An interesting article titled “Factors Determining Outcome After Trigeminal Nerve Surgery for Neuropathic Pain” appears in the July 2016 issue of Journal of Oral and Maxillofacial Surgery written by John R. Zuniga and David M. Yates. It is known that the inferior alveolar and lingual nerves which are part of the trigeminal nerves can be damaged after wisdom teeth surgery. Additional surgery can be performed to repair the trigeminal nerve but in some cases this injury remains and is only partially resolved. The others set out to better explore why neuropathic pain can persist after trigeminal nerve surgery.
The study included 28 patients who underwent trigeminal nerve repair in Texas between 2006 and 2014. The patients were grouped into three different cohorts: 1) those who had no recurrence (NR) were any neuropathic pain went away, 2) those who had complete recurrence (CR) were the pain level of any neuropathic pain was the same postoperatively, and 3) those who had incomplete recurrence (ICR) were the pain intensity was below the pain intensity prior to surgery. Seven patients were in the NR cohort (25%), ten were in the CR cohort (36%), and eleven were in the ICR cohort (39%). There were statistically significant differences found among groups at 3 months, 6 months, and 12 months. The postsurgical percentages of decreased pain intensity in the NR group were 72% at 3 months and 100% at 6 and 12 months. The postsurgical percentages of decreased pain intensity in the ICR group were 69% at 3 months, 54% at 6 months, and 38% at 12 months. There was no statistical difference between or within groups by age, gender, Sunderland classiﬁcation, nerve injured, etiology of nerve injury, nerve repair performed, or duration from injury to repair.
The authors state
“This study showed that trigeminal neuropathic pain continues to be a difﬁcult and poorly understood consequence of injury … regardless of age, gender, type of injury, cause of injury, health comorbidity, or duration of injury. Importantly, this study pointed out that the type of trigeminal nerve repair had no predictive effect on outcome. “
The authors feel that the understanding of neuropathic pain is incomplete. It is difficult to predict what will happen to patients who have trigeminal nerve surgery performed but it does offer the chance to fully reduce the pain level and partially reduce it. It is noted that a few patients had a bit more intense pain than prior to the surgery in the current study.