Most patients with head and neck skin tumors present with normal facial nerve function. A common treatment strategy for these patients is facial nerve preservation surgery, although the degree to which the nerve is successfully preserved is still unclear. Data on the incidence and recovery of facial nerve dysfunction are woefully lacking in the field of dermato-oncology.
In 23 patients with normal preoperative facial nerve function, we retrospectively reviewed twenty-six head and neck surgical interventions that included facial nerve exposure and protection, focusing particularly on the differences in outcome between intraparotid and extraparotid exposure of the facial nerve branches.
Eleven of the 26 cases (42.4%) developed transient paresis, but only one (3.8%) developed permanent paresis. Of 41 dissected facial nerve branches, 14 developed transient paresis (34.1%) and one, a marginal mandibular branch, developed permanent paresis (2.4%). The branches most susceptible to developing paresis were the temporal (4/6 branches, 66.7%) and marginal mandibular branches (8/17 branches, 47.1%). Although the rate of paresis was higher, and ensuing recovery period slightly longer in the extraparotid dissection group compared to the intraparotid dissection group, there were no statistically significant differences between the two groups. The extraparotid and intraparotid rates of paresis were 48% (11/23 branches) and 21.1% (4/19 branches), respectively, P = 0.139; and the average recovery periods were 10.3 and 9.3 weeks, respectively, P = 0.64.
The functional outcome, regardless of the different sites of facial nerve exposure, was almost always either complete facial nerve sparing or transient dysfunction that resolved within 6 months.