Introduction to Roentgenology

Introduction to Roentgenology

• Roentgenology is the science or study of radiation as used in medicine.
• It's a medical branch dealing with X-rays, radioactive substances, and radiant energy for disease diagnosis and treatment.
• Radiology is the newer term.

Purpose of Dental Radiographs

• Preoperative tool for inspecting hidden structures of the oral cavity.

Qualities of Diagnostic Radiographs

• Proper contrast
• Proper density
• Maximal definition
• Minimal distortion
• Outline the anatomy of the region being examined.

Definition of Radiography

• Art and practice of creating radiographs (requires practice, study, experience, and judgment).
• A science encompassing physics, mathematics, and chemistry.

Practitioner's Responsibilities

• Produce acceptable radiographs.
• Determine and correct errors.
• Practice correct radiation safety.
• Demonstrate knowledge of physics, chemistry, and mathematics.

Uses of Radiographs

• General Dentistry:
  • Loss of tooth structure
  • Decay (occlusal, proximal)
  • Non-carious conditions (attrition, abrasion, erosion, fracture)
  • Periodontal disease
  • Endodontic disease
  • Impacted teeth
  • Trauma (root and alveolar fractures, foreign bodies)
  • Other bone pathologies
• Periodontics:
  • Alveolar bone height
  • Alveolar bone health
  • Localized vs. generalized alveolar bone loss
  • Peri-radicular infection
• Orthodontics:
  • General growth and development
  • Delayed eruption
  • Ectopic teeth
  • Eruption paths
  • Impacted teeth
  • Supernumerary teeth
• Oral medicine and oral surgery:
  • Extractions
  • Jaw fractures
  • Tumors
  • Infections
  • Foreign bodies
• Endodontics
  • Anatomy of the pulp chamber and canal
  • Presence of peri-radicular and peri-apical pathology
  • Root resorption
  • Dental trauma
  • Canal length determination
  • Root filling
  • Follow-up/monitoring healing (periapical, fracture, resorption)

Common Dental X-rays

• Bitewings
• Periapical
• Panoramic

Intra-oral Radiography

• Radiographic film/detector is exposed while inside the patient's mouth.
• Images a small area, focusing on a few teeth and adjacent supporting structures.

Periapical Radiographs

• Indications:
  • Detecting apical infection/inflammation
  • Dental trauma (to the tooth and associated alveolar bone)
  • Assessing root morphology
  • Endodontic diagnosis, planning, treatment, and monitoring

Occlusal Radiographs

• Indications:
  • Presence/absence of developing teeth
  • Supernumerary teeth
  • Impacted teeth
  • Pathology not fully demonstrated in an intraoral view
  • Contour of buccal and lingual cortical plate
  • Localization technique (used with another film)
  • When unable to take intra-oral radiographs
  • Limited opening of mouth
  • Uncooperative child

Extra-oral Radiography

• Radiographic film/detector is positioned outside the patient's mouth.
• Images larger areas like the mandible, maxilla, face, and skull.
• Skull radiographs:
  • Lateral head
• Other extra-oral radiographic views
  • Anterio-posterior view
  • Lateral oblique jaw
  • TMJ
• Tomography
• Panoramic radiograph (OPG)
• TMJ
• Maxillary sinus views
• Modern OPG machines alter tomographic layer extent and shape.

OPG Indications

• Assessment of wisdom teeth
• TMJ pathology
• Maxillary sinus
• Jaw bone pathologies
• Orthodontic diagnosis
• Jaw bone fractures

Other Technologies and Imaging Modalities

• Computerized tomography (CT)
• Magnetic resonance imaging (MRI)
• Ultrasound

CT (Computerized Tomography)

• Radiographic cutting of a region/structure into thin slices.
• Relatively high radiation doses.
• Good diagnostic information.
• Used in oral maxillofacial surgery (for diagnosis and treatment planning of tumors, fractures, and neuropathies).

MRI (Magnetic Resonance Imaging)

• Provides better soft tissue images than CT scans.
• Utilizes magnetic fields and sound waves (no radiation).
• Very good diagnostic information.
• Used in oral maxillofacial surgery (for diagnosis and treatment planning of tumors, fractures, and neuropathies)
• Gold standard for TMJ imaging.

Ultrasound

• Limited uses in dental care.
• Salivary gland tumors
• Possibly TMJ
• Locating foreign objects in soft tissue
• Soft tissue cysts

Three-Dimensional Digital Imaging (CBCT)

• Cone-beam computed tomography (CBCT).
• Offers more detailed and accurate diagnosis than traditional techniques.

Properties of X-rays

• Invisible
• Charge-less
• Travel at the speed of light
• Mass/weightless
• Travel in straight lines
• Cause ionization
• Affect photographic film emulsion
• Affect living tissue
• Penetrate opaque tissues and structures.
• Radiopaque (light) vs. Radiolucent (dark)

Conventional vs. Digital Imaging

• Conventional radiography uses radiographic film as the detector/sensor.
• Digital imaging uses charged-coupled devices (CCDs) or CMOS/APS as the detector/sensor.

CMOS/APS Advantages

• 25% greater resolution
• Cheaper
• Greater durability

Digital Imaging Advantages

• No use of films, intensifying screens, or cassettes.
• Computer hardware and software allow easy image viewing and storage
• Multiple images can be obtained without changing film holders or using new film
• Reduced exposure to radiation

History of Roentgenology

• 1870-1895: Vacuum tube experimentation (Hittorf, Goldstein, Crookes)
• November 8, 1895: Wilhelm Conrad Roentgen's discovery of X-rays.
• First roentgenogram of his wife's hand.
• Timeline of significant events in dental radiography (various years and events).

This quiz covers the fundamentals of roentgenology, the study of radiation in medicine, particularly focusing on dental radiographs and diagnostic qualities. It explores the key principles and the practitioner's responsibilities in producing effective radiographs while ensuring safety. Test your knowledge on the science behind radiography and its applications in dentistry.