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2010;141(suppl 3):7S-13SJADA James K. Mah, John C. Huang and HyeRan ChooComputed Tomography in OrthodonticsPractical Applications of Cone-Beam

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JADA 141(10 suppl) http://jada.ada.org October 2010 7S

There have been recent advances inthree-dimensional (3-D) imaging. In thisarticle, we reflect on current practices inorthodontics and how the limits of tech-nology have influenced the clinical rou-

tine of orthodontists. For example, instead offocusing on the vertical and transverse dimensions,malocclusions generally are described by usinganteroposterior terminology (which may seem awk-ward to a clinician who does not practice orthodon-tics, because clinical malocclusion is a 3-D manifes-tation), which may be why most orthodonticappliances are targeted to result in anteroposteriorcorrection. Furthermore, many orthodontic treat-ment procedures are geared toward resolving con-ditions that cannot be appraised adequately byusing conventional two-dimensional (2-D) radi-ographs. For example, dentoalveolar limits of toothmovement, particularly in attempts at nonextrac-tion expansion treatments, cannot be determinedwithout 3-D imaging. In addition, many relation-ships of the craniofacial complex, such as the posi-tion of the mandibular condyles in the temporo-mandibular fossa with respect to the occlusalscheme and the association of airway abnormali-ties to craniofacial morphology, cannot be evalu-ated with conventional imaging approaches.

Cone-beam computed tomography (CBCT) canbe used in clinical orthodontics and research inmany ways. In this article, we focus on practicalapplications of CBCT that emphasize its impor-tance in comprehensive orthodontic care. Theseapplications include dental development, limits oftooth movement, airway assessment, craniofacialmorphology and superimposition.

DENTAL DEVELOPMENT

The development of the primary and permanentdentition is one of the most complicated processesin human development. Comprehensive evaluationof this 3-D process presents a challenge to clinicianswho use conventional imaging, particularly if thereare deviations in tooth numbers, shapes, sequenceand positions (Figure 1). The complexity of dental

Practical applications of cone-beam computed tomography in orthodonticsJames K. Mah, DDS, DMSc; John C. Huang, DMD, DMSc; HyeRan Choo, DDS, DMD, MS

Background. Comprehensive visualization and recordsof the craniofacial complex have been goals in orthodonticimaging. These tasks have been performed by means ofplaster, photographs and radiographs. These approacheshave evolved across time, and cone-beam computed tomog-raphy (CBCT) has emerged as a comprehensive imagingmodality for orthodontics.Methods. The authors provide a practical guide forapplying CBCT in orthodontics, with an emphasis on situ-ations in which conventional imaging is limited. These situations include dental development, limits of toothmovement, airway assessment, craniofacial morphologyand superimposition.Results. Complexities of the craniofacial complex, dentition and airway present challenges in obtaining conventional images. CBCT has image-fidelity advantagesover conventional imaging that can lead to improved visualization.Conclusions. CBCT is changing orthodontics withrespect to clinically assessing patients and is evolving withrespect to diagnosis, clinical techniques and outcomes.Clinical Implications. The clinical value propositionof CBCT is to describe craniofacial anatomy accurately andprovide comprehensive information regarding anatomicalrelationships and individual patient findings for improveddiagnosis, treatment planning and prognostication.Key Words. Cone-beam computed tomography; cranio-facial morphology; orthodontics; cephalometry; airway;superimposition.JADA 2010;141(10 suppl):7S-13S.

A B S T R A C T

Dr. Mah is an associate clinical professor, Herman Ostrow School of Dentistry of USC, University of Southern California, Los Angeles; and an associate clinicalprofessor, School of Dental Medicine, University of Nevada, Las Vegas. Addressreprint requests to Dr. Mah at Herman Ostrow School of Dentistry of USC, Universityof Southern California, 925 W. 34th St., Suite 312, Los Angeles, Calif. 90089, e-mail “[email protected]”.Dr. Huang is an associate clinical professor and vice chair, Division of Orthodontics,School of Dentistry, University of California, San Francisco; and the director,Orthodontics 3-D Craniofacial Function and Imaging Research Center, Universityof California, San Francisco.Dr. Choo is an attending craniofacial orthodontist, Department of Plastic andReconstructive Surgery, Children’s Hospital of Philadelphia.

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.

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8S JADA 141(10 suppl) http://jada.ada.org October 2010

development and its variations are mostly lost in a2-D record. For example, prognostication ofimpacted maxillary canines with respect to lengthof treatment and complexity is restricted when clin-icians obtain panoramic radiographs.1 CBCT offersan undistorted view of the dentition that shows thedetails of individual dental morphology, includingintricate features of tooth roots, and missing, super-numerary and anomalous teeth, as well as the 3-Dspatial orientation of the teeth and roots. CBCTimaging puts the clinician in a much better positionthan does conventional imaging to evaluate erup-tion patterns and their variations.2 The informationprovided can help clinicians study the process ofdental development and individualized planning foreruption guidance, selective extractions and custombiomechanical approaches. The 3-D views of thedentition are similar to textbook images that showdental development (Figure 2).

Advances in computer software have allowed forthe production of interactive digital models (Anato-Model, Anatomage, San Jose, Calif.) from theCBCT data volume (viewable CBCT data).3 Theadvantages of using these models include elimi-nating the need to take impressions, and thatduring visualization the clinically visible crownsappear with the tooth roots and surrounding alve-

olar bone (Figure 3).Conventional radio -graphic imaging, such as panoramicand small dentalradio graphs, has limitations—such asmagnification, distor-tion, superimposition,limited perspective andlack of resolution—when it is used to visu-alize root resorption.4-6

Root resorption can beobserved readily inCBCT images, and theimage clarity allowsclinicians to classify

the type of root resorption. For teeth with multipleroots, resorption can be localized to a specific root.Another advantage is that the occlusal scheme isrelated to the position of the condyles within thetemporomandibular fossa. No other imagingmodality offers this feature. Clinicians can viewthe soft tissues of the face with respect to both thedentition and skeletal structure, and they can com-pare the occlusal views of the arches with theshape of the alveolus. The accuracy of dental mea-surements of overjet, overbite and arch length fromthese virtual models is comparable with that ofother digital study models produced from impres-sions.7 There is ongoing research and developmentin the area of manufacturing dental appliancesfrom dental models developed by means of CBCT.

LIMITS OF TOOTH MOVEMENT

The multidimensional nature of volumetric imagingallows for comprehensive visualization of the denti-tion and recognition of some of the limits of toothmovement. Many situations cannot be visualized bymeans of traditional orthodontic records. Enostosis,condensing osteitis, dense bone island and focalapical osteopetrosis8 are radiopaque lesions notednear the apexes of teeth, and they appear to haveno causative factors. A high percentage (88 to 100percent) of these lesions occur in the mandible,9 andthe most common extraoral positions are the pelvisand long bones.10 These lesions may not be visual-ized readily on panoramic radiographs, and theycan prevent tooth movement (Figure 4). In these

Figure 1. Deviations in tooth numbers, shapes, sequence and posi-tions. A. The patient in this three-dimensional (3-D) image has 17supernumerary teeth in addition to the normal permanent denti-tion. B. The maxillary right canine and first premolar of the patientin this 3-D image are transposed. Images were created using Invivo5(Anatomage, San Jose, Calif.).

Figure 3. Segmentation of dental structures with cone-beam com-puted tomography scans eliminates the need for dental impressionsto be taken to construct digital study models. A. Crown and rootmorphology. B. Visualizing the clinically visible crowns and toothroots within the supporting alveolar bone structures. Images werecreated using Invivo5 (Anatomage, San Jose, Calif.).

BAFigure 2. Three-dimensionalviews of the dentition are similarto textbook images showingdental development. Manipula-tion of the volumetric recon -struction can provide immediatevisuospatial relationships of theprimary and permanent teeth.Images were created using Invivo5(Anatomage, San Jose, Calif.).

ABBREVIATION KEY. CBCT: Cone-beam computedtomography. MRI: Magnetic resonance imaging. OSA: Obstructive sleep apnea. RP: Retropalatal. 3-D: Three-dimensional. 2-D: Two-dimensional.

BA


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situations, space closure and the establishment ofproper torque may not be possible, and, if biome-chanical forces are applied to move the adjacenttooth against the dense lesion, external apical rootresorption may result. A more common situation isthat of a patient with a deep bite. Common treat-ments include the use of biteplates to extrude pos-terior teeth or intrusion arches to intrude the max-illary anterior teeth to reduce the degree ofoverbite. A cross-sectional view of the incisors canreveal the vertical dimension of bone apical to themaxillary central incisors and the limited space forintrusion (Figure 5). In these situations, extrusionof the posterior teeth to address the deep bite wouldbe a more appropriate treatment and would pre-vent damage to the apexes of the central incisorsagainst the dense bone of the nasal floor.

AIRWAY ANALYSIS

The causal relationship between airway disordersand malocclusion was described as early as 1935.11

This relationship is a common cause of malocclu-sion and leads to the classic appearance of adenoidfacies. Perhaps as a result of the lack of diagnosticinstruments in this area, the focus on patientairway assessment seems to have subsided untilCBCT arrived and aided in the evaluation of air-ways. The results of a retrospective review of 500orthodontic patients showed that 18.2 percent ofthe patients had airway-related problems.12

Lateral cephalograms have been used to analyzethe airway. Despite the number of studies in thisarea, the overall strength of these studies is weak,owing to small sample sizes, lack of control partici-pants, inconsistent head positions and poor studydesigns.13 As a result, there are no effective anatom-ical measures from lateral cephalograms that arecorrelated with sleep apnea. In contrast, use of 3-Dimaging (magnetic resonance imaging [MRI])revealed more specific anatomical findings inpatients with apnea. It seems that the predominantfactor causing airway movement is the thickness ofthe lateral pharyngeal muscular walls, as opposedto the fat pads in this area.14 Trudo and colleagues15

studied healthy volunteers during wakefulness andsleep by means of MRI and found a narrowing inthe retropalatal (RP) region of the airway owing toposterior movement of the soft palate, thickening ofthe lateral pharyngeal walls and an increase intongue oblique distance. Chen and colleagues16

found that the anteroposterior and lateral diame-ters of the RP region, as well as the smallest area ofthe RP region, are significantly smaller in patientswith obstructive sleep apnea (OSA). Although thegold standard for diagnosis of OSA is a sleep

study,17 3-D imagingcan be an adjunctivediagnostic tool.

Within the CBCTdata, there is dis-tinction between thesoft tissue of thepharynx and theairway space. Thisdistinction allowsfor relativelystraightforward seg-mentation of theairway in the per-formance of volu-metric analysis(Figure 6).

CRANIOFACIAL MORPHOLOGY

Conventional cephalometrics is limited by anumber of factors, including x-ray beam geometryresulting in image magnification, left and rightside differences, and head positioning. Thephysics of lateral cephalograms impose substan-tial constraints on the resultant image, which canreflect a magnification error.18 The side closer tothe film is magnified less than the side furtherfrom the film, which causes the double border ofthe mandible that can be seen on lateral cephalo-grams. It becomes a clinical judgment to estimatethe norm of this double border and whether anincreased or decreased double border signifiesasymmetry. There are no magnification issueswith CBCT because the 3-D object is recon-structed from raw data by means of a mathemat-ical algorithm that has the ability to calculate

Figure 4. Osseous lesions, such as enostosis adjacent to themandibular premolar (arrows), can obstruct or limit the movementof teeth through the bone. Images were created using Invivo5(Anatomage, San Jose, Calif.).

A BFigure 5. A patient with a deepbite and retroclined incisors. A. Volumetric rendering shows extru-sion of the maxillary incisors causingthe deep overbite. B. Cross-sectionalview of the incisors reveals the lim-ited movement available for intrusionof the incisors owing to bony restric-tions of the maxilla (scale in millime-ters). Images were created usingInvivo5 (Anatomage, San Jose, Calif.).


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and eliminate the magnification factor eventhough the x-rays are not parallel. The isotropicimages generated by CBCT facilitate visual obser-vations of asymmetries and abnormalities, whichcan be confirmed by using linear and angularmeasurement tools included in 3-D imaging soft-ware packages. These measurements are reliableand anatomically accurate.19

The CBCT data set can be reformatted to gen-erate a CBCT-reconstructed lateral cephalogram sothat conventional measurements can be made andcompared with existing 2-D norms. The advantagesof using CBCT-reconstructed lateral cephalogramsinclude the ability to digitally reorient the headposition in cases in which the patient did notundergo scanning with the proper head positionand the ability to enhance the image quality by vir-tually sculpting away extraneous superimposingskeletal structures that are not relevant to the lat-eral cephalometric measurement process. In addi-tion, separate images can be created of the left andright sides for assessment of asymmetries. Softwaredevelopers are starting to incorporate a way toidentify anatomical and cephalometric landmarks

Figure 6. Volumetric segmentation of the airway in three dimensions. A. Left, frontal and right views of the segmented airway space. B. Presurgery and postsurgery segments of the airway can quantify effectiveness of jaw advancement in patients with compromised airwayspaces (scale in millimeters). C. Three-dimensional superimposition showing preorthognathic and postorthognathic surgery profiles alongwith concomitant changes in airway dimensions. Figures 6A and 6B were created using Amira (Visage Imaging, San Diego). Figure 6C wascreated using OnDemand3D (Cybermed, Irvine, Calif.). cm: Centimeters.

A B C

on the volumetric data set. This is a starting pointfor the ability to use new anatomical landmarks notvisible on 2-D cephalograms and to measure newdistances and angles that will give insight into thegrowth and development of the craniofacial com-plex (Figure 7). With this possibility in mind, it alsois important to think beyond conventional metricsof measuring distances and angles. Using the con-cept of morphometrics, clinicians can construct a 3-D norm and then superimpose individual 3-Dscans on this norm to determine variations andstandard deviations (Figure 8). Clinicians can quan-tify localized differences by using a color-mappingscheme to determine magnitude of difference. Pre-treatment and posttreatment superimpositions alsocan be added to evaluate tooth movement (Figure 9).

Anteroposterior cephalograms are anotherradiographic tool that can be used to identifytransverse asymmetries. However, slight devia-tions of head position can produce substantiallyvarying results on conventional radiographs.CBCT-reconstructed anteroposterior cephalo-grams can reorient the head position after the ini-tial scan and have the ability to remove extra-neous superimposing structures (for example,vertebrae) for better image clarity.

SUPERIMPOSITIONS

Assessing treatment outcomes is important whendocumenting treatment changes and research.The approach to lateral cephalometric superimpo-sition used by the American Board of Orthodon-tics20 involves cranial base registration on the out-line of the sella turcica and the best fit of theanterior cranial base bony structures, using thelingual curvature of the palate with the best fit onthe maxillary bony structures, and registration onthe internal cortical outline of the symphysis withthe best fit on the mandibular canal for superim-position of the maxilla and mandible, respec-tively. Clinicians who have performed this type ofcephalometric superimposition are aware that it

Figure 7. Advances in three-dimensional (3-D) software (3D Cephalo-metric Analysis, Anatomage, San Jose, Calif.) allow clinicians to locatecephalometric landmarks on the 3-D image, customize a cephalo-metric analysis and generate linear and angular measurements.


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is a challenging process owing to issues related toimage fidelity, landmark selection and identifica-tion.21 Because the method is limited to superim-position of lateral cephalograms, the informationis only from the sagittal plane.

The introduction of CBCT allows clinicians toperform superimpositions in three dimensionsand has eliminated some of the errors that occurwith traditional lateral cephalometric superimpo-sition. Recently, a method for superimposition ofCBCT images that does not first require segmen-tation or landmark selection was developed thatis accurate, fast and automatic.22 Because thismethod eliminates the need for segmentation andselecting landmarks, the errors associated withthese steps are eliminated, thereby reducing theoverall cumulative errors. Common weaknesses ofmany outcomes studies are image fidelity andmethod errors in the superimposition process,leading to confounding and often conflictingresults. The application of CBCT and this newmethod of assessing treatment outcomes have thepotential to settle many controversies in ortho-dontics, such as the mechanism of functionalappliances, nonextraction philosophies, molar dis-talization, temporomandibular effects and others.

UTILIZATION ISSUES

Although CBCT appears to hold promise foradvances in research and clinical orthodontics,there is some uncertainty and controversy relatedto its radiation dose, direct patient benefit and pro-fessional guidelines for use. In consideration of afundamental concept of diagnostic imaging knownas the As Low as Reasonably Achievable principle,a clinician has the responsibility of determining ifthe risks from diagnostic imaging outweigh thebenefits of its use in patient care, which suggeststhat clinicians also must consider the potentialharm to the patient if the imaging is inadequateand if a diagnosis or a problem is missed. In addi-tion, imaging should be performed with a validdiagnostic goal. For example, it is common in orthodontics to obtain panoramic radiographs toassess tooth tip positions. However, the literatureon this topic has shown that this practice is unreli-able and that clinicians using this practice shouldhave intimate knowledge of panoramic distortionsand use caution.23-27

Orthodontics involves the use of various radi-ographic modalities in its diagnostic protocols,ranging from panoramic radiographs and lateralcephalograms to complete series of radiographs.The radiation doses of these modalities and that ofCBCT are found in the introduction to this supple-

ment.28 Although studies of radiation dosimetry arenot directly comparable,29 the exposure from CBCTis within the same range as traditional dentalimaging.30 The combination of traditional dentalradiographs, particularly in a complete series, canresult in a radiation dose that is substantiallyhigher than that of CBCT.29 Nevertheless, critics ofCBCT seem to focus on the radiation dose topatients who undergo CBCT, although there hasbeen little or no discussion on this topic as it relatesto traditional dental imaging.

With respect to the topic of patient benefit, sev-

Figure 8. Morphometrics can be used to evaluate three-dimensional(3-D) objects. A. By taking a large sample of segmented 3-D objects,clinicians can generate a norm for that particular group (for example,age defined). B. A patient’s segmented skeletal structure (whitearea) can be superimposed on the norm (yellow area) to identifydifferences in morphology. Images created using Amira (VisageImaging, San Diego).

Figure 9. Superimposition of a patient’s pretreatment and post-treatment cone-beam computed tomography scans can be used todetermine what movements of the dentition and root structuresoccurred as a result of orthodontic therapy. As the number of tie-points increases, the image becomes more accurate; the upper leftimage has the fewest number of tie-points. Color-mapping repre-sents distance variations of surfaces between two superimposedobjects. Blue indicates a surface of closest proximity, and red indi-cates a surface of largest discrepancy. Quantification is in millime-ters and can be calibrated by the user. Images created using OnDemand3D (Cybermed, Irvine, Calif.).

A

B


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eral articles describe the application of and ratio-nale for using CBCT, as well as specific measuresor diagnostic functions that are possible orimproved with 3-D imaging. Investigators havedescribed comprehensive patient analysis andrationale for using CBCT,2,31-33 including reports ofuse in academic34 and private practice35 settings.Specific measures and functions of CBCT in clinicalactivities include more accurate assessment oflower incisor position36; measures of root length andmarginal bone level37; management of impactedcanines38-41; visualization of upper airways,42

including a report of substantial incidental findingsof airway abnormalities in orthodontic patients12;evaluation of bone dehiscence and fenestration43;and anomalous mandibular premolars.44 Despitethis information, in an article in which the authorreported that three difficult cases were treated suc-cessfully by using conventional imaging, there wascriticism that CBCT has no proven benefit in ortho-dontics.45 However, reports of orthodontic complica-tions treated by means of conventional imaging arepublished rarely.46 Case reports have been pub-lished recently that show discrepancies betweenpanoramic radiographs and CBCT images in indi-vidual cases47 and for the assessment of root con-tact.48 The therapeutic benefits of CBCT includemeasurement of the dentition7 and tooth volume,49

planning and evaluation of temporary anchoragedevices,19,50-52 monitoring of alveolar bone densityand height in interdisciplinary periodontal andorthodontic treatment,53 3-D treatment simulation54

and use in appliance manufacturing.55 Most of theseactivities can be performed in one imaging sessionwith a radiation dose that is in the same range asthat of conventional images, which do not providethe same amount of data.

In 2010, the House of Delegates of the AmericanAssociation of Orthodontists adopted a resolutionthat states: “RESOLVED, that the AAO recognizesthat while there may be clinical situations where acone-beam computed tomography (CBCT) radio -graph may be of value, the use of such technology isnot routinely required for orthodontic radiog -raphy.”56 Although this resolution is intended toprotect the public and provide guidance to clini-cians, this statement has created a difficult situa-tion in the acknowledgment of a routine patient.The criteria for classifying a patient as routine arenot defined, and the necessary diagnostic protocolsto determine if a patient is routine also are unde-fined. In practice, it would be impossible to deter-mine if a patient is routine without conducting acomprehensive evaluation. Rather, a more practi-

cable guideline would be that CBCT is indicated forcomprehensive orthodontic treatment for whichprecise knowledge of the dentition; dentoalveolarvolume; root morphology; possible supernumerary,impacted or ankylosed teeth and other dentalabnormalities; temporomandibular joints; air-ways; and skeletal structures is necessary tounderstand completely the cause of the malocclu-sion, diagnosis, treatment planning and specificbiomechanical therapy in the management of thepatient’s condition.

CONCLUSIONS

CBCT offers advantages for imaging in orthodon-tics. As a result, CBCT is being adopted in manydental practices. The clinical value proposition ofCBCT is that it can describe craniofacial anatomyaccurately and provide comprehensive informationregarding anatomical relationships and individualpatient findings for improved diagnosis, treatmentplanning and prognostication. Research and devel-opment of future applications of CBCT, such assimulation, growth prediction, forensics, modelingand manufacturing, is ongoing. ■

Disclosure. The authors did not report any disclosures.

1. Schubert M, Baumert U. Alignment of impacted maxillary canines:critical analysis of eruption path and treatment time. J Orofac Orthop2009;70(3):200-212.

2. Huang JC, Bumann A, Mah J. 3-Dimensional radiographicanalysis in orthodontics. J Clin Orthod 2005;39(7):421-428.

3. Mah J. The evolution of digital study models. J Clin Orthod 2007;41(9):557-561.

4. Dado DV, Rosenstein SW, Alder ME, Kernahan DA. Long-termassessment of early alveolar bone grafts using three-dimensional com-puter assisted tomography: a pilot study. Plast Reconstr Surg 1997;99(7):1840-1845.

5. Ericson S, Kurol J. Incisor root resorptions due to ectopic maxillarycanines imaged by computerized tomography: a comparative study inextracted teeth. Angle Orthod 2000;70(4):276-283.

6. Heimisdottir K, Bosshardt D, Ruf S. Can the severity of rootresorption be accurately judged by means of radiographs? A case reportwith histology. Am J Orthod Dentofac Orthop 2005;128(1):106-109.

7. Kau CH, Littlefield J, Rainy N, Nguyen JT, Creed B. Evaluation ofCBCT digital models and traditional models using the Little’s Index.Angle Orthod 2010;80(3):435-439.

8. Yonetsu K, Yuasa K, Kanda S. Idiopathic osteosclerosis of the jaws:panoramic radiographic and computed tomographic findings. Oral SurgOral Med Oral Pathol Oral Radiol Endod 1997;83(4):517-521.

9. Bsoul SA, Alborz S, Terezhalmy GT, Moore WS. Idiopathicosteosclerosis (enostosis, dense bone silands, focal periapical osteopet-rosis). Quintessence Int 2004;35(7):590-591.

10. Petrikowski CG, Peters E. Longitudinal radiographic assessmentof dense bone islands of the jaws. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1997;83(5):627-634.

11. Brusse AB. Orthodontics as an aid to the rhinologist. Int J OrthodDent Child 1935;21(7):646-648.

12. Cha JY, Mah J, Sinclair P. Incidental findings in the maxillofacialarea with 3-dimensional cone-beam imaging. Am J Orthod DentofacialOrthop 2007;132(1):7-14.

13. Miles PG, Vig PS, Weyant RJ, Forrest TD, Rockette HE Jr. Cran-iofacial structure and obstructive sleep apnea syndrome: a qualitativeanalysis and meta-analysis of the literature. Am J Orthod DentofacialOrthop 1996;109(2):163-172.

14. Sforza E, Bacon W, Weiss T, Thibault A, Petiau C, Krieger J.Upper airway collapsibility and cephalometric variables in patients withobstructive sleep apnea. Am J Respir Crit Care Med 2000;161(2, pt 1):347-352.


on April 26, 2013

jada.ada.orgD

ownloaded from



15. Trudo FJ, Gefter WB, Welch KC, Gupta KB, Maislin G, SchwabRJ. State-related changes in upper airway caliber and surroundingsoft-tissue structures in normal subjects. Am J Respir Crit Care Med1998;158(4):1259-1270.

16. Chen NH, Li KK, Li SY, Wong CR, Chuang ML, Hwang CC, WuYK. Airway assessment by volumetric computed tomography in snorersand subjects with obstructive sleep apnea in a Far-East Asian popula-tion (Chinese). Laryngoscope 2002;112(4):721-726.

17. Kushida C, Littner M, Morgenthaler T, et al. Practice parametersfor the indications for polysomnography and related procedures: anupdate for 2005. Sleep 2005;28(4):499-521.

18. Broadbent BH. A new X-ray technique and its application toorthodontia. Angle Orthod 1931;1(2):45-66.

19. Baumgaertel S, Palomo JM, Palomo L, Hans MG. Reliability andaccuracy of cone-beam computed tomography dental measurements.Am J Orthod Dentofacial Orthop 2009;136(1):19-25.

20. American Board of Orthodontics. Case report preparation: trac-ings—cephalometric tracings. “www.americanboardortho.com/professionals/clinicalexam/casereportpresentation/preparation/tracings.aspx”. Accessed Sept. 8, 2010.

21. Arat ZM, Rübendüz M, Akgül AA. The displacement of craniofa-cial reference landmarks during puberty: a comparison of three super-imposition methods. Angle Orthod 2003;73:374-380.

22. Choi JH, Mah JK. A novel method for comparison of CBCT vol-umes. J Clin Orthod 2010;44(5):303-312.

23. Mckee IW, Glover KE, Williamson PC, Lam EW, Heo G, MajorPW. The effect of vertical and horizontal head positioning in panoramicradiography on mesiodistal tooth angulations. Angle Orthod 2001;71(6):442-451.

24. Mckee IW, Williamson PC, Lam EW, Heo G, Glover KE, Major PW.The accuracy of 4 panoramic units in the projection of mesiodistal toothangulations. Am J Orthod Dentofacial Orthop 2002;121(2):166-175.

25. Garcia-Figueroa MA, Raboud DW, Lam EW, Heo G, Major PW.Effect of buccolingual root angulation on the mesiodistal angulationshown on panoramic radiographs. Am J Orthod Dentofacial Orthop2008;134(1):93-99.

26. Hardy TC, Suri L, Stark P. Influence of patient head positioningon measured axial tooth inclination in panoramic radiography. J Orthod2009;36(2):103-110.

27. Owens AM, Johal A. Near-end of treatment panoramic radiographin the assessment of mesiodistal root angulation. Angle Orthod 2008;78(3):475-481.

28. Hatcher DC. Operational principles for cone-beam computedtomography. JADA 2010;141(10 suppl):3S-6S.

29. De Vos W, Casselman J, Swennen GRJ. Cone-beam computerizedtomography (CBCT) imaging of the oral and maxillofacial region: a sys-tematic review of the literature. Int J Oral Maxillofac Surg 2009;38(6):609-625.

30. Mah J, Danforth RA, Bumann A, Hatcher D. Radiation absorbedin maxillofacial imaging with a new dental CT. Oral Surg Oral MedOral Pathol Oral Radiol Endod 2003;96(4):508-513.

31. Merrett SJ, Drage NA, Durning P. Cone beam computed tomog-raphy: a useful tool in orthodontic diagnosis and treatment planning. J Orthod 2009;36(3):202-210.

32. Chenin DL. 3D cephalometrics: the new norm. Alpha Omegan2010;103(2):51-56.

33. German DS, German J. Cone-beam volumetric imaging: a two-minute drill. J Clin Orthod 2010;44(4):253-265.

34. Cattaneo PM, Melsen B. The use of cone-beam computed tomog-raphy in an orthodontic department in between research and dailyclinic. World J Orthod 2008;9(3):269-282.

35. Hechler SL. Cone-beam CT: applications in orthodontics. DentClin North Am 2008;52(4):809-823, vii.

36. Yu Q, Pan XG, Ji GP, Shen G. The association between lowerincisal inclination and morphology of the supporting alveolar bone: acone-beam CT study. Int J Oral Sci 2009;1(4):217-223.

37. Lund H, Gröndahl K, Gröndahl HG. Cone beam computed tomog-

raphy for assessment of root length and marginal bone level duringorthodontic treatment. Angle Orthod 2010;80(3):466-473.

38. Walker L, Enciso R, Mah J. Three-dimensional localization ofmaxillary canines with cone-beam computed tomography. Am J OrthodDentofacial Orthop 2005;128(4):418-423.

39. Laffranchi L, Dalessandri D, Fontana P, Visconti L, Sapelli P.Cone beam computed tomography role in diagnosis and treatment ofimpacted canine patient’s: a case report. Minerva Stomatol 2010;59(6):363-376.

40. Haney E, Gansky SA, Lee JS, et al. Comparative analysis of tra-ditional radiographs and cone-beam computed tomography volumetricimages in the diagnosis and treatment planning of maxillary impactedcanines. Am J Orthod Dentofacial Orthop 2010;137(5):590-597.

41. Oberoi S, Gill P, Nguyen A, Hatcher D, Vargervik K. Three-dimensional assessment of the eruption path of the canine in individ-uals with bone grafted alveolar clefts using cone beam computedtomography (published online ahead of print Feb. 24). Cleft PalateCraniofac J 2010.

42. Celenk M, Farrell ML, Eren H, Kumar K, Singh GD, Lozanoff S.Upper airway detection and visualization from cone beam image slices.J Xray Sci Technol 2010;18(2):121-135.

43. Evangelista K, Vasconcelos Kde F, Bumann A, Hirsch E, NitkaM, Silva MA. Dehiscence and fenestration in patients with Class I andClass II Division 1 malocclusion assessed with cone-beam computedtomography. Am J Orthod Dentofacial Orthop 2010;138(2):133.e1-e7.

44. Cleghorn BM, Christie WH, Dong CC. Anomalous mandibularpremolars: a mandibular first premolar with three roots and amandibular second premolar with a C-shaped canal system. Int EndodJ 2008;41(11):1005-1014.

45. Kokich VG. Cone-beam computed tomography: have we identifiedthe orthodontic benefits? Am J Orthod Dentofacial Orthop 2010;137(4 suppl):S16.

46. Davidovitch Z, Krishnan V. Adverse effects of orthodontics: areport of 2 cases. World J Orthod 2008;9(3):e64-e77.

47. Mostafa YA, El-Beialy AR, Omar GA, Fayed MS. Four curiouscases of cone-beam computed tomography. Am J Orthod DentofacialOrthop 2010;137(4 suppl):S136-S140.

48. Leuzinger M, Dudic A, Giannopoulou C, Kiliaridis S. Root-contactevaluation by panoramic radiography and cone-beam computed tomog-raphy of super-high resolution. Am J Orthod Dentofacial Orthop 2010;137(3):389-392.

49. Liu Y, Olszewski R, Alexandroni ES, Enciso R, Xu T, Mah JK.The validity of in vivo tooth volume determinations from cone-beamcomputed tomography. Angle Orthod 2010;80(1):160-166.

50. Kim SH, Choi YS, Hwang EH, Chung KR, Kook YA, Nelson G.Surgical positioning of orthodontic mini-implants with guides fabri-cated on models replicated with cone-beam computed tomography. AmJ Orthod Dentofacial Orthop 2007;131(4 suppl):S82-S89.

51. Fayed MM, Pazera P, Katsaros C. Optimal sites for orthodonticmini-implant placement assessed by cone beam computed tomography.Angle Orthod 2010;80(5):939-951.

52. Miyazawa K, Kawaguchi M, Tabuchi M, Goto S. Accurate pre-surgical determination for self-drilling miniscrew implant placementusing surgical guides and cone-beam computed tomography (publishedonline ahead of print April 22, 2010). Eur J Orthod 2010

53. Ma ZG, Fan LF, Fang B. The role of CBCT in evaluation of alve-olar bone state during orthodontic-periodontal treatment. ShanghaiKou Qiang Yi Xue 2010;19(2):113-117.

54. Chenin DL, Chenin DA, Chenin ST, Choi J. Dynamic cone-beamcomputed tomography in orthodontic treatment. J Clin Orthod 2009;43(8):507-512.

55. SureSmile. Technology: precision never before possible. “www.suresmile.com/About-SureSmile/Technology.aspx”. Accessed Sept. 8, 2010.

56. American Association of Orthodontists. House of delegates acts onresolutions. “www.aaomembers.org/Resources/Publications/ebulletin-05-06-10.cfm”. Accessed Sept. 7, 2010.


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