Post-traumatic trigeminal neuropathy (PTTN) is defined by a painful or non-painful lesion of the trigeminal nerve, caused by trauma with symptoms and/or clinical signs of trigeminal nerve dysfunction. In the case of painful PTTN, the term post-traumatic trigeminal neuropathic pain is currently used as defined by the recently introduced International Classification of Orofacial Pain (ICOP) (International Classification of Orofacial Pain, 1st edition (ICOP) 2020).

PTTN is a well-known complication in the field of oral and maxillofacial surgery and dentistry. A previous study, on which this one builds, has already shown that about half of the cases are caused by dentists, and the other half by oral and maxillofacial surgeons (Van der Cruyssen et al., 2020). Because the trigeminal nerve supplies most of the face and mouth with sensory and partly motor innervation, damage can occur during numerous procedures in this region. The most common cause of PTTN is the removal of wisdom teeth, a frequently performed procedure. In the United States ten million third molars are removed each year (Friedman, 2007). Other causes of PTTN may include tooth extractions, endodontic treatment, administration of local anesthetics, orthognathic surgery, placement of dental implants, and maxillofacial trauma (Klazen et al., 2018; Schenkel et al., 2016). The true incidence of PTTN is not well known but it is estimated that 1% of dental, oral or maxillofacial procedures result in persistent PTTN (Baad-Hansen and Benoliel, 2017; Politis et al., 2014).

Symptoms of PTTN are considered very disabling for the patient (Smith et al., 2013; Van der Cruyssen et al., 2020). They range from numbness in one part of the face to severe electrical or burning pain radiating to various orofacial regions. When the symptoms persist for more than three months, the condition is known as persistent PTTN (Schug et al., 2019). Diagnosing and managing PTTN can be challenging, and long referral delays to specialist centers, medical shopping, overtreatment, and legal claims are often a consequence of this (Klazen et al., 2018; Politis et al., 2014; Van der Cruyssen et al., 2020). Treatment of PTTN remains cumbersome and may include surgical intervention or a pharmacological approach (Biglioli et al., 2015; Renton and Van der Cruyssen, 2019). Recent animal studies show promise for the use of low-level laser or ozone treatment and more disease-specific treatments are on the way (Yuca et al., 2020; Finnerup et al., 2021).

To date, no data exist on the specific resource utilization pattern of patients with PTTN as well as its estimated costs to patients, health systems and society. A single study from the UK by Durham et al. in patients with persistent orofacial pain, not limited to PTTN, shows a per annum overall direct cost per patient of 362£ at 2012 prices (i.e., €478 in Belgian 2019 prices (Shemilt et al., 2010)). However, no stratification according to the cause of orofacial pain was made. Another study shows the cost of neuropathic pain conditions in five European countries (Liedgens et al., 2016). Annual direct costs per patient ranged from €1939 to €3131 (i.e., €2335–€4158 in Belgian 2019 prices (Shemilt et al., 2010)) and were highest for diabetic peripheral neuropathy, radiculopathy, and neuropathic back pain. Total annual costs were mainly driven by indirect costs of productivity loss and varied from €9305 to €14446 per patient (€11207–€17168) in Belgian 2019 prices (Shemilt et al., 2010).

The present aim of the present study is to estimate direct health care costs of patients suffering from PTTN and to compare the use of health care services, medications, and costs between temporary and persistent PTTN cohorts over a 5-year period, starting from the onset of symptoms.

These analyses are carried out from the point of view of the health insurer.