The study of genetic predisposition on periodontitis and peri-implantitis.

Background: Peri-implant mucositis and peri-implantitis cases increase in number with the increase of implant applications. Peri-implant mucositis and peri-implantitis are defined as inflammatory diseases with inflammation and loss in soft and hard tissue, similar to the other periodontal diseases. As observed in many diseases, genetic predisposition factors also affect the progress of periodontitis and peri-implantitis. Aim: This study examines if there is any solid genetic predisposition causing periodontitis and peri-implantitis formation in Turkish patients. Patients & Methods: In order to evaluate single nucleotide polymorphism (SNP), Interleukin-8 (IL-8) and N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP), playing a role in the chemotaxis of neutrophils, and Fc Gamma Receptor IIA (FcγRIIA) and Fc Gamma Receptor IIIA (FcγRIIIA), playing a role in the antigen-antibody complexes and phagocytosis, were selected. Thirty-two Turkish non-smoking subjects, having periodontitis, thirty-three Turkish non-smoking subjects, having peri-implantitis and thirty-three Turkish non-smoking healthy subjects were selected. In total 98 adults participated in our study. Collected saliva samples from the participants were used for DNA isolation. SNPs were determined in these subgroups of the study by means of genotype-specific polymerase chain reactions. Results: When IL-8 A-251T, FcγRIIa -H131 and FcγRIIIa -V158 polymorphism were evaluated, no significant difference was found between periodontitis, peri-implantitis and healthy groups. However, this study observed that fMLP Receptor (FPR1) gene polymorphism creates a significant difference in individuals at higher risk of periodontitis or peri-implantitis. Conclusion: Results show that individuals with the G genotype have a higher risk of periodontitis, while individuals with G / C genotype have higher risk of peri-implantitis.

Evaluation of Local and Systemic Levels of Interleukin-17, Interleukin-23, and Myeloperoxidase in Response to Periodontal Therapy in Patients with Generalized Aggressive Periodontitis.

We aimed to investigate serum and gingival crevicular fluid levels of myeloperoxidase, interleukin-17, and interleukin-23 before and after nonsurgical periodontal therapy in generalized aggressive periodontitis patients and compare to those in healthy controls. Interleukin-17, interleukin-23, and myeloperoxidase levels were measured by enzyme-linked immunosorbent assay in gingival crevicular fluid and serum samples taken from 19 systemically healthy generalized aggressive periodontitis patients and 22 healthy controls. In addition, the levels of IL-17, IL-23, and myeloperoxidase were reassessed at 3 months after periodontal therapy in the generalized aggressive periodontitis (GAP) group. Periodontal clinical parameters were also evaluated at baseline and 3 months post-therapy. The investigated molecule levels in serum decreased significantly at 3 months as a result of the therapy (p = 0.014 for IL-17, p = 0.000 for IL-23, and p = 0.001 for myeloperoxidase (MPO)). Significant reductions were also observed in gingival crevicular fluid (GCF) IL-17, IL-23, and MPO levels at 3 months after therapy (p = 0.000 for all molecules). However, the GCF levels of IL-17, IL-23, and MPO in GAP patients were still higher than those in the controls at 3 months (p = 0.001). A significant decrease in the local and systemic levels of IL-17, IL-23, and MPO based on the therapy might indicate the role of these mediators for tissue destruction in periodontal tissues.

Fluid dynamics of gingiva and gingival health in children with end stage renal failure.

OBJECTIVES: Impaired homeostasis and fluid balance are important physiopathological alterations in patients with chronic renal failure which may adversely affect the fluid dynamics and health status of tissues and organs. There are insufficient data about this phenomenon in periodontal tissues. The aim of this study was to evaluate the fluid dynamics of gingiva in children with end stage renal failure (ESRF), correlating this entity with gingival health in the same patient group. DESIGN: Fifteen paediatric ESRF patients undergoing peritoneal dialysis (test group) and 15 systemically healthy children (control group) who were without periodontitis participated in the study. Fluid dynamics of gingiva were assessed via the gingival crevicular fluid (GCF) volume and tissue osmotic pressure (GOP) levels in the groups. GCF volume was measured using a Periotron 8000, whereas GOP was measured using a digital osmometer. Silness and Löe Plaque index (PI) and, Löe and Silness gingival index (GI) scores were utilized to determine the gingival health status in the study population. RESULTS: There were increases in the GCF volume and GOP of the test group compared to those of the control group (p<0.01). The PI and GI scores were higher in the test group than in the control group (p<0.01). Strong and positive correlations were found between GI and GCF volume, GI and GOP and, GCF volume and GOP in both groups (p<0.01). CONCLUSIONS: Our findings suggest that the fluid dynamics of gingiva may alter in children with ESRF, and this phenomenon may consequently affect the gingival health of these patients.

Apoptosis in gingival overgrowth tissues.

Variations in the balance between cell proliferation and apoptosis could contribute to the etiology of gingival overgrowth. The aim of this study was to test the hypothesis that, in fibrotic gingival lesions, fibroblast proliferation is stimulated and apoptosis is decreased. Apoptotic index, caspase 3 expression, the proliferative index, FOXO1 expression, and histological inflammation were measured in situ. Analysis of data showed that apoptosis decreased in all forms of gingival overgrowth examined (p < 0.05), and inflammation caused a small but significant increase compared with non-inflamed tissues (p < 0.05). The greatest decrease of apoptosis occurred in the most fibrotic tissues. Cell proliferation was elevated in all forms of gingival overgrowth tested, independent of inflammation (p < 0.05). To identify potential mechanisms of transcriptional regulation of apoptosis, we assessed FOXO1 and caspase 3 expression levels and found them to correlate well with diminished apoptosis. Analysis of data suggests that increased fibroblast proliferation and a simultaneous decrease in apoptosis contribute to gingival overgrowth.

Epithelial and connective tissue cell CTGF/CCN2 expression in gingival fibrosis.

Gingival overgrowth is a side effect of certain medications and occurs in non-drug-induced forms either as inherited (human gingival fibromatosis) or idiopathic gingival overgrowth. The most fibrotic drug-induced lesions develop in response to therapy with phenytoin; the least fibrotic lesions are caused by cyclosporin A; and intermediate fibrosis occurs in nifedipine-induced gingival overgrowth. Connective tissue growth factor (CTGF/CCN2) expression is positively related to the degree of fibrosis in these tissues. The present study has investigated the hypothesis that CTGF/CCN2 is expressed in human gingival fibromatosis tissues and contributes to this form of non-drug-induced gingival overgrowth. Histopathology/immunohistochemistry studies showed that human gingival fibromatosis lesions are highly fibrotic, similar to phenytoin-induced lesions. Connective tissue CTGF/CCN2 levels were equivalent to the expression in phenytoin-induced gingival overgrowth. The additional novel observation was made that CTGF/CCN2 is highly expressed in the epithelium of fibrotic gingival tissues. This finding was confirmed by in situ hybridization. Real-time polymerase chain reaction (PCR) analyses of RNA extracted from drug-induced gingival overgrowth tissues for CTGF/CCN2 were fully consistent with these findings. Finally, normal primary gingival epithelial cell cultures were analysed for basal and transforming growth factor beta1 (TGF-beta1) or lysophosphatidic acid-stimulated CTGF/CCN2 expression at protein and RNA levels. These data indicate that fibrotic human gingival tissues express CTGF/CCN2 in both the epithelium and connective tissues; that cultured gingival epithelial cells express CTGF/CCN2; and that lysophosphatidic acid further stimulates CTGF/CCN2 expression. These findings suggest that interactions between epithelial and connective tissues could contribute to gingival fibrosis.

MMP20 active-site mutation in hypomaturation amelogenesis imperfecta.

The Amelogenesis Imperfecta (AI) are a group of clinically and genetically heterogeneous disorders that affect enamel formation. To date, mutations in 4 genes have been reported in various types of AI. Mutations in the genes encoding the 2 enamel proteases, matrix metalloproteinase 20 (MMP20) and kallikrein 4 (KLK4), have each been reported in a single family segregating autosomal-recessive hypomaturation AI. To determine the frequency of mutations in these genes, we analyzed 15 Turkish probands with autosomal-recessive hypomaturation AI for MMP20 and KLK4 gene mutations. No KLK4 mutations were found. A novel MMP20 mutation (g.16250T>A) was found in one family. This missense mutation changed the conserved active-site His226 residue of the zinc catalytic domain to Gln (p.H226Q). Zymogram analysis demonstrated that this missense mutation abolished MMP20 proteolytic activity. No MMP20 mutations were found in the remaining 14 probands, underscoring the genetic heterogeneity of hypomaturation AI.

Phenotype of ENAM mutations is dosage-dependent.

Five mutations in the ENAM gene have been found to cause hypoplastic amelogenesis imperfecta (AI), with phenotypes ranging from localized enamel pitting in carriers to severe hypoplastic AI. To determine the generality of ENAM mutations in hypoplastic AI, we sequenced the ENAM gene in ten Turkish families segregating autosomal hypoplastic AI. In two families, ENAM mutations were found. A novel nonsense mutation (g.12663C>A; p.S246X) was identified in one family segregating local hypoplastic AI as a dominant trait. Affected individuals in a second family segregating autosomal-recessive AI were compound heterozygotes for a novel insertion mutation (g.12946_12947insAGTCAGTACCAGTACTGTGTC) and a previously described insertion (g.13185_13186insAG) mutation. Heterozygous carriers of either insertion had a localized enamel-pitting phenotype. These findings substantiate that enamel phenotypes of ENAM mutations may be dose-dependent, with generalized hypoplastic AI segregating as a recessive trait and localized enamel pitting segregating as a dominant trait.

Radiological evaluation of sinus lift operation: what the general radiologist needs to know.

This article provides an overview of the sinus lift operation, including radiographic evaluation of the procedure. Plain radiographs such as dental or panoramic radiographs have conventionally been used to measure the bone volume in the operation site, but full three-dimensional assessment of the region before and after the sinus lift operation is advisable both to allow planning of the lift and to see the results of it. The general radiologists sometimes misinterpret the graft material used in sinus lift cases as odontogenic tumour or some other pathology. The aim of this article is to put an end to this wrong interpretation and to familiarize the general radiologist with pre-operative and post-operative imaging of sinus lift cases.

Novel ENAM mutation responsible for autosomal recessive amelogenesis imperfecta and localised enamel defects.

The genetic basis of non-syndromic autosomal recessive forms of amelogenesis imperfecta (AI) is unknown. To evaluate five candidate genes for an aetiological role in AI. In this study 20 consanguineous families with AI were identified in whom probands suggested autosomal recessive transmission. Family members were genotyped for genetic markers spanning five candidate genes: AMBN and ENAM (4q13.3), TUFT1 (1q21), MMP20 (11q22.3-q23), and KLK4 (19q13). Genotype data were evaluated to identify homozygosity in affected individuals. Mutational analysis was by genomic sequencing. Homozygosity linkage studies were consistent for localisation of an AI locus in three families to the chromosome 4q region containing the ENAM gene. ENAM sequence analysis in families identified a 2 bp insertion mutation that introduced a premature stop codon in exon 10. All three probands were homozygous for the same g.13185_13186insAG mutation. These probands presented with a generalised hypoplastic AI phenotype and a class II openbite malocclusion. All heterozygous carriers of the g.13185_13186insAG mutation had localised hypoplastic enamel pitting defects, but none had AI or openbite. The phenotype associated with the g.13185_13186insAG ENAM mutation is dose dependent such that ARAI with openbite malocclusion segregates as a recessive trait, and enamel pitting as a dominant trait.

Radiologic and histomorphometric evaluation of maxillary sinus grafting with alloplastic graft materials.

BACKGROUND: Sinus lifting procedures are widely used to obtain adequate bony support for implant placement at the atrophic maxillae. The aim of this study was to compare various sinus lifting and grafting techniques and materials. METHODS: Nine maxillae were treated with delayed and 46 maxillae with immediate implant placement techniques. A total of 104 implants were inserted. Panoramic radiographs were obtained prior to, after, and 6 to 8 months after surgery. Computed tomographies were also taken before and after surgery. The height of new bone was compared. Biopsy specimens were obtained during delayed implant placement and analyzed histomorphologically. RESULTS: There were no statistically significant differences between the panoramic radiographs for delayed and immediately placed implants, or between the graft materials. We observed correlations between the panoramic radiographs and computerized tomographies. CONCLUSION: Both delayed and immediate placement of implants can be used safely for sinus lifting. There were no statistically significant differences between the various graft materials.

Evaluation of human leukocyte N-formylpeptide receptor (FPR1) SNPs in aggressive periodontitis patients.

Polymorphonuclear neutrophils (PMNs) are attracted to sites of infection by N-formylpeptide (fMLP) chemoattractants. The high-affinity fMLP receptor (FPR1) of phagocytic cells interacts with bacterial fMLP and mediates chemotaxis, degranulation, and superoxide production. These cellular functions are disrupted in PMN from aggressive periodontitis (AP) patients. Two FPR1 gene single nucleotide polymorphisms (SNPs), c.329T>C and c.378C>G, have been associated with a localized form of AP in African-American patients. To evaluate the generality of these SNPs in AP patients, we sequenced a 363 bp interval of the FPR1 gene in an ethnically diverse group of patients (n=111) and controls (n=115). Neither c.329T>C nor c.378C>G were detected in the 452 alleles sequenced. Six SNPs were identified including two located in the FPR1 second extracellular loop that were significantly associated with the AP phenotype in African-American patients (p.R190W, P=0.0033; and p.N192K, P=0.0018). These two SNPs show three predominant haplotypes, each associated with a different disease risk in African-Americans. These data do not support the hypothesis that the FPR1 SNPs c.329T>C and c.378C>G play an etiologic role in aggressive periodontitis, but do suggest that SNPs in the second extracellular loop may be etiologically important.

Gingival crevicular fluid levels of aspartate amino transferase, sulfide ions and N-benzoyl-DL-arginine-2-naphthylamide in diabetic patients with chronic periodontitis.

BACKGROUND: The aim of this study is to analyze the correlations between plaque index (PlI), gingival index (GI), probable pocket depth (PPD), clinical attachment level (CAL), aspartate aminotransferase (AST), N-benzoyl-DL-arginine-2-naphthylamide (BANA) and sulfide ion activity (SIA) of diabetic patients with chronic periodontitis with regard to disease activity detected by AST levels. MATERIAL AND METHODS: A total of 95 sites from eight diabetic patients with chronic periodontitis and 74 sites from eight systemically healthy patients with chronic periodontitis were enrolled in the study. The patients had no history of periodontal treatment or any antibiotic therapy during the last 6 months and were nonsmokers. All the sites selected for the study had a CAL of at least 2 mm. Gingival crevicular fluid volumes (GCFV) were measured in all sites. RESULTS: According to the result of AST analysis, 45 sites were AST positive and 50 were AST negative in the diabetic group and 36 sites were AST positive and 38 were AST negative in the control group. There was a significant correlation between BANA hydrolysis and PPD in both diabetic and control groups, but no correlation between PPD and AST levels. A significant correlation was observed between AST-positive sites and GI, but not between GI and BANA hydrolysis. In both groups, the correlation between SIA and BANA hydrolysis was significant, but no correlation was revealed between SIA and AST levels in either diabetic or control groups. CONCLUSION: The GCF metabolites had significant correlations with periodontally diseased sites in patients with chronic periodontitis, whether diabetic or systemically healthy, and may help to confirm clinical findings.

Connective tissue growth factor in drug-induced gingival overgrowth.

BACKGROUND: Drug-induced gingival overgrowth is a known side effect of certain chemotherapeutic agents used for the treatment of systemic disorders. The pathogenesis and mechanisms responsible for this condition are not fully understood. This study assesses for the presence and localization of connective tissue growth factor (CTGF) in drug-induced gingival overgrowth tissues. CTGF immunostaining was compared with sections stained with transforming growth factor (TGF)-beta1 and CD31 antibodies in order to investigate possible pathogenic mechanisms. METHODS: Gingival overgrowth samples were obtained from patients undergoing therapy with phenytoin (n = 9), nifedipine (n = 4), cyclosporin A (n = 5), and control tissues from systemically healthy donors (n = 9). Tissue sections were subjected to peroxidase immunohistochemistry and were stained with CTGF and TGF-beta1 polyclonal primary antibodies. Possible relationships between CTGF staining and angiogenesis were also studied using an anti-CD31 antibody as a marker for endothelial cells. Staining was analyzed by computer-assisted quantitative and semiquantitative methodology at 5 defined sites in all samples based on the location of specific landmarks including epithelium and underlying connective tissues. RESULTS: Cellular and extracellular CTGF content in phenytoin gingival overgrowth tissues was significantly (P<0.05) higher compared to the other gingival overgrowth tissues and the controls. Higher CTGF staining in phenytoin gingival overgrowth tissues was accompanied by an increased abundance of fibroblasts and connective tissue fibers. No strong association of CTGF staining with TGF-beta1 or CD31 staining was found. CONCLUSIONS: The data from the present study show significantly higher CTGF staining in phenytoin-induced gingival overgrowth tissues compared to controls, cyclosporin A-, or nifedipine-induced gingival overgrowth. Moreover, semiquantitative analyses of histologic samples support the concept that the phenytoin overgrowth tissues are fibrotic. These associations suggest a possible role for CTGF in promoting development of fibrotic lesions in phenytoin-induced gingival overgrowth.

Treatment of aggressive periodontitis by osseointegrated dental implants. A case report.

BACKGROUND: Generalized aggressive periodontitis is described as a clinical entity affecting both deciduous and permanent dentition with extensive alveolar bone loss, mobility, and exfoliation of all or many teeth. Controversy exists on dental implant use to restore missing dentition in younger patients. METHODS: This case report presents a patient diagnosed with aggressive periodontitis who has lost all but 4 of her teeth. Her personal and functional desires led us to include implant therapy in her treatment plan. The hematological data are presented with an analysis of the immunological profile. RESULTS: Dental implants were placed, and following 3 months of osseointegration, an implant-supported prosthesis was completed. The patient was followed up for 36 months. CONCLUSIONS: This case report presents an alternative treatment for rehabilitating dentition in a young patient treated for aggressive periodontitis. Similar case studies may help eliminate some of the controversy that exists regarding the use of dental implants in aggressive periodontitis patients.

Evidence of a founder effect for four cathepsin C gene mutations in Papillon-Lefèvre syndrome patients.

We describe a mutation and haplotype analysis of Papillon-Lefèvre syndrome probands that provides evidence of a founder effect for four separate cathepsin C mutations. A total of 25 different cathepsin C mutations have been reported in 32 families with Papillon-Lefèvre syndrome (PLS) and associated conditions. A characteristic of these findings is the diversity of different cathepsin C mutations that have been identified. To evaluate the generality of cathepsin C mutations, PLS probands representative of five reportedly unrelated Saudi Arabian families were evaluated by mutational and haplotype analyses. Sequence analysis identified two cathepsin C gene mutations: a novel exon 7 G300D mutation was found in the proband from one family, while probands from four families shared a common R272P mutation in exon 6. The R272P mutation has been previously reported in two other non-Saudi families. The presence of the R272P mutation in probands from these four Saudi families makes this the most frequently reported cathepsin C mutation. To distinguish between the presence of a possible founder effect or a mutational hot spot for the R272P mutation, we performed haplotype analysis using six novel DNA polymorphisms that span a 165 kb interval containing the cathepsin C gene. Results of haplotype analysis for genetic polymorphisms within and flanking the cathepsin C gene are consistent with inheritance of the R272P mutation "identical by descent" from a common ancestor in these four Saudi families. Haplotype analysis of multiple PLS probands homozygous for other cathepsin C mutations (W249X, Q286X, and T153I) also supports inheritance of each of these mutations from common ancestors. These data suggest that four of the more frequently reported cathepsin C mutations have been inherited from common ancestors and provide the first direct evidence for a founder effect for cathepsin C gene mutations in PLS. Identification of these six short tandem repeat polymorphisms that span the cathepsin C gene will permit haplotype analyses to determine other founder haplotypes of cathepsin C mutations in additional PLS families.

Haim-Munk syndrome and Papillon-Lefèvre syndrome are allelic mutations in cathepsin C.

Of the many palmoplantar keratoderma (PPK) conditions, only Papillon-Lefèvre syndrome (PLS) and Haim-Munk syndrome (HMS) are associated with premature periodontal destruction. Although both PLS and HMS share the cardinal features of PPK and severe periodontitis, a number of additional findings are reported in HMS including arachnodactyly, acro-osteolysis, atrophic changes of the nails, and a radiographic deformity of the fingers. While PLS cases have been identified throughout the world, HMS has only been described among descendants of a religious isolate originally from Cochin, India. Parental consanguinity is a characteristic of many cases of both conditions. Although autosomal recessive transmission of PLS is evident, a more "complex" autosomal recessive pattern of inheritance with phenotypic influences from a closely linked modifying locus has been hypothesised for HMS. Recently, mutations of the cathepsin C gene have been identified as the underlying genetic defect in PLS. To determine if a cathepsin C mutation is also responsible for HMS, we sequenced the gene in affected and unaffected subjects from the Cochin isolate in which both the PLS and HMS phenotypes appear. Here we report identification of a mutation of cathepsin C (exon 6, 2127A--> G) that changes a highly conserved amino acid in the cathepsin C peptide. This mutation segregates with HMS in four nuclear families. Additionally, the existence of a shared common haplotype for genetic loci flanking the cathepsin C gene suggests that affected subjects descended from the Cochin isolate are homozygous for a mutation inherited "identical by descent" from a common ancestor. This finding supports simple autosomal recessive inheritance for HMS in these families. We also report a mutation of the same exon 6 CTSC codon (2126C-->T) in a Turkish family with classical PLS. These findings provide evidence that PLS and HMS are allelic variants of cathepsin C gene mutations.

Identification of cathepsin C mutations in ethnically diverse papillon-Lefèvre syndrome patients.

INTRODUCTION: Papillon-Lefèvre syndrome (PLS) is an autosomal recessive disorder characterised by palmoplantar keratoderma and severe, early onset periodontitis, which results from deficiency of cathepsin C activity secondary to mutations in the cathepsin C gene. To date, 13 different cathepsin C mutations have been reported in PLS patients, all of which are homozygous for a given mutation, reflecting consanguinity. AIM: To evaluate the generality of cathepsin C mutations in PLS, we studied an ethnically diverse group of 20 unrelated families. METHODS: Mutations were identified by direct automated sequencing of genomic DNA amplified for exonic regions and associated splice site junctions of the cathepsin C gene. Long range PCR was performed to determine the genomic structure of the cathepsin C gene. RESULTS: The cathepsin C gene spans over 46 kb, with six introns ranging in size from 1.6 to 22.4 kb. Eleven novel mutations and four previously reported mutations were identified in affected subjects from 14 families. Missense mutations were most common (9/15), followed by nonsense mutations (3/15), insertions (2/15), and deletions (1/15). Among these 14 probands, two were compound heterozygotes. Affected subjects with transgressions of the dermal lesions onto the knees or elbows or both had mutations in both the pro- and mature regions of the enzyme, although most were in the mature region. CONCLUSION: Mutations in the mature region of cathepsin C were more likely to be associated with the transgressions of the dermatological lesions, although the results were not statistically significant. A comprehensive list of all cathepsin C mutations described to date, representing 25 mutations from 32 families with PLS and related conditions, is also presented.