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-densitylines at the midline on the maxillary portion of the palate.The mid palatal suture cannot be visualized in palatinebone, and the density of the para sutural palatine boneis higher compared with the para sutural maxillary bone…

stage E, sutural fusion has occurred in themaxilla. 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 ORTHODONTICSCONE 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 weretaken using the Classic i-CAT® (Imaging SciencesInternational, Inc., Hatfield, USA) cone beam CTscanner. All scans were taken by the same technicianusing either the 16 x 13 or the 16 x 22 centimeter fieldof view with a voxel size of 0.4 millimeters. Patientswere positioned in a vertical seat with their headstabilized in the headrest to prevent any unwantedmovement during the 20-second scan, teeth togetherin centric occlusion, and the Frankfort Horizontalplane parallel to the floor, as determined by the externalauditory 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 assessed with cone-beam computed tomographyAmerican Journal of Orthodontics and Dentofacial Orthopedics July 2008,

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 platesgives us information about the alveolar process ofbending or tipping. Any additional expansion beyondthat of sutural separation would be derived from tipping

of the alveolar ridges…

Garrett et alSkeletal effects to the maxilla after rapid maxillary expansion assessed with cone-beam computed tomographyAmerican Journal of Orthodontics and Dentofacial Orthopedics July 2008,

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 buccalbone 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 theposterior teeth and alveolar process, is an integralpart of rapid maxillary expansion. It is known topractitioners who deal with orthopedic expansionthat hand in hand with the gradual opening of theMid palatal suture, the force delivered by the expandercauses periodontal ligament compression,

lateral tipping of the alveolar process and subsequentflaring 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 maxillaryexpansion, 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 thelevel 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 slowmaxillary 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 maxillabut extend to the surrounding nasal and craniofacialstructures. Haas showed that the nasal aperture could be significantly widened, thereby increasing nasal respiration..

Garrett et alSkeletal effects to the maxilla after rapid maxillary expansion assessed with cone-beam computed tomographyAmerican Journal of Orthodontics and Dentofacial Orthopedics July 2008,

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 increasearch-length with a development-dependent bonded or banded appliance, Angle Orthodontist, Vol 83, No 5, 2013,

Some Conclusions

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

SKELETAL AND 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