International consensus on osteoradionecrosis of the jaw-2025

This is a detailed teaching summary: International consensus on osteoradionecrosis of the jaw

Article at a glance

Title: International Expert-Based Consensus Definition, Classification Criteria, and Minimum Data Elements for Osteoradionecrosis of the Jaw: An Interdisciplinary Modified Delphi Study
Authors: Moreno et al., representing the international ORAL Consortium
Journal: International Journal of Radiation Oncology, Biology, Physics, 2025;122(2):341–354
Study design: International, interdisciplinary modified Delphi consensus study
Participants: 69 experts in radiation oncology, oral medicine, dentistry, oral and maxillofacial surgery, head-and-neck surgery, medical oncology, and related fields
Primary purpose: To create a standardized definition of osteoradionecrosis of the jaw (ORNJ) and identify the minimum information needed to diagnose, classify, monitor, and report it consistently. Full article and PubMed record.

The one-sentence message

The article argues that ORNJ should be recognized from a combination of clinical and radiographic evidence—not only persistent exposed bone—and that clinicians should record a small, standardized set of findings so disease severity can be compared reliably across specialties and institutions.

1. What clinical problem does the article address?

Osteoradionecrosis of the jaw is a late complication of therapeutic head-and-neck irradiation. Radiation damages bone, its microvasculature, and surrounding soft tissue. The resulting tissue becomes hypovascular, biologically impaired, and less able to remodel or heal after trauma.

Patients may develop:

Nonhealing oral mucosal ulceration
Exposed or sequestrating bone
Pain
Dental instability or tooth loss
Infection or purulent drainage
Trismus
Impaired mastication, swallowing, and speech
Orocutaneous, oroantral, or oronasal fistulas
Pathologic fracture in advanced disease

The authors note that reported ORNJ incidence has generally ranged from approximately 5% to 15% among head-and-neck cancer survivors, although the true rate is difficult to establish because previous studies have not used a common definition.

Why the historical approach is problematic

Before this work, the literature contained:

More than nine definitions of ORNJ
At least 16 staging or classification systems
Different minimum durations of bone exposure—often three months
Variable requirements for excluding infection
Variable emphasis on clinical examination versus imaging
Systems that classify disease by the treatment given rather than by its actual phenotype

This creates several problems:

The same patient may be diagnosed or staged differently by different clinicians.
Early radiographic disease may be missed if exposed bone is required.
Studies cannot reliably compare incidence, severity, or treatment outcomes.
Electronic records do not contain consistent data for research or quality improvement.
Multicenter trials and predictive models become difficult to construct.
Communication between oncology, dental, radiology, and surgical teams is unreliable.

When the experts applied 14 existing systems to standardized cases, they were sometimes unable to classify as many as 76% of cases. This was powerful evidence that the problem lies partly in the classification systems themselves.

2. What did the investigators do?

The investigators formed the Orodental Radiotherapy-Associated Late-Effects Consortium, or ORAL Consortium.

They invited 75 experts, including authors of existing ORNJ classification systems. Sixty-nine participated in at least one survey.

Using a web-based modified Delphi process, the experts underwent several iterative rounds in which they:

Reviewed existing definitions and terminology
Examined established classification systems
Identified important clinical and imaging features
Considered difficult diagnostic questions, such as whether exposed bone must persist for a defined period
Classified written clinical scenarios
Classified cases containing clinical photographs and imaging
Reviewed anonymized group responses after each round
Reconsidered areas of disagreement
Developed consensus statements and minimum data elements

The process was aligned with the ACCORD reporting standard for consensus studies.

What is a modified Delphi study?

A Delphi study is a structured method for developing expert consensus through repeated rounds of questioning and feedback.

It is valuable when:

Clinical evidence is incomplete
Terminology varies
Multiple specialties approach a condition differently
A standardized framework is needed

However, it produces expert consensus, not the same level of evidence as prospective diagnostic validation or a randomized clinical trial.

3. The proposed consensus definition of ORNJ

The consortium reached high consensus—reported as 86%—on the following conceptual definition:

ORNJ is bone death caused by loss of blood flow after exposure to ionizing radiation. Bone death may be demonstrated clinically and/or radiographically, occurs sometime after radiation, and is present without active cancer at the affected site.

In practical clinical language:

ORNJ is necrosis of previously irradiated jawbone, demonstrated clinically or radiographically, when active malignancy at that site is not responsible for the abnormality.

Essential components

The definition contains four central ideas:

It is a disorder of bone.
It is caused by ionizing radiation.
It involves vascular insufficiency or loss of blood flow leading to bone death.
There is no active local malignancy explaining the affected bone.

Important changes from older definitions

Exposed bone is not mandatory

Radiographic evidence can support a diagnosis even if the oral mucosa remains intact. Examples include:

Osteolysis
Sclerosis
Cortical erosion or thinning
Pathologic fracture
Other convincing abnormalities in previously irradiated bone

This is one of the article’s most important messages. ORNJ can exist before bone becomes visibly exposed.

No mandatory three-month waiting period

Older definitions often required exposed bone to remain unhealed for at least three months. The consortium rejected a compulsory duration.

Waiting for an arbitrary time threshold can:

Delay diagnosis
Underestimate disease
Prevent recognition of rapidly progressive cases
Create an artificial distinction between clinically similar patients

Serial documentation remains important, but duration is not an obligatory diagnostic gate.

Infection does not exclude ORNJ

Osteomyelitis or local inflammation may coexist with radiation-induced necrosis. Infection can be secondary to devitalized bone rather than an alternative explanation.

Therefore:

Infection should be identified and treated when present.
Its presence does not automatically rule out ORNJ.

Active malignancy must still be considered

Recurrent or persistent cancer can mimic ORNJ clinically and radiographically. When findings are suspicious or atypical, clinicians may need:

Cross-sectional imaging
Review of the radiation field and cancer history
Multidisciplinary assessment
Biopsy when clinically appropriate

“Not active malignancy” is therefore a key diagnostic safeguard.

4. Proposed clinical spectrum

The experts considered ORNJ as a spectrum:

Not ORNJ or not an ORNJ precursor
Precursor or stage 0
Early ORNJ
Intermediate ORNJ
Advanced ORNJ

The article’s deeper contribution is not simply a new set of labels. It identifies the observable features that should drive classification.

5. How to understand the stages

A. Not an ORNJ precursor

An abnormality in an irradiated patient is not automatically ORNJ.

For example, a negative probe-to-bone test with only a periosteal reaction confined to the alveolar bone was ultimately considered more likely unrelated to ORNJ than a true precursor state.

Interns should avoid anchoring on radiation history alone. Differential diagnoses include:

Recurrent malignancy
Dental or periodontal infection
Routine post-extraction remodeling
Traumatic ulceration
Odontogenic osteomyelitis
Medication-related osteonecrosis
Metastatic or primary bone disease

B. Precursor disease or stage 0

This category captures evidence of radiation-associated bone injury before unequivocal clinical ORNJ.

Examples supported by the consensus process included:

Intact mucosa with abnormal imaging confined to alveolar bone
Negative probe-to-bone testing with imaging abnormalities other than an isolated periosteal reaction
MRI evidence of vascular damage without exposed bone
MRI vascular changes plus other imaging abnormalities limited to alveolar bone
Possibly minor superficial bone spicules, although experts showed meaningful disagreement about this feature

This category is valuable because it encourages surveillance before destructive complications appear.

C. Early ORNJ

A positive probe-to-bone test combined with imaging abnormalities limited to alveolar bone was generally considered early ORNJ.

A positive probe-to-bone test means that a probe passed through an ulcer, periodontal pocket, or fistulous tract contacts bone.

Important points:

It can identify disease when bone is not visibly exposed.
The test result must be interpreted alongside imaging and mucosal findings.
A standardized positive or negative result should be documented.

Other clinical evidence of limited necrotic or exposed bone may also fit early disease, depending on imaging depth and associated findings.

D. Intermediate ORNJ

Intermediate disease is broadly characterized by more extensive osseous involvement—particularly extension beyond the alveolar bone or toward the basal jaw—but without the defining catastrophic complications of advanced disease.

The clinically important distinction is anatomical depth:

Alveolar bone involvement suggests earlier disease.
Extension below or beyond alveolar bone into basal bone represents greater severity.

This is why reporting merely “sclerosis present” is insufficient. The location and extent of sclerosis matter.

E. Advanced ORNJ

The consortium agreed that ORNJ should be categorized as advanced when previously irradiated bone is associated with:

Pathologic fracture
Orocutaneous fistula
Oroantral fistula
Oronasal fistula

These are individually stage-defining complications and should be recorded separately rather than collapsed into a generic “advanced disease” label.

A patient can, for example, have both a pathologic fracture and an orocutaneous fistula. Recording both preserves clinically meaningful information.

6. The nine minimum data elements

The authors recommend collecting a small set of standardized, “atomic” clinical and radiographic observations at serial dental and oncology visits.

“Atomic” means recording each finding separately instead of burying several observations in free-text prose.

1. Date of assessment

ORNJ changes over time. Every set of findings needs a date so clinicians can determine:

Onset
Persistence
Progression
Resolution
Relationship to treatment or dental procedures

2. Minor bone spicules

Record whether small mobile or superficial bone spicules are present.

These may be:

Benign superficial sequestra
A precursor state
Early ORNJ

Because experts disagreed about their significance, they should be documented explicitly rather than assumed to establish a stage.

3. Length of exposed bone in millimetres

Avoid vague descriptions such as “small area” or “significant exposure.”

Measure and document the visible exposed bone, ideally with:

A millimetre measurement
Serial clinical photographs
Consistent anatomic orientation

This permits objective follow-up.

4. Mucosal status

Record whether the mucosa is:

Intact
Ulcerated
Associated with visible bone exposure

Intact mucosa does not exclude ORNJ, but it changes how clinical and imaging findings are interpreted.

5. Probe-to-bone test result

Record it explicitly as:

Positive
Negative
Not performed, if applicable

The test is especially important when bone is not directly visible.

6. Specific associated disorders or complications

Document each separately:

Oral mucosal ulceration
Orocutaneous fistula
Oroantral fistula
Oronasal fistula
Pathologic fracture

The latter four complications may define advanced disease.

7. Imaging modality

Record the type of imaging used, such as:

Panoramic radiography
CT
Cone-beam CT
MRI
PET/CT, where relevant

The imaging technique affects sensitivity and what abnormalities can be evaluated.

8. Radiographic morphology

Record each abnormal morphology separately, including:

Bony sclerosis
Osteolysis
Bony erosion
Cortical thinning
Pathologic fracture
Other relevant features such as periosteal reaction

Do not use “abnormal imaging” as the entire report.

9. Vertical extent relative to alveolar bone

Document whether the abnormality is:

Confined within or above the alveolar bone, or
Extending beyond or below the alveolar bone into basal bone

This anatomical boundary is a major marker of disease severity.

7. A practical assessment framework for interns

When assessing a patient who has received head-and-neck radiotherapy, use the following sequence.

Step 1: Establish the radiation context

Ask:

What cancer was treated?
When was radiotherapy completed?
Which jaw region was in the radiation field?
What dose was delivered to the involved bone, if available?
Was there reirradiation?
Were teeth extracted before or after radiotherapy?
Was there recent dental trauma, implant placement, or surgery?

ORNJ can occur months or years after treatment; absence of a recent dental procedure does not exclude it.

Step 2: Assess symptoms

Ask about:

Pain
Swelling
Nonhealing ulcer
Exposed or rough bone
Drainage or bad taste
Tooth mobility
Trismus
Numbness or altered sensation
Difficulty chewing or swallowing
Changes in facial contour
Skin drainage

Symptoms describe burden but are not, by themselves, sufficient to determine anatomical severity.

Step 3: Examine systematically

Record:

Exact anatomic location
Mucosal integrity
Ulceration
Visible bone exposure
Length of exposed bone in millimetres
Minor bone spicules
Purulence
Tooth and periodontal status
Fistula formation
Probe-to-bone result
Trismus and functional impairment

Step 4: Review imaging

Look for:

Sclerosis
Lysis
Cortical erosion
Cortical thinning
Sequestration
Periosteal reaction
Failure of an extraction socket to fill
Pathologic fracture
Extent within versus beyond the alveolar bone
Maxillary sinus involvement
Soft-tissue or fistulous extension

Cross-sectional imaging is especially important when clinical findings underestimate the depth of bone involvement.

Step 5: Exclude major mimics

Always consider:

Recurrent cancer
Primary odontogenic infection
Non-radiation osteomyelitis
Medication-related osteonecrosis of the jaw
Traumatic bone exposure
Metastatic disease

Step 6: Describe the phenotype before assigning a stage

A strong clinical note should say what is actually present:

Intact mucosa over the left posterior mandible; probe-to-bone test negative; CT demonstrates mixed sclerosis and osteolysis confined to alveolar bone; no fracture or fistula.

That is more useful than writing only “possible stage 0 ORNJ.”

8. Example cases for teaching

Case 1: Radiographic precursor disease

A patient completed mandibular radiotherapy 18 months ago. The mucosa is intact and there is no visible exposed bone. CT shows focal sclerosis and osteolysis confined to the alveolar process.

Interpretation: This can represent precursor/stage 0 disease. Exposed bone is not required.

Teaching point: Do not equate intact mucosa with normal bone.

Case 2: Early ORNJ

A patient has a small ulcer over irradiated mandibular alveolar bone. No bone is visibly exposed, but the probe-to-bone test is positive. Imaging abnormalities remain confined to alveolar bone.

Interpretation: The probe-to-bone result upstages the finding toward early ORNJ.

Teaching point: A positive probe-to-bone test is clinically meaningful even when bone is not directly visible.

Case 3: Intermediate disease

A patient has exposed mandibular bone, and CT shows osteolysis extending below the alveolar region into basal bone. There is no fracture or fistula.

Interpretation: More extensive, intermediate ORNJ.

Teaching point: The depth of radiographic involvement matters more than exposed surface size alone.

Case 4: Advanced ORNJ

A head-and-neck cancer survivor develops facial drainage. CT demonstrates necrotic irradiated mandibular bone and an orocutaneous fistula.

Interpretation: Advanced ORNJ.

Teaching point: Fistula formation and pathologic fracture are stage-defining complications.

9. What the study found about clinician agreement

Experts did not always agree, especially in borderline cases.

Important areas of disagreement included:

Minor bone spicules
The boundary between precursor and early disease
Advanced osseous involvement without fracture or fistula
Interpretation of isolated periosteal reactions
Differences between clinical photographs and written descriptions

Agreement was generally better for:

Precursor/stage 0 disease
Early ORNJ
Intermediate ORNJ
Advanced disease with obvious fistula or fracture

The disagreement is educationally important. It demonstrates why structured measurements and imaging descriptions are more reliable than gestalt impressions.

The study also found specialty-related differences. Radiation oncologists, surgeons, and dental specialists sometimes interpreted the same combinations differently. The minimum-data approach is meant to create a common language across these disciplines.

10. Relationship to CTCAE and other classification systems

The Common Terminology Criteria for Adverse Events, or CTCAE, remains useful for oncology toxicity reporting. However, the panel concluded that it is not detailed enough to replace a disease-specific ORNJ classification system.

The article’s position is:

CTCAE can be used in parallel for general toxicity reporting.
It should not replace explicit documentation of clinical and radiographic ORNJ features.

Likewise, older systems such as Notani may still offer useful anatomical shorthand, but they do not capture the complete range of precursor, clinical, and imaging findings proposed here.

11. Strengths of the study

Large, international, multidisciplinary panel
Inclusion of authors who developed previous ORNJ classifications
Iterative assessment rather than a single survey
Use of written and image-based clinical cases
Explicit attention to difficult borderline presentations
Alignment with SNOMED-CT terminology
Standardized minimum elements suitable for electronic records
Compliance with a formal consensus-reporting framework
Recognition of radiographic-only and precursor disease

12. Limitations and cautions

Expert consensus is not prospective validation

The classifications reflect expert agreement. They still need validation against:

Natural history
Histopathology where appropriate
Disease progression
Treatment response
Patient-reported outcomes
Surgical outcomes
Interobserver performance in routine practice

The panel was not a population-based sample

Participants were selected experts, and no patients participated. Community clinicians or patients may prioritize different features.

Borderline features remained difficult

Minor bone spicules and some imaging-only abnormalities did not produce uniform agreement. They should prompt surveillance and documentation, not automatic irreversible treatment.

The framework is primarily diagnostic and descriptive

This article does not establish which treatment is best for each category. It should not be read as a therapeutic trial or a complete management guideline.

Imaging interpretation needs additional standardization

Terms such as sclerosis or erosion can be read differently. The authors are working toward standardized radiology definitions and a machine-readable ORNJ ontology.

Absence of a mandatory time threshold has consequences

Removing the three-month requirement supports earlier recognition, but it may reduce specificity if transient traumatic exposure is mislabeled. Serial assessment and careful differential diagnosis remain essential.

13. Clinical implications

The article changes the mental model from:

“ORNJ equals bone exposed for three months after radiation”

to:

“ORNJ is a spectrum of radiation-associated jawbone necrosis identified through clinical and/or radiographic evidence, after excluding active local malignancy.”

Its practical implications are:

Diagnose from the whole clinical-radiographic picture.
Do not wait three months merely to satisfy an old definition.
Do not require visibly exposed bone.
Do not rule out ORNJ because infection is present.
Always consider recurrent malignancy.
Measure exposed bone rather than describing it vaguely.
Record probe-to-bone findings.
Report the imaging morphology and anatomical depth.
Record fracture and each type of fistula separately.
Reassess serially using the same data elements.
Discuss complex cases in a multidisciplinary setting.

14. Suggested intern teaching script

“After head-and-neck radiotherapy, jawbone injury can develop because radiation impairs vascular supply and the bone’s ability to remodel and heal. Historically, osteoradionecrosis was often defined as exposed bone persisting for three months. This international consensus argues that definition is too narrow. ORNJ may be detected radiographically before bone becomes exposed, and clinicians should not have to wait for an arbitrary duration. The key requirements are evidence of bone death in previously irradiated jawbone and absence of active cancer at that site. Severity is judged using clinical findings, imaging morphology, depth of involvement, and major complications. A fracture or oro-facial fistula represents advanced disease. The most important habit is to document specific findings—mucosal status, exposed-bone measurement, probe-to-bone result, imaging changes, anatomical extent, fistulas, and fracture—rather than simply writing ‘ORN present.’”

15. Take-home points for interns

ORNJ is radiation-associated bone death, not merely an area of exposed bone.
Clinical or radiographic evidence can establish the phenotype.
Intact mucosa does not exclude early or precursor disease.
A mandatory three-month exposure period is not required.
Infection can coexist with ORNJ and does not automatically exclude it.
Active local malignancy remains an essential alternative diagnosis.
A positive probe-to-bone test may reveal disease without visible bone exposure.
Anatomical depth on imaging is central to severity assessment.
Pathologic fracture and oro-facial fistulas indicate advanced disease.
Standardized serial documentation is the article’s most immediately actionable recommendation.
The framework standardizes diagnosis and reporting; it does not independently dictate treatment.
Ambiguous cases require longitudinal and multidisciplinary assessment.