Increased bFGF level in the serum of patients with phenytoin-induced gingival overgrowth

Abstract. To elucidate the involvement of bFGF (basic fibroblast growth factor) in the pathogenesis of phenytoin-induced gingival overgrowth, we measured the concentration of bFGF in the serum of 36 epileptic patients taking phenytoin and in 94 normal volunteers by enzyme-linked immunosorbent assay technique. The concentration of phenytoin in serum was determined by high-performance liquid chromatography. In 34 of 36 patients taking phenytoin in this investigation, apparent gingival overgrowth was noticed. The mean concentration of bFGF was 33.9±18.5 pg/ml in the overgrowth group and 10.6±5.2 pg/ml in the volunteer group ( p <0.01). The serum phenytoin level did not correlate ( r =0.22, p = 0.2) with the degree of gingival overgrowth but there was a significant correlation ( r =0 38, p =0.023) between the degree of gingival overgrowth and the serum bFGF level. However, no correlation was observed among age, daily phenytoin dose, total phenytoin dose, duration of phenytoin therapy, serum phenytoin level, or serum bFGF level. The results suggested that enhanced serum bFGF level was implicated in the pathogenesis of phenytoin-induced gingival overgrowth.     

Phenytoin induced gingival overgrowth in institutionalized epileptics

In a cross-sectional, epidemiological study of phenytoin induced gingival overgrowth in 77 institutionalized persons with epilepsy, the severity of the gum lesions was quantified by means of a precise new technique. Lesion severity was then compared statistically to other clinical and laboratory parameters. Positive correlations were detected between overgrowth severity and gingival inflammation, probing depths, calculus accumulation, plaque score and the measurement gingival margin to mucogingival junction (GM-MGJ). No correlation was observed between lesion severity and patients age, daily drug dosage, plasma or saliva phenytoin level, or salivary concentration of the major phenytoin metabolite.     

Subpopulations of lymphocytes in connective tissue from phenytoin-induced gingival overgrowth

The presence of mononuclcar cells was studied in gingival biopsies from seven children exhibiting phenyloin(PHT)-induced gingival overgrowth, three children with gingivitis and a control group consisting of three children without clinical signs of inflammation. The mononucle-ar cells were detected using monoclonal antibodies defining functional T-lymphocytc subpopulations, B-lymphocytes and monocytes. Gingival biopsies from the individuals in the PHT-group showed a substantial number of mononuclear cells. The distribution of mononuclear cells in separate individuals were as follows: 69-95% OKT3 +/Leu4+ cells (T-lymphocytes), 50-64% OKT4 +/Leu3 + cells (T-helper phenotype) and 29-46% OKT8 + cells (T-suppressor/cytotoxic phenotype). None of the biopsies in the PHT-group contained more than a few scattered plasma cells. The vast majority of all mononuclear cells present in the biopsies reacted with OKIal, a monoclonal antibody defining the HLA-DR framework. In contrast, biopsies from the control group and the gingivitis group contained few mononuclear cells, the majority of which were T-cells. This suggests that immunologic reactions mediated by T-cells may play a role in the pathogenesis of the PHT-induced lesion.     

Synthesis of sulfated glycosaminoglycans by human gingival fibroblasts from phenytoin-induced gingival overgrowth in vitro

Abstract – The in vitro synthesis of sulfated glycosaminoglycans (GAGs) was studied in gingival fibroblasts from two patients exhibiting phenytoin(PHT)-induced gingival overgrowth, i.e. pseudopockets, which required surgical excision, from one patient on PHT medication not exhibiting pseudopockets and from two normal controls. The results showed that the newly synthesized GAGs were distributed to the culture medium, to a pericellular pool and to the cell fraction. Gingival fibroblasts from the PHT-induced gingival overgrowth showed a significantly increased incorporation of ³⁵SO₄^2- into GAGs compared to the other strains, and this, increase was mainly confined to the dermatan sulfate fraction. These results are in accordance with our previous biochemical studies where increased amounts of GAGs were found in gingival biopsies from the PHT-induced lesion.     

The effect of multiple anticonvulsant therapy on the expression of phenytoin-induced gingival overgrowth

The potential effect of co-medication with phenobarbitone, primidone and carbamazepine on plasma and saliva concentrations of 5-(4-hydroxyphenyl)-5-phenylhydantoin (4-HPPH), the major metabolite of phenytoin in man and on the incidence of phenytoin-induced gingival overgrowth was investigated in a group of 36 adult epileptic patients. There were no significant differences in plasma or saliva concentrations of 4-HPPH or phenytoin in patients prescribed phenytoin alone, compared to those who received phenytoin with either phenobarbitone, primidone, or carbamazepine. In addition, the extent and the incidence of gingival overgrowth were similar in the 2 groups. The results suggest that chronic co-medication with other anti-convulsant drugs which induce phenytoin metabolism, does not affect the plasma or saliva 4-HPPB steady-state levels, nor the degree of gingival overgrowth in adult epileptic patients on therapy with phenytoin.     

Relationship of periodontal bacteria and Porphyromonas gingivalis fimA variations with phenytoin-induced gingival overgrowth

OBJECTIVES: We investigated the relationship between phenytoin-induced gingival overgrowth (GO) and the harboring of periodontal bacteria. MATERIALS AND METHODS: Periodontal conditions and subgingival bacterial profiles were examined in 450 sites of 75 subjects. A polymerase chain reaction method was used to detect six bacterial species; Porphyromonas gingivalis (Pg), Actinobacillus actinomycetemcomitans (Aa), Tannerella forsythia, Treponema denticola (Td), Prevotella intermedia (Pi), and Prevotella nigrescens (Pn). Genetic variations of the Pg fimA gene were also examined. Bacterial occurrence was compared with the severity of GO, and alterations in the bacterial occurrence rate and quantities were monitored following periodontal treatment. RESULTS: The occurrences of Aa, Td, Pi, Pn, and Pg with type II fimA (type II Pg) were significantly associated with the severity of GO. Td occurrence was reduced in association with gingival improvement following ultrasonic scaling, however, no such relationship was observed with Aa, Pi, Pn, and Pg. In addition, Pg and Pi markedly persisted after treatment. Clinical improvement of the sites, following an Er:YAG laser treatment, significantly associated with quantitative reduction of Pg in improved sites, however, not that of Pi. CONCLUSION: Type II Pg and Td were each found to have a significant relationship with the development and deterioration of GO.     

Phenytoin metabolism to 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH) in man, cat and rat in vitro and in vivo, and susceptibility to phenytoin-induced gingival overgrowth

Interspecies differences in phenytoin (PHT) metabolism to 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH) were examined in human, cat and rat hepatic microsomes in vitro. Rat liver microsomes were 25 and 650 times more efficient at the conversion of PHT to HPPH than human and cat liver microsomes, respectively. Sulphaphenazole (83%) and tolbutamide (TOL) (64%) were the most potent inhibitors of HPPH formation in human liver microsomes, while ciprofloxacin (27%), enoxacin (27%) and TOL (26%) produced the greatest inhibition in cat liver microsomes. TOL was tested for its effect on HPPH formation and gingival overgrowth in cats in vivo. Eight cats received PHT sodium (4 mg/kg/d) and another 8 cats received PHT sodium together with TOL (20 mg/kg/d) for 10 wk. Six cats (75%) in the PHT group and 4 cats (50%) in the PHT & TOL group developed significant gingival overgrowth by the end of the study. However, the extent and incidence of the overgrowth were similar in the 2 groups. There were no significant differences in mean AUC 0-10 weeks for plasma PHT (552.90 +/- 29.6 micrograms.d/mL [PHT alone] vs. 582.41 +/- 24.49 micrograms.d/mL [PHT & TOL]) and unconjugated HPPH (1016.4 +/- 295.5 ng.d/mL [PHT alone] vs. 1174.5 +/- 397.2 ng.d/mL [PHT & TOL]) concentrations between the 2 groups of cats. Neither PHT nor HPPH were detectable in the plasma of 8 rats which received PHT (4 mg/kg/d) over a 10-wk period. The rats showed no sign of gingival inflammation (mean gingival index = 0) or gingival overgrowth (mean gingival overgrowth index = 0). Thirty-six adult epileptic patients on chronic PHT therapy were examined; 17 (47%) of the patients demonstrated clinically significant overgrowth. The mean steady-state plasma PHT concentration was comparable to, and the mean plasma unconjugated HPPH concentration 5-fold greater than, that observed in the cats. The results suggest that the rapid metabolism and elimination of PHT and HPPH in the rat may enable it to become more resistant towards developing gingival overgrowth, compared to the cat and man.     

The pharmacokinetics of phenytoin in gingival crevicular fluid and plasma in relation to gingival overgrowth

Abstract The aim of this study was to determine whether phenytoin (PHT) could be detected in gingival crevicular fluid (GCF), and to relate its concentration to both plasma level and degree of gingival overgrowth. 23 patients medicated with phenytoin for at least 6 months were clinically examined for signs of periodontal disease and gingival overgrowth. 12 patients out of these demonstrated clinically significant overgrowth and their plaque scores and gingival inflammation were greater than for the non-overgrowth group (p<0.001). Phenytoin concentrations were determined by high performance liquid chromatography, and was detected in GCF. There was a significant correlation between the GCF and plasma phenytoin concentrations (p<0.05), but it was not related to the extent of gingival overgrowth. Inflammation increased the GCF volume, but was not a determinant of GCF phenytoin concentration. It is concluded that effusion of phenytoin into GCF is regulated by the plasma levels of the drug, but its concentration in GCF is not related to the incidence of gingival overgrowth.     

Factors influencing phenytoin-induced gingival enlargement

AIM: To ascertain the prevalence and severity of phenytoin-induced gingival enlargement (PIGE) as well as the relationship between PIGE and risk factors. METHOD: An outpatient population of patients on phenytoin treatment and attending the epilepsy clinic at Prince Mshiyeni Memorial Hospital (PMMH) in Durban, South Africa, was requested to participate. A structured questionnaire was used to collect data on patients' demographics, social habits (e.g., drinking and smoking), dental and oral hygiene practices and medication history. Gingival enlargement, dental plaque and gingival bleeding was also measured to assess gingival health. Venous blood was collected for serum folate and phenytoin serum levels measurements. A regression analyses was then undertaken to ascertain the association between PIGE and the risk factors. Factors tested for correlation were serum phenytoin and folate levels, age, bacterial plaque, gingival inflammation, toothbrushing, smoking and alcohol consumption. The association between PIGE and the risk factors was assessed either individually, i.e., as a single entity or in combination--multifactorially. RESULTS: Of the 134 patients studied, 62% had PIGE scores > or = 1, while 8% had a PIGE score of zero. With the exception of plaque, which showed a moderate association with PIGE (r=0.4), no other factor on its own was statistically significantly related to PIGE. In the multiple linear regression analysis, factors which on their own did not have a strong influence became more important. Bacterial plaque (p=0.0001), younger age (p=0.01) and higher free serum phenytoin levels (p= 0.03), were associated with PIGE. Although known to be associated with periodontal diseases, smoking and alcohol, (p=0.03 and p=0.04 respectively), appeared to give some protection against PIGE. CONCLUSION: Risk factors associated with PIGE may have a synergistic effect. Bacterial plaque, however, appears the most important determinant of PIGE severity. This latter finding emphasises the importance of instituting a preventive plaque-control programme, particularly in young patients on phenytoin therapy.     

Incidence and severity of phenytoin-induced gingival overgrowth in epileptic patients in General Medical Practice

This investigation examines the incidence of phenytoin-induced gingival overgrowth in a population of epileptic patients who attend General Medical Practices for treatment of their epilepsy and compares the gingival changes with an otherwise healthy group of patients. The plaque score, gingival index, and gingival overgrowth did not differ significantly between the two groups (P > 0.05). A significant correlation was observed between plaque score and gingival overgrowth in the phenytoin-treated patient, but in this group there was no correlation between gingival overgrowth and salivary concentration of the drug. The overall incidence of clinically significant overgrowth (13%) is considerably less than in other studies.     

The pathogenesis of drug-induced gingival overgrowth

Abstract Gingival overgrowth is a well-documented unwanted effect, associated with phenytoin, cyclosporin. and the calcium channel blockers. The pathogenesis of drug-induced gingival overgrowth is uncertain, and there appears to be no unifying hypothesis that links together the 3 commonly implicated drugs. In this review, we consider a multifactorial model which expands on the interaction between drug and/or metabolite, with the gingival fibroblasts. Factors which impact upon this model include age. genetic predisposition, pharmacokinetic variables, plaque-induced inflammatory and immunological changes and activation of growth factors. Of these, genetic factors which give rise to fibroblast heterogeneity, gingival inflammation, and pharmacokinetic variables appear to be significant in the expression of gingival overgrowth, A more thorough understanding of the pathogenesis of this unwanted effect will hopefully elucidate appropriate mechanisms for its control.     

Altered collagen metabolism in nifedipine-induced gingival overgrowth

Fibroblasts from nifedipine-induced fibrotic gingiva (NFG) have been characterized with respect to several cellular functions which could contribute to the characteristic clinical overgrowth of the gingiva: collagen synthesis and breakdown, glycosaminoglycan production, fibronectin synthesis, and proliferation. Histologic examination of NFG tissue revealed a hyperplastic epithelium with elongated, branched rete pegs. The connective tissue consisted of densely-packed collagen fibers and numerous enlarged fibroblasts, as well as regions of thinner, disorganized collagen fibers in the vicinity of scattered inflammatory and mast cells. Results of in vitro experiments showed that the fibroblast strains from the fibrotic gingiva (NFG) produced significantly greater amounts of collagen and lower levels of collagenase activity when compared to age- and sex-matched normal human gingival fibroblast strains. The NFG fibroblasts did not produce significantly greater amounts of fibronectin, and their level of glycosaminoglycan production was less than that of the normal fibroblasts. The NFG fibroblasts did not proliferate significantly more rapidly than the normal fibroblast strains. These findings therefore show that there are defects in the regulation of collagen production by NFG fibroblasts in vitro , and suggest that these alterations in collagen metabolism contribute to the over-deposition of collagen in this tissue, rahter than hyperproliferation of the fibroblasts or through the production of increased amounts of fibronectin and glycosaminoglycans.     

Effect of folic acid on recurrence of phenytoin-induced gingival overgrowth following gingivectomy

This study examined the effect of folic acid supplementation on the recurrence of phenytoin-induced gingival overgrowth following gingivectomy. 8 residents of an institution for the developmentally disabled were randomly assigned to a treatment (N = 4) or control (N = 4) group. Subjects in the treatment group received an oral supplementation of 5 mg of folic acid daily during the study; those in the control group did not. A gingivectomy with an external beveled incision made to the crest of the alveolus was completed by quadrants. The following data were obtained prior to gingivectomy, 2 weeks following the last quadrant of surgery, and at 3 and 6 months post-surgery: plaque and gingival index scores, red blood cell folic acid levels, free phenytoin blood levels, photographs, and impressions. % change in overgrowth was determined from cross-sectional area measurements made on dies obtained from bucco-lingual cuts on stone models. Differences across time between and within groups were tested by a two-factor repeated measure analysis of variance. The groups did not differ in plaque and gingival index scores or free phenytoin blood levels. The treatment group had significantly higher red blood cell folic acid levels (p less than or equal to 0.0001). Reduction in gingival overgrowth as a result of surgery was similar in both groups. Although the treatment group had significantly less recurrence of gingival overgrowth (p less than or equal to 0.05), the mean differences amounted to only 6-7% at 3 and 6 months.     

Lack of pathogenic mutations in SOS1 gene in phenytoin-induced gingival overgrowth patients

ObjectiveGingival overgrowth is a side effect associated with some distinct classes of drugs, such as anticonvulsants, immunosuppressants, and calcium channel blockers. One of the main drugs associated with gingival overgrowth is the antiepileptic phenytoin, which affects gingival tissues by altering extracellular matrix metabolism. It has been shown that mutation of human SOS1 gene is responsible for a rare hereditary gingival fibromatosis type 1, a benign gingival overgrowth. The aim of the present study is to evaluate the possible contribution of SOS1 mutation to gingival overgrowth-related phenotype.DesignWe selected and screened for mutations a group of 24 epileptic patients who experienced significant gingival overgrowth following phenytoin therapy. Mutation scanning was carried out by denaturing high-performance liquid chromatography analysis of the entire coding region of the SOS1 gene. Novel identified variants were analyzed in-silico by using Alamut Visual mutation interpretation software, and comparison with normal control group was done.ResultsMutation scanning of the entire coding sequence of SOS1 gene identified seven intronic variants and one new exonic substitution (c.138G > A). The seven common intronic variants were not considered to be of pathogenic importance. The exonic substitution c.138G > A was found to be absent in 100 ethnically matched normal control chromosomes, but was not expected to have functional significance based on prediction bioinformatics tools.ConclusionsThis study represents the first mutation analysis of the SOS1 gene in phenytoin-induced gingival overgrowth epileptic patients. Present results suggest that obvious pathogenic mutations in the SOS1 gene do not represent a common mechanism underlying phenytoin-induced gingival overgrowth in epileptic patients; other mechanisms are likely to be involved in the pathogenesis of this drug-induced phenotype.     

Verapamil-induced gingival overgrowth: a clinical, histologic, and biochemic approach

Verapamil-induced overgrowth was most prominent in the anterior regions and interproximal areas associated with plaque retention. Despite periodontal therapy, overgrowths recurred 1 month after gingivectomy. Discontinuation of the drug resulted in regression of the overgrowths. Histologic findings showed inflamed connective tissue covered by an acanthotic, thickened oral epithelium with long rete pegs containing dyskeratotic pearls. The proliferation rate and protein and collagen production of fibroblasts from the overgrowth sites were markedly lower than in the control cells cultured from healthy gingiva. Incubation of fibroblasts in the presence of verapamil reduced protein and collagen synthesis.     

The effect of a plaque control program on the development of phenytoin-induced gingival overgrowth

The effect of a plaque control program on the development of phenytoin(PHT)-induced gingival overgrowth was studied in 16 epileptic children, 8-16 years of age during a 2-year longitudinal study. The parameters studied were: visible plaque index (VPI), gingival bleeding index (GBI), probing depth and gingival overgrowth. A preventive program was instituted before the start of the PHT-medication and included oral hygiene instruction and frequent professional tooth cleaning during the observation period. When gingival overgrowth was evaluated on the basis of probing depth, no patients on PHT therapy for 2 years developed pseudopockets (greater than or equal to 4 mm). During the 2-year observation period, there was a statistically significant increase (p less than 0.01) in the thickness of the marginal gingiva bucco-lingually in all patients. This gingival enlargement was already evident (p less than 0.01) after 1 month. The degree of gingival enlargement in this patient group did not increase significantly after the 1st year of PHT-medication and was not significantly correlated to the plasma concentration of PHT. The results of this study show that the development of PHT-induced gingival overgrowth could not be prevented by this specific plaque control program.     

Risk factors for drug-induced gingival overgrowth

Background/Aims: Drug‐induced gingival overgrowth remains a significant problem for the periodontologist. Many patients medicated with the drugs implicated in this unwanted effect experience significant, recurrent gingival problems that require repeated surgical excisions. In this review, we attempt to identify and quantify the various “risk factors” associated with both the development and expression of the drug‐induced gingival changes. Method: The risk factors appraised include age, sex, drug variables, concomitant medication, periodontal variables and genetic factors. Elucidation of such factors may help to identify “at risk patients” and then develop appropriate treatment strategies. Results: Of the factors identified, the only one that can be affected by the periodontologist is the patents' periodontal condition. However, drug variables and concomitant medication do impact upon the expression of gingival overgrowth. Conclusion: The identificatioin of risk factors associated with both the prevalence and severity of drug‐induced gingival overgrowth is important for all parties involved with this unwanted effect. Both periodontologist and patient have an important rôle to play in improving oral hygiene and gingival health. Likewise, there is always an opportinity to establish a close liaison between the patient's physician and the periodontologist to try and identify alternative drug regimens that can help reduce the impact of this unwanted effect.     

Effect of phenytoin on intracellular 45Ca2+ accumulation in gingival fibroblasts in vitro

Effect of 5,5 diphenylhydantoin (phenytoin; PHT) alone or in combination with epidermal growth factor (EGF) on the intracellular accumulation of the radioisotope 45Ca2+ (4 min labelling period) was determined in gingival fibroblasts. EGF as well as PHT increased the intracellular accumulation of the radioisotope in normal gingival fibroblasts by approximately 2 and 1.6-fold, respectively. In contrast, in fibroblasts derived from the phenytoin-induced gingival overgrowth, neither EGF nor PHT stimulated intracellular accumulation of 45Ca2+. When normal gingival fibroblasts were treated in vitro with EGF in combination with PHT, the EGF-induced increase in intracellular accumulation of the radioisotope 45Ca2+ was abolished. The rate of efflux of the radioisotope 45Ca2+ in prelabelled normal gingival fibroblasts was decreased by PHT treatment in vitro to a level already present in fibroblasts derived from PHT-induced gingival overgrowth. This study indicates that PHT influences the cellular calcium metabolism in fibroblasts which may contribute to the pathogenesis of gingival overgrowth.     

Effect of phenytoin and nifedipine on collagen gene expression in human gingival fibroblasts

Phenytoin (PHT), a widely used anticonvulsant, and nifedipine (NF), an anti-anginal drug, cause clinically similar gingival overgrowths in some patients. The aim of this work was to investigate their effects on collagen and protein synthesis and cellular proliferation in normal human gingival fibroblasts in vitro. Gingival fibroblasts were cultured from biopsies taken from three healthy individuals during operations on maxillary canines and incubated with various concentrations of NF (100 and 200 ng/ml) and PHT (5 and 10 micrograms/ml) for up to 7 days. The results showed that NF and PHT have a specific effect in reducing total protein and collagen synthesis but do not influence cell proliferation in healthy gingival fibroblasts in vitro. In addition the level of mRNA for type I collagen was decreased after incubation of the cells with the drugs for 1 or 2 days. The decrease in the level of type I collagen mRNA seemed to be specific since the level of type IV collagenase mRNA used as a reference RNA did not decrease.