Developing Skill and Expertise in the Use of Panoramic Radiography

Developing Skill and Expertise 

in the Use of 

Panoramic Radiography 

Friday, June 21, 2013 

2:30pm-5:30pm

5/13/2013 

Welcome! 

Developing Skill and Expertise 

in the Use of Panoramic 

Radiography 

Today’s Presentation: 

•Part I: The Art & Science of Panoramic 

Radiography 

(50 min) 

 

•Part II: Anatomy & Pathology (50 min) 

• 

•Part III: Interpretation and Identification Activity 

(50 min) 

Learning Objectives 

• Describe the fundamentals of panoramic imaging 

• Describe the purpose and use of panoramic radiography 

• List the four basic components common to most panoramic x- 

ray machines 

• Explain the concept of the focal trough 

• Identify the planes used to position the arches correctly within 

the focal trough 

• Describe correct patient positioning errors seen on panoramic 

images 

• Identify common positioning errors and the necessary measures 

needed to correct such errors 

• Identify hard tissue anatomic landmarks of the maxilla and 

mandible 

• Identify soft tissue and air space images on a radiograph 

• Identify artifacts on a radiograph 

• Identify pathology 

• Discuss the advantages and disadvantages of panoramic 

imaging 

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References 

• Frommer, HH, & Stabulas-Savage, JJ (2011). Radiology for the 

Dental Professional, 9 th Ed., Mosby Elsevier, St. Louis, MO. 

• Haring, JI & Lind, LJ, (1993). Radiographic Interpretation for the 

Dental Hygienist, Saunders, Philadelphia, PA. 

• Iannucci & Howerton (2011). Dental Radiography Principles and 

Techniques, 4 th Ed, Mosby Elsevier, St. Louis, MO. 

• Langland, OE, Langlais, RP & Preece, JW (2002). Principles of 

Dental Imaging, 2 nd Ed, Lippincott, Williams & Wilkins, 

Baltimore, MD. 

• Matteson SR, Tyndall DA, Burkes EJ et al: The radiology of 

benign and malignant lesion, Dent Radiogr Photogr 57:35-52, 

78-84, 1985. 

• Preece, John W., (2009). University of Texas Health Sciences, 

San Antonio, TX. 

• Thomson, EM & Johnson, ON, (2007). Essentials of Dental 

Radiography, 9 th Ed., Pearson, Upper Saddle River, NJ. 

• White, SC & Pharoah, MJ (2009). Oral Radiology Principles and 

Interpretation, 6 th Ed., Mosby Elsevier, St. Louis, MO. 

History 

• First introduced 1959 by S.S. 

White Corp. as their 

"Panorex" unit 

• Designed based on work 

done in 1949 by Dr. Y.V. 

Paastero, a Finnish dentist 

• Essential part of dental 

diagnosis 

• Complement to intraoral 

films 

• Panorama = "unobstructed 

view of a region in any 

direction" 

Uses in Dentistry 

Benefits 

• Broad coverage of the facial 

bones & teeth 

• Low patient radiation dose 

• Convenience of the 

examination for the patient 

• Use in patients unable to 

open their mouths 

• Short time required to make 

a panoramic image vs. FMX 

• Patients don’t mind! 

Uses 

• Impacted teeth 

• Eruption patterns 

• Growth & Development 

• Detect diseases, lesions 

and conditions of the jaws 

• Examine the extent of large 

lesions 

• Evaluate trauma 

Not Recommended for 

Dx: 

• Caries 

• Periodontal disease 

• Periapical lesions 

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Panoramic Imaging 

• A single tomographic image of the facial structures including: 

• Maxilla 

• Mandible 

• All the supporting structures 

• A tomographic series is comprised of multiple cuts 

(exposures) 0.5cm apart 

• Requires rotating, slit-beam exposure with rotating (reciprocating) 

receptor 

• Can be film or digital sensors 

Courtesy of Mosby, Inc., Elsevier Pub, 2009.. 

Image Layer -or- 

Focal Trough -or- 

Focal Plane 

• A narrow, specific, curved, fixed space between the x-ray 

source (x-ray tube) and the film 

• Can vary in shape from one unit to another, but is specifically 

shaped to record the human jaw 

• Is where the images projected onto the radiograph are recorded 

clearly 

• When the patient is improperly positioned within this space, it is 

the source of many errors that can result in an undiagnostic 

image 

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Panoramic Units 

•Many different kinds of units available today 

•Variables include: 

• # and locations of the centers of rotation 

• Fixed or adjustable focal trough 

• Type and shape of film transport mechanism 

• Manual or automatic setting controls 

• Head-positioning devices/bite blocks 

• Wall-mounted or free-standing 

• kVP and mA ranges 

• Sit or stand patient position 

Panoramic Units 

•Analog film units 

• Film size 5.5" or 6.5” 

• Fast film 

• Intensifying screens 

• 1 pano exposure = 4 BWX exposure (F-speed film) 

•Digital units 

•Charge-coupled device (CCD) 

•Photostimulatable phosphor plate (PSP) 

•DICOM (2004) 

•All have common positioning requirements 

• Mid-Saggital Plane 

• Frankfort Plane -OR- Ala-Tragus Line 

• Each machine has its own unique technique for operating, which can be easily 

learned 

Midsagittal 

Plane 

• Should be perpendicular to 

the floor 

• Be positioned evenly 

between the eyes 

• Go down center of nose, 

philtrum and down middle 

of bite block 

Controls “head tilting” and 

“twisting” of head 

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Head Twisted: One side of the mouth is magnified and ramus 

is distorted, more of the spine appears on one side of film 

Frankfort 

Plane: 

• An imaginary line from 

the floor of the orbit 

(eye) to the external 

audiology meatus. 

• Should be parallel to 

the floor 

Controls chin positioning 

(high/low) 

Ala-Tragus Line 

• *An imaginary line from 

the ala of the nose to 

the external auditory 

meatus 

Controls chin positioning 

(high/low) 

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Common Positioning Requirements: 

Bite Block 

Anterior teeth should be positioned in the proper 

groove(s). 


Bite Block 

• Biting too far forward: 

• Anterior teeth appear 

narrow and smaller 

• The spine appears in 

radiograph 

• Biting too far back: 


widened and blurred 

• Condyles of mandible 

are not visible 

Common Positioning Requirements: Bite 

Block 

• Biting too far forward: 


narrow and smaller 

• The spine appears in 

radiograph 

• Biting too far back: 


widened and blurred 

• Condyles of mandible 

are not visible 

Courtesy of Mosby, Inc., Elsevier Pub, 2009.. 

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The patient’s anterior teeth appear to be narrow and smaller on the 

panoramic image when patient’s teeth are positioned too far forward 

on the bite-block. (More of the spine is on image also.) 

Anterior teeth appear widened and blurred on the panoramic image when the 

patient’s teeth are positioned too far back on the bite-block. 


Focal Trough Position 

• Some units will have adjustments to 

assure positioning within the Focal 

Trough (or Image Layer) 

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Chin Position 

Should not be angled up or down 

Controlled by the correct alignment of the 

Frankfort Plane or Ala-Tragus Line 

Chin too high: An “exaggerated frown line” is seen on a 

panoramic image when the patient’s chin is tipped up. (Chin 

rest is too high, Frankfort plane is not parallel to the floor) 

Chin too low: exaggerated smile 

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Head Tilt 

• Head positioning devices 

should be firm enough to 

prevent tipping or 

rotating 

• Correct midsagittal 

orientation should be 

maintained throughout 

the whole procedure 

• Can also prevent patient 

movement during 

exposure 

Head Tilted: One side of the mouth is enlarged, overall image 

is tilted and slightly distorted. 


Lead Apron 

Should not have a thyroid 

collar (interferes with 

primary beam) 

Place on patient with the 

long side on the patient’s 

back 

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A lead apron artifact appears as a large cone-shaped 

radiopacity obscuring the mandible. 


Patient Posture 

• Spine should be kept erect 

• “Stand tall” 

• Shoulders relaxed 

• Hands on grips/handles 

• Cross hands if need more 

room 

• Prevents spine from being 

superimposed on anterior 

teeth 

(No slumping!) 

Patient slumped: If the patient is not standing erect (slumped), a 

superimposition of the cervical spine (arrows) may be seen at the center 

of the panoramic image.spine shadow ghost appears on anterior teeth 

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Tongue Position 

If the patient does not place his or her tongue on the roof of the 

mouth and hold it there throughout the imaging procedure, a 

radiolucent shadow will be superimposed over the image of the apices 

of maxillary teeth. 

Other Considerations 

These items should be removed to allow visualization of 

all structures and prevent creating ghost images: 

• Dentures/prosthetic appliances 

• Jewelry (including necklaces) 

• Oral/facial/ear piercings 

• Hearing aids/glasses 

•Hairpins 

• Bib chains 

Large hoop earrings (1) and ghost images (2). The ghost 

image of the earring appears on the opposite side of the image 

and is enlarged and laterally distorted. 

* 

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Panoramic Anatomy 

Why is Anatomy 

Important 

• You must understand what is normal to be 

able to distinguish between: 

• Normal 

• Variation of Normal 

• Disease 

• Why is it difficult with panoramic 

• Complex structures of the mid-face 

• Super-imposition of the structures 

• Large number of potential artifacts 

• Out of practice 

Anatomy: basic concepts 

• Understanding density changes 

• Air obscures hard tissue 

• Soft tissue obscures air 

• Hard tissue obscures soft tissue 

• Ghost images obscure everything 

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Panoramic Radiographic Anatomy: 

Air spaces 

1. Palatoglossal air space 2. nasopharyngeal air space 3. oropharyngeal air 

space 


Air spaces 


Air Spaces 

1. palatoglossal air space 2. nasopharyngeal air space 3. oropharyngeal air 

space (AIR OBSCURES HARD TISSUE) 

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Soft tissues 

1. tongue 2. soft palate and uvula 3. lip line 4. ear 


Soft Tissues 


Soft Tissues 

1.dorsum of tongue 2. soft palate and uvula 3. ear. (SOFT TISSUE OBSCURES 

AIR) (HARD TISSUE OBSCURES SOFT TISSUE) 

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Ghost Images 

b 

a 

a 

a, Ghost image of contralateral side of the mandible. b, Ghost image of the 

cervical spine. 


Ghost Images 

Ghost images (GHOST IMAGES OBSCURE EVERYTHING) 

Break for activity 

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Radiographic Anatomy: Panoramic 

Maxilla and surrounding structures 

1. mastoid process 2. styloid process 3. external auditory meatus 4. glenoid fossa 5. 

articular eminence 6. lateral pterygoid plate 7. pterygomaxillary fissure 8. maxillary 

tuberosity 9. infraorbital foramen 10. orbit 11. incisive canal 12. incisive foramen 13. 

anterior nasal spine 14. nasal cavity and conchae 15. nasal septum 16. hard palate 17. 

maxillary sinus 18. floor of maxillary sinus 19. zygomatic process of maxilla 20. zygomatic 

arch 21. hamular process 



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1. external auditory meatus 2. zygomatic process of maxilla 3. infraorbital foramen 4. orbit 

5. anterior nasal spine 6. nasal septum 7. nasal conchae 8. hard palate 9. zygomatic 

process of maxilla 10. pterigomaxillary fissure 



1. glenoid fossa 2. articular eminence 3. maxillary tuberosity 4. maxillary sinus 

5. zygoma 

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Mandible and surrounding structures 

1. condyle 2. mandibular notch 3. coronoid process 4. mandibular foramen 5. lingula 6 

mandibular canal 7. mental foramen 8. hyoid bone 9. mental ridge 10. mental fossa 11. 

lingual foramen 12. genial tubercles 13. inferior border of mandible 14. mylohyoid ridge 

15. internal oblique ridge 16. external oblique ridge 



1. condyle 2. mandibular notch 3. coronoid process 4. mandibular foramen 5. 

mental foramen 6. genial tubercles 7. styloid process 

Panoramic Radiographic 

Anatomy: Mandible and surrounding structures 

1. mandibular canal 2. hyoid 3. external oblique ridge 4. angle of mandible 

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1. inferior border of mandible 2. submandibular fossa 3. external oblique ridge 4. 

soft tissue of ear 

Radiographic Pathology 

Describing Radiographic Lesions 

LESION 

Radiolucent 

Radiopaque 

Mixed 

Well-Defined 

Poorly Defined 

Single 

Multiple 

Asymptomatic 

Symptomatic 

Tooth Associated 

Not tooth associated 

Hard Tissue 

Soft Tissue 

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Benign Tumors 

• Benign lesions growing in bone 

tend to be round or oval 

• They tend to grow slowly and 

displace adjacent tissues and/or 

teeth. 

Malignant Tumors 

• Symptoms: 

• Ill-defined Radolucent and/or Radiopaque, moth 

eaten appearance 

• Fast growing 

• Perforation of bone 

• Pain and swelling 

• Loose teeth 

• Altered sensations 

Radiolucent Periapical 

• Periapical Abscess 

• Periapical Granuloma 

• Periapical Cyst 

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Radiolucent/Radiopaque Periapical: 

Periapical Cemento-Osseous Dysplasia 

• Radiolucent 

early/Radiopaque late 

with radiolucent rim 

• Associated with apex of 

mandibular anterior teeth 

• Teeth are vital 

• Asymptomatic 

• Common in middle aged 

African American women 

• Tx: None 

Unilocular Radiolucent Pericoronal: 

Dentigerous Cyst 

• Tx: surgical removal 

• Recurrence: unlikely 

Unilocular Radiolucent Pericoronal: 

Adenomatoid Odontogenic Tumor 

(AOT) 

• Well Circumscribed 

Radiolucent Unilocular or 

Radiolucent with 

Radiopaque flecks 

• Tx: Surgical Removal 

• Recurrence: none 

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Radiolucent Unilocular: 

Nasopalatine Duct Cyst 

• Corticated border 


• Recurrence: Rare 

Residual Cyst 

• Unilocular Radiolucent 

– Corticated or noncorticated 

border 

• Tx: surgical removal 

• Recurrence: unlikely 

Multilocular Radiolucent 

Lesions 

• “COMA”: 

– Central Giant Cell Granuloma 

– Odontogenic Keratocyst (OKC) 

– Myxoma 

– Ameloblastoma 

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Central Giant Cell Granuloma 

• Radiolucent Well-Defined 

Multilocular or Unilocular 

– Corticated or noncorticated 

border 

• Dx: Biopsy 

• Tx: Curettage 

Odontogenic Keratocyst (OKC) 

• Radiolucent, well-defined 

smooth borders 

• Sclerotic or corticated 

border 

• Tx: Surgical Excision and 

osseous curettage 

• Recurrence: 30% 

Odontogenic Myxoma 

• Radiolucent Multilocular 

or Unilocular 

• Irregular or scalloped 

margins 

• Thin boney trabelculae 

arranged at right angles 

• Tx: Curettage 

• Recurrence: 25% 

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Ameloblastoma 

• Multilocular radiolucent 

“soap bubble” or 

“honeycomb” 

• Tx: Depends on size of 

lesion 

• Small: aggressive curettage 

or bloc resection 

• Large: bloc or segmental 

resection 

• Recurrence: 55-90% 

Malignant Tumors 

• Symptoms: 

• Ill-defined Radolucent and/or Radiopaque, moth 

eaten appearance 

• Fast growing 

• Perforation of bone 

• Pain and swelling 

• Loose teeth 

• Altered sensations 

• Poorly defined mixed 

Radiolucent/Radiopaque 

lesion 

– Sunburst or sunray 

appearance in 20% of 

cases 

• Tx: Radical surgical 

excision, Radiation and 

chemotherapy 

• Prognosis Poor (30-50%) 

survival rate 

Osteosarcoma 

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Chondrosarcoma 

• Poorly Defined 

Radiolucent lesion or 

mixed Radiolucent/ 

Radiopaque lesion 

• Expansile, with 

widening of the PDL 

• Tx: Wide excision, 

Chemotherapy and 

radiation 

• Prognosis Poor: less 

than 20% after 5 

years, metastasis 

usually to lungs or 

other bones 

Metastatic Tumors of the 

Jaw 

• Poorly Defined 

Radiolucent Lesion 

• Tx: Surgical Excision, 

chemotherapy and 

radiation 

• Poor Prognosis: 10% 

after five years 

www.orad.org 

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Radiopacities 

Radiopacities: 

Idiopathic Osteosclerosis 

• Idiopathic= unknown 

cause 

• Sclerosis= scar-like 

• Area of increased 

density of bone 

• Tx: None necessary 


Condensing Osteitis 

• Condensing Osteitis 

• Tooth with deep 

restoration, welldefined 

radiolucent 

lesion, radiopaque 

“halo” around lesion 

• Bone may or may not 

go back to normal 

after extraction 

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Odontoma, Compound 

• Radiopaque lesion often 

with radiolucent zone 

surrounding 

• Often related to impacted 

teeth 




Odonotoma, Complex 

• Radiopaque lesion often 

with radiolucent zone 

surrounding 

• Often related to 

impacted teeth 




Cementoblastoma 

• Slow growing radiopaque 

lesion associated with 

tooth root 

• Often has fine radiolucent 

border 

• Tx: surgical removal with 

extraction or root 

amputation 

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Interpretation & 

Identification 

Special Thanks to 

John W. Preece, DMD, MS 

University of Texas Health Sciences 

San Antonio, Tx 

Co-author of Principles of Dental Imaging, 2 nd Ed, 

Lippincott, Williams & Wilkins, Baltimore, MD. 

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Left 

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Left 

Left 

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Left 

Left 

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Case 

History 

Chief complaint 

A 45-year-old high school teacher seeks your 

advice regarding his “swollen jaw.” 

History of Present Illness 

He has been aware of persistent and 

gradually increasing jaw swelling for 

many years. He has had no symptoms. 

He wishes to know if the lesion is 

malignant. If benign, he will decline 

treatment for religious reasons. 

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Past Medical History 

He has no systemic diseases and no 

allergies. He is taking no medications. 

He does not smoke or drink. 

How would you describe the intraoral changes 

Copyright © 2008 by Saunders, an imprint of Elsevier Inc. 

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How would you describe the intraoral changes 

Next step 


Describe the radiographic appearance 


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The biopsy specimen showed revealed Ameloblastoma 


Follow-up 

Initially the patient refused treatment but returned 7 years later with 

advanced disease. Because of the size and persistent growth of the 

tumor mass, the patient consented to a hemimandibulectory procedure 

that he tolerated well and recovered without complications. 


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Left 

Ignore 

this area 

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Left 

Another Case 

•45 year old female 

•“Unusual sensation” in 

upper left 

•Vitality reading of teeth 

“ambiguous” 

•Now what 

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Other ill-defined lesions 

•4 months later, 

symptoms not 

improved 

•Now what 

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Developing Skill and Expertise in the Use of Panoramic Radiography

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