Post-traumatic Neuropathy of the Trigeminal Nerve

Study Overview
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Brief Summary
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This is retrospective research mainly aims to determine the patterns of symptoms, clinical and radiological findings and outcomes in patients with trigeminal neuropathy following trauma or iatrogenic damage and how this translates into costs for the patient and society, work disability and medication use. The trigeminal nerve and its branches are at risk of damage during multiple dental and maxillofacial procedures: endodontics, extractions, removal of wisdom teeth, implant placement, use of local anaesthesia, orthognatic surgery. In the event of damage to these nerve branches, there is a high risk of developing a neuropathic pain that is considered very disabling for patients and that interferes with daily activities (eating, drinking, speaking, kissing, etc.). Moreover, there are few medicinal or surgical techniques available to eliminate neuropathy or reduce the symptoms. Causal procedures (e.g. the removal of wisdom teeth) are among the most frequently performed surgical procedures. The number of injuries increases every year, partly due to an increase in dental procedures. The often relatively minimal intervention combined with the major impact of these injuries on the patient's quality of life sometimes leads to medico-legal actions. The limited symptom control with current therapies of these post-traumatic neuropathies of the trigeminal nerve causes frustration and impotence in both the patient and the attending physician, which can also lead to medical shopping. Based on chart analysis, this study will examine the causes, possible risk factors and presenting symptoms, how this is reflected in clinical research and examinations, and which treatments are being instituted. Patient records from the Oral and Maxillofacial Surgery department between January 2010 and October 2018 will be checked. In addition, we wish to check the costs incurred by these patients as well as the work disability. To this end, a collaboration is being organised with Christian Mutuality (CM), the largest health insurance provider in Belgium. In order to increase the power of the study, the clinical data from the already coded, retrospective dataset of Prof. Tara Renton, co-investigator, will be transferred to the dataset of this new study.

Official Title
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Post-traumatic Neuropathy of the Trigeminal Nerve

Conditions
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Nerve Injury, Orofacial Pain, Trigeminal Nerve Injuries, Trigeminal Neuropathy

Intervention / Treatment
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* Other: Groupwise comparison of primary and secondary outcomes


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Presentation with post traumatic, iatrogenic, injury of the trigeminal nerve or its branches (eg. inferior alveolar nerve, lingual nerve) Iatrogenic nerve injury caused by M3 removal, implant placement, orthognathic surgery, endodontic therapy, non-M3 removal, local anesthesia injection, trauma. Clinical diagnosis of neurosensory deficit in the distribution of the trigeminal nerve caused by a previous dental or maxillofacial procedure in the vicinity of the affected branch. Exclusion Criteria: Neuropathic pain in another region than the trigeminal nerve Neuropathic pain not caused by iatrogenic injury
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Painful post-traumatic trigeminal nerve injuries<br>Patients presenting with painful post-traumatic trigeminal nerve injuries according to the recent ICOP criteria. | Other: Groupwise comparison of primary and secondary outcomes<br>* Statistical comparison of cohorts. Cfr supporting information on statistical plan.<br>|
| Non-painful post-traumatic trigeminal nerve injuries<br>Patients presenting with non-painful post-traumatic trigeminal nerve injuries according to the recent ICOP criteria. | Other: Groupwise comparison of primary and secondary outcomes<br>* Statistical comparison of cohorts. Cfr supporting information on statistical plan.<br>|
| Temporary nerve injuries<br>Patients with a trigeminal nerve injury with symptom resolution within 3 months after data of trauma. | Other: Groupwise comparison of primary and secondary outcomes<br>* Statistical comparison of cohorts. Cfr supporting information on statistical plan.<br>|
| Persistent nerve injuries<br>Patients with a trigeminal nerve injury and complaints persisting longer than 3 months after the trauma. | Other: Groupwise comparison of primary and secondary outcomes<br>* Statistical comparison of cohorts. Cfr supporting information on statistical plan.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Healthcare costs | What is the difference in total healthcare costs per patient and in total in patients with iatrogenic trigeminal nerve injury seen in our department according to cause of injury, injured nerve and outcome (temporary or permanent injury)? A temporary injury will be defined as an injury that completely recovered with no more symptoms and clinical exam parameters within the normal limits during one of the consultations during the follow up period. Permanent injury will be defined as an injury where no significant improvement in symptoms or clinical exam parameters was seen during one of the consultations during the follow up period. | 10 years | 
| Productivity loss | What is the average productivity loss in days in patients with iatrogenic trigeminal nerve injury seen in our department according to cause of injury, injured nerve and outcome (temporary or permanent injury)? | 10 years | 
| Medication use | Amount of medication use per medication class per patient in patients with iatrogenic trigeminal nerve injury seen in our department according to cause of injury, injured nerve and outcome (temporary or permanent injury)? | 10 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Clinical predictors of persistency | Are symptoms or clinical exam parameters (2 pointdiscrimination, directional sense, light touch, percentage of dermatome affected, pinprick threshold), MRCS classification and Sunderland classification predictive of a temporary or permanent injury? If so, which parameters can be withheld? | 10 years | 
| Legal action | If data is present in the patient file regarding legal action taken by the patient against the caregiver who caused the injury this will be registered. We will evaluate how many patients undertook legal action and if they received compensation. | 10 years | 
| Survival analysis | If sufficient follow up data is present, we will evaluate how long symptoms are present in case of a temporary injury and evaluate evolution of symptoms in relation to time. | 10 years | 
| Influence of imaging on treatment decision | Was imaging performed in light of the injury? If yes, what imaging modality was used (conebeam CT, CT, MRI, orthopantomogram) and did this influence treatment decisions? | 10 years | 
| PROMS comparison between cohorts | When looking at PROMS questionnaires applied in our department: are the results from the questionnaires comparable between the different causes of nerve injury, different affected branches? Are results comparable between patients suffering from a temporary or permanent injury? | 10 years | 
| Quality of life between cohorts | Is there a correlation between quality of life measured with EQ5D questionnaire and cause of injury, temporary versus permanent injuries, healthcare costs, productivity loss or medication use? | 10 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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post-traumatic trigeminal neuropathic pain