Which nerve is likely damaged if a patient has lost feeling in the anterior 2/3 of the tongue?

The loss of sensation in the anterior two-thirds of the tongue is primarily associated with the lingual nerve. This nerve is a branch of the mandibular division of the trigeminal nerve (cranial nerve V). It provides sensation, including touch, temperature, and pain, to the anterior part of the tongue. When this nerve is damaged, a patient may experience a loss of feeling in that specific area.

The lingual nerve also carries taste fibers from the chorda tympani branch of the facial nerve, but the primary responsibility for sensation lies with the lingual nerve itself. This anatomical relationship is key to understanding the symptom of loss of feeling in that region.

In contrast, other options such as the maxillary nerve and the facial nerve do not directly innervate the anterior two-thirds of the tongue, making them less likely to be the source of this sensory loss. The mandibular nerve, while it contains the lingual nerve as a branch, would not be specifically indicated unless there were a broader range of symptoms involving further branches or motor functions. Therefore, the lingual nerve is the correct answer when considering isolated sensory loss in the anterior portion of the tongue.