Loss of Coronoid Process — VA Disability Rating (DC 9909)
Diagnostic Code 9909 · 38 CFR §4.150
What Is It?
The coronoid process is a thin, triangular projection at the top front of each side of the mandible (lower jaw). The temporalis muscle — one of the main muscles that closes your jaw — attaches to the coronoid process. Losing this structure weakens the mechanical leverage of the temporalis muscle, reducing your bite force and making chewing less effective. Veterans may lose the coronoid process from combat trauma, blast injuries, jaw fractures, or surgical removal due to tumors or to treat jaw ankylosis (fusion). The VA rates this condition based on whether the loss is on one side (unilateral) or both sides (bilateral), since bilateral loss affects more chewing function.
Rating Criteria
| Rating | Criteria |
|---|---|
| 20% | Bilateral (both sides) loss of the coronoid process. Loss on both sides reduces the attachment points for both temporalis muscles, significantly weakening bite force and chewing ability. |
| 10% | Unilateral (one side) loss of the coronoid process. Loss on one side reduces the attachment for one temporalis muscle. Some bite force reduction occurs but the opposite side partially compensates. |
Evidence Needed
CT scans or panoramic X-rays showing the absence of the coronoid process on one or both sides are essential. Surgical records documenting the cause of the loss — combat injury, fracture, tumor removal, or surgical coronoidectomy — are needed. Service treatment records establishing the in-service cause are required. If the loss was from a coronoidectomy to treat jaw ankylosis, include the records of the underlying condition and its service connection.
C&P Exam Tips
The examiner will review imaging to confirm the coronoid process loss and may assess bite force and jaw function. Describe any difficulty you have with chewing — particularly whether you notice reduced bite strength or fatigue when chewing tough foods. If you have other jaw issues (limited opening, TMD, other bone loss), make sure all of those are documented separately as they may qualify for additional ratings under other diagnostic codes.
How to File
File on VA Form 21-526EZ with DC 9909. Submit imaging showing the bone loss, surgical records, and service treatment records. Clearly state whether the loss is unilateral or bilateral since it affects the rating level. If you also have TMD or other jaw conditions, file those separately.
Common Mistakes
Not obtaining imaging that clearly shows the coronoid process is absent on one or both sides can delay the claim. Not specifying whether the loss is unilateral or bilateral means the VA may default to the lower rating. If the coronoidectomy was done to treat a service-connected condition, make sure to establish that chain of service connection.
Frequently Asked Questions
What is a coronoidectomy?
A coronoidectomy is the surgical removal of the coronoid process, sometimes performed to treat jaw ankylosis (fusion of the jaw joint) or to relieve restricted jaw opening caused by the coronoid process impinging on surrounding structures. If this surgery was performed to treat a service-connected jaw condition, the resulting bone loss is service-connected as well.
How is the coronoid process different from the condyloid process?
The condyloid process (rated under DC 9908) is the rounded knob that forms the TMJ — the actual jaw joint. The coronoid process (DC 9909) is a separate projection where the temporalis muscle attaches. They serve different functions: the condyloid process enables jaw movement, while the coronoid process provides leverage for bite force.