Proceedings of 21

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Proceedings of 21

^st

IADMFR/TAOMFR 2017 World Congress, Kaohsiung, Taiwan

Editor-in-chief:

Professor Li-Min Lin,

DDS, MS, PhD

Center for Oral and Maxillofacial Images, School of Dentistry College of Dental Medicine &

Departments of Oral Pathology & Maxillofacial Radiology Kaohsiung Medical University Hospital

Kaohsiung Medical University, Kaohsiung, Taiwan 80708

Scientific Editors:

Professor Andy Y-T Teng,

DDS, MS, PhD

Center for Osteo-immunology & Biotechnology Research (COBR) School of Dentistry, College of Dental Medicine &

Department of Family/General Dentistry, Kaohsiung Medical University Hospital Kaohsiung Medical University, Kaohsiung, Taiwan 80708

Professor Yuk-Kwan Chen,

DDS, MS

Center for oral and Maxillofacial Images, School of Dentistry College of Dental Medicine &

Kaohsiung Medical University, Kaohsiung, Taiwan 807088

Professor Claudia Noffke,

BChD, MSc Private consultant: Head and Neck Imaging, South Africa

Professor Erich Raubenheimer,

MChD, PhD, DSc Extraordinary Professor, Department of Oral Pathology Histopathology Laboratory

University of Pretoria and Ampath, South Africa

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It is accepted and agreed by all of the contributors to the Proceedings (ISBN: 978–986– 95957–0–4) that the full accountability for all matters related to the scientific accuracy, medical and professional integrity rest with the authors and have been waived from the official Publisher. It is the individual contributor‟s responsibility and liability to maintain accepted standards regarding the copy right and related issues. No part of the present Proceedings may be reproduced in verbatim, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or photocopied, recording or otherwise without the prior written permission of the official Publisher, TAOMFR, (address at: Oral and Maxillofacial Imaging Center, No.100, Shih-Chuan 1st Road, Kaohsiung, Taiwan, postal code: 80708). No responsibility is accepted by the official Publisher for any untoward result, following the use or manipulations of the instructions, data and ideas contained in the Proceedings.

Kaohsiung Medical University (KMU) TAOMFR

Group Photograph

The 21^st International Congress of Dental and Maxillo-Facial Radiology

Photo Taken on April 27, 2017, Kaohsiung, Taiwan

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PREFACE AND INTRODUCTION

It has been my wish to compile a book of Proceedings with the key abstracts of papers and posters presented at the 2017 IADMFR academic meeting in Koahsiung.

After months of communication with the delegates and editorial preparation of the abstracts submitted, I am presenting you with the final product.

The theme of the congress was arranged in three main topics: TMJ disorders, oral oncology and clinical diagnosis. We invited 42 prominent international speakers and received 236 papers (including one key note speech, 41 presentations on specialized topics, 91 oral presentations and 103 posters) from more than 400 attendees representing 34 countries. Importantly, without the sponsorship of several associations, organizations and companies, the high standard achieved would not have been possible.

The main goal of the proceedings was to provide an opportunity for the young researchers and those in the Asian continent, in particular, to nurture their skills for scientific writing in English. This will contribute towards the greater participation of researchers in our field in next generation of scientific achievements. The compendium of papers also serves as a directory of current active research themes pursued across the continents and will facilitate international cooperation, as the contact details of the main researcher is reflected in the title block of each paper.

Several researchers also exploited the opportunity to acknowledge their funding agencies and the Proceedings also provide a reference for future grant applications and annual reports.

Over 100 authors (107 papers) responded enthusiastically to our invitation for submit their abstracts. The lower than expected response rate is probably the result of a lack of fluency in English (a factor the Proceedings aimed to address) and the belief that the material could not be published subsequent to the data appearing in printed form (the copy right issues). The last reason is unfounded as a full publication is significantly different from the abbreviated text presented in the

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In closing, I would like to thank my dear colleagues professors Andrew Teng and Yuk-Kuan Chen (members of the Academic Committee), and Ming-Gene Tu (Local General Secretary of IADMFR and President of TAOMFR). The editorial assistance of professors Claudia Noffke and Erich Raubenheimer from South Africa is also acknowledged. I wish to thank Professor Allan Farman for his eminent support in making this world congress and Proceedings possible.

Lastly, the harmonious international cooperation is a testimony to the common root of all mankind.

Professor Li-Min Lin,DDS, MS, PhD

Center for oral and Maxillofacial Images, School of Dentistry College of Dental Medicine &

Kaohsiung Medical University

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LOCAL ORGANIZING COMMITTEE

Horonary President

Ching-Kuan Liu President, Kaohsiung Medical University Joh-Jong Huang Director-General of Department of Health,

Kaohsiung City Government Horonary Vice President

Chun-Pin Chiang School of Dentistry, National Taiwan University Ming-Lun Hsu School of Dentistry, National Yang-Ming University Dayen Peter Wang College of Oral Medical, Taipei Medical University Yi-Hsing Hsieh School of Dentistry, National Defense Medical Center Lih-Jyh Fuh School of Dentistry, China Medical University

Yu-Chao Chang College of Oral Medicine, Chung Shan Medical University Che-Min Lee College of Dental Medicine, Kaohsiung Medical University Organizing Committee

President

Li-Min Lin Faculty of Dentistry, Kaohsiung Medical University Vice President

Shi-Long Lian Faculty of Dentistry, Kaohsiung Medical University Vice President

Huey-Er Lee Faculty of Dentistry, Kaohsiung Medical University Secretary General

Ming-Gene Tu School of Dentistry, China Medical University Scientific Program Committee

Andy Y-T. Teng Faculty of Dentistry, Kaohsiung Medical University Yuk-Kwan Chen Faculty of Dentistry, Kaohsiung Medical University Yuan-Chien Chen Faculty of Dentistry, China Medical University Social Program Committee

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General Affairs Committee

Ching-Hung Chung Private practice Wei-Chen Chang Private practice Lo-Lin Tsai Private practice

Yeong-Lei Huang Faculty of Dentistry, Kaohsiung Medical University Erh-Hui Tsai Faculty of Dentistry, Taipei Medical University International Affairs Committee

Kazjuaki Harada Visiting Professor of Kyushu Dental University Andy Teng Faculty of Dentistry, Kaohsiung Medical University Treasure Committee

Wen-Chen Wang Faculty of Dentistry, Kaohsiung Medical University Lien-Yu Chang Faculty of Dentistry, National Yang-Ming University Cheng-Mei Yang Faculty of Dentistry, Kaohsiung Veterans General Hospital Exihibition Committee

Ching-Hung Chung Private practice Ming-Zhe Wu Private practice Home Page Committee

Chuan-Hang Yu Faculty of Dentistry, Chung-Shan Medical University Ming-Gene Tu School of Dentistry, China Medical University Yuk-Kwan Chen Faculty of Dentistry, Kaohsiung Medical University Ya-Ting Chiang Student Affairs, China Medical University

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LOCAL IADMFR OFFICERS

International Congress Committees

President Li-Min Lin

Immediate Past President Andres Briner

Secretary General M.E. Parker

Secretary General Elect Reinhilde Jacobs

Treasurer Curly Nortje

President Elect Jie Yang

Senior Vice President Elisa Parraguez Junior Vice President Shi-Long Lian Vice President Designate Mustafa Badi Secretary to the Board Jie Yang Editor of the Journal Ralf Schulze

Regional Directors (2015

–

2017)

Africa Claudia Noffke

Asia Soon-Chul Choi & Yoshinori Arai Middle East Ebtihall Al Abdeen

Europe Ingrid Rozylo-Kalinowska & EvaLevring Jaghagen North America Christos Angelopoulos & Jefferey B Price

Central America Jorg Arturo Beltran Silva

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PREVIOUS IADMFR CONGRESS

Presidents Country Year of Congress

Gregorio Faivovich Chile 1971

Yoshishige Fujiki Japan 1974

Karl-Ake Omnell Sweden 1977

Cline Fixott USA 1980

Jan van Aken The Netherlands 1983

Abul Adatia United Kingdom 1985

Charles Morris USA 1987

Birgit Glass USA 1989

Levente Pataky Hungary 1991

Dong Song You Korea 1994

Allan Farman USA 1997

Hajime Fuchihata Japan 1999

Douglas Lovelovk United Kingdom 2001

Edemir Costa Brazil 2003

Chris Nortje South Africa 2005

Xu Chen Ma Peoples Republic of China 2007

Paul van der Stelt Netherlands 2009

Kelji Tanimoto Japan 2011

Torre Lartheim Norway 2013

Andres Briner Chile 2015

Lin-Min Lin Chinese Taipei 2017

Secretaries General Country Year

Takuro Wada Japan 1968-71

Lars Hollender Sweden 1971-85

Robert Langlais USA 1985-97

Gerard Sanderink The Netherlands 1997-07

Mohamed Ebrahim Parker South Africa 2007-17

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Two radiological methods used for observing root canal morphology of maxillary teeth

Antohi C, Haba D. Departament of Endodontology and Departament of Oral and Maxillofacial Radiology, “Gr.T.Popa” University of Medicine and Pharmacy, Iasi, Romania University of Medicine and Pharmacy “Gr.T.Popa”, Iasi, Romania.

Antohi C: crisantohi_med@yahoo.com

Introduction: Endodontic exploration by using conventional radiography did help when multiple angles were used. Today CBCT provides the opportunity to assess canal anatomy 3-dimensionally in a non-invasive manner. By using the CBCT the dentist can be prepared to identify variations in canal anatomy in order to clean them effectively. Our aim was to correlate the clinical findings with radiological images on the morphology of root canals for putting correct diagnoses and make a treatment planning in correlation with the anatomy.

Materials and methods: Our study included 20 patients diagnosed with different types of morphologies of root canals of the first maxillary premolar and first maxillary molar. After clinical examination we discovered a different morphology of some teeth than found on PA radiographs and we proceeded to performing CBCT on such cases.

Results: From 20 patients : 4 (2 molars- Figs. 1,2 and 2 premolars- Figs. 3,4 ) were diagnosed with different morphologies on PA radiographs, which can contribute to wrong clinical decisions, because the CBCT disproved the results. This compared with 16 patients examined with CBCT in whom the data achieved were decisive.

Conclusions: The MIP reconstruction in sagittal, coronal, axial, panoramic, cross section and oblique plane discovered different types of morphological root canal anatomy compared with PA radiographs. Evaluation with CBCT has a higher accuracy than PA radiographs.

References

1. Surathu N, Ramesh S. Root canal morphology of maxillary first molars using cone beam computed tomography. IOSR-JDMS 2015;14: 1–4.

2. Tian YYI, Guo B, Zhang R, et al. Root and canal morphology of maxillary first premolars in a Chinese subpopulation evaluated using cone-beam computed

tomography. Int Endod J 2012;45: 996–1003.

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Figure 1: Control PA radiograph – iatrogenic perforation but no bleeding

Figure 2: CBCT 3D section – confirm the iatrogenic perforation and develop a morphological variation on MV root

Figure 3: PA radiograph – first maxillary premolar with 2 roots

Figure 4: CBCT 3D section – first maxillary premolar with 3 roots

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Next generation dental CBCT with 7 degrees of freedom

Arai Y. Nihon University School of Dentistry, Tokyo, Japan.

Arai Y: mhg01033@nifty.com

Introduction: In the 1990s, high resolution limited cone beam computed tomography was invented.^1,2 A hybrid system with panoramic radiography and CBCT was developed in 2007. It is compact and very useful for general practice.

However, the image quality of the hybrid system is lower than that of dedicated CBCT systems such as Accuitomo (J Morita MFG in Kyoto Japan).

The hybrid system needs to take the panoramic radiograph. Therefore, the main X-ray beam has to be set a few degrees off the horizontal plane. For that reason, the main X-ray beam cannot be perpendicular to the axis of the cylindrical Field of View (FOV), which is the ideal configuration for CBCT. In order to solve this problem, a next generation dental CBCT has been developed which is named Verview X800 (J. Morita MFG. Kyoto, Japan, Fig. 1). This developed new system has 7 independent degrees of freedom; X-Y position of the rotation center, rotation of the X-ray source and sensor through 360 degrees, up-down motion of the base of the rotational arm, up-down motion of the chin-rest for the patient, and width by height of the X-ray beam collimator. The system fits into the same space as the conventional system when this new system is taken by the CBCT image. The height of chin-rest is fixed. Then, the base of the rotational arm is moved to bring the horizontal beam to the center of the FOV. Thus, the main X-ray beam can be fixed in the ideal position as in dedicated CBCT systems. The study is aimed to show the image quality by new hybrid system.

Materials and methods: Two systems of CBCT images were compared. One of the images was taken traditional hybrid system as Veraview epocs 3Df (J Morita MFG) which X-ray main beam was set about 5 degrees off the horizontal. Another one was the new system as Veraview X800 which one was set horizontal. The equivalent human head phantom (Kyoto Kagaku Co. Kyoto, Japan) was taken both systems and compared the image quality.

Results: When the main beam was set horizontal as X800, that images were clearer than traditional hybrid system as 3Df. The radial artifact was reduced on new one (Fig. 2).

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References

1. Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Development of a compact computed tomographic apparatus for dental use. Dentomaxillofac Radiol 1999;28: 245–248.

2. Hashimoto K, Arai Y, Iwai K, Kawashima S, Terakado M. A comparison of a new limited cone beam computed tomography machine for dental use with a multidetector row helical CT machine. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003; 95: 371–377.

Figure 1: Veraview X800

Figure 2: Comparison of the images

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Observation of bone remodeling in vivo micro CT

Arai Y. Nihon University School of Dentistry, Tokyo, Japan.

Arai Y: mhg01033@nifty.com

Introduction: I succeeded in developing a high resolution and limited area cone beam computed tomography (HLCBCT) for dentistry in 1997. These days, the equipment is commonly used in dental offices. However, there is still a problem of a lack of basic research on clinical applications. This is because in clinical applications we cannot determine the pathology and a lot of the number of CT scans because of radiation dose issues. Therefore, I developed in vivo micro CT for experimental animals in 2005.¹ As a result, it became possible to observe the continuation of the remodeling of the bone formation using the same experimental animals over a long period. This presentation will focus on bone remodeling, sclerosis, and peri-implantitis using HLCBCT and in vivo micro CT. It is thought that when inflammation occurs the bone develops sclerosis in order to defend against infection. So, sclerosis is a biological defense reaction. But after the treatment, the lamina dura and the periodontal ligament space become clearly visible and the alveolar bone becomes more radiolucent because the bone has remodeled to fresh bone. This phenomenon is observed in periapical disease as it is in peri-implantitis.

The study is aimed to show remodeling bone using in vivo micro CT.

Materials and methods: The Titanium implant was inserted into the tibia in the individual rat after drilling. The tibia of a region was taken by in vivo micro CT (R_mCT, Rigaku Co., Tokyo, Japan) at just post operation, after the 1^st week, 2^nd week and 5^th week, continuously (Fig. 1).

Results: After 1^st week, the newly bone was remodeling and looked like a cloud.

After the 2^nd week, the beam structure of bone was starting to appear. After the 5^th week, the big beam structure of bone was visible. It was supporting the implant (Fig. 2).

Conclusion: In vivo micro CT was a very useful observation of remodeling bone continuously. This study showed that if there were many times of remodeling bone over and over, finally the thick beams were developed, and the implant was supported with the beams.²

References

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results in immediate peri-implant bone loss. Clin Exper Dent Res 2016;1: 65–

72.

Figure 1: In vivo micro CT (RmCT)

Figure 2: The thick beams structure (5^th week)

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Differential diagnosis of the lesions in the oral and maxillofacial region using CT and MRI

Asaumi J. Oral and Maxillofacial Radiology, Okayama, Japan.

J Asaumi: asaumi@md.okauama-u.ac.jp

Introduction: Among the modality of diagnosis, CT/MRI has proved to have excellent ability in demonstrating normal anatomy and pathologic processes in the oral and maxillofacial region. Whereas CT best depicts bone structures, MRI is superior to CT in evaluating soft tissues. The contents of bone lesions may also be better visualized on MRI. In this report, I will present the representative CT and MR images of lesions in the oral and maxillofacial region and discuss their imaging characteristics that provide important clues to differential diagnosis.

Materials and methods: The characteristic imaging features, especially in the MRI, were shown in the following lesions: cystic lesions in the jaw bone such as radicular cyst, dentigerous cyst, nasopalatine duct cyst, odontogenic keratocyst, simple bone cyst and aneurysmal bone cyst, and benign odontogenic tumors in the jaw bone such as ameloblastoma, adenomatoid odontogenic tumor (AOT), odontogenic myxoma/myxofibroma, and odontogenic fibroma.

Results: Among the radicular cyst, dentigerous cyst and nasopalatine duct cyst, we can differentiate them on the basis of signal intensity (SI) on T1WI. Radicular cysts, dentigerous cysts and nasopalatine duct cysts have different contents in the lesion. The dentigerous cyst includes higher density protein. The nasopalatine duct cyst includes abundant keratin and viscous fluid. Thus, the MRI may reflect the histopathological findings well. Characteristic findings of odontogenic keratocyst are that T1WI includes slight high SI area, T2WI low SI area. These reflect a large amount of keratin. The simple bone cyst shows that the uptake of the contrast agent in the cystic cavity gradually increases. The aneurysmal bone cyst demonstrates the characteristic feature showed a „bubbly‟ appearance, on T2WI and created a

„honeycomb‟ like appearance in MRI. In the unicystic ameloblastoma, on CE-T1WI, only the surrounding area including the mural nodule and the thick wall shows well enhancement in the lesion. In comparison with odontogenic benign tumors, we confirmed that the DCE-MRI makes it possible to differentiate central odontogenic fibroma from the other odontogenic benign tumors such as ameloblastoma, AOT, odontogenic myxoma.

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2. Matsuzaki H, Asaumi J, Yanagi Y, Unetsubo T. Perfusion imaging in maxillofacial lesions. Chapter 18, In: Perfusion imaging in clinical practice, Saremi F, Ed., Wolters Kluwer Health, 2015; pp. 310–322.

MRI protocol in Okayama University

T1&T2WI (STIR) DWI CE-T1WI

Dynamic MRI, 1^st scan 2^nd scan 3^rd scan

1, 2, 3･････････････19, 20, 21 1, 2 1, 2 scans

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Salivary diagnostics – A reflection of our experience

Ramnarayan Belur Krishna Prasad. Department of Oral Medicine and Radiology, Dayananda Sagar College of Dental Sciences, Bengaluru, Karnataka, India.

Ramnarayan Belur Krishna Prasad: ramnarayanbk@gmail.com

Introduction: Saliva hosts most of the biomolecules that are circulating in our blood. A myriad of these salivary proteins could serve as biological markers for diagnosing and tracking the progression of various health conditions.¹ The advantages of using saliva as a diagnostic body fluid compared to blood are:

sampling is non-invasive, rapid and allows multiple sample collections; collection process is painless and ideal for population based screening programs; there is minimal threat to the collector of contracting infectious agents, such as hepatitis and/or human immunodeficiency virus (HIV). This paper highlights the role of saliva and discusses our experience of salivary diagnostics in various oral and systemic conditions and in deoxyribose nucleic acid (DNA) isolation for human identification.

Material and methods: The studies were conducted on patients who reported to our institution between 2007 and 2016. The patients were grouped based on the presence of HIV infection, gastro-intestinal disorders, coronary artery disease, diabetes, potentially malignant disorders (PMDs) and for DNA isolation for human identification. Whole saliva was collected and analyzed for HIV antibodies, anti H.

pylori IgG, lipid profile, glucose levels, interleukin-8 (IL-8) and lactate dehydrogenase (LDH) levels and for DNA isolation respectively.

Results and discussion: Positive predictive value was found to be 100%, 85.19%

in HIV infection and gastro-intestinal disorders respectively. Significantly positive levels of salivary glucose in diabetics and salivary total cholesterol, triglyceride and low density lipoprotein levels in patients with acute myocardial infarction were found. Levels of IL-8 and LDH were statistically significant in patients with PMD.

DNA was isolated on day 1 and day 7 at 0 ôC and 7 ôC. Highest yield was at 0 ôC on day 1 followed by day 7 (Table 1).

Conclusion: Identification of minor components of saliva by using advanced techniques has led us to conclude that saliva can be used as an efficient tool for detection of several diseases. It would not be too optimistic for us to believe that in

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Table 1

Salivary Diagnostics in Diabetes Mellitus

Comparison of Serum RNFPG and Salivary glucose levels in the study groups RNFPG*

( mean) mg/dl

Un-stimulated salivary glucose

(mean) mg/dl

r value

Stimulated salivary glucose

( mean) mg/dl

r value

Control

group 103.30 1.15 0.663 0.98 0.512

Controlled

diabetes 169.23 2.04 0.847 1.88 0.830

Uncontrolled

diabetes 290.00 3.99 0.704 3.61 0.636

p < 0.001 – statistically significant in all the three groups

*RNFPG – Random Non-fasting Plasma Glucose

Salivary Diagnostics in Acute Myocardial Infarction

Comparison of Serum and Salivary Total Cholesterol, Triglycerides and Low Density Lipoproteins

Total cholesterol Triglycerides Low Density Lipoprotein Group I

Serum Saliva

151.01( 23.67) 25.19 ( 3.8)

140.80 ( 24.7) 47.75 ( 9.71)

63.78 ( 15.47) 8.44 ( 3.17) Group II

Serum Saliva

207.35 ( 38.27) 42.07 ( 7.52)

273.70 (  59.25) 98.64 ( 22.07)

103.23 (  27.05) 12.77 ( 5.05) Group III

Serum Saliva

215.07 ( 54.9) 44.72 ( 11.31)

290.40 ( 190.09) 106.33 ( 70.86)

136.87 ( 44.57) 18.60 ( 6.78) p value – 0.001- highly statistically significant

Salivary Diagnostics in HIV Infection

Test Serum

Sensitivity Specificity PPV* NPV*

Saliva Reactive Non-Reactive

Reactive 39 0

Non-Reactive 1 40

0.9750 1.0000 1.0000 (100%)

0.9756 (97.56%)

Total 40 40

The sensitivity of saliva test was found to be 97.50% and the specificity was found to be 100%. The probability of the patients having HIV is 100 % when the test is positive. PPV- Positive predictive value, NPV- Negative predictive value

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Salivary Diagnostics in Detection of anti H-Pylori Antibodies

Test Histopathology

Sensitivity Specificity PPV* NPV*

ELISA Positive Negative Total

Positive 23 4 27

Negative 6 7 13

0.7931 0.6364 0.8519

(85.19%) 0.5385

Total 29 11 40

The sensitivity of saliva test was found to be 79.31 % and the specificity was found to be 63.64%. The probability of the patients having H. pylori infection is 85.19 % when the test is positive. PPV- Positive predictive value, NPV- Negative predictive value

Salivary Diagnostics in DNA Isolation

Nature of genomic DNA

Storage time 1 Day 7 days

Storage

temperature RT* 0 ⁰C -7 ⁰C RT* 0⁰C -7 ⁰C

Quantity

(µg/250ml) 9.24 8.64 6.66 8.88 7.83 6.24

Quality at

Å 260/280 1.82 1.80 1.83 1.81 1.82 1.76

Comparison of the quality of DNA stored for 1 day and 7 days at three temperatures Quality

Å 260/280

Storage period

P value

1 day 7 days

Room

temperature 1.82 1.81 0.0696

0 ⁰C 1.80 1.82 0.001

-7 ⁰C 1.83 1.76 0.0001

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Retrospective study of CT scans. Report of a case of calsifying myositis of the medial pterygoid

Berticelli RS, Togashi A, Conci R, Griza G, Popiolek IM, Vale NG, Boffo BS, Christ E. Department of Oral Radiology, State University of West Paraná- Cascavel–PR–Brazil.

Rosana Berticelli: roberticelli@gmail.com

Introduction and objectives: The deposition of calcium salts, if in soft tissues, occurs in a disorganized fashion.When calcification of the musculature occurs after a history of trauma, is called traumatic ossificans myositis. The purpose of this study was to observe calcifications in soft tissues related to the maxilla and the mandible through panoramic radiographs and/or multislice CT scans.

Material and methods: Data was gathered through the retrospective analysis of patients, with panoramic radiographs and multislice CT scans obtained from November 2014 to November 2016. The following machines were used in this study: the Rotograph Plus, Italy, for X-ray and the Somatom Sensation 64 Tomograph, by Siemens, Germany, for the CT scans.

Results and dscussion: 2,444 panoramic radiographies were observed and analyzed and only in two patients, calcifications were observed overlapping the mandibular ramus and body, and CT scans showed extensive calcifications of the submandibular gland. One patient had a large focus of heterotopic ossification identified within the lower fibers of the right medial pterygoid muscle, in close contact and neoarticulated with the mandibular ramus of this side, close to the mandibular angle. Inferiorly, the ossification extended to the hyoid bone;

posteriorly, it crossed the right submandibular gland; medially, it reached the posterior belly of the digastric muscle; and, in its more medial aspect, led to an extrinsic bulging upon the lateral wall of the nasopharynx.

Conclusion: The diagnostic sensitivity and the levels of specificity with multislice CT scans are as high as or higher than those obtained with panoramic radiography and other methods of diagnosis. Multislice CT is the preferred latent image modality for the diagnosis of heterotopic calcifications of muscular tissues and salivary calculi.

References

1. Sacarfe WC, Farman AG. Soft tissue calcifications in the neck: Maxillofacial CBCT presentation and significance. 4^th publication on the American Association of Dental Radiographic Technicians 2:35, 2010.

2. Reddy SD, Prakash AP, Keerthi M, et al. Myositis ossificans traumatic of temporalis and medial pterygoid muscle. Oral Maxillofac Pathol 2014;18: 271–

275.

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Figure 1: 3D calcification, inferior view of the mandible

Figure 2: Coronal section showing the calcification join with the angle of the right mandible

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C-arm: A new diagnostic imaging modality for evaluating dynamic changes in TMJ

Bhuyan SK. Professor and Head of the Department of Oral Medicine and Radiology, Institute of Dental Sciences, Sum Hospital, Soa University Bhubaneswar, Odisha India.

Bhuyan SK: drsanatkumar68@gmail.com

Introduction: Radiological investigations are of paramount importance in the diagnostic assessment of a patient with TMD. The limitations of conventional radiography and various TMJ projections to evaluate the soft tissue components of TMJ have been replaced with advanced imaging techniques like USG, CT, MRI, CBCT and Nuclide Imaging. Within a span of 30 years the technological advances in imaging has gained rapid momentum expanding the arena for diagnosing the TMJ disorders. The insight into the latest procedure guided imaging like C-arm into various medical specialities and its extension into dentistry cannot be undermined. Application of C-arm technology to study the dynamics of TMJ is unique of its kind as this is the only modality where TMJ can be studied in motion and provides an excellent insight into the biomechanics of the most unique joint in the body.

TMJ imaging has been broadly classified into non-invasive and invasive modalities. Non-invasive modalities include CT, MRI, USG, CBCT, and other conventional method and TMJ projections. Invasive modalities includes arthrography, arthroscopy.

C-arm comprises a generator (X-ray source) and an image intensifier or flat-panel detector, which was discovered by Ziehm in 2006. An innovative imaging technique composed of flat panel detectors it generates 2D CT like images and finds it wide application in RCT, implant imaging and in trauma assessment.

Objective: The basic objective of the study to evaluate the efficacy of c arm in measuring the range of dynamic movement.

Methdology: C arm with a specification of 14 kHz, 1.9 kW, 40–120 kV, 8.0–250 mA with a fluoroscopy rate of one image per second. With a sample size of 22 and equal division of control and sample size included patients with complaints of persistent TMJ pain. Patient were positioned supine with head tilted at 30° from the mid sagittal plane and forming an angle of 10° upwards & FH plane being perpendicular to the floor. The Interincisal distance for each sample was measured (mesio-incisal angle of upper central incisor to the mesio-incisal angle of lower central incisor) and condylar distance (most superior point of articular eminence to most superior aspect of convexity of condyle).

Result: The age distribution shows (GRAPH 1) that 20–30 years age group in the

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present study are affected most which can be explained as the study sample is very small and larger symptomatic cases need to be included. Maximum cases (GRAPH 2) are in the range of 10–15mm of condylar distance in diseased group and in healthy group as well. So one important finding that evolves is that there should be other parameters determining the TMJ symptoms or coexisting factors along with the present variable. There is uniform distribution of data from 35–65 mm; so, the interincisal distance (GRAPH 3) determining any TMJ disorder is ambiguous.

Conclusion: The programming of C arm in dental use mostly in TMJ helps in evaluation with respect to adjusting the image clarity, contrast, sharpness and preventing the overlapping of the adjacent structures. This machine has been widely used in gastroenterology, neurology and orthopaedics but no considerable work has been done in the field of TMJ in order to see the dynamic movement. So, it can be considered in near future for further in depth research in TMJ dynamics.

Sectional Image of C-arm (normal TMJ) GRAPH 1

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GRAPH 2 Maximum cases are in the range of 10–15 mm of condylar distance in diseased group and in healthy group as well

GRAPH 3 As the graph is more or less symmetric in case group i.e.

there is uniform distribution of data from 35–65 mm so the Interincisal distance determining any TMJ disorder is ambiguous

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High resolution cone beam tomography of the temporomandibular joint

Briner A. Universidad de Chile, Santiago, Chile.

Briner A: andresbriner@gmail.com

Introduction: Oral and maxillofacial imaging diagnostic capability has dramatically grown since the introduction of cone beam Computed Tomography (CBCT). This radiological modality has allowed obtaining high quality volumetric images of the maxillofacial region with low radiation dose and at reasonable costs.

Since the introduction in the market of the first Cone Beam units less than two decades ago, we witnessed the introduction of hundreds of models and trademarks of machines using this technology but with great differences in the quality of the images they procure. Subtle osseous morphologic changes in the temporomandibular joint (TMJ) can only be detected in sufficiently high spatial resolution CBCT images. The current presentation focuses on imaging diagnosis of the TMJ through high resolution CBCT images.

Objectives: To discuss the following topics:

- Principles for generating high resolution images in cone beam.

- CBCT imaging settings to obtain the best possible diagnostic TMJ images.

- Anatomy of ATM in CBCT.

- Anatomic Variations of ATM observed in CBCT.

- Degenerative morphological changes of TMJ in CBCT, description and sequence of the imaginologic signs.

- TMJ positional and dynamics changes observed in CBCT.

- Prevalent pathology of the TMJ.

- Ongoing investigations that relate the anatomy of TMJ predisposing to certain diseases.

Conclusions: CBCT performed with high resolution and limited field of view (FOV) allows us to successfully apply this technology in the study and diagnostic of the TMJ. The diagnostic capability of the high resolution CBCT images makes it feasible to detect subtle changes in the anatomy of the bony components of the TMJ as well as changes in the cortical and cancellous bone structure.

He uses CBCT in TMJ is having a major impact as a primary diagnostic tool,

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References

1. Tsiklakis K, Syriopoulos K, and Stamatakis HC. Radiographic examination of the temporomandibular joint using cone beam computed tomography.

Dentomaxillofac Radiol 2004;33: 196–201.

2. Alkhader M, Kuribayashi A, Ohbayashi N, Nakamura S, Kuribayashi T.

Usefulnes of cone beam computed tomography in temporomandibular joints with soft tissue pathology. Dentomaxillofac Radiol 2009;38: 141–147.

3. Dos Anjos Pontual ML, Freire JSL, Barbosa JMN, Frazão MAG, Dos Anjos Pontual A. Evaluation of bone changes in the temporomandibular joint using cone beam CT. Dentomaxillofac Radiol 2012;41: 24–29.

4. Koenig L. Diagnostic Imaging Oral and Maxillofacial. 1^st edition, Amirsys Inc.;

2012, ISBN: 978–1–931884–20–4.

Figure 1: Typical high resolution CBCT study of a healthy TMJ

Figure 2: Coronal and sagittal high resolution CBCT slices showing erosions and flattening of the articular surfaces, loss of the interarticular space, subcortical sclerosis, osteophyte formation, osteolysis and subchondral cyst formation

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Measurement of dose perception and radiation risk of radiographs by teachers and students of dentistry

Briner JB, Briner AB, Briner MB. Universidad del Desarrollo, Santiago, Chile.

Briner JB: Joy.briner@gmail.com

Introduction: All types of radiographs have become an essential tool in the world of dentistry. However, there are some studies that have been raising the concern from practitioners and patients about the potential risks associated to ionizing radiation exposure of these tests.¹

Objective: To analyze and compare the perception of radiation dose and risk of cancer of maxillofacial radiological exams by academics and students of dentistry at the Universidad del Desarrollo, Santiago, Chile.

Material and method: A cross-sectional analytical study was carried out during the months of August to October 2016. The sample consisted of teachers and students of the 5^th and the 6^th year of dentistry. Radiology teachers and specialists were excluded from the study. The participants answered an online survey designed for the measurement of the perception of radiation doses and the cancer risk associated with each radiographic examination commonly used in dentistry. All the data collected were submitted to statistical analysis, which included averages, variance and Mann Whitney U Test.

Results: The average values obtained, for students and teachers, of doses perception and cancer risk associated with dental X-ray exams, were in all cases higher (overestimated) than the real values obtained from multiple studies, except for the cone beam CT (medium and large field of view) and CT scan, where the perception on radiation doses was lower than the real values (Figs. 1,2). In general, the answers between these two groups did not have significant differences.

Conclusion: Students and teachers of dentistry in Universidad del Desarrollo, overestimate the amount of ionizing radiation and cancer risk associated with dental radiographic exams. The need to use new education strategies in terms of ionizing radiation doses and potential risks associated with each radiographic exam is evidenced in order to reduce apprehensions and fears, thus obtaining the maximum benefit of the important tool that radiology constitutes.

References

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Figure 1: Radiation dose associated to dental X-ray

Figure 2: Cancer risk associated to dental X-ray

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Gubernaculum dentis: A report of 31 cases

Briner MB, Briner AB, Briner JB. Imax: Oral and Maxillofacial Radiology Clinic, Santiago, Chile.

Briner MB: Michellebrinergarrido@gmail.com

Introduction: Gubernaculum dentis (GD) is a rare vestigial anatomic structure, composed by the gubernacular tract (GT), which is a bony pathway in alveolar bone that enables communication between the dental follicle and the alveolar crest.

Its content is the gubernacular cord.¹ It acts as an eruption pathway rather than a stimulus for eruption. During the eruptive phase, the successor tooth moves in an axial direction towards the oral cavity and the gubernacular tract, which can be seen on radiographs, is widened by local osteoclastic activity.² GD is barely described in the radiology literature, leading to omissions, errors or diagnostic confusion with normal anatomic structures.

Objectives: To describe the imaging characteristics- and elaborate on the differential diagnosis of the GD.

Material and methods: GD visualization was retrospectively analyzed using CBCT, panoramic and periapical radiographs from January 2015 to October 2016.

Thirty one cases of GD were observed in 16 patients.

Results: Out of the 31 cases that were studied, 14 were canines in the process of eruption or impacted, one deciduous molar, two supernumeraries, six premolars, two incisors accompanied by odontomas, one compound odontoma, and five third molars. In all cases the radiographic images presented similar characteristics. In only one case radiographic signs of cystic or tumoral pathology were observed.

Conclusion: The GD should be described on radiographs as Gubernacular Tract. It is visualized as a radiolucent canal, with cortical, parallel and generally rectilinear borders, which diameter and length varies in all cases. It extends from the pericoronal space of an unerupted or impacted tooth or an odontoma to the corresponding zone at the alveolar crest (Fig. 1). It is always bilateral, unless the contralateral counterpart has erupted or does not exist (Fig. 2). It must be differentiated from bone trabeculae, medullary spaces, neurovascular bundles, fistula tracts and the nasopalatine canal. It is a normal structure which is seen in all cases with erupting teeth and is not related to pathology.

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2. Araújo D, Caroline A, Consolaro A, et al. Gubernacular cord and canal-does these anatomical structures play a role in dental eruption? RSBO 2013;10: 167–

171.

Figure 1: Gubernaculum dentis in tooth 23

Figure 2: Gubernaculum dentis in third molars bilaterally

Proceedings of 21