Maxillary nerve compression in cynomolgus monkey and altered somatic sensation. (A) Diagrammatic drawing of the face of Macaca fascicularis. The circle below the animal’s eye marks the position of infraorbital foramen, where the maxillary division of the trigeminal nerve penetrates the skull; the external portion of this maxillary nerve’s terminal branch is commonly referred to as the infraorbital nerve. (B) Sensitivity to facial mechanical stimulation in monkeys. Avoidance response in monkeys is shown as the number of brushing to the side of the face before a monkey turned its face away from that side to avoid further brushing stimulation. Responses are shown as mean ± SEM. Open bar, ‘control’ (control animals’ both left and right sides, n = 10); striped bar, ‘contra’ (contralateral side of the MNC animals, n = 7); filled bar, ‘ipsi’ (ipsilateral side of the MNC animals, n = 7). #, significantly different from control (p < 0.05, unpaired t test with Welch's correction). *, significantly different from both control and contralateral side (p < 0.05, unpaired t test with Welch's correction).