Vigabatrin-induced gingival overgrowth

On the Cellular and Molecular Mechanisms of Drug-Induced Gingival Overgrowth

Introduction:

Gingival overgrowth has been linked to multiple factors such as adverse drug effects, inflammation, neoplastic processes, and hereditary gingival fibromatosis. Drug-induced gingival overgrowth is a well-established adverse event. In early stages, this gingival enlargement is usually located in the area of the interdental papilla. Histologically, there is an increase in the different components of the extracellular matrix.

Objective:

The aim of this manuscript is to describe and analyze the different cellular and molecular agents involved in the pathogenesis of Drug-induced gingival overgrowth.

Method:

A literature search of the MEDLINE/PubMed database was conducted to identify the mechanisms involved in the process of drug-induced gingival overgrowth, with the assistance of a research librarian. We present several causal hypotheses and discuss the advances in the understanding of the mechanisms that trigger this gingival alteration.

Results:

In vitro studies have revealed phenotypic cellular changes in keratinocytes and fibroblasts and an increase of the extracellular matrix with collagen and glycosaminoglycans. Drug-induced gingival overgrowth confirms the key role of collagenase and integrins, membrane receptors present in the fibroblasts, due to their involvement in the catabolism of collagen. The three drug categories implicated: calcineuron inhibitors (immunosuppressant drugs), calcium channel blocking agents and anticonvulsant drugs appear to present a multifactorial pathogenesis with a common molecular action: the blockage of the cell membrane in the Ca2+/Na+ ion flow. The alteration of the uptake of cellular folic acid, which depends on the regulated channels of active cationic transport and on passive diffusion, results in a dysfunctional degradation of the connective tissue. Certain intermediate molecules such as cytokines and prostaglandins play a role in this pathological mechanism. The concomitant inflammatory factor encourages the appearance of fibroblasts, which leads to gingival fibrosis. Susceptibility to gingival overgrowth in some fibroblast subpopulations is due to phenotypic variability and genetic polymorphism, as shown by the increase in the synthesis of molecules related to the response of the gingival tissue to inducing drugs. The authors present a diagram depicting various mechanisms involved in the pathogenesis of drug-induced gingival overgrowth.

Conclusion:

Individual predisposition, tissue inflammation, and molecular changes in response to the inducing drug favor the clinical manifestation of gingival overgrowth.

Adverse Drug Reactions in the Orofacial Region

A wide spectrum of drugs can sometimes give rise to numerous adverse orofacial manifestations, particularly dry mouth, taste disturbances, oral mucosal ulceration, and/or gingival swelling. There are few relevant randomized double-blind controlled studies in this field, and therefore this paper reviews the data from case reports, small series, and non-peer-reviewed reports of adverse drug reactions affecting the orofacial region (available from a MEDLINE search to April, 2003). The more common and significant adverse orofacial consequences of drug therapy are discussed.

Drug-induced gingival overgrowth: A critical insight into case reports from over two decades

Drug-induced gingival overgrowth (DIGO) is a well-recognized adverse effect of certain systemic medications. Calcium channel blockers, anticonvulsants, and immunosuppressants are frequently implicated drugs in the etiology of DIGO. Drug variables, plaque-induced inflammation, and genetic factors are the three important factors in the expression of gingival changes after systemic medication use. Careful clinical examination and thorough history taking form the basis for diagnosis of DIGO. Histopathological examination is often neglected; however, it is an important aid that helps in differential diagnosis. Cessation or change of drug and meticulous plaque control often leads to regression of the lesion, which however might need surgical correction for optimal maintenance of gingival health. The purpose of the present article is to review case reports and case series published in the last two decades and to assimilate and compile the information for clinical applications such as diagnosis and therapeutic management of DIGO.

A Clinical Evaluation of Gingival Overgrowth in Children on Antiepileptic Drug Therapy

INTRODUCTION

Gingival overgrowth, a well-known side effect of chronic phenytoin therapy has also been known to be caused by other anti epileptic drugs (AED's). Various factors like plaque, gingival inflammation, and periodontal health have been postulated to effect gingival overgrowth.

AIM

To identify the AED having an effect on gingival overgrowth and to study the factors affecting it.

MATERIALS AND METHODS

Three groups of 30 children each on monotherapy of phenytoin, sodium valproate, and carbamazepine were longitudinally followed for six months. Their oral and epileptic health status was assessed and were monitored for change in plaque levels, gingival inflammation, probing depth and the status of gingival overgrowth at baseline, at the end of 3 months and finally at the end of 6 months. The data was recorded and statistically analysed.

RESULTS

Phenytoin caused gingival overgrowth in a significant number of children (53.6%) within 3 months. Sodium valproate also led to gingival overgrowth, but not upto statistically significant levels. Patients on carbamazepine did not show any signs of gingival overgrowth. Gingival overgrowth is seen more on buccal side, in the anterior segment and in the lower arch. No correlation could be found between, either plaque level, or gingival inflammation with gingival overgrowth. Probing depth could be positively correlated with gingival overgrowth.

CONCLUSION

Phenytoin is the drug, which can be chiefly implicated for causing gingival overgrowth. Sodium valproate carries the potential for gingival overgrowth, although only up to clinically insignificant levels in 6 months. Carbamazepine can be considered a safe drug in children in relation to gingival overgrowth.

Hereditary gingival fibromatosis

Hereditary gingival fibromatosis (HGF) is a rare condition that can occur as an isolated disease, chromosomal abnormality, or as part of a number of syndromes. The gingival enlargement in HGF can be so severe that it can cover the crowns of teeth completely, causing severe functional derangement and facial disfigurement. Through review of literature revealed that HGF is usually an autosomal dominant condition, however the recessive forms are also reported. The hyperplastic gingiva is firm on palpation and has normal color with abundant stippling on the adjacent gingiva. The buccal and lingual gingiva may be involved in both the mandible and maxilla. The degrees of gingival enlargement show both intra- and interindividual variations. Here, an interesting case report of massive HGF has been presented.

Phenytoin-induced gingival overgrowth: a review of the molecular, immune, and inflammatory features

Gingival overgrowth (GO) is a side effect associated with some distinct classes of drugs, such as anticonvulsants, immunosuppressant, and calcium channel blockers. GO is characterized by the accumulation of extracellular matrix in gingival connective tissues, particularly collagenous components, with varying degrees of inflammation. One of the main drugs associated with GO is the antiepileptic phenytoin, which affects gingival tissues by altering extracellular matrix metabolism. Nevertheless, the pathogenesis of such drug-induced GO remains fulfilled by some contradictory findings. This paper aims to present the most relevant studies regarding the molecular, immune, and inflammatory aspects of phenytoin-induced gingival overgrowth.

Efficacy of AZM therapy in patients with gingival overgrowth induced by Cyclosporine A: a systematic review

BACKGROUND

In daily clinical practice of a dental department it's common to find gingival overgrowth (GO) in periodontal patients under treatment with Cyclosporine A (CsA). The pathogenesis of GO and the mechanism of action of Azithromycin (AZM) are unclear. A systematic review was conducted in order to evaluate the efficacy of Azithromycin in patients with gingival overgrowth induced by assumption of Cyclosporine A.

METHODS

A bibliographic search was performed using the online databases MEDLINE, EMBASE and Cochrane Central of Register Controlled Trials (CENTRAL) in the time period between 1966 and September 2008.

RESULTS

The literature search retrieved 24 articles; only 5 were Randomised Controlled Trials (RCTs), published in English, fulfilled the inclusion criteria. A great heterogeneity between proposed treatments and outcomes was found, and this did not allow to conduct a quantitative meta-analysis. The systematic review revealed that a 5-day course of Azithromycin with Scaling and Root Planing reduces the degree of gingival overgrowth, while a 7-day course of metronidazole is only effective on concomitant bacterial over-infection.

CONCLUSION

Few RCTs on the efficacy of systemic antibiotic therapy in case of GO were found in the literature review. A systemic antibiotic therapy without plaque and calculus removal is not able to reduce gingival overgrowth. The great heterogeneity of diagnostic data and outcomes is due to the lack of precise diagnostic methods and protocols about GO. Future studies need to improve both diagnostic methods and tools and adequate classification aimed to determine a correct prognosis and an appropriate therapy for gingival overgrowth.

Drug-induced gingival enlargement - Part II. Antiepileptic drugs: not only phenytoin is involved

INTRODUCTION: Gingival enlargement is the term now used to describe medication-related gingival overgrowth or gingival hyperplasia, a common reactionary phenomenon that occurs with the use of several types of therapeutic agents, including antiepileptic drugs. This disorder has been recognized since 1939, shortly after the introduction of phenytoin. METHODS: Review of literature concerning etiology, pathogenesis and management of antiepileptic drug induced gingival enlargement. CONCLUSIONS: It is important that neurologists become aware of the potential etiologic agents of antiepileptic drug induced gingival enlargement and its characteristic features in order to be able to prevent, diagnose and successfully manage it.

Gingival enlargement in children treated with antiepileptics

This study was conducted to determine the occurrence, severity, and risk factors of gingival enlargement in children treated with valproate and other nonvalproate antiepileptic drugs. A cross-sectional study was carried out in which data obtained from 68 epileptic children under treatment were compared with those from 50 controls. A structured questionnaire was used to collect data on patients' demographics, dental and oral hygiene practices, and medication history. Gingival enlargement, gingival index, plaque index, and probing depth were measured to assess periodontal health. The chi-square and Fisher exact tests were used in statistical analysis. In case of significance, a detailed chi-square analysis was carried out to determine the origin of the difference. Patients in both the valproate and nonvalproate groups showed significantly higher gingival enlargement, gingival index, plaque scores, and pocketing (P < .001 and P < .01, respectively) than the control group. In the valproate group, the duration of the treatment had a significant effect on gingival enlargement (P < .001) but not on gingival index, plaque index, and probing depth values (P > .05). Toothbrushing was most frequent in the control group (P = .000) and more frequent in the valproate group than the nonvalproate group (P = .024). Our study showed significant differences regarding gingival enlargement in children treated with valproate. These findings illustrate that epileptic children on valproate are at risk of periodontal problems.

Prevalence and risk of gingival enlargement in patients treated with anticonvulsant drugs

BACKGROUND

Predictors of gingival enlargement in patients treated with anti-epileptics have not been previously assessed. This study was conducted to determine, with the aid of two indices that score vertical and horizontal overgrowth, the prevalence and risk factors for gingival enlargement in patients treated with phenytoin and other anticonvulsant drugs.

MATERIALS AND METHODS

A cross-sectional study was conducted and data from 59 patients taking antiepileptics were compared with 98 controls. Gingival enlargement was evaluated with two indices to score vertical overgrowth [Gingival overgrowth index (GO] and horizontal overgrowth [Miranda-Brunet index (MB)]. Gingival index, plaque index, and probing depth were also evaluated.

RESULTS

The prevalence of gingival enlargement was significantly higher (P < 0.0001) for both indices in the anticonvulsants treated groups than in the control group. Gingival overgrowth was significantly higher for both indices in the phenytoin group than in the non phenytoin group. Among the possible risk factors, only the gingival index showed a significant association with gingival enlargement. For the MB index the risk of gingival enlargement (odds ratio) associated to phenytoin therapy and other anticonvulsants therapy were 52.6 (13.5-205) and 6.6 (1.5-28.2). Gingival index-adjusted odds ratios for the same drugs were 5.7 (1.3-24.7) and 18.1 (2-158), respectively. The concordance between GO and MB indices in the control group and in the phenytoin-group and non phenytoin-group showed a Kappa value of 0.773 and 0.697, respectively.

CONCLUSION

This study reports significant differences in the prevalence and severity of gingival overgrowth in two groups of patients, one treated with phenytoin, and another treated with other anticonvulsants. Gingival inflammation is a significant risk factor for gingival enlargement in these patients.

Periodontitis modified by systemic factors

Microbial dental plaque is the initiator of periodontal disease but whether it affects a particular subject, what form the disease takes, and how it progresses, are all dependent on the host defenses to this challenge. Systemic factors modify all forms periodontitis principally through their effects on the normal immune and inflammatory defenses. Some good examples of this effect exist such as when there is a reduction in number or function of polymorphonuclear leukocytes (PMNs) that may result in an increased rate and severity of periodontal destruction. Many other systemic factors are much less clear cut and are difficult to causally link to periodontitis. In many cases the literature is insufficient to make definite statements on links between systemic factors and periodontitis. It is also at times difficult to be precise regarding the causative agent in systemic exposures such as smoking and even prescribed drug therapy. The possible role of systemic diseases and systemic exposures in initiating or modifying the progress of periodontal disease is clearly a complex issue. It is however generally agreed that several conditions may give rise to an increased prevalence, incidence, or severity of gingivitis and periodontitis. The categorization of the systemic modifying factors causing periodontitis and the evidence to support the role of these factors are the focus of this review. An attempt has been made to consider the conditions under broad headings, but it will be clear that many conditions fall within more than one category and that for several conditions only case reports exist whereas in other areas an extensive literature is present.

A clinical review of drug-induced gingival overgrowths

There is an increasing number of medications associated with gingival overgrowth. These medications are used to treat a number of common conditions in the Australian population and as such dentists can expect to manage a number of patients with medication-related gingival overgrowth. This review highlights the clinical features and management of the common overgrowths associated with anticonvulsants, immunosuppressants and the calcium channel blockers.

Medication induced gingival overgrowth

A number of idiopathic, pathological and pharmacological reactions may result in an overgrowth of the gingiva. This review concentrates on those overgrowths associated with various pharmacological agents. The pharmaco-kinetics and side effects of each drug associated with gingival overgrowth are discussed along with the clinical and histological features and treatment. By examining the possible pathogeneses for these overgrowths we propose a unifying hypothesis for the causation based around inhibition of apoptosis and decreased collagenase activity modulated by cytoplasmic calcium.