Diagnostic Code 9904 · 38 CFR §4.150
Mandible malunion means a fracture of the lower jaw healed, but it healed in the wrong position. This misalignment causes the upper and lower teeth to not meet properly, creating what is called an open bite — a gap between the upper and lower teeth when you try to close your mouth. Veterans typically develop mandible malunion from jaw fractures sustained during combat, vehicle accidents, training injuries, or falls during military service. The severity of the rating depends on how much the malunion displaces your bite. A severe open bite means your front or back teeth cannot touch at all when you close your jaw, making it very difficult to bite into food or chew effectively. Treatment may involve corrective jaw surgery (orthognathic surgery), orthodontic treatment, or prosthetic appliances to compensate for the misalignment.
| Rating | Criteria |
|---|---|
| 20% | The mandible healed with displacement causing a severe anterior or posterior open bite. Your front teeth or back teeth have a significant gap when you try to close your mouth, making biting and chewing extremely difficult. |
| 10% | The mandible healed with displacement causing a moderate anterior or posterior open bite. There is a noticeable gap when you close your mouth, but some teeth still make contact and you retain partial chewing function. |
| 0% | The mandible healed with some displacement, but it does not cause an anterior or posterior open bite. Your teeth still meet when you close your mouth, so chewing function is largely preserved despite the malunion. |
Imaging studies (CT scan, panoramic X-ray, or cephalometric X-ray) clearly showing the malunion and degree of displacement are essential. A dental or oral surgery evaluation documenting the open bite — specifically whether it is anterior (front teeth do not meet), posterior (back teeth do not meet), and the severity — is critical. Service treatment records documenting the original jaw fracture establish the service connection. If you have had any corrective surgery or orthodontic treatment, include those records as well.
Malunion (DC 9904) means the fractured bone segments healed but in an incorrect position, causing bite misalignment. Nonunion (DC 9903) means the bone segments never joined together at all, causing abnormal movement (false motion) at the fracture site. Both affect jaw function but are rated under different diagnostic codes with different criteria.
Potentially yes. Mandible malunion (DC 9904) rates the bite displacement caused by improper bone healing, while TMD (DC 9905) rates limited jaw opening and dietary restrictions. If you have measurable impairment in both areas, both should be documented and claimed separately.