Diagnostic Code 9902 · 38 CFR §4.150
DC 9902 covers partial loss of the mandible (lower jaw) including the ramus — the vertical portion that connects the main jawbone to the skull at the TMJ. This kind of bone loss typically results from combat injuries, blast trauma, gunshot wounds, or surgical removal due to tumors. The rating depends on three factors: how much bone was lost (more than half versus less than half), whether the TMJ is involved, and whether a prosthesis can replace the lost bone and restore function. When the TMJ is involved, ratings are higher because it directly affects your ability to open and move your jaw. Prosthetic reconstruction can partially restore form and function, but when it cannot adequately replace what was lost, the rating is higher to reflect the permanent functional deficit.
| Rating | Criteria |
|---|---|
| 70% | Loss of one-half or more of the mandible (including ramus) with TMJ involvement, and the lost bone cannot be replaced by a prosthesis. This reflects severe jaw loss that directly impairs the jaw joint and cannot be reconstructed. |
| 50% | This rating applies in two scenarios: (1) loss of one-half or more of the mandible with TMJ involvement, where a prosthesis can replace the lost bone; or (2) loss of less than one-half of the mandible with TMJ involvement, where a prosthesis cannot replace the lost bone. In both cases, the TMJ is compromised. |
| 40% | Loss of one-half or more of the mandible without TMJ involvement, and the lost bone cannot be replaced by a prosthesis. Significant bone is gone but the jaw joint itself is intact. |
| 30% | Loss of one-half or more of the mandible without TMJ involvement, where a prosthesis can replace the lost bone. The extent of loss is significant but reconstruction is feasible and the jaw joint works. |
| 20% | Loss of less than one-half of the mandible without TMJ involvement, and the lost bone cannot be replaced by a prosthesis. A smaller area is affected but reconstruction is not possible. |
| 10% | Loss of less than one-half of the mandible without TMJ involvement, where a prosthesis can replace the lost bone. This is the mildest form — a smaller area of bone loss that can be reconstructed. |
Surgical records documenting the extent of mandible and ramus loss are needed. CT scans or panoramic X-rays showing exactly how much bone is missing and whether the TMJ is involved are critical since both factors determine the rating. Records of prosthetic reconstruction attempts and their success or failure are directly relevant to the prosthesis determination. Service treatment records establishing the in-service cause are essential. An oral surgeon evaluation assessing TMJ function and prosthetic feasibility ties everything together.
TMJ involvement means the bone loss extends to or affects the temporomandibular joint — the hinge where your jaw connects to your skull. This is typically determined by imaging (CT scan) and a clinical examination. If the condyloid process (the part of the mandible that forms the TMJ) is missing or damaged, TMJ involvement is present.
An oral surgeon or prosthodontist evaluates whether sufficient bone remains to anchor a prosthesis and whether a prosthesis can adequately restore jaw function. Factors include the amount and location of remaining bone, soft tissue condition, and the complexity of the defect.