Why Is Gingival Enlargement Common In Epileptic Patients?
Epilepsy is one of the common chronic neurological disorders in humans that is also associated with severe oral manifestations such as drug-induced gingival enlargement (DIGO). The prevalence of epilepsy in developed countries ranges from one percent to two percent globally. Epilepsy treatment is currently based upon successful systemic drug therapies that aim to help these patients to suffer from fewer seizure attacks and ultimately prevent the recurrence of seizures through drugs alone without any adverse effects on the patient. However, research is still underway as many patients with epilepsy, in several cases, may have to switch over drug therapies, especially when the recommended or physician-prescribed first-choice drug fails to treat the underlying epileptic cause or also due to a lack of efficacy or the patient's intolerance to the side effects of the medication.
Other anticonvulsant therapies have also been associated with gingival overgrowth. Nevertheless, drug-induced gingival inflammatory overgrowth or contour changes related to chronic use may also be seen in patients on anticonvulsant therapies such as Valproic acid, Carbamazepine, Phenobarbital, and Vigabatrin. Although, in comparison to phenytoin therapy, the occurrence of gingival overgrowth with these drugs is much lower.
Other drugs like immunosuppressants in patients suffering from immunocompromised diseases (like Cyclosporine A) and antihypertensive therapy like calcium channel blockers (Dihydropyridines, Diltiazem, and Verapamil) have also been known to induce gingival overgrowth. However, in most cases, gingival enlargement is a significant side effect in those patients who regularly consume these anticonvulsant drugs.
What Is the Etiology and Pathogenesis of Phenytoin-Induced Gingival Overgrowth?
The first report of gingival overgrowth associated with the chronic use of phenytoin was made preliminarily in 1939; however, this antiepileptic agent remains the most commonly prescribed anticonvulsant medication owing to its increased efficacy and potency in treating epileptic patients. Phenytoin therapies may also be used for facial neuralgias or even in treading cardiovascular or cardiac arrhythmias. It is estimated that nearly almost 30 to 50% of patients regularly undergoing phenytoin therapy are not only prone to developing significant gingival alterations but also may be at a higher risk of developing the sequence of events associated with oral gingival infections like periodontal diseases, alveolar bone loss and loss of bone volume.
Inflammatory changes orchestrated within the gingival tissues are influenced by a drug interaction between the drug and fibroblast tissues. The metabolites of phenytoin alongside the high-activity fibroblast cells present within the gingiva eventually lead to an over increased collagen production causing soft tissue or gingival overgrowth or enlargement. Research indicates a positive synergistic relationship between the dose of phenytoin and the severity of the gingival overgrowth. Furthermore, according to dental literature, the risk of high immunosuppression and folic acid depletion may also be attributed to the pathogenesis of drug-induced growths.
What Are the Clinical Features of Phenytoin-Induced Gingival Overgrowth?
The incidence rate of phenytoin-induced gingival overgrowth may range from three percent to ninety-three percent. Still, fifty percent of these patients on long-term therapies would develop gingival overgrowths that are seen initially in the papillary region of the gingiva. These lesions or overgrowths then subsequently, during pathogenesis, involve the marginal gingiva and may weaken the tooth's periodontal apparatus (initiating periodontal disease). Also, as the gingival tissue enlarges because of the thickened growth, the appearance of the lesion is characteristically lobulated, and either may be partially or sometimes completely covering the tooth surfaces (the overgrowth may be to a height that obstructs the view of the natural tooth appearance).
The color of the gingival outgrowth ranges from pink to a deep bluish red, which is usually dependent or proportional to the amount of inflammatory infiltrate present in the tissues. If bacteria infect these overgrowths, this phase may also be characterized by edema, ulcerations, or excessive gingival bleeding. The overgrowth takes two to three months to be clinically noticeable in the patients on phenytoin therapy. After that, it may reach maximum severity, especially if the lesions are left untreated by the dentist for around 12–18 months.
Gingival overgrowths in anterior teeth are more common when compared to posterior teeth. They are also seen with a greater involvement over the buccal surface than on the lingual tooth surfaces. Common signs of oral discomfort experienced by the patient include:
-
Unsightly aesthetic appearance.
-
Pain due to any oral ulcers.
-
Interference of these growths with chewing (mastication and speech).
-
Potential impediments to regular oral hygiene activities in bad breath or halitosis.
In severe cases, even the alignment of the teeth may be altered by the progressive phases of gingival and periodontal diseases.
How Is Phenytoin-Induced Gingival Overgrowth Managed?
The dentist or the maxillofacial surgeon should motivate the affected individuals to maintain high standards of oral hygiene practiced by chemical or mechanical plaque control methods that ensure minimal risk of Phenytoin side effects and reduce the likelihood of any surgical intervention for treating these outgrowths.
Reducing the dose of Phenytoin drug therapy or providing an alternative drug substitute can also help relieve the oral discomfort and partial or complete regression of the clinical symptoms of these lesions. However, this should be considered only after the physician and dentist's interaction and mutual consent.
The treatment options in case of severe gingival enlargement require surgical gingival resection, scalpel gingivectomy, flap surgery, electrosurgery, and laser gingivectomy.
Conclusion
To conclude, there should be proper interdisciplinary communication between the physician or neurologist and the dentist in managing phenytoin-induced gingival overgrowths, be it by alternative drug substitution or reduced dosage of such therapy if gingival symptoms are severe. Physicians should also explain the possibility of gingival overgrowth as a potential and highly possible adverse effect of Phenytoin therapy in epileptic patients.
