Image Types · Indigo RHS

1The first question

Every image answers one question: how much do you need to see?

Dental radiographs split into two families. Intraoral images put the receptor inside the mouth, right behind the teeth — so they're sharp and detailed, but each one only covers a small area. Extraoral images keep the receptor outside the mouth and shoot through the head — so they cover a lot of ground at once, at the cost of fine detail.

So the whole skill is a trade-off you make on purpose: detail versus coverage. Nail that and the six names below fall into place.

2The instrument

Name the goal. See the right image.

Pick what the dentist is trying to find, and look at a real radiograph of that exact image type — then read why it's the right call.

Which image? — matcher

Fig. 8.1 · interactive

Pick the clinical goal

What that image captures

Bitewing

Real photo pending — a maxillary occlusal is anterior-focused, taken at a steep beam angle. We'll swap in an accurate one.

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3The rule, in one line

Inside the mouth → detail.
Outside the mouth → coverage.

Ask "detail or coverage?" first, and intraoral-vs-extraoral answers itself: intraoral (periapical, bitewing, occlusal) for a close look; extraoral (panoramic, cephalometric, CBCT) for the wide view.

4The six, side by side

Your one-screen reference.

Image

Family

What it shows & when to reach for it

Periapical

Intraoral

The whole tooth — crown to root apex — plus the surrounding bone. Reach for it for abscesses, root fractures, and periapical pathology.

Bitewing

Intraoral

The crowns of upper and lower teeth in one shot, with the crestal bone. The go-to for interproximal decay and bone levels. Shows no root tips.

Occlusal

Intraoral

A larger receptor on the biting surface giving a broad arch view. Locates impacted or extra teeth, salivary stones, and jaw fractures.

Panoramic

Extraoral

One broad image of both jaws, sinuses, and TMJs. Ideal for impacted third molars and whole-mouth surveys; too little detail for decay.

Cephalometric

Extraoral

A lateral view of the skull and facial profile. Used in orthodontics to assess growth and jaw relationships.

CBCT

Extraoral

A 3-D volume of the jaws. Used for implant planning, impactions, and complex TMJ or anatomical assessment.

★ Bonus clip

Cephalometric, up close.

A quick extra look at the lateral skull view — how it's taken and what it's used for.

5See them for real

What each one actually looks like.

Reading the words is one thing — recognizing the picture is what the exam tests. Learn the shape of each view.

Periapical

Intraoral

One or two whole teeth, crown to apex, with the bone around the root tips.

Bitewing

Intraoral

Upper and lower crowns meeting in one shot — built to catch decay between teeth.

Occlusal

Intraoral

Anterior-focused — the front teeth and palate from a steep beam angle, not a full symmetric arch.

Panoramic

Extraoral

Both jaws, sinuses, and joints in one wide sweep — great for impacted molars.

CBCT

Extraoral · 3-D

A rotatable 3-D reconstruction of the jaws — depth a flat film can't show.

Lateral jaw

Extraoral

The side of the mandible — ramus and body — for large lesions and fractures.

6Panoramic positioning

Get the head right, or the pano lies.

The panoramic is the one image where patient position makes or breaks it. Level the Frankfort plane — external auditory meatus to the floor of the orbit — parallel to the floor, then watch for these five. They're exam favorites.

Positioning error

What shows on the pano

The fix

Chin tipped upFrankfort plane angled up

A flat, downturned "reverse smile" (frown); the hard palate shadows over the maxillary roots.

Lower the chin so the plane is level.

Chin tipped downFrankfort plane angled down

An exaggerated smile (deep V); the lower front teeth blur and the condyles can be cut off.

Raise the chin to level the plane.

Tongue not on the palate

A dark radiolucent shadow (trapped air) over the apices of the maxillary teeth.

Press the tongue to the roof of the mouth.

Slumped, not straight

The spine projects a radiopaque column over the anterior teeth.

Sit or stand tall — reach up out of the shoulders.

Too far forward / back

Narrow & blurred anteriors (too far forward) or wide & magnified (too far back).

Bite in the groove so teeth sit in the focal trough.

7Spot it on the exam

DANB describes the clinical goal — you pick the image.

"decay between the teeth"→Bitewing

"root tip / periapical abscess / whole tooth length"→Periapical

"impacted wisdom teeth / whole-mouth survey"→Panoramic

"floor of mouth / salivary stone / locate a tooth"→Occlusal

"orthodontic / facial growth profile"→Cephalometric

"3-D / implant planning"→CBCT

8Check yourself

A dentist needs to check for decay in the contact areas between the upper molars. Which image is the right tool?

Bitewing. It captures the crowns of the upper and lower posterior teeth together — the ideal view for interproximal (between-the-teeth) decay.

8Check yourself

A lower premolar has swelling suggesting an abscess at the root tip. Which single image best shows the apex and the bone around it?

Periapical. It shows the whole tooth to its apex plus the surrounding bone — exactly what a periapical abscess question is after.

8Check yourself

The dentist wants a broad survey of both jaws to evaluate impacted third molars. Which image fits?

Panoramic. One broad extraoral image of both arches, the sinuses, and TMJs — built for whole-mouth surveys and impactions.

Recap

The whole thing in 5 lines.

✓Two families: Intraoral (inside the mouth, more detail) and Extraoral (outside the mouth, more coverage).
✓Ask "detail or coverage?" first — the specific image name follows.
✓Periapical = whole tooth to the apex. Bitewing = crowns, best for decay. Occlusal = broad arch view.
✓Panoramic = both jaws in one sweep. Cephalometric = skull profile for ortho. CBCT = 3-D volume.
✓On a panoramic, level the Frankfort plane — a tipped chin or dropped tongue creates five classic, exam-favorite errors.