Image

Contents

Chapter 2

Chapter 3

Chapter 4

Part 1 Imaging, Diagnostic, and Assessment Methods

1 The Legalities of Cone Beam Imaging

INTRODUCTION

EDUCATION AND TRAINING

DISCLOSURE AND INFORMED CONSENT

NEGLIGENCE AND MALPRACTICE

WRITTEN DOCUMENTATION FOR AN IMAGING SCAN

DOCUMENTATION OF DIAGNOSTIC FINDINGS

WAIVERS FOR IMAGING LIABILITY

STORAGE FORMATS AND CONFIDENTIALITY

OWNERSHIP

CONCLUSION

REFERENCES

2 Three - Dimensional Surface Acquisition Systems for Facial Analysis

INTRODUCTION

TYPES OF SURFACE ACQUISITION SYSTEM

CHALLENGES AND PITFALLS

CLINICAL APPLICATIONS

CONCLUSION

REFERENCES

3 Diagnostic Imaging

INTRODUCTION

COMPUTED TOMOGRAPHY

CONE BEAM COMPUTED TOMOGRAPHY

MAGNETIC RESONANCE IMAGING

CONCLUSION

REFERENCES

4 Diagnostic Oral Pathology with Computed Tomography

INTRODUCTION

ASSESSING THE LESIONAL BORDER

CHARACTERIZING THE L ESION

DETERMINING THE LOCATION OF THE LESION

MARROW DISORDERS

FOLLOW - UP

CONCLUSION

FURTHER READING

5 Three - Dimensional Diagnosis and Treatment Planning of Dentoalveolar Problems

INTRODUCTION

CLINICAL APPLICATIONS

TREATMENT PLANNING FOR RETAINED OR IMPACTED TEETH

ORTHODONTIC INTEGRATION OF IMPACTED OR RETAINED TEETH

SURGICAL REMOVAL OF IMPACTED OR RETAINED TEETH

CYSTIC LESIONS

ENDODONTIC LESIONS

PERIODONTAL LESIONS

IMPLANT SURGERY AND AUGMENTATION

Conclusion

REFERENCES

6 Referencing and Registration of Three - Dimensional Images

INTRODUCTION

REGISTRATION ON 3D SURFACES VERSUS LANDMARKS

METHODOLOGY FOR SURFACE REGISTRATION

POST - S URGICAL TREATMENT OUTCOMES FROM 3D REGISTRATION ON THE CRANIAL BASE SURFACE

CLINICAL A PPLICATION AND F UTURE I NVESTIGATIONS

CONCLUSION

REFERENCES

7 Averaging Facial Images

INTRODUCTION

PREREQUISITES OF AVERAGING

ORIGIN OF THE FACE

REFERENCE PLANES OF THE FACE

AVERAGING METHODS

COMPARISON OF THE AVERAGING METHODS

DISCUSSION

CONCLUSION

REFERENCES

Part 2 Applications, Physiological Development, and Surgical Procedures

8 Studying Facial Morphologies in Different Populations

INTRODUCTION

THE STUDY

UNDERSTANDING THE RESULTS

WHAT THE FUTURE MIGHT HOLD?

CONCLUSION

REFERENCES

9 A New Clinical Protocol to Plan Craniomaxillofacial Surgery Using Computer - aided Simulation

INTRODUCTION

CRITICAL REVIEW OF TRADITIONAL METHODS USED TO PLAN CRANIOMAXILLOFACIAL SURGERY

CLINICAL SURGICAL PLANNING PROTOCOL

CONCLUSION

REFERENCES

10 Controversial Issues in Computer - aided Surgical Planning for Craniomaxillofacial Surgery

INTRODUCTION

MANDIBULAR LATEROGNATHIA

POSTURE

NATURAL HEAD POSITION

QUANTIFYING CRANIOMAXILLOFACIAL DEFORMITIES

ANGULAR MEASUREMENTS

ASSESSMENT OF THE OCCLUSAL PLANE

CONCLUSION

REFERENCES

11 Predicting and Managing Surgical Intervention in Craniofacial - Disharmony a Biomechanical Perspective

INTRODUCTION

SURGICAL PLANNING

ASSESSMENT OF FACIAL MOVEMENT

BIOMECHANICAL MODELING AND SURGICAL PREDICTION

CONCLUSION

REFERENCES

12 Understanding the Facial Changes Associated with Postoperative Swelling in Patients Following Orthognathic Surgery

INTRODUCTION

APPLICATION OF SURFACE IMAGING

RESULTS

DISCUSSION

CONCLUSION

REFERENCES

13 Visualizing Facial Growth

INTRODUCTION

STANDARDIZED REFERENCE FRAMEWORK

NATURAL HEAD POSTURE

FACIAL VARIATION

ANALYSIS OF FACIAL VARIATION

VISUALIZING FACIAL GROWTH

CONCLUSION

REFERENCES

14 Use of Digital Models/Dental Casts and their Role in Orthodontics/Maxillofacial Surgery

INTRODUCTION

TECHNOLOGIC ADVANTAGES OF DIGITAL DENTAL MODELS

CLINICAL APPLICATIONS OF DIGITAL DENTAL MODELS IN ORTHODONTICS AND MAXILLOFACIAL SURGERY

CONCLUSION

ACKNOWLEDGMENTS

REFERENCES

15 A Custom -fitting Surgical Guide

INTRODUCTION

PLANNING AND DESIGN

PROSTHESIS CONSTRUCTION

CONCLUSION

ACKNOWLEDGMENTS

REFERENCES

Part 3 Movement and Facial Dynamics

16 Assessment of Facial Movement

INTRODUCTION

SUBJECTIVE GRADING SCALES

OBJECTIVE GRADING SCALES

TWO - DIMENSIONAL MOTION ANALYSIS SYSTEMS

THREE - DIMENSIONAL MOTION ANALYSIS SYSTEMS

ASSESSMENT OF FACIAL MOVEMENT

CONCLUSION

REFERENCES

17 Facial Actions for Biometric Applications

INTRODUCTION

WHICH FACIAL ACTIONS MAKE A SUITABLE BIOMETRIC?

VERBAL FACIAL ACTIONS

NONVERBAL FACIAL ACTIONS

DATA ACQUISITION

FACIAL IDENTITY RECOGNITION

MATCHING FACIAL DYNAMICS

THE IDENTIFICATION PROBLEM

PERMANENCE AND UNIQUENESS OF FACIAL ACTIONS

CONCLUSION

ACKNOWLEDGMENTS

REFERENCES

18 Nonrigid Image Registration Using Groupwise Methods

INTRODUCTION

REGISTRATION

PROBLEM DECOMPOSITION

REGISTRATION EXPERIMENTS

REGISTERING SURFACES

CONCLUSION

REFERENCES

19 Three - Dimensional Developments for the Future

THE PAST

THE PRESENT

THE FUTURE

REFERENCES

Appendix 1: Sample of Informed Consent for Imaging Procedures

Index

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List of Contributors

Ken Abramovitch, Department of Diagnostic Sciences, University of Texas Health Science Center at Houston Dental Branch, Houston, TX, USA

Christos Angelopoulos, Columbia University Dental School, New York, USA

Liliana Beldie, Arup Campus, Blythe Valley Park, Solihull, Birmingham, West Midlands, UK Lanthao Benedikt, School of Computer Science, Cardiff University, UK Richard Bibb, Department of Design and Technology, Loughborough University, UK

Alan Bocca, Centre for Applied Reconstructive Technologies in Surgery (CARTIS), Maxillofacial Unit, Morriston Hospital, ABM University Health Board, Swansea, UK

Peter Borbely, 1072 Budapest, Rackoczi ut 4, Hungary

Jerry E. Bouquot, Department of Diagnostic Sciences, University of Texas Health Science Center at Houston Dental Branch, Houston, TX, USA

Lucia H.S. Cevidanes, Department of Orthodontics, UNC School of Dentistry, Chapel Hill, NC, USA

Darren Cosker, School of Computer Science, University of Bath, UK

Andrew Cronin, Consultant in Maxillofacial Surgery, University Dental Hospital, Cardiff, UK

Nicholas Drage, Consultant in Dental and Maxillofacial Radiology, University Dental Hospital, Cardiff, UK

Dominic Eggbeer, Centre for Applied Reconstructive Technologies in Surgery (CARTIS), National Centre for Product Design & Development Research (PDR), University of Wales Institute Cardiff (UWIC), Cardiff, UK

Jeryl D. English, Department of Orthodontics, University of Texas Health Science Center at Houston, Houston, TX, USA

Peter Evans, Centre for Applied Reconstructive Technologies in Surgery (CARTIS), Maxillofacial Unit, Morriston Hospital, ABM University Health Board, Swansea, UK

Kelvin W.C. Foong, Department of Preventive Dentistry, Faculty of Dentistry, National University of Singapore, Singapore

Jaime Gateno, Department of Oral and Maxillofacial Surgery, Methodist Hospital, Houston, TX, USA

Frank Hartles, Department of Applied Clinical Research and Public Health, University Dental Hospital, Cardiff University, UK

Chung How Kau, Department of Orthodontics, University of Alabama at Birmingham, Birmingham, AL, USA

Yongtao Lu, Institute of Theoretical, Applied and Computational Mechanics (ITACM), Research Office, Cardiff School of Engineering, UK

David Marshall, School of Computer Science, Cardiff University, Cardiff, UK

John Middleton, Biomaterials/Biomechanics Research Centre, Wales College of Medicine, Cardiff Medicentre, UK

Robert Mischkowski, Department for Craniomaxillofacial and Plastic Surgery and Interdisciplinary Outpatient Department for Oral Surgery and Implantology, University of Cologne, Germany

Jörg Neugebauer, Department for Craniomaxillofacial and Plastic Surgery and Interdisciplinary Outpatient Department for Oral Surgery and Implantology, University of Cologne, Germany

Maja Ovsenik, Department of Dental and Jaw Orthopaedics, Medical Faculty, University of Ljubljana, Slovenia

Hashmat Popat, Department of Applied Clinical Research and Public Health, University Dental Hospital, Cardiff University, UK

William R. Profitt, Department of Orthodontics, UNC School of Dentistry, Chapel Hill, NC, USA

Stephen Richmond, Department of Applied Clinical Research and Public Health, University Dental Hospital, Cardiff University, UK

Lutz Ritter, Department for Craniomaxillofacial and Plastic Surgery and Interdisciplinary Outpatient Department for Oral Surgery and Implantology, University of Cologne, Germany

Paul L. Rosin, School of Computer Science, Cardiff University, UK

John Rout, Consultant in Dental and Maxillofacial Radiology, Birmingham Dental Hospital, Birmingham, UK

Martin Scheer, Department for Craniomaxillofacial and Plastic Surgery and Interdisciplinary Outpatient Department for Oral Surgery and Implantology, University of Cologne, Germany

Kirill Sidorov, School of Computer Science, Cardiff University, UK

Randall O. Sorrels, Abraham, Watkins, Nichols, Sorrels, Agosto & Friend, Houston, TX, USA

Martin Styner, Department of Orthodontics, UNC School of Dentistry, Chapel Hill, NC, USA

Adrian Sugar, Centre for Applied Reconstructive Technologies in Surgery (CARTIS), Maxillofacial Unit, Morriston Hospital, ABM University Health Board and Swansea University, Swansea, UK

Wael Tawfik, National Research Center, Dokki, Cairo, Egypt

John F. Teichgraeber, Department of Pediatric Surgery, University of Texas Health Science Center at Houston, Houston, TX, USA

Arshed Toma, Department of Applied Clinical Research and Public Health, University Dental Hospital, Cardiff University, UK

Brian Walker, The Arup Campus, Blythe Gate, Blythe Valley Park, Solihull, Birmingham, West Midlands, UK

Caroline Wilkinson, School of Media Arts and Imaging, Duncan of Jordanstone College of Art and Design, University of Dundee, UK

James J. Xia, Department of Oral and Maxillofacial Surgery, Methodist Hospital, Houston, TX, USA

Alexei Zhurov, Biomaterials/Biomechanics Research Centre, Wales College of Medicine, Cardiff Medicentre, Cardiff, UK

Joachim E. Zöller, Department for Craniomaxillofacial and Plastic Surgery and Interdisciplinary Outpatient Department for Oral Surgery and Implantology, University of Cologne, Germany

Preface

When we embarked on this project, we appreciated that a wide range of disciplines would be involved in developing acquisition systems and software analysis packages for a host of applications for medical, medically allied, entertainment, and military/security groups. In fact, three - dimensional imaging potentially is of interest to all and certainly has the potential to have an impact on everyone in daily life.

We took a clear initiative to build a text that is not only informative, illustrative, and applied, but also provides the latest in state - of - the - art technology. The book is set out in three sections - (1) diagnostic and assessment methods, (2) applications, physiological development, and surgical procedures, and (3) movement and facial dynamics - to cover clinical interest in the craniofacial complex not only for dentists, specialists, and specialties related to dentistry, but also for other professions that deal with the craniofacial complex, such as speech therapists and psychologists.

We have chosen a group of authors world - renowned in their field, and their topics cover a wide range of applications representing different levels of sophistication, experience, and knowledge. The chapters are well illustrated to facilitate knowledge and skills transfer. Each chapter is well referenced to enable interested readers to facilitate their understanding and build a foundation of knowledge. Certain chapters direct readers to utilize open- sourced, readily available software, commercially available packages, and also the mathematical theory behind problem- solving.

This book addresses a gap in the applications of three- dimensional imaging in dentistry and allied health professionals. We hope that we have derived a blend of topics that will be of interest to the novice as well as to experts in different disciplines.

Stephen Richmond

Chung How Kau

Part 1

Imaging, Diagnostic, and Assessment Methods

1

The Legalities of Cone Beam Imaging

Kenneth Abramovitch, Christos Angelopoulos, and Randall O. Sorrels

INTRODUCTION

When a patient requires an imaging procedure, there are several underlying scenarios that are part of the process. These events have a complicity of legal implications. The legal implications may vary from one jurisdiction to another, regardless of whether one is referring to national, state/provincial, county/ parish, city, or municipality. The intent here is to describe legal processes that can establish guidelines consistent with good quality healthcare delivery.

Imaging procedures are required to evaluate the presence or absence of a disease state or to perform the craniofacial morphometric analyses necessary to develop dentoalveolar and craniofacial treatment plans. The latter are frequently indicated to evaluate craniofacial esthetic and functional relationships.

The indications for a cone beam computed tomography (CBCT) scan are usually associated with some degree of morbidity, hence there is an element of risk associated with either performing or abstaining from the procedure. These associated risks may be from either the physical harm from the procedure, the potential morbidity of a misdiagnosis, or the potential morbidity from a failure to diagnose. Physical harm from imaging procedures is related to the harmful biologic effects of ionizing radiations. These risks are very low and are discussed in another chapter. Legal issues associated with misdiagnosis and a failure to diagnose, as well as disclosure and informed consent and adequate documentation, are discussed here.

EDUCATION AND TRAINING

The utilization of any diagnostic procedure, including cone beam imaging, should be ordered and performed based on a sound knowledge of the potential diagnostic yield of the procedure. Due to the increased popularity of and excitement generated by this imaging modality, cone beam imaging is often thought of as the “gold standard” for craniofacial imaging. It is expected by novices to provide a solution to every diagnostic need. As with every diagnostic procedure that may be potentially harmful, cone beam scans should be ordered and performed when there is justification that the benefits of the examination outweigh the possible risks (European Academy of Dento- Maxillofacial Radiology). It is the duty of the oral health professional to be educated as to the diagnostic potential and to the possible benefits as well as risks of this technology.1,2

The auxiliary personnel involved in all the stages of image acquisition (patient referrals, patient history, patient preparation, image acquisition, and data- handling) must have received the appropriate education and training for proper technique and for radiation safety and protection measures for the patient as well as for the operators. Similarly, training is imperative for the dental professionals who will utilize the acquired data. Proper image selection for the diagnostic task at hand and proper reconstructions in order to yield the required information is frequently the result of training and experience together. CBCT is becoming part of the routine curriculum in most accredited graduate dental programs. Accredited continuing education courses are also available to practicing clinicians. These courses are readily found through routine Internet- based search engines. An example of one resource is listed in the reference section.3

DISCLOSURE AND INFORMED CONSENT

When an imaging procedure is requested for a patient, the patient must be given specific information about the procedure. The legal process of informing a patient about the medical procedure is referred to as disclosure. The patient is informed of the imaging procedure indicated and then the need and benefits associated with the procedure. The patient must also be informed of any harm or side effects from the procedure (biologic harm), as well as the risks associated if a disease is not diagnosed because the procedure is not performed or the patient refuses the procedure. The patient must also be informed of other possible diagnostic tests or alternate diagnostic procedures that may be available instead of the imaging procedure, for example ultrasound, standard computed tomography, serum analysis, etc. Patients must also be permitted to ask additional questions to clarify their understanding of the information that has been presented.

If this degree of disclosure has been performed, the patient has been presented with adequate information to be better informed to make a decision on whether or not to give his or her consent for the imaging procedure. The process of informing the patient with this degree of information is the knowledge base necessary for a patient to give informed consent. The components of informed consent are summarized in Box 1.1.

Box 1.1 Summary of inclusions necessary for the process of informed consent

a. the imaging procedure and the purpose of the procedure

b. potential benefits of the procedure

c. risks to the patient’ s health if the procedure is performed

d. risks to the patient’ s health if the procedure is not performed

e. opportunity for the patient, legal guardian or trustee to ask for additional information or for clarifications

From Iannucci and Howerton.19

Box 1.2 Factors that contribute to negligence with informed consent

a. lack of patient (legal guardian or trustee) consent

b. consent from a minor

c. consent from an inappropriate (illegal) guardian

d. consent from an individual under emotional duress or under the influence of drugs or alcohol

e. consent based on fraudulent or incorrect statements

f. d isclosure from unqualified (non-licensed) personnel

From Iannucci and Howerton.19

The basic tenet of informed consent is that the clinician supplies adequate medical and dental knowledge necessary for the patient to make an intelligent decision on whether or not to undergo the recommended imaging procedure. Since the written documentation of this process should be in the patient’ s record, this is best achieved with a written consent form. The informed consent (if given) is confirmed with the patient’ s signature and is often also signed by at least one witness. This consent often serves as a legal document if it contains disclosure and is obtained freely.

After an appropriate disclosure, a patient may decide to decline the procedure. In such instances, the clinician’ s ability to treat the patient may be compromised. If the dentist’ s treatment will be compromised by the lack of essential diagnostic data, the patient should be so informed. In these situations where the “untrained” patient dictates the course of the diagnostic workup and treatment and this limits the diagnostic ability of the clinician, it is often best to terminate further professional interaction.

NEGLIGENCE AND MALPRACTICE

Procedures performed on a patient without their consent is not considered good practice, that is, is negligent behavior, and is susceptible to a legal claim of malpractice. Negligence in most jurisdictions means the failure of a healthcare provider to act as an ordinary reasonable healthcare provider would act in the same or similar circumstances. This means that the act or action taken would not be performed by a reasonable clinician. In litigation scenarios, negligence may also mean failing to do something that a reasonable clinician would not do in a similar situation.

Although it may be subject to legal and professional opinion, there are several situations in which negligence can be legally determined. These situations are outlined in Box 1.2. Each situation is subject to legal and professional opinion before the decision of negligence is made.

WRITTEN DOCUMENTATION FOR AN IMAGING SCAN

“Do it right - write it down” and “If it’ s not in the record - it did not occur” are popular axioms that serve as guiding principles for dentists and other healthcare professionals to minimize professional risks. In keeping with the rationale and need for a patient record, the written record preserves the memory of the patient - clinician interactions (treatments or discussions) that have occurred. This written record can be used to share protected health information. These records are also permissible for legal proceedings in the event that there is litigation. But proper documentation protects the treating clinician. It is recommended that a standard entry in a patient record for an imaging procedure should include the patient’ s informed consent and the specific imaging strategies and reconstructions utilized to investigate the diagnostic task. The imaging procedure should have some documentation of the exposure settings, that is, kilovolt and milliamp è re values, and seconds of exposure or scan sequence. In many instances, a review of the scan sequence will disclose these aforementioned technical parameters. The size of the area exposed, that is, the field of view, should also be included. This exposure information is required in the record in the event that effective dose or dose equivalence needs to be calculated for a specific procedure.

The types of image reconstruction and the software utilized for the reconstructions should be included to demonstrate the steps followed and the views evaluated in arriving at professional decisions and diagnoses. In the event that one had to replicate these reconstruction data to see how diagnoses or decisions on treatment planning were made, the sequence steps would be available in the record. This information is also helpful in the event that the imaging strategy does not provide the diagnostic information necessary. With this imaging history, the treating or consulting clinician can develop other imaging strategies (software reconstructions, software programs, or different imaging acquisitions) to address the diagnostic task at hand.

DOCUMENTATION OF DIAGNOSTIC FINDINGS

Most regulatory agencies stipulate that there must be an entry in the record reporting the diagnostic information obtained from the imaging procedure. This entry is usually complementary to the clinical indication for the procedures in the informed consent, for example reporting morphometric data for an edentulous ridge site prior to dental implant surgery.

If a patient is referred for an implant evaluation, it is understood that the focused area of the implant receptor sites and possibly bone graft donor sites will be evaluated. Hence if an area of edentulous ridge will be used as a receptor site for an implant placement, the selection site should be identified, along with the reasons why. However, it is not acceptable to merely report these findings and not document other significant information, that is, disease that may affect the patient’ s long-tem prognosis.

In another instance, a CBCT scan may be requested to evaluate pathology around an impacted mandibular third molar, but there may be other disease processes in the jaws that are within the field of view imaged. This latter would include a number of possible entities involving the orbits, paranasal sinuses, and scanned cranial and cervical areas. Multiple reportable findings are noted on CBCT scans.4,5 Hence, it is not acceptable to avoid the rest of the dataset. There is probable liability for failing to diagnose conditions in the entire dataset of the CBCT scan. If a significant finding is missed, and this causes harm to the patient, the referring clinician and even the imaging facility (if it is not the patient’ s treating clinician) may be liable for being negligent.

The entire dataset in all planes of view needs to be viewed, and any abnormalities must be reported. In cases with positive findings, appropriate referrals may be further indicated. If the imaging facility or the referring clinicians are not able to review the data, there are dental and or medical radiology reporting services that can perform these services. This process can minimize liability from failing to report pathology and referring it in a timely manner.6

WAIVERS FOR IMAGING LIABILITY

It is fairly standard in dental education that dentists receive training in reading two- dimensional images of the dentoalveolar structures and adjacent anatomy in the head and neck region on bitewing, periapical, panoramic, and skull cephalograms (lateral and posteroanterior). However, most dentists are not trained to interpret the multiangle and three- dimensional (3D) projections obtained from cone beam scanners and the related software imaging. It has been suggested that patients can sign waivers of liability for disease that may be present in the scan data. The reasoning for the liability waiver is because it is not a disease that the clinician is specifically investigating or is not within a dental clinician’ s training or expertise.7

However, liability cannot be signed off by a patient. Statutes, legal opinions, and malpractice insurance companies have stepped forward to negate the legitimacy of this waiver of liability. Both the referring/ treating clinician and the imaging facility have a legal obligation to assure that the entire dataset is reviewed and that potential conditions not in the areas specifically reviewed by a referring doctor are reported.8

A patient is not as knowledgeable to assess the risk - benefit analysis for the necessity to have a scan read. Dental clinicians are more knowledgeable than patients concerning the incidence, pathophysiology, and recognition of diseases in the jaws. Hence the patient is not as knowledgeable to assess the same risks and make a reasoned opinion on whether or not to overlook interpreting the data. In the event that an occult lesion is noticed at a later date but was found to be present in the data of a cone beam scan ordered for dental treatment, there is a strong likelihood that the dentist will be liable for failure to diagnose. The dentist has more expertise than the patient to recognize the disease process, and hence should not have left the decision to interpret all the data with the patient. The doctor is liable in the event that a disease process is detected.8,9

Because of the potential harm to patients from failing to report on all the data in a CBCT scan, professional organizations have prepared recommendations and guidelines that pertain to the need for formal written interpretation reports in the patient’ s record based on a review of the entire CBCT dataset.1,2,10,11 The treating or consulting clinician must review the entire dataset and interpret the significance of the findings. Since interpreting advanced images is not a standard curricular subject in accredited teaching institutions, most dentists do not have this training. If a dentist without advanced training assumes the responsibility of reading the data, he is accepting a greater duty to the patient than he or she may be prepared for. If an occult disease is missed, the clinicians have breached this greater duty that they assumed, and this may be considered to be an act of professional negligence.

The data must be read by a trained clinician. Oral and maxillofacial radiologists have acquired this knowledge in advanced training programs. Although the data do not have to be read by a trained oral and maxillofacial radiologist, the clinician reporting and interpreting the data must demonstrate equivalent skills.1 In the advent of litigation where a provider was negligent in evaluating pathology from a CBCT scan they had ordered, the creditability of the clinician’ s diagnosis or lack of a diagnosis will be compared with the credentials of a certified OMR (Oral and Maxillofacial Radiology practitioner). In a court of law, the clinician may be culpable of inappropriate care. If a dentist does not have a level of equivalent training, it is best to send the data to qualified services.1,2,10,12,13

It is anticipated that, in the future, it will become common to find imaging clinics staffed with oral and maxillofacial radiologists to respond to the imaging needs of the profession. The range of services is likely to include assisting with image acquisition, interpretation, and conversion of the data to the multitude of two- dimensional and 3D imaging software programs.14

This issue remains highly controversial. Some attorneys are of the opinion that if the subject matter is not part of the standard dental school curriculum, dentists are not trained to make a diagnosis beyond the level of their training.7 However, it becomes a clinician’ s responsibility to seek this information from other disciplines of expertise in the profession, that is, the OMR.

A similar analogy exists in the case of surgery to remove an oral lesion. A sessile nodular growth presenting in the floor of the mouth may appear to be a benign squamous papilloma or a fibrous hyperplasia (fibroma). However, the histologic diagnosis based on the types and arrangement of the cells may actually be a verrucous or squamous cell carcinoma. The histologic diagnosis is imperative to properly manage the case. This diagnosis is made by a certified Oral Maxillofacial Pathology practitioner (OMP). It would be indefensible for the treating clinician either to overlook the lesion or to remove it on the provision that it is a benign lesion solely from the clinical findings. Furthermore, if a histologic diagnosis is made, it would be made with the expertise of an OMP.

STORAGE FORMATS AND CONFIDENTIALITY

There are many different acquisition and reconstruction softwares available with the various cone beam scanning units. This actually has the potential to be a deterrent to quality patient care as healthcare providers cannot reasonably be expected to keep an inventory of all of the proprietary softwares to manage digital image files.

In response to this dilemma, industry, government, and professional organizations assembled over several sessions as the International Standards Organization (ISO) to develop a standard imaging file format for file transfers, the Digital Imaging and Communications in Medicine (i.e., DICOM) standard file format, ISO12052:2006. 15 The DICOM file format is a dynamic standard, being reviewed and modified on a regular basis. Dental input to this process comes from many organizations including dental. The American Dental Association, as a conduit for its various councils and standing committees, has been a member of the DICOM Standard Committee since 1996.16 The American Dental Association recommended as early as 2000 that dental manufacturers make their files convertible to the DICOM file format. In so doing, manufacturers who do not follow the DICOM standard will not be able to stay viable in a competitive marketplace.14,16

With improved access to utilizing these file formats comes the responsibility of protecting the patient’ s personal health information. In the United States, there are federal regulations from the federal department of Health and Human Services on the protection of patient personal health information that were initially set forth by the Health Insurance Portability and Accountability Act in 1996.17 According to the legislation, failure to keep a patient’ s personal health information confidential on encrypted files or secured file transfer protocols will result in significant penalty. Hence most of the time, the data are transferred via secured websites and networks. The degree of measures necessary to maintain confidentiality is dependent on the size and contents of the image files. Details of these measures are available from other sources.18

OWNERSHIP

The facility or practice that exposes the patient to X- radiation and acquires the CBCT scan is the rightful owner of the image data, regardless of who actually ordered or paid for the diagnostic procedure.19 The facility or practice would of course document that the procedure was performed and also establish a protocol to document the diagnostic information acquired from the scan, that is, the interpretation report. Ownership of the data may be transferred at the option of the rightful owner to another practice or facility. However, as previously discussed, proper protection of the patient’ s personal health information must be maintained.17,18 The rightful owner should also maintain documentation of the details of any records transfer.

Patients maintain the right of access to the information in their health record. This information cannot be withheld from patients. If requested, copies should be provided to the patient or their legal guardian or trustee. If there are costs associated with the duplication, reasonable fees in addition to the original remuneration may be requested.

CONCLUSION

Cone beam imaging has generated remarkable excitement in the dental profession. As with any other diagnostic and treatment modality, its value is greater when properly utilized. Responsibility is the key factor for the utilization of cone beam technology. From proper referrals and patient selection, to diagnostic image acquisition and proper image interpretation, adherence to principles will maximize the yield. In this case, the major principle served is to do the right thing for the patient.

REFERENCES

1. Carter L, Geist J, Scarfe WC, Angelopoulos C, Nair M, Hidebolt CF, et al. American Academy of Oral and Maxillofacial Radiology executive opinion statement on performing and interpreting diagnostic cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008; 106: 561–2.

2. Flygare L, Tsiklakis K, Whaites E, Horner K. Basic Principles for Use of Dental Cone Beam CT Consensus Guidelines of the European Academy of Dental and Maxillofacial Radiology. January 2009. Available at: http://www.eadmfr.org (accessed May 12, 2009).

3. iCAT Imaging Institute. Education and Training Center. Available at: http://www.i-cat3d.com/tc_about.asp (accessed May 13, 2009).

4. Miles DA. Clinical experiences with cone beam volumetric imaging. Report of findings in 381 cases. US Dent 2006; Sep: 39–42.

5. Cha JY, Mah J, Sinclair P. Incidental findings in the maxillofacial area with 3- dimensional cone- beam imaging. AM J Orthod Dentofacial Orthop 2007; 132: 7–14.

6. Dentists Professional Liability Trust of Colorado. iCAT Cone-Beam Technology/Implants. Bulletin of October 16, 2007.

7. Henry K. 10 tips from a trial lawyer -Art Curley. June 2008.Available at: http://www.dentaleconomics.com (accessed May 12, 2009).

8. Holmes SM. iCAT Scanning in the dental office. The Fortress Insurance Company Newsletter - The Fortress Guardian 2007; 9: 2.

9. Holmes SM. Risk management advice for imaging services in the OMS office. OMS National Insurance Company Newsletter - The Monitor 2008; 19: 1, 5.

10. Turpin DL. Befriend your oral and maxillofacial radiologist. Am J Orthod Dentofacial Orthop 2007; 131: 697.

11. Jerrold L. Liability regarding computerized axial tomography scans. Am J Orthod Dentofacial Orthop 2007; 132: 122–4.

12. Miles DA. Color Atlas of Cone Beam Volumetric Imaging for Dental Applications. Hanover Park, IL: Quintessence, 2008.

13. Bowlin J. Beware of the legal pitfalls of cone-beam technology. The Bulletin 2007; 25: 12–13.

14. Howerton WB, Jr., Mora MA. Advancements in digital imaging. What is new and on the horizon? JADA 2008; 139: 20S-24S.

15. Digital Imaging and Communications in Medicine. The DICOM Standard. January 2008. Available at: ftp://medical.nema.org/medical/dicom/2008 (accessed May 12, 2009).

16. Farman AG. Raising standards: digital interoperability and DICOM. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 99: 525–6.

17. US Department of Health and Human Services. Public Law 104–191. The Health Insurance Portability and Accountability Act of 1996. Available at: http://aspe.hhs.gov/admnsimp/pl104191.htm (accessed May 12, 2009).

18. Bennett B (ed.). E-Health Business and Transactional Law with 2008 Cumulative Supplement. Edison, NJ: BNA Books, 2002.

19. Iannucci JM, Howerton LJ. Legal issues and the dental radiographer. Dental Radiography: Principles and Techniques, 3rd edn. Philadelphia: Saunders Elsevier, 2006. pp. 156–60.