maxillary first molars’ center of
resistance.

THE RESULTS OF THE FINITE ELEMENT
METHOD SIMULATIONS TESTED IN THIS
STUDY INDICATED THE FOLLOWING:
 1. Greater amounts of buccal crown tipping were
registered when the hyrax screw was positioned closer to
the occlusal plane.
 2. There were extrusive tendencies when the screw was
simulated above the center of resistance of the teeth.
 3. There were mesial displacement tendencies when the
screw was simulated below the center of resistance of the
teeth and distal displacements when it was above the
maxillary first molars’ center of resistance
Araugio et al,American Journal of Orthodontics and Dentofacial
Orthopedics February 2013 Vol 143 Issue 2

SKELETALAND DENTAL CHANGES IN THE
SAGITTAL, VERTICAL, AND TRANSVERSE
DIMENSIONS AFTER RAPID PALATAL
EXPANSION
 1. There was a slight maxillary forward movement
induced by RPE treatment (P .05). However, the amount
was small and might not be clinically significant
 2. The maxilla displaced downward after RPE (P .05).
 3. The mandible moved downward and backward, and
the anterior facial height increased significantly after
RPE (P .05)

 4. Rapid palatal expansion treatment increased the inter
orbital, maxillary, and nasal widths significantly (P 05).
Chun-Hsi Chung, DMD, MS,a and Blanca Font, DDSb Philadelphia,
Pa, and Palma de Mallorca, Spain. American Journal of
Orthodontics and Dentofacial Orthopedics November 2004,Volume
126, Number 5.

THE EFFECTS OF MAXILLARY QUAD-HELIX
APPLIANCE EXPANSION ON CEPHALOMETRIC
MEASUREMENTS IN GROWING ORTHODONTIC
PATIENTS

 1. The orthodontic changes included a mean increase in
maxillary molar width of 5.88 mm., a mean increase in
average molar relation of 2.95 mm., and a mean increase
in maxillary inter canine width of 2.74 mm. These
increases were found to be stable through active
treatment.
 2. Nasal width showed no significant differences from
growth during treatment.
 3.No significant change in mandibular intermolar width
was observed.

 4. A slight bite opening was observed on the lateral
progress cephalograph during the expansion phase of
treatment. A further bite opening was noted when the T,-
T, (5- 1 months) time interval was examined. The facial
axis decrease was approximately 1 degree.
 5. The cases that demonstrated the most orthopedic
changes during expansion were the same cases that
required the greatest orthodontic changes at the beginning
of treatment.

 6. The amount of orthopedic and orthodontic changes
observed in this growing sample did not correlate with
the age of the patient.
 10. The amount of orthopedic or orthodontic expansion
did not correlate with the patient’s facial type.This was
thought to be due to the fact that this sample was skewed
to the brachy facial side.
Frank and Engel, Am. .I. Orthod. h&v 1982

MEASUREMENT OF THE BUCCOLINGUAL
INCLINATION OF TEETH: MANUAL
TECHNIQUE VS 3-DIMENSIONAL SOFTWARE

 The overall difference between the 2 methods was 4.4.
The reliability of measurements in the 3D method was
higher than that with the TIP device.
Nouri et al, American Journal of Orthodontics and Dentofacial
Orthopedics, October 2014 Vol 146 Issue 4 A

ACCURACY AND RELIABILITY OF BUCCAL
BONE HEIGHT AND THICKNESS
MEASUREMENTS FROM CONE-BEAM
COMPUTED TOMOGRAPHY IMAGING

PALATAL EXPANSION WITH SIX BANDS:
AN ALTERNATIVE FOR YOUNG ADULTS
 Opening of the mid palatal suture without
surgical assistance in individuals after the growth
spurt is not a predictable procedure increased
anchorage by bands in the second premolars and
extensions in the second molars favors an
increased orthodontic effect thus creating a
potentially valuable treatment for young adults.
Rev Clín Pesq Odontol. 2009
jan/abr;5(1):61-66

Two-dimensional coronal slices perpendicular to the midsaggital plane to carry out the
linear and angular measurements for this study. A. Measurements of the maxillary first
molar: intermolar width (1), buccal-lingual angulation of right (2) and left (3) maxillary
first molar, and right (4) and left (5) maxillary first molar buccal bone thickness. B.
Measurements of the maxillary first premolar: interpremolar width (1), buccal-lingual
angulation of right (2) and left (3) maxillary first premolar, and right (4) and left (5)
maxillary first premolar buccal bone thickness.

LONGITUDINAL STABILITY OF RAPID AND
SLOW MAXILLARY EXPANSION

 Long-term rapid and slow maxillary expansion stability
are quite similar. Significantly greater inter canine width
decrease was observed in rapid maxillary expansion,
only.
 The percentage of clinically relapsed cases of posterior
cross bite was similar for both rapid and slow maxillary
expansion
Dental Press J Orthod. 2014 Nov-Dec; 19(6):
70–77.

Evaluation of opening pattern and bone
neoformation at median palatal suture area in
patients submitted to surgically assisted rapid
maxillary expansion (SARME) through cone
beam computed tomography

 Rapid maxillary expansion results in significant
displacement of the fronto nasal, inter maxillary,
zygomatico maxillary and mid palatal sutures in
growing children in all three planes of space.
AN ASSESSMENT OF THE MAXILLA AFTER RAPID
MAXILLARY EXPANSION USING CONE BEAM
COMPUTED TOMOGRAPHY IN GROWING
CHILDREN
Dental Press J Orthod. 2014 Jan-Feb; 19(1):
26–35.

BONE DENSITY OF THE MID PALATAL SUTURE 7
MONTHS AFTER SURGICALLY ASSISTED RAPID
PALATAL EXPANSION IN ADULTS

 The mid palatal suture displays wide inter individual variety.
There is no linear correlation between density and age.
 The Misch bone density classification can be used to illustrate the
change in mid palatal suture density. Ossification proceeds from
the posterior to anterior part of the suture. The V-shaped opening
of the suture may be involved in this ossification pattern.
 Based on the HU values after SARPE, we assume that the stability
of the mid palatal suture is insufficient to prevent relapse.
Retention time should be lengthened to allow bone to mineralize
and become strong enough to resist high forces

HOW to measure CBCT BEFORE AND AFTER MID PALATAL SUTURE OPENING

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (19)

Similar to HOW to measure CBCT BEFORE AND AFTER MID PALATAL SUTURE OPENING

Similar to HOW to measure CBCT BEFORE AND AFTER MID PALATAL SUTURE OPENING (20)

More from Hawa Shoaib

More from Hawa Shoaib (6)

Recently uploaded

Recently uploaded (20)

HOW to measure CBCT BEFORE AND AFTER MID PALATAL SUTURE OPENING