Dental X-rays are a crucial part of comprehensive oral exams, allowing dentists to detect issues that aren’t visible during a standard visual inspection. There are two primary types of dental X-rays: intraoral (taken with the film inside the mouth) and extraoral (taken with the film outside the mouth).

Intraoral X-Rays

Intraoral X-rays are the most common type and provide detailed images of the teeth, roots, and surrounding bone. They help dentists identify cavities, monitor tooth development, and evaluate the health of tooth roots and jawbone.

Extraoral X-Rays

Extraoral X-rays capture broader images of the jaw, skull, and temporomandibular joints (TMJ). While they also show the teeth, they are primarily used to diagnose impacted teeth, malocclusions (bite alignment issues), and TMJ disorders.

Together, these imaging techniques give dentists a complete view of oral structures, ensuring early detection and accurate treatment planning for both functional and cosmetic dental concerns.

Types of Intraoral X-Rays

There are three main types of intraoral x-rays, and each provides a different perspective of the teeth and surrounding structures. Together, they help the dentist evaluate tooth health, bone structure, and bite alignment with precision.

Bitewing X-rays

Bitewing X-rays—named because patients bite down on a special tab to hold the film—show detailed images of both the upper and lower teeth in one area of the mouth. These X-rays are commonly used to:

• Detect tooth decay between teeth
• Evaluate bone density changes caused by gum disease
• Assess the fit of crowns or check the integrity of dental fillings

Because they capture an entire section of teeth, bitewings are among the most frequently used diagnostic X-rays in dentistry.

Periapical X-rays

Periapical X-rays focus on a smaller number of teeth but show each one in full—from crown to root tip, along with the surrounding bone structure. These images are particularly useful for identifying root infections, abscesses, cysts, or bone abnormalities that may not be visible during a routine exam.

Occlusal X-rays

Occlusal X-rays are larger than other types and provide a broad view of the entire arch of the upper or lower jaw. They are often used in children to monitor tooth development, eruption patterns, and alignment. Occlusal X-rays help dentists evaluate bite problems and detect teeth that are impacted or improperly positioned.

Types of Extraoral X-Rays

There are several types of extraoral dental x-rays, each designed to capture different areas of the mouth, jaw, and skull. These imaging techniques help dentists and specialists diagnose conditions that extend beyond the teeth and gums.

Panoramic X-rays

Panoramic X-rays capture a complete image of the entire mouth in a single view, showing all upper and lower teeth at once. They are invaluable for assessing the position of developing, erupted, or impacted teeth and for detecting tumors, cysts, or bone abnormalities.

Tomograms

Tomograms focus on a specific layer or section of the mouth, intentionally blurring surrounding structures to provide a clearer view of the targeted area. These images are useful when nearby tissues or bones might otherwise obscure important details.

Cephalometric Projections

Cephalometric X-rays provide a full side view of the head, showing the relationship between the teeth, jaw, and facial structure. Orthodontists commonly use these images when planning treatments to correct bite alignment (malocclusion) or to evaluate jaw growth and symmetry.

Sialography

Sialography is a specialized X-ray technique that allows visualization of the salivary glands and ducts. A contrast dye is injected into the glands to make them visible on the X-ray. This method is used to detect blockages, inflammation, or conditions such as Sjögren’s syndrome that affect saliva production.

Computed Tomography

Also known as CT or cone beam CT scans, this advanced imaging technology provides three-dimensional (3D) views of internal facial structures. CT scans are often used to evaluate bone structure, facial fractures, tumors, or to precisely plan dental implant placement and complex tooth extractions.

Additional Resources

MedlinePlus
National Institutes of Health
Centers for Disease Control and Prevention
Eunice Kennedy Shriver National Institute of Child Health and Human Development
U.S. Department of Health and Human Services
WebMD