INBDE Oral Radiology · Updated October 2026
Radiolucent and Radiopaque Jaw Lesions for the INBDE
Sort every jaw lesion first by how it looks (dark, white or mixed) and where it sits (at the apex, around a crown, between roots or below the canal), then test the tooth. A dark spot at the apex of a non-vital tooth is usually apical periodontitis (a granuloma or radicular cyst); the same spot on a vital tooth points you to cemento-osseous dysplasia, a developmental cyst or a bone cavity instead.
Written by the faculty of The Study Boards: one table per pattern, with the typical patient, the key clue, vitality and the next step.
6radiographic patterns to sort by
4things to describe on every lesion
1test that settles many cases: pulp vitality
0root canals needed for classic COD
How The Study Boards helps you with jaw lesions
- Our faculty-written modules teach radiolucent and radiopaque lesions pattern by pattern, with images, the same way this page sorts them.
- Daily tasks and nightly live tests at 9 PM New York time put these films inside patient cases, so you practise the describe-then-test-vitality routine on the clock.
- The course is extremely personalised: it learns from the way you are studying, and red lines and assignments are given to you on the go when a look-alike pair keeps tripping you up.
- Every explanation is written by US-licensed dentists, and Dr. T and Dr. Kaur are there to assist you.
Step one, every time
How to describe a jaw lesion
Describe a lesion in a fixed order before you name it.1 Tick each box as you look at a film. When every box in a group is ticked, a short note tells you what you have learned.
1. Location
Location done: odontogenic or not?
3. Internal structure
Internal structure done. Often the most useful clue.
4. Effect on neighbours
Neighbours done. Now add age, sex, symptoms and vitality.
Where a lesion sits narrows the list before you look at anything else. Schematic drawn by our faculty, based on the odontogenic versus non-odontogenic rule in Kumar et al.1
The reference tables
Jaw lesions by radiographic pattern
Pick a pattern. Non-vital means the pulp test is negative. Vital means the teeth respond normally.
Periapical and inter-radicular radiolucencies
| Lesion | Typical age and site | Key radiographic clue | Vitality | Next step |
|---|---|---|---|---|
| Apical periodontitis (periapical granuloma or radicular cyst) | Any adult; peak 3rd to 5th decade.1 | Dark area at the apex, continuous with the PDL space; lamina dura lost at the apex. A thin sclerotic rim suggests a cyst, but only histology separates cyst from granuloma.116 | Non-vital4 | Root canal treatment or extraction; biopsy if it does not heal.16 |
| Residual cyst | Adult, at an old extraction site. | Well-defined, thin sclerotic rim, tooth missing above it; usually under 1 cm.1 | No tooth | Enucleate and send for histology.16 |
| Early periapical cemento-osseous dysplasia (COD) | Middle-aged women, mostly of African descent; apices of mandibular incisors.5 | Round dark area at the apex that later fills in with white; often several teeth.6 | Vital5 | No treatment, periodic radiographs. Do not start endo on a vital tooth.6 |
| Lateral periodontal cyst | Adults, 5th to 7th decade (mean 52); mandibular premolar area, then anterior maxilla.11 | Small round or teardrop dark area along the side of a root.11 | Vital11 | Enucleation, usually without harming the adjacent teeth.11 |
| Nasopalatine duct (incisive canal) cyst | Men, 4th to 6th decade; midline anterior maxilla.12 | Round, oval or heart-shaped corticated midline lesion above the central incisor roots, pushing them apart. A canal wider than 6 mm raises suspicion.112 | Vital, lamina dura kept1 | Test the incisors to rule out a radicular cyst; enucleate if symptomatic.112 |
| Simple (traumatic) bone cyst | Under 20, female predominance; posterior mandible.1 | Empty cavity with no lining that scallops up between the roots; roots rarely resorbed.118 | Test every tooth: the cavity is not of pulpal origin | Curettage; surgery also confirms it.1 |
| Stafne bone defect | Older men (mean age 61 in a 91-case series); near the angle.13 | Oval, well-defined, sclerotic-rimmed lucency below the mandibular canal; a lingual dent caused by the submandibular gland.113 | Not tooth-related | No treatment; it is an incidental finding.1 |
Pericoronal radiolucencies (around the crown of an unerupted tooth)
| Lesion | Typical age and site | Key radiographic clue | Vitality | Next step |
|---|---|---|---|---|
| Dentigerous cyst | 2nd and 3rd decades; mandibular third molar (65%), then maxillary canine.2 | Unilocular, well-defined; attaches at the CEJ with the crown inside and the roots outside. The space should be at least 3 to 4 mm.12 | Unerupted tooth | Remove the tooth and enucleate the cyst; histology rules out a mural ameloblastoma.1 |
| Odontogenic keratocyst (OKC) | 2nd to 4th decade; posterior body and ramus; mandible to maxilla 5:1.12 | Scalloped, corticated; grows along the length of the jaw with little expansion. A large one can envelop the whole tooth, roots included.1 | Unerupted tooth in about 27%2 | Biopsy. Treated by enucleation with a bony margin; it recurs. Multiple OKCs: think Gorlin (nevoid basal cell carcinoma) syndrome.1 |
| Unicystic ameloblastoma | Mean age 25; about half in the 2nd decade; over 90% posterior mandible.2 | Looks like a dentigerous cyst around a third molar crown; may have a solid nodule in the wall.12 | Unerupted tooth in 50 to 80%2 | Biopsy; the diagnosis is made under the microscope. |
| Adenomatoid odontogenic tumor (AOT) | Mean age 17; about 2:1 female; 90% anterior jaws; impacted maxillary canine in 40 to 60%.2 | Corticated unilocular lucency around the crown and often part of the root; fine radiopaque foci in two-thirds.214 | Unerupted tooth | Conservative enucleation; recurrence is exceptionally rare.14 |
| Ameloblastic fibroma | Mean age 15; over 70% under 20; mandibular premolar and molar area.2 | Well-defined pericoronal lucency, small unilocular to large multilocular.2 | Unerupted tooth in 75%2 | Biopsy. |
Multilocular radiolucencies
| Lesion | Typical age and site | Key radiographic clue | Vitality | Next step |
|---|---|---|---|---|
| Ameloblastoma (conventional) | Adults (peak 3rd to 5th decades); over 80% mandible, 70% molar-ramus.2 | Soap bubble (large locules) or honeycomb (small locules); marked bucco-lingual expansion; root resorption.12 | Teeth may be displaced or resorbed | Biopsy, then surgical resection and long follow-up; recurrence is high.1 |
| Central giant cell granuloma | Young women, 2nd and 3rd decades; anterior jaws, tends to cross the midline.1 | Expansile, multilocular, honeycomb septa; may displace or resorb teeth.1 | Teeth may be displaced | Biopsy; check laboratory values, because the brown tumor of hyperparathyroidism looks identical.1 |
| Odontogenic myxoma | Young adults, 2nd and 3rd decades.15 | Thin straight septa forming a “tennis racket” pattern; also soap bubble.315 | Not a pulpal lesion | Biopsy; recurs often after conservative surgery.15 |
| Intraosseous venous malformation (“hemangioma”) | Women, 2nd to 5th decade; body of mandible.1 | Variable: honeycomb, soap bubble or sunburst.1 | Teeth may be mobile | Needle aspiration before any biopsy; it can bleed catastrophically.1 |
| Cherubism | Children; bilateral, symmetrical; ramus and tuberosity, condyle spared.3 | Bilateral expansile multilocular lucencies with dental derangement.3 | Developing teeth displaced | Grows until puberty, then gradually regresses.3 |
Ill-defined, moth-eaten or permeative radiolucencies
Treat these as urgent until proven otherwiseIll-defined margins, cortical destruction, a soft-tissue mass or a periosteal reaction suggest infection or malignancy.1
| Lesion | Typical age and site | Key radiographic clue | Vitality | Next step |
|---|---|---|---|---|
| Osteomyelitis | Mandible more than maxilla; after dental infection, trauma or surgery.1 | Changes appear only 1 to 2 weeks after onset; ill-defined lysis, periosteal reaction; a sequestrum (dense dead bone) in chronic cases.1 | Often a non-vital source tooth | Antibiotics and surgical debridement.1 |
| MRONJ and osteoradionecrosis | MRONJ: antiresorptive or antiangiogenic drugs, no jaw radiation. Osteoradionecrosis: after head and neck radiation.1 | Exposed bone (MRONJ: for more than 8 weeks); ill-defined lysis and sclerosis, later sequestra or fracture.1 | Not a pulpal lesion | Mainly conservative: oral care, treat infection, control pain; surgery only if non-responsive.1 |
| Squamous cell carcinoma invading bone | Men over 50.1 | Ill-defined lysis next to a soft-tissue mass; may involve the canal and cause paresthesia.1 | Not a pulpal lesion | Urgent biopsy and referral. |
| Metastasis | Patients with a known or hidden cancer; posterior body and angle of mandible; primaries such as lung, prostate, kidney, breast.1 | Ill-defined lysis without periosteal reaction; prostate can give sclerotic deposits. May be the first sign of cancer.1 | Not a pulpal lesion | Urgent biopsy. |
| Multiple myeloma | Adults; the jaw lesion may be one of several bone lesions. | Punched-out lucencies with no sclerotic rim, or permeative destruction.1 | Not a pulpal lesion | Biopsy and medical referral. |
| Langerhans cell histiocytosis | Children and adolescents.1 | Alveolar bone destroyed around the roots: “floating teeth” or a “scooped-out” crest.1 | Teeth loose | Biopsy, then treatment by extent.1 |
| Osteosarcoma (lytic form) | Jaw cases mostly 30 to 40 years; posterior mandible.3 | Symmetrical widening of the PDL space may be the earliest sign.3 | Not a pulpal lesion | Urgent biopsy. |
Mixed radiolucent-radiopaque lesions
| Lesion | Typical age and site | Key radiographic clue | Vitality | Next step |
|---|---|---|---|---|
| Cemento-osseous dysplasia (periapical, focal, florid) | Middle-aged women; periapical type at mandibular incisors, focal at one posterior tooth, florid in several quadrants.5 | Matures from dark, to mixed, to white with a thin dark rim at the apices.6 | Vital5 | No treatment, periodic review. Pain or a non-healing extraction socket usually means secondary osteomyelitis.56 |
| Cemento-ossifying fibroma | 3rd and 4th decades; about 5:1 female; posterior mandible.10 | Well-demarcated and expansile; often pushes roots apart, unlike COD.35 | Not a pulpal lesion | Biopsy, then removal: unlike COD it is a neoplasm with real growth potential.10 |
| Fibrous dysplasia | Childhood and adolescence; maxilla favoured. Polyostotic form with McCune-Albright syndrome.310 | Ground-glass bone with ill-defined borders that blend into normal bone; expands along the bone; does not displace teeth.3 | Not a pulpal lesion | Biopsy confirms it.10 |
| Calcifying epithelial odontogenic tumor (Pindborg) | Mean age 37; mandibular molar region.2 | Mixed in 65%; radiopacities close to the crown of an unerupted tooth are the characteristic sign.2 | Unerupted tooth in 52 to 60%2 | Biopsy. |
| Calcifying odontogenic cyst | Wide age range; about 65% near incisors and canines.2 | Well-defined lucency with small irregular calcified bodies.2 | Sometimes an unerupted canine | Biopsy. |
| Ameloblastic fibro-odontoma | Mostly 9 to 11 years; molar region.2 | Well-demarcated lucency with irregular opaque material, over an unerupted tooth.2 | Unerupted tooth | Biopsy. |
| Osteosarcoma (sclerotic or mixed) | 30 to 40 years; posterior mandible.3 | Sunburst spicules with cortical destruction; the sunburst is not always present in the jaws.317 | Not a pulpal lesion | Urgent biopsy. |
Periapical cemento-osseous dysplasia at the apex of a sound mandibular anterior tooth: panoramic view and cross-sections.
Image: Silva BSF et al., Brazilian Oral Research 2017, via Wikimedia Commons, licence CC BY 4.0.
Radiopaque lesions
| Lesion | Typical age and site | Key radiographic clue | Vitality | Next step |
|---|---|---|---|---|
| Condensing osteitis | Apex of a tooth with deep caries or a large restoration; mandibular second premolar and first molar most often.8 | Diffuse opacity at the apex: a bony reaction to low-grade inflammation. It can sit with apical periodontitis on the same tooth.48 | Non-vital or inflamed pulp5 | Treat the pulp (usually root canal treatment); the opacity may then regress partly or fully.4 |
| Idiopathic osteosclerosis (dense bone island) | 2nd to 4th decade; mandibular premolar and molar region, about 95% mandible.7 | Dense, homogeneous opacity with no dark halo and no thickened lamina dura; can sit at the apex, between roots or apart from the teeth.7 | Vital, healthy untreated teeth7 | No treatment; record and follow.7 |
| Mature cemento-osseous dysplasia | Middle-aged women; mandible.5 | White mass at the apex with a thin dark rim; often several teeth.6 | Vital5 | No treatment, periodic review.6 |
| Hypercementosis | Adults; idiopathic, or with occlusal trauma, an unopposed tooth, or Paget disease.5 | Bulbous root that follows the root outline; the PDL space still runs around it.5 | Not a pulpal lesion | No treatment. If many teeth are affected, consider a systemic cause such as Paget disease.5 |
| Cementoblastoma | Young: about half under 20, three-quarters under 30; mandibular first molar.9 | Round opaque mass fused to the root, with a dark rim; the root outline is lost.59 | Vital9 | Surgical excision, even if painless, because it keeps growing; usually with the tooth.59 |
| Compound odontoma | 2nd decade; anterior maxilla.2 | Cluster of small tooth-like denticles in a dark halo; often blocks eruption.23 | Neighbouring teeth may be affected | Enucleation, which is simple because odontomas are encapsulated.19 |
| Complex odontoma | 2nd decade; posterior jaws.2 | Amorphous dense mass with a dark halo, often over an unerupted molar; the halo separates it from an osteoma.3 | Associated tooth often unerupted | Enucleation.19 |
| Torus or exostosis | Any adult. | Dense opacity over the roots that matches a bony bump you can see and feel in the mouth.5 | Not a pulpal lesion | None; confirm clinically.5 |
Sitting the DLOSCE instead?
The same radiology content, taught with images inside patient cases, sits inside our DLOSCE course for licensure candidates.
The most tested comparison
Five white spots at the apex, side by side
Five lesions make a white area near a root. Two questions sort them: is the tooth vital, and where is the PDL space?
Schematic drawn by our faculty from the features described in the AAE diagnostic terms and the cited reviews.4579 Darker grey here stands for denser (whiter on a film) bone.
Where marks are lost
Look-alike pairs and how to split them
| Pair | The deciding clue |
|---|---|
| Dentigerous cyst vs OKC vs unicystic ameloblastoma | A dentigerous cyst attaches at the CEJ with the roots outside. An OKC can envelop the whole tooth and grows lengthwise. A unicystic ameloblastoma can look identical, so all three need histology.12 |
| AOT vs dentigerous cyst | AOT often covers part of the root as well as the crown, is usually anterior (canine), and two-thirds show fine opaque flecks.214 |
| Fibrous dysplasia vs ossifying fibroma | Fibrous dysplasia blends into normal bone and does not move teeth. Ossifying fibroma has a clear border and pushes roots apart.35 |
| Nasopalatine duct cyst vs large incisive foramen | A normal foramen is usually under 6 mm; above that, suspect a cyst. Check incisor vitality to rule out a radicular cyst.12 |
Landmarks cause the other half of misreads: the mental foramen and incisive canal sit right next to apices. Our companion guide on normal radiographic anatomy for the INBDE shows how to tell them apart from real lesions.
Check yourself
Three quick questions
Original questions by our faculty, not real exam items.
A 47-year-old woman has well-defined periapical radiolucencies at the apices of teeth #24 and #25. Both teeth have no caries or restorations and respond normally to cold and electric pulp testing.
What is the best management?
ARoot canal treatment of #24 and #25
BPeriodic clinical and radiographic review
CExtraction and curettage
DAntibiotics for 7 days, then re-image
A 16-year-old girl has an unerupted maxillary canine. The radiograph shows a corticated unilocular radiolucency around the crown and the upper part of the root, with fine radiopaque flecks inside.
What is the most likely diagnosis?
ADentigerous cyst
BAdenomatoid odontogenic tumor
CAmeloblastoma
DOdontogenic keratocyst
A 19-year-old man has intermittent pain near #30, which tests vital. The film shows a round radiopaque mass fused to the distal root, with a thin radiolucent rim, and the root outline is lost.
What is the next step?
ARoot canal treatment of #30
BNo treatment; review in 12 months
CSurgical excision of the mass, usually with the tooth
DPrescribe an antibiotic
We teach the INBDE
How to prepare: our full plan
Radiology is one slice of the exam. Here is the rest of the plan.
INBDE
The Study Boards INBDE courseBuilt by US-licensed dentists:
- 12 sequenced course sections and 35,000+ focused questions
- Master Files, Master Test Series and 8-hour Grand Test mock exams
- A surprise live test every night at 9 PM New York time
- Students who complete the course pass on their first attempt 99% of the time
Plan
Build your own scheduleFit radiology into a full plan:
- The month-by-month INBDE study plan
- INBDE study materials that are worth your time
- Free INBDE practice questions
- Sitting the DLOSCE instead? See the DLOSCE course blueprint
Quick answers
Frequently asked questions
What is the most common radiolucent lesion of the jaw?
The radicular (periapical) cyst is the most common odontogenic cyst, and it sits at the apex of a non-vital tooth. The dentigerous cyst is the most common developmental (non-inflammatory) cyst of the jaws.1
What are the common radiopaque lesions of the jaw?
At the apex: condensing osteitis, idiopathic osteosclerosis, mature cemento-osseous dysplasia, hypercementosis and cementoblastoma. Away from the apex: odontomas, tori and exostoses.5
How do you tell condensing osteitis from idiopathic osteosclerosis?
How does The Study Boards help you prepare for oral radiology on the INBDE?
Our INBDE course teaches radiographic diagnosis inside patient cases, tests it in timed practice and nightly live tests, and gives you explanations from US-licensed dentists. See the INBDE course blueprint for every section.
Normal radiographic anatomy for the INBDELandmarks that mimic lesions High-yield conditions for the INBDEWhat to know across subjects How the INBDE is scoredThe 75 standard and pass rates Oral and maxillofacial radiology residencyFor dentists who love this subject
Stuck on a film? Ask us.
Our Admin Team with Dr. T and Dr. Kaur will contact you over WhatsApp.
References
- Kumar J, et al. Radiolucent Jaw Lesions: Imaging Approach. Indian J Radiol Imaging. 2021. PMC8299495
- Mortazavi H, Baharvand M. Jaw lesions associated with impacted tooth: a radiographic diagnostic guide. Imaging Sci Dent. 2016. PMC5035719
- Sahu B, et al. A Pattern-based Imaging Approach to Pediatric Jaw Lesions. Indian J Radiol Imaging. 2021. PMC8299508
- American Association of Endodontists. Endodontic Diagnosis. Endodontics: Colleagues for Excellence, Fall 2013 (definitions of apical periodontitis and condensing osteitis). aae.org
- Decolibus K, et al. Cemento-Osseous Dysplasia of the Jaw: Demographic and Clinical Analysis of 191 New Cases. Dent J (Basel). 2023. PMC10217321
- Huh JK, Shin SJ. Misdiagnosis of florid cemento-osseous dysplasia leading to unnecessary root canal treatment. Restor Dent Endod. 2013. PMC3761125
- Nahuincopa Lopez PM, Romero Rodriguez LM. An updated review of idiopathic osteosclerosis of the jaws. Rev Cient Odontol (Lima). 2021. PMC10919836
- Farhadi F, et al. Frequency and pattern of idiopathic osteosclerosis and condensing osteitis lesions in panoramic radiography. Dent Res J (Isfahan). 2016. PMC4993059
- Huber AR, Folk GS. Cementoblastoma. Head Neck Pathol. 2009. PMC2715464
- Pick E, et al. Clinical, Radiological, and Pathological Diagnosis of Fibro-Osseous Lesions of the Oral and Maxillofacial Region. Diagnostics (Basel). 2022. PMC8870765
- de Carvalho LF, et al. Lateral periodontal cyst: a case report and literature review. J Oral Maxillofac Res. 2011. PMC3886068
- Lake S, et al. The Incisive Canal: A Comprehensive Review. Cureus. 2018. PMC6166911
- Hisatomi M, et al. Stafne bone defects radiographic features in panoramic radiographs: assessment of 91 cases. Med Oral Patol Oral Cir Bucal. 2019. PMC6344010
- Handschel JG, et al. Adenomatoid odontogenic tumor of the mandible: review of the literature and report of a rare case. Head Face Med. 2005. PMC1266042
- Francisco AL, et al. Clinicopathologic analysis of 14 cases of odontogenic myxoma and review of the literature. J Clin Exp Dent. 2017. PMC5410678
- Karamifar K, et al. Endodontic Periapical Lesion: An Overview on the Etiology, Diagnosis and Current Treatment Modalities. Eur Endod J. 2020. PMC7398993
- Nthumba PM. Osteosarcoma of the jaws: a review of literature and a case report. World J Surg Oncol. 2012. PMC3502285
- Hs CB, et al. Simple bone cyst of mandible mimicking periapical cyst. Clin Pract. 2012. PMC3981309
- Khalifa C, et al. Compound-complex odontoma: a rare case report. Clin Case Rep. 2022. PMC8978784
Current as of October 2026. Educational content for exam preparation; it does not replace a radiologist’s report or a biopsy. The quiz questions above are original and are not real exam items.