Diagnostic Code 9907 · 38 CFR §4.150
DC 9907 covers loss of less than half of the mandibular ramus — the vertical portion of the lower jawbone behind the molars. Compared with the larger loss captured by DC 9906, a partial ramus loss preserves more of the hinge mechanics with the temporomandibular joint and the muscles of mastication, but it still produces meaningful functional impairment: reduced chewing strength on the affected side, altered bite, and often visible facial asymmetry. The classic veteran mechanisms remain combat trauma (shrapnel, gunshot), blast injuries with facial bone fractures, and surgical resection. The rating distinguishes between cases that can be replaced by a prosthesis with reasonable functional restoration (20%) and cases where prosthesis replacement is not feasible or does not restore adequate function (30%). The 30% tier is the schedular ceiling under DC 9907; if disfigurement or TMJ impairment is the dominant functional consequence, separate evaluation under DC 7800 or DC 9905 may produce a higher rating and is applied instead.
| Rating | Criteria |
|---|---|
| 20% | Loss of less than half of the mandibular ramus, replaceable by prosthesis with reasonable functional restoration of chewing and bite. The 20% rating reflects the residual functional limitation that persists even with successful prosthetic reconstruction. |
| 30% | Loss of less than half of the mandibular ramus, not replaceable by prosthesis OR with significant residual functional limitation after attempted reconstruction. As with DC 9906, when disfigurement under DC 7800 or TMJ impairment under DC 9905 rates higher, the higher rating is applied instead. |
The same imaging, surgical, and functional evidence base applies as for DC 9906 — panoramic X-ray, CT of the maxillofacial region, original trauma and reconstruction records, dental and prosthetic records, current oral surgery consult, and photographs of the residual asymmetry. The key distinction for DC 9907 is documenting that the bone loss is less than half of the ramus, which is determined by oral surgery measurement and imaging. Records of prosthetic reconstruction attempts and the functional outcome distinguish the 20% (replaceable by prosthesis) tier from the 30% (not adequately replaceable) tier.
The line is whether the bone loss is half or more of the mandibular ramus. DC 9906 applies at half or more; DC 9907 applies at less than half. The determination is made by imaging and oral surgery measurement, not by clinical judgment alone. The rating ceiling for DC 9906 is 50%; for DC 9907 it is 30%. When the extent of loss is borderline, request precise measurement on CT or 3D imaging to ensure the correct code applies.
No. The 20% tier under DC 9907 specifically covers cases where a prosthesis has been or can be successfully placed and restores reasonable function. Prosthetic reconstruction is generally worth pursuing for its functional benefits even though it may lower the rating, because eating, speaking, and quality of life are substantially improved by a well-fitting prosthesis. The 30% tier remains available if the prosthesis fails to adequately restore function or if no prosthetic option works for the specific defect.
A successful reconstruction can lower the rating if it materially restores function, but the protection rules under 38 CFR §3.951 still apply: a rating in continuous effect for five years or more cannot be reduced without clear evidence of sustained material improvement. The reduction would also need to follow the prescribed procedural rules in 38 CFR §3.105(e). Most rating decisions favor keeping the existing rating when the residuals after reconstruction are still measurable.