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1.
J Clin Periodontol ; 45(3): 354-363, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29218774

RESUMO

AIM: This study assessed the impact of anti-infective periodontal therapy on the status of vascular health. MATERIALS AND METHODS: Periodontal and vascular health of 55 patients with severe untreated chronic periodontitis was evaluated before and 12 months after anti-infective periodontal therapy. Observed parameters were bleeding on probing (BoP), pocket probing depth (PPD), periodontal inflamed surface area index (PISA), pulse wave velocity (PWV), augmentation index (AIx), central pulse pressure (PPao) and peripheral systolic pressure (RRsys). RESULTS: ΔPISA (baseline-12 months) correlated with ΔPWV (τ 0.21; p < .03), ΔAIx (τ 0.29; p < .002) and ΔPPao (τ 0.23; p < .02). ΔBoP% (baseline-12 months) correlated with ΔPWV (τ 0.18; p < .05) and ΔAIx (τ 0.25; p < .01), while mean ΔPPD (baseline-12 months) correlated with ΔPWV (τ 0.24; p < .01) and ΔAIx (τ 0.21; p < .03). Grouping patients evenly into three groups based on tertiles of BoP resolution after 12 months revealed a significant decrease in the observed PWV median value by -0.6 m/s (p < .04) in the best response tertile (ΔBoP ≥ 88%). In the worst response tertile (ΔBoP ≤ 66%), by contrast, significant increase in PPao (+10.5 mmHg; p < .02) and AIx (+5.5; p < .02) was observed. CONCLUSION: Efficacious resolution of periodontal inflammation may beneficially impact on vascular health.


Assuntos
Anti-Infecciosos/uso terapêutico , Pressão Sanguínea , Periodontite Crônica/tratamento farmacológico , Periodontite Crônica/fisiopatologia , Rigidez Vascular , Periodontite Crônica/complicações , Humanos , Pessoa de Meia-Idade , Índice Periodontal , Análise de Onda de Pulso
2.
J Adhes Dent ; 15(4): 351-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23593635

RESUMO

PURPOSE: To evaluate the influence of peripheral enamel bonding, chlorhexidine digluconate (CHX) pretreatment, and storage time on resin-dentin microtensile bond strength (µTBS) of a self-etching adhesive system and selfetching cement. MATERIALS AND METHODS: Fifty-six noncarious human third molars were coronally sectioned to provide a flat dentin surface; the circumferential enamel was removed from half of these and the other half was left intact. Pretreatment with 0.2% or 2% CHX or none (control) was performed before bonding composite blocks with Panavia F2.0 or RelyX Unicem to dentin. Specimens were stored in 0.5% chloramine for 3 days (control) or 6 months. Bonded specimens were sectioned into 1-mm2 dentin-only beams and a tensile load was applied until failure. The resulting 14 test groups, defined by control group/storage time/cement/CHX application mode/enamel bonding, were analyzed using two-way and three-way ANOVA, as well as Tukey's HSD post-hoc test (α = 0.05). Failure patterns of the specimens were observed and measured using scanning electron microscopy. RESULTS: The comparison of the control vs experimental subgroups with peripheral enamel bonding and without CHX pretreatment after six months found no significant differences regarding the µTBS between the cements (p > 0.05) but did for the storage time (p <= 0.05). When storing the specimens for six months, the absence of peripheral enamel bonding significantly decreased the µTBS (p <= 0.05). Panavia F2.0 specimens showed significantly higher µTBS values than RelyX Unicem specimens (p <= 0.05). CHX pretreatment, regardless the concentration, showed a significant influence on the µTBS (p <= 0.05). SEM revealed that peripheral enamel bonding reduced failures at the resin/dentin interface. CONCLUSIONS: The absence of peripheral enamel bonding and a longer storage time decrease the µTBS of twostep self-etching adhesive system and a one-step self-etching cement. CHX pretreatment of the dentinal surfaces seems to improve the durability of the bond to dentin.


Assuntos
Clorexidina , Colagem Dentária/métodos , Esmalte Dentário , Adesivos Dentinários , Dentina , Cimentos de Resina , Análise de Variância , Clorexidina/química , Corrosão Dentária , Análise do Estresse Dentário , Humanos , Dente Serotino , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração
3.
J Prosthodont ; 22(8): 618-25, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23915027

RESUMO

PURPOSE: The main goal of this study was to establish a new, high precision procedure to evaluate the influence of cement film thickness on the retention of cemented implant-retained crowns. MATERIALS AND METHODS: Ninety-six tapered titanium abutments (6° taper, 4.3 mm diameter, Camlog) were shortened to 4 mm. Computer-aided design was used to design the crowns, and selective laser sintering, using a cobalt-chromium alloy, was used to produce the crowns. This method used a focused high-energy laser beam to fuse a localized region of metal powder to build up the crowns gradually. Before cementing, preset cement film thicknesses of 15, 50, 80, or 110 µm were established. Glass ionomer, polycarboxylate, or resin cements were used for cementation. After 3 days storage in demineralized water, the retention of the crowns was measured in tension using a universal testing machine. RESULTS: The cement film thicknesses could be achieved with a high level of precision. Interactions between the factors cement and cement film thickness could be found (p ≤ 0.001). For all cements, crown retention decreased significantly between a cement film thickness of 15 and 50 µm (p ≤ 0.001). At 15 µm cement film thickness, the resin cement was the most retentive cement, followed by the polycarboxylate and then the glass ionomer cement (p ≤ 0.05). CONCLUSIONS: The results suggest that cement film thickness has an influence on the retentive strength of cemented implant-retained crowns.


Assuntos
Coroas , Cimentos Dentários/química , Retenção em Prótese Dentária , Prótese Dentária Fixada por Implante , Cimentação/métodos , Ligas de Cromo/química , Desenho Assistido por Computador , Dente Suporte , Implantes Dentários , Materiais Dentários/química , Planejamento de Prótese Dentária , Análise do Estresse Dentário/instrumentação , Cimentos de Ionômeros de Vidro/química , Humanos , Lasers , Teste de Materiais , Cimento de Policarboxilato/química , Cimentos de Resina/química , Estresse Mecânico , Propriedades de Superfície , Fatores de Tempo , Titânio/química , Água/química
4.
Clin Oral Implants Res ; 23(8): 930-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21722192

RESUMO

OBJECTIVES: The main goals of this in vitro study were to evaluate the influence of thermocycling, ultrasonic stress and the removal force preload on the retrievability of cemented implant crowns using a clinical removal device (Coronaflex) and evaluating the tensile strength using a universal testing machine (UTM). METHODS: Thirty-six crowns were cast from a Co-Cr alloy for 36 tapered titanium abutments (5° taper, 4.3 mm diameter, 6 mm height, Camlog, Germany). The crowns were cemented with a glass-ionomer (Ketac Cem) or a polycarboxylate (Durelon) cement, followed by 3 days of storage in ionized water without thermocycling or 150 days of storage with 37,500 thermal cycles between 5°C and 55°C. Before removal, the crowns were subjected to ultrasonic stress for 0, 5 or 10 min with a contact pressure of either 50 or 500 g. The Coronaflex was used with a removal force preload of 50 or 400 cN, respectively, applied on the point of loading. Scanning electronic microscopy (SEM) was used to evaluate the impact of the removal on the abutment screws. RESULTS: Crowns cemented with the glass-ionomer cement were significantly easier to remove with the Coronaflex or the UTM than crowns cemented with the polycarboxylate cement (P≤0.05). Ultrasonic stress showed no significant impact on the retrievability regardless of the contact pressure or duration applied (P>0.05). No significant differences could be found for both cements when removed with the Coronaflex or the UTM (P>0.05) after thermocycling was applied. A removal force preload of 400 cN resulted in significantly reduced removal attempts in comparison with 50 cN for both cements (P≤0.05). CONCLUSIONS: Ultrasound and thermal cycling did not result in reduced cement strength, but to retrieve the crowns, the full impact of a removal instrument has to be applied. Ketac Cem can be used as a "semipermanent" solution, whereas Durelon might serve for permanent cementation. None of the abutment screws showed signs of wear caused by the removal process.


Assuntos
Coroas , Prótese Dentária Fixada por Implante , Remoção de Dispositivo/instrumentação , Ultrassom , Análise de Variância , Cimentação , Cromo , Cobalto , Dente Suporte , Retenção em Prótese Dentária , Cimentos de Ionômeros de Vidro , Temperatura Alta , Técnicas In Vitro , Óxido de Magnésio , Microscopia Eletrônica de Varredura , Cimento de Policarboxilato , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração , Titânio , Óxido de Zinco
5.
Int J Colorectal Dis ; 26(11): 1483-91, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21800050

RESUMO

OBJECTIVES: The pathogenesis of rectal prolapse (RP) defined by a circumferential, full-thickness invagination of the rectal wall into the anal canal is controversial. RP is normally encountered in elderly women and attributed to several etiological factors (e.g., advanced age, pudendal nerve injury, laxity of supporting ligaments). RP affecting young male patients is unlikely to be explained by these factors and may be due to a rectal motility disorder. Therefore, the enteric nervous system (ENS) as key regulator of intestinal motility was evaluated by a systematic morphometric analysis. PATIENTS AND METHODS: Full-thickness rectosigmoid specimens obtained from young male patients with symptomatic RP (n = 5) and male controls (n = 15) were processed for conventional histology and immunohistochemistry using anti-HuC/D as pan-neuronal marker. Enteric ganglia, nerve and glial cells were quantified separately in the myenteric (MP) and submucosal plexus (SMP). RESULTS: Compared to controls, patients with RP showed significantly (p < 0.05) increased mean ganglionic area both in MP and SMP, increased mean neuronal content of submucosal ganglia, and nearly threefold higher frequency of submucosal ganglia containing ≥7 neurons. CONCLUSION: The morphometric analysis reveals distinct quantitative alterations of the ENS in young male patients with RP mainly characterized by submucosal hyperganglionosis similar to histopathological features described in intestinal neuronal dysplasia. The data give evidence that RP in this unusual subgroup is associated with morphological changes of enteric ganglia which may contribute to the development of RP and complement established etiological concepts.


Assuntos
Sistema Nervoso Entérico/patologia , Prolapso Retal/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Contagem de Células , Feminino , Gânglios/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Plexo Mientérico/patologia , Neuroglia/patologia , Neurônios/patologia , Prolapso Retal/complicações , Plexo Submucoso/patologia
6.
Int J Prosthodont ; 29(1): 83-90, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26757337

RESUMO

PURPOSE: The main goal of this in-vitro study was to evaluate whether tensile strength and retrievability of cemented implant-retained crowns correlate when using artificial aging. MATERIALS AND METHODS: A total of 128 crowns were fabricated from a cobalt-chromium alloy for 128 tapered titanium abutments (6 degrees taper, 4.3 mm diameter, 4 mm length, Camlog). The crowns were cemented with glass-ionomer (Ketac Cem, 3M) or resin cements (Multilink Implant, Telio CS Cem [Ivoclar Vivadent], Retrieve [Parkell]). Multilink Implant was used without priming. The experimental groups were subjected to either 37,500 thermal cycles between 5°C and 55°C, 1,200,000 chewing cycles, or a combination of both. Control groups were stored for 10 days in deionized water. The crowns were removed with a universal testing machine or a clinically used removal device (Coronaflex, KaVo). Data were statistically analyzed using nonparametrical tests. RESULTS: Retention values were recorded between 31 N and 362 N. Telio CS Cem showed the lowest retention values, followed by Retrieve, Ketac Cem, and Multilink Implant (P≤.0001). The number of removal attempts with the Coronaflex were not significantly different between the cements (P>.05). Thermal cycling and chewing simulation significantly influenced the retrieval of Retrieve Telio CS Cem, and Ketac Cem specimens (P≤.05). Only for Multilink Implant and Telio CS Cem correlations between removal with the universal testing machine and the Coronaflex could be revealed (P≤.0001). CONCLUSIONS: Ketac Cem and Multilink Implant (without silane) can be used for a semipermanent cementation. Retrieve and Telio CS Cem are recommendable for a temporary cementation.


Assuntos
Cimentação/métodos , Coroas , Implantes Dentários , Prótese Dentária Fixada por Implante , Força de Mordida , Ligas de Cromo/química , Desenho Assistido por Computador , Dente Suporte , Descolagem Dentária/instrumentação , Materiais Dentários/química , Retenção em Prótese Dentária , Análise do Estresse Dentário/instrumentação , Cimentos de Ionômeros de Vidro/química , Humanos , Teste de Materiais , Cimentos de Resina/química , Temperatura , Resistência à Tração , Fatores de Tempo , Titânio/química , Água/química
7.
Int J Prosthodont ; 28(1): 60-4, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25588175

RESUMO

In this study, the influence of restoration type, symmetry, and color on the perception of dental appearance was evaluated. An esthetic questionnaire was completed by 29 patients before and after esthetic rehabilitation. In addition, 94 dentists from four countries (Germany, the United Kingdom [UK], China, and Switzerland) evaluated the influence of the above factors using before-and-after rehabilitation pictures. The most invasive treatment was recommended by Chinese dentists, while German, Swiss, and UK dentists recommended comparable treatment options. As for restorative symmetry, restoration type, and color, significant differences could be found among and within the dentists of the four countries (P ± .05).


Assuntos
Planejamento de Prótese Dentária , Prótese Dentária , Estética Dentária , Pigmentação em Prótese , Atitude do Pessoal de Saúde , Atitude Frente a Saúde , China , Coroas/psicologia , Prótese Dentária/psicologia , Planejamento de Prótese Dentária/psicologia , Restauração Dentária Permanente/psicologia , Facetas Dentárias/psicologia , Prótese Parcial Fixa/psicologia , Prótese Parcial Removível/psicologia , Feminino , Alemanha , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Satisfação do Paciente , Fotografia Dentária/métodos , Pigmentação em Prótese/psicologia , Suíça , Clareamento Dental/psicologia , Reino Unido , Escala Visual Analógica
8.
Int J Esthet Dent ; 10(3): 486-99, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26171449

RESUMO

AIM: One of the most challenging tasks in daily practice when it comes to defining treatment goals and how to attain them is the communication with the patient and the self-reflection of the treating dentist. Failures due to mis-communication are common, especially in esthetic dentistry. The purpose of this study was to evaluate the influence of dental education on students' and dentists' judgment of patients' dental appearance. MATERIALS AND METHODS: Based on internationally accepted guidelines about dental esthetics, a questionnaire was developed to measure "dental appearance" (QDA). Eleven items defined a QDA score (0 = "absolutely dissatisfied", 100 = "absolutely satisfied"). The QDA was completed by 29 patients (21 women, 8 men) before and after a complete oral rehabilitation, including restoration of the anterior teeth. Overall, 95 students (1st, 5th, and 10th Semester) and 30 dentists evaluated the patients' esthetics before and after rehabilitation on a visual analog scale (VAS; 0 = "absolutely unesthetic", 100 = "absolutely esthetic"). RESULTS: Students and dentists alike judged a significant esthetic improvement after treatment (P ≤ 0.0001). Significant differences could be found when comparing the students' and dentists' judgment and the patients' self-evaluation (P ≤ 0.05). CONCLUSION: Since it seems that students judge dental appearance differently from patients' self-assessment, teaching esthetic rules at university should incorporate the aspect of patient feedback in order to avoid misconceptions.


Assuntos
Odontólogos/psicologia , Educação em Odontologia/organização & administração , Estética Dentária , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
PLoS One ; 9(11): e112681, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25393241

RESUMO

BACKGROUND: Targeted and stringent measures of tuberculosis prevention are necessary to achieve the goal of tuberculosis elimination in countries of low tuberculosis incidence. METHODS: We ascertained the knowledge about tuberculosis risk factors and stringency of tuberculosis prevention measures by a standardized questionnaire among physicians in Germany involved in the care of individuals from classical risk groups for tuberculosis. RESULTS: 510 physicians responded to the online survey. Among 16 risk factors immunosuppressive therapy, HIV-infection and treatment with TNF-antagonist were thought to be the most important risk factors for the development of tuberculosis in Germany. Exposure to a patient with tuberculosis ranked on the 10th position. In the event of a positive tuberculin-skin-test or interferon-γ release assay only 50%, 40%, 36% and 25% of physicians found that preventive chemotherapy was indicated for individuals undergoing tumor necrosis factor-antagonist therapy, close contacts of tuberculosis patients, HIV-infected individuals and migrants, respectively. CONCLUSIONS: A remarkably low proportion of individuals with latent infection with Mycobacterium tuberculosis belonging to classical risk groups for tuberculosis are considered candidates for preventive chemotherapy in Germany. Better knowledge about the risk for tuberculosis in different groups and more stringent and targeted preventive interventions will probably be necessary to achieve tuberculosis elimination in Germany.


Assuntos
Antituberculosos/uso terapêutico , Atitude , Erradicação de Doenças/organização & administração , Médicos/psicologia , Tuberculose Pulmonar/prevenção & controle , Adulto , Fármacos Anti-HIV/uso terapêutico , Coinfecção , Coleta de Dados/estatística & dados numéricos , Feminino , Alemanha , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Fatores de Risco , Migrantes , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo
10.
Int J Prosthodont ; 27(6): 523-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25390865

RESUMO

PURPOSE: The purpose of this study was to compare patients' and dentists' perception of dental appearance. MATERIALS AND METHODS: Based on internationally accepted guidelines about dental esthetics, a questionnaire was developed to measure "dental appearance" (QDA). Eleven items defined a QDA score (0 = "absolutely dissatisfied" to 100 = "absolutely satisfied"). The QDA was completed by 29 patients (21 women, 8 men) before and after a complete oral rehabilitation that included restoration of the maxillary anterior teeth. Overall, 94 dentists from four countries (Germany, the United Kingdom, China, and Switzerland) evaluated the esthetics before and after rehabilitation on a visual analog scale (VAS: 0 = "absolutely unesthetic" to 100 = "absolutely esthetic"). RESULTS: Patients and dentists of all countries found a significant esthetic improvement after treatment (P ≤ .0001). Significant differences could be found when comparing the evaluation of the dentists from the various countries among one another and with the patients' self-evaluation (P ≤ .05). With the exception of the professional rating of the initial situation, no gender-related differences could be found in any of the test groups. CONCLUSIONS: In daily practice, it seems of utmost importance for dentists to incorporate the patients' feedback in order to avoid esthetic treatment failures.


Assuntos
Cultura , Prótese Dentária/psicologia , Estética Dentária , Adulto , Idoso , Atitude do Pessoal de Saúde , Atitude Frente a Saúde , China , Coroas/psicologia , Restauração Dentária Permanente/psicologia , Facetas Dentárias/psicologia , Odontólogos/psicologia , Prótese Parcial Fixa/psicologia , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Autoimagem , Suíça , Resultado do Tratamento , Reino Unido , Escala Visual Analógica , Adulto Jovem
11.
J Zhejiang Univ Sci B ; 15(7): 649-60, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25001224

RESUMO

The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (µTBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and µTBS was tested and analyzed. With the exception of SB (no TM application) and GB, the µTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P≤0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the µTBS of GB (no EDTA) and SB (with EDTA) after 3 d (P≤0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest µTBS values followed by GB and SB (P≤0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on µTBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on µTBS of dentin bonds after a period of 6 months.


Assuntos
Caseínas/química , Colagem Dentária , Resinas Sintéticas , Camada de Esfregaço , Humanos , Microscopia Eletrônica de Varredura , Fatores de Tempo
12.
Indian J Dent Res ; 23(5): 591-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23422602

RESUMO

OBJECTIVE: This study aimed to investigate the influence of fluoride and an acidic environment on the mechanical properties of NiTi orthodontic wires (NiTiW) in artificial saliva. DESIGN: A prospective laboratory investigation. SETTING: Department of Stomatology, First Affiliated Hospital, Zhejiang University, Hangzhou, China. MATERIALS AND METHODS: Commercial, round 0.016-inch NiTiW were immersed in 0% or 0.05% Natrium-Fluoride-containing artificial saliva at a pH of 4 or 6 for one or three days, respectively. NiTiW were examined with a three-point bending test, Vickers' microhardness tests and surface morphology observation (SEM). RESULTS: A pH of 4 increased microhardness and decreased the three-point bending strength significantly (P≤0.05), whereas immersion time and fluoride concentration had no significant influence on the microhardness or on the three-point bending strength (P>0.05). When examining the test group NiTiWs after three days of immersion at a pH of 4 the SEM revealed a rough surface morphology, a damaged oxide layer and signs of corrosion. CONCLUSIONS: The most influential factor for decreasing the unloading force and increasing the hardness seems to be the pH value, whereas immersion time and NaF addition do not have a major influence.


Assuntos
Cariostáticos/química , Ligas Dentárias/química , Níquel/química , Fios Ortodônticos , Saliva Artificial/química , Fluoreto de Sódio/química , Titânio/química , Ácidos/química , Corrosão , Dureza , Humanos , Concentração de Íons de Hidrogênio , Teste de Materiais , Microscopia Eletrônica de Varredura , Óxidos/química , Maleabilidade , Estudos Prospectivos , Estresse Mecânico , Propriedades de Superfície , Fatores de Tempo
13.
Forensic Sci Int Genet ; 6(6): 778-84, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22459949

RESUMO

A large number of short tandem repeat (STR) markers spanning the entire human X chromosome have been described and established for use in forensic genetic testing. Due to their particular mode of inheritance, X-STRs often allow easy and informative haplotyping in kinship analyses. Moreover, some X-STRs are known to be tightly linked so that, in combination, they constitute even more complex genetic markers than each STR taken individually. As a consequence, X-STRs have proven particularly powerful in solving complex cases of disputed blood relatedness. However, valid quantification of the evidence provided by X-STR genotypes in the form of likelihood ratios requires that the recombination rates between markers are exactly known. In a collaborative family study, we used X-STR genotype data from 401 two- and three-generation families to derive valid estimates of the recombination rates between 12 forensic markers widely used in forensic testing, namely DXS10148, DXS10135, DXS8378 (together constituting linkage group I), DXS7132, DXS10079, DXS10074 (linkage group II), DXS10103, HPRTB, DXS10101 (linkage group III), DXS10146, DXS10134 and DXS7423 (linkage group IV). Our study is the first to simultaneously allow for mutation and recombination in the underlying likelihood calculations, thereby obviating the bias-prone practice of excluding ambiguous transmission events from further consideration. The statistical analysis confirms that linkage groups I and II are transmitted independently from one another whereas linkage groups II, III and IV are characterised by inter-group recombination fractions that are notably smaller than 50%. Evidence was also found for recombination within all four linkage groups, with recombination fraction estimates ranging as high as 2% in the case of DXS10146 and DXS10134.


Assuntos
Mapeamento Cromossômico/métodos , Cromossomos Humanos X , Impressões Digitais de DNA/métodos , Loci Gênicos , Repetições de Microssatélites , Genótipo , Haplótipos , Humanos , Funções Verossimilhança , Reação em Cadeia da Polimerase Multiplex
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