Purpose The aim of the present study was to establish the incidence of maxillofacial (MF) injury accompanying mild traumatic brain injury (mTBI) and the associated neurocognitive deficits and white matter changes. Materials and Methods A prospective review of 41 patients with mTBI and maxillofacial injury (with or without intracranial lesion) due to motor vehicle accidents who had admission computed tomography (CT), neurocognitive evaluation, and quantitative diffusion tensor imaging available was performed during admission and at 6 months of follow-up. Descriptive statistics were used for the demographic data, and a paired t test and repeated measure analysis of variance were used to establish the intergroup differences and susceptibility. Results The included patients were relatively young adults, with a mean age of 27.3 ± 8.8 years and 11.3 ± 2.1 years of education. Of the 41 patients, 20 (48.8%) had maxillofacial injuries involving the soft tissue and muscles, 18 (43.9%) had facial bone fractures, and 3 (7.3%) had mixed injuries. Of the 41 patients with MF injuries, 28 (68.3%) had intracranial abnormalities found on the admission CT scan. Executive function and attention were significantly altered across the time points, with patients with both MF injury and an intracranial lesion doing poorly at baseline but with improvement 6 months later. In contrast, the patients with no visible intracranial lesion but with MF injuries remained impaired, with signs of a slowed recovery. The fractional anisotropy of the genu of the corpus callosum, anterior limb of the internal capsule, and cingulum for patients with MF injuries but without an intracranial lesion showed trends of reduced integrity over time. Conclusions The presence of MF injury without any intracranial traumatic lesions in patients with mTBI increases the risk of short- and long-term neurocognitive derangement compared with patients with mTBI, MF injury, and intracranial traumatic lesions.