ABSTRACT Objective: To characterize drug hypersensitivity associated with dental treatments. Material and Methods: Data from 5,302 dental patients extracted from the Faculty of Dental Medicine were used to investigate drug use history, drug hypersensitivity, and associations with oral health outcomes. The chi-square test was used, and values of p ≤ 0.05 were considered statistically significant. Results: The frequency of patients’ self-reported drug hypersensitivity was 26.42% (n = 1,401). The highest frequencies were for opioid/narcotic analgesics (20.84%, n = 292), antibiotics (18.13%, n = 961), and non-steroidal anti-inflammatory drugs (10.46%, n = 141). Most of the patients (68.65%, n = 3,640) reported using medications, mostly for cardiovascular disease (43.1%, n = 1,569), for psychiatric/neurological disorders (39.75%, n = 1,447), drugs that affect the endocrine system (32.55%, n= 1,185), and drugs for pain (24.92%, n = 907). Higher drug hypersensitivity frequencies were associated with older White female subjects (p<0.0001). Associations were also identified between drug hypersensitivity and history of the following dental procedures: tooth extractions (p=0.003), root canal treatment (p=0.0004), prosthodontic treatments (p<0.0001), and orthodontic treatments (p=0.007). Conclusion: A high frequency of self-reported drug hypersensitivity in dental patients was found, with a higher occurrence in older White women and those with a history of more extensive and invasive dental care. Objective Methods 5302 5 302 5,30 outcomes chisquare chi square 005 0 05 0.0 significant Results selfreported self 2642 26 42 26.42 1,401. 1401 1,401 . 1 401 1,401) opioidnarcotic opioid narcotic 20.84%, 2084 20 84 (20.84% 292, 292 , 292) 18.13%, 1813 18 13 (18.13% 961, 961 961) nonsteroidal non steroidal antiinflammatory anti inflammatory 10.46%, 1046 10 46 (10.46% 141. 141 141) 68.65%, 6865 68 65 (68.65% 3,640 3640 3 640 medications 43.1%, 431 43 (43.1% 1,569, 1569 1,569 569 1,569) psychiatricneurological psychiatric neurological 39.75%, 3975 39 75 (39.75% 1,447, 1447 1,447 447 1,447) 32.55%, 3255 32 55 (32.55% 1,185, 1185 1,185 185 1,185) 24.92%, 2492 24 92 (24.92% 907. 907 907) p<0.0001. p00001 p<0.0001 0001 (p<0.0001) procedures p=0.003, p0003 p=0.003 003 (p=0.003) p=0.0004, p00004 p=0.0004 0004 (p=0.0004) p<0.0001, p=0.007. p0007 p=0.007 007 (p=0.007) Conclusion found care 530 30 5,3 00 0. 264 2 4 26.4 140 1,40 40 20.84% 208 8 (20.84 29 18.13% 181 (18.13 96 10.46% 104 (10.46 14 68.65% 686 6 (68.65 3,64 364 64 43.1% (43.1 156 1,56 56 39.75% 397 7 (39.75 144 1,44 44 32.55% 325 (32.55 118 1,18 24.92% 249 9 (24.92 90 p0000 p<0.000 000 (p<0.0001 p000 p=0.00 (p=0.003 p=0.000 (p=0.0004 (p=0.007 53 5, 26. 1,4 20.84 (20.8 18.13 (18.1 10.46 (10.4 68.65 (68.6 3,6 36 43.1 (43. 15 1,5 39.75 (39.7 32.55 (32.5 11 1,1 24.92 (24.9 p<0.00 (p<0.000 p00 p=0.0 (p=0.00 (p=0.000 1, 20.8 (20. 18.1 (18. 10.4 (10. 68.6 (68. 3, 43. (43 39.7 (39. 32.5 (32. 24.9 (24. p<0.0 (p<0.00 p0 p=0. (p=0.0 20. (20 18. (18 10. (10 68. (68 (4 39. (39 32. (32 24. (24 p<0. (p<0.0 p=0 (p=0. (2 (1 (6 ( (3 p<0 (p<0. p= (p=0 p< (p<0 (p= (p< (p

ABSTRACT Objective: To identify the clinical presentation of molar incisor hypomineralization (MIH) and hypomineralization of second primary molars (HSPM), including the distribution patterns of presence and severity of lesions, and to investigate the association of risk factors during the pre-and postnatal period with the presence of lesions. Material and Methods: This cross-sectional study was conducted with 160 individuals (72 with MIH/HSPM and 88 without lesions). The symmetry analysis regarding the presence and severity of MIH/HSPM was evaluated in pairs of homologous and opposite teeth. Sociodemographic and medical information was obtained using a detailed questionnaire. Data were analyzed by means of chi-square tests, Student’s t-test, and logistic regression (p<0.05). Results: Symmetry of presence and severity of hypomineralization lesions were present in homologous permanent teeth in 53.8% and 70.5% of cases, respectively, with statistically significant results only for the symmetrical pattern of severity of MIH lesions in the maxillary first molars (p=0.016) and mandibular first molars (p=0.02). Otherwise, a non-symmetric presence was statistically significant in homologous second primary molars (p=0.002) and opposite primary and permanent teeth (p≤0.001). An association between MIH/HSPM and systemic diseases during pregnancy and children medication was found (p<0.05); however, no evidence was found between these and MIH/HSPM severity. Conclusion: The symmetric pattern of severity of MIH lesions was statistically significant in permanent homologous teeth. Risk factors during pre and postnatal periods may be related to MIH/HSPM; however, these do not seem to interact with severity. Objective (MIH HSPM, HSPM , (HSPM) preand Methods crosssectional cross sectional 16 72 (7 MIHHSPM 8 . lesions) questionnaire chisquare chi square tests Students Student s ttest, ttest t test, test t-test p<0.05. p005 p p<0.05 0 05 (p<0.05) Results 538 53 53.8 705 70 5 70.5 cases respectively p=0.016 p0016 016 (p=0.016 p=0.02. p002 p=0.02 02 (p=0.02) Otherwise nonsymmetric non p=0.002 p0002 002 (p=0.002 p≤0.001. p0001 p≤0.001 001 (p≤0.001) however Conclusion (HSPM 1 7 ( p00 p<0.0 (p<0.05 53. 70. p=0.01 p001 01 (p=0.01 p=0.0 (p=0.02 p=0.00 p000 00 (p=0.00 p≤0.00 (p≤0.001 p0 p<0. (p<0.0 (p=0.0 p=0. p≤0.0 (p≤0.00 p<0 (p<0. (p=0. p=0 p≤0. (p≤0.0 p< (p<0 (p=0 p= p≤0 (p≤0. (p< (p= p≤ (p≤0 (p (p≤

ABSTRACT Objective: To analyze caries experience depending on periodontitis affection concomitant or not with cardiovascular risks or mental health issues with the hypothesis that worse accumulated caries experience is not necessarily the result of the presence of concomitant overall health issues. Material and Methods: All subjects of this cross-sectional study were participants of the Dental Registry and DNA Repository project. Variables age, ethnicity, sex, caries experience, periodontitis and mental disease statuses and blood pressure assessment, dental clinical data (DMFT, DMFS and periodontitis) were evaluated and collected from the clinical records. We used chi-square, Fisher's exact, or Student's t-tests to determine differences in frequencies of sex, age, ethnicity, and dental clinical data depending on caries experience, periodontitis, mental health status, and cardiovascular risks. The established alpha was 5%. Results: Of the total 1,437 subjects included in this study, 407 were individuals with high blood pressure and 1,030 were individuals without high blood pressure. Also, 558 were individuals with mental disease and 879 were individuals without mental disease. High blood pressure patients were mostly men (47.17%) and women were the majority when analyzing patients with mental illness (60.04%). Most of the patients in the different groups were white, with a mean age ranging from 15.4 to 88 years. Conclusion: We concluded that caries experience concomitant or not with periodontitis affection does not associate with high blood pressure and mental disease.

ABSTRACT Objective: To assess the association between environmental factors during pregnancy and early childhood with the presence and severity of Molar Incisor Hipomineralization (MIH). Material and Methods: This cross-sectional study was conducted with 120 patients between 7 and 14 years of age. MIH was evaluated according to EAPD criteria. Data collected included the child’s medical history and the mother’s health. Chi-square and logistic regression were performed to determine any statistical evidence of the environmental factors, with the significance level set at 5%. Results: The participants were divided into groups with MIH (n=60) and without MIH (n=60), with average ages of 9.9 (±1.9) and 9.7 (±1.7) years, respectively. There was a statistically significant difference between intercurrences during pregnancy (OR=3.55; IC95%=1.35-10.57) and medication taken by the child (OR=3.01; IC95%=1.74-8.42) and the presence of MIH. In addition, other variables were also associated with the MIH (p≤0.05). However, there was no association with variables and degree of MIH severity (p>0.05). Conclusion: The use of medications in childhood and complications during pregnancy can be association to the presence of MIH. However, these factors do not interaction to MIH severity.

Resumo A homeostasia entre cálcio e fósforo salivares é importante para a manutenção da saúde bucal. O objetivo deste estudo foi avaliar se polimorfismos genéticos no receptor de estrógeno alfa (ESR1), receptor de estrógeno beta (ESR2) e no microRNA17 (microRNA17) estão associados com os níveis salivares de cálcio e fósforo. Saliva de 276 crianças com 12 anos de idade foi coletada com estímulo mastigatório e os níveis de cálcio e fósforo foram determinados por Espectrofotometria de Massa. O DNA genômico foi extraído da saliva remanescente e os polimorfismos genéticos em ESR1 (rs12154178, rs1884051, rs9340799 e rs2234693), em ESR2 (rs4986938 e rs1256049) e no miRNA17 (rs4284505) foram genotipados pela reação em cadeia da polimerase em tempo real utilizando sondas TaqMan. As diferenças estatísticas nas distribuições alélicas e genotípicas entre “baixo” e “alto” níveis de cálcio e fósforo foram determinadas usando os testes qui-quadrado e teste exato de Fisher. As análises foram ajustadas por sexo (alfa de 5%). O polimorfismo rs9340799 em ESR1 foi o genótipo menos comum associado com altos níveis de cálcio (p=0,03). O alelo menos comum em ESR1 rs1884051 foi associado com baixos níveis de fósforo (p=0,005) e houve um excesso de heterozigotos para miRNA17 rs4284505 entre os indivíduos com baixos níveis de cálcio salivar (p=0,002), ambos ajustados pelo sexo. Este estudo fornece evidências de que polimorfismos genéticos em ESR1 e miRNA17 estão envolvidos na determinação dos níveis de cálcio e fósforo salivares.

Abstract Homeostasis between salivary calcium and phosphorus is important for maintaining oral health. The aim of this study was to evaluate if polymorphisms in ESR1 (Estrogen Receptor Alpha), ESR2 (Estrogen Receptor Beta) and miRNA17 (microRNA17) are associated with calcium and phosphorus levels in saliva. Saliva from 276 12-year-old children were collected by masticatory stimulation and calcium and phosphorus levels were determined by Mass Spectrometry. Genomic DNA was extracted from remaining saliva and genetic polymorphisms in ESR1 (rs12154178, rs1884051, rs9340799 and rs2234693), in ESR2 (rs4986938 and rs1256049) and in miRNA17 (rs4284505) were genotyped using TaqMan chemistry and a real-time PCR equipment. Statistical differences in genotype and allele distributions between ‘low’ and ‘high’ calcium and phosphorus levels were determined using chi-square or Fisher´s exact tests. The analysis was also adjusted by sex (alpha of 5%). ESR1 rs9340799 had the less common genotype associated with higher calcium levels (p=0.03). The less common allele of ESR1 rs1884051 was associated with lower phosphorus levels (p=0.005) and there was an excess of heterozygotes for miRNA17 rs4284505 among individuals with lower calcium levels (p=0.002), both adjusted by sex. This study provides evidence that genetic polymorphisms in ESR1 and miRNA17 are involved in determining salivary calcium and phosphorus levels.

Aim: To describe the management of dental education in three dental schools during the COVID-19 crisis. Methods: Adopted strategies in the Federal University of Paraíba (UFPB), Brazil, University of Pittsburgh (UP), USA, and Griffith University (GU), Australia were detailed. Results: In the UFPB, all on-site teaching was suspended, and resources for distance learning set up as a supplementary semester to be available as face to face classes later. A protocol for clinical care followed safety measures recommended by Brazilian official health institutions. The adequacy of the physical structure, human resources, and personal protective equipment (PPE) acquisition for the return to clinical activities are currently under discussion. In the UP, learning activities were shifted to virtual teaching using lecture recordings and live sections. All elective patients care was postponed. Urgent dental cases were discussed via teledentistry. The physical layout of the dental clinics and pre-clinical laboratories were changed, allowing a safe distance between students. In the GU, all clinical and pre-clinical activities were cancelled, and theoretical activities were maintained online for all students. Several clinically based scenarios where created and delivered in the format of online problem-based learning. The reception area was redesigned, ensuring social distancing. Safety measures follow the Australia Dental Association. Conclusions: Dealing with dental education depends on the stage of the epidemic and the characteristics of each country.

Abstract The study of dental development in individuals born with cleft lip and palate (CLP) serves to determine when orthodontic intervention should start. Objective To evaluate the permanent second molar development in children born with cleft lip and palate according to Demirjian’s and Nolla’s methods. Methodology Out of a total of 513 digital panoramic radiographs, 113 pairs of children aged 3 to 16 years were selected. The exams were from children born with or without cleft lip and palate, of the same sex, with an age difference of up to 30 days. The images were analyzed by three examiners and reliability was checked through intra-examiner agreement by the Kappa test. The data were analyzed by Wilcoxon's and Mann-Whitney tests according to each dataset. Results The findings indicated delayed development of the permanent second molars in children with CLP (P<0.001). The development of the right permanent second molar was delayed compared to the left molar in children with CLP. Moreover, mandibular teeth showed significantly earlier development than maxillary teeth in both the case and control groups. There was no significant difference in the development of permanent second molars between sexes. Conclusion Children with CLP presented delay in the development of permanent second molars.

Abstract Objective: To define the prevalence of Molar Incisor Hypomineralization (MIH) in Brazil since the reports ranged from 2.5% to 40.2%. Material and Methods: We studied 407 children from 7 to 14 years of age. MIH was measured using the European Academy of Paediatric Dentistry criteria of 2003. Clinical data were collected by a calibrated dentist (Kappa=0.88) and included affected teeth and degree of MIH severity (mild/severe). Mild MIH cases were considered when the tooth presented demarcated opacity ≥ 1.0mm, without any loss of structure. While severe cases were defined by teeth in which loss of structure was present, or past or current lesion that required treatment, or presence of atypical restorations. In addition, published data (nine studies) reporting MIH in Brazilians were identified, and the heterogeneity of these studies was tested (I2 index/ p≤0.01). Results: In the original sample studied, the majority of patients were males (55.3%; n = 225), with an average age of 10.1 years (± 2.1 years). The prevalence of MIH in this group was 14.5% (59 affected in 407), and most of the affected teeth had a mild degree of alteration (77.4% or 202 in 261 teeth). Conclusion: A meta-analysis including nine published reports, and our original data showed that MIH prevalence in Brazil is 13.48 (95% CI, 8.66% -18.31%).

Abstract This study was performed to evaluate the interplay between dental caries, nutritional status, and genetic polymorphisms in TAS1R1 and TAS1R2 (taste receptor, type 1, member 1 and 2) in preschool children and pre-adolescents. We included 525 subjects (306 preschool children and 219 pre-adolescents). Parents/caregivers answered a self-administered questionnaire about their children’s systemic health, characteristics, oral hygiene habits, and diet. Clinical examination was performed to evaluate dental caries and nutritional status. Saliva samples were collected for DNA extraction. The genotyping of rs17492553 ( TAS1R1 ), rs3935570, and rs4920566 ( TAS1R2 ) polymorphisms was performed using real-time PCR with Taqman Genotyping Master Mix and SNP assay. Both univariate and multivariate Poisson regression analyses with robust variance were used for the data analysis. In preschool children, consumption of sweets between meals increased the prevalence of dental caries by 85% (PR c = 1.85; 95%CI 1.39–2.46; p < 0.001), whereas in pre-adolescents, this prevalence increased by 34% (PR a = 1.34; 95%CI 1.11–1.62; p = 0.002), regardless of genetic polymorphisms . Moreover, individuals carrying at least one allele C in rs17492553 presented 23% more prevalence of dental caries (PR a = 1.23; 95%CI 1.02–1.49 p = 0.030). Nutritional status was not associated with dental caries, neither with genetic polymorphisms . Consumption of sweets between meals increased the prevalence of dental caries. In pre-adolescents, rs17492553 genetic polymorphism in TAS1R1 was associated with dental caries.

Abstract Objective: To determine if there are differences in protein profiles in saliva depending if children of caries-free versus caries affected. Material and Methods: A cohort of 91 children with ages between 6 and 19 years, along clinical status of caries experience. Protein profiles in saliva were determined using electrophoresis and the calculation of the percentage of a specific band at a specific molecular weight in relationship to the total protein in that sample (% of total) using molecular weight standards. This quantification was repeated for each protein band across a range of molecular weights for each sample. Chi-square, Fisher’s exact, and Student t-tests were used to compare the distributions between caries-free and caries affected children (α=0.05). Results: Histatin was more likely to be non-detectable or reduced in caries-free children (OR=7.56; 95% CI 1.62-35.13) and these children had on average one less gel band detected by the assay we used. Conclusion: We have found differences in proteins between caries affected and caries-free children, suggesting that this line of investigation holds the promise of providing new tools for caries management.

Abstract Objective: To determine if protein profiles identified in saliva could be used to determine risk and severity of erosive tooth wear. Material and Methods: Three types of saliva sampling were performed to obtain saliva from 34 18-year old individuals that received regular dental check-ups, along with clinical status of the dentition and risk factor related to erosive tooth wear using the VEDE scale. Protein profiles in saliva were determined using electrophoresis and the calculation of the percentage of a specific band at a specific molecular weight in relationship to the total protein in that sample (% of total) using molecular weight standards. This quantification was repeated for each protein band across a range of molecular weights for each sample to test for association with erosive tooth wear status. Results: There were no differences in the number of detectable proteins sourced from the parotid gland, nor the unstimulated and stimulated whole saliva. Five out of the 34 individuals had no signs of erosive tooth wear despite an acidic diet and were more likely to have proteins with molecular weight smaller than 1 KDa (p=0.03). Conclusion: There is potential for the use of protein profiling to determine risks for erosive tooth wear.

Abstract Objective: To describe and compare how three dental schools from different countries (Australia, Brazil, and the USA) have managed experiences in dental education during the COVID-19 crisis. Material and Methods: It is a descriptive study reporting the experience that three distinct dental schools faced during the COVID-19 pandemic. They represent countries that adopted different measures to tackle the pandemic and were undergoing different stages of the disease. Results: After the WHO declared the COVID-19 pandemic, the Federal University of Paraíba suspended all on-site teaching, research, and service activities. For the return to teaching activities, the use of information and communications technology resources for distance learning was recommended. At the School of Dental Medicine (University of Pittsburgh), all research activities were suspended or, otherwise, could not be interrupted because of the employment of unique materials or supplies. When the pandemic started, Australia was one of the first countries to introduce strong regulations related to social distancing, travel restrictions, testing and tracking of infected patients. As such, the universities started to be closed from mid-March, cancelling all clinical and pre-clinical activities, maintaining online theoretical activities, such as seminars, lectures, and journal clubs. Conclusion: Numerous and critical difficulties have arisen as a result of the pandemic for individuals, communities and institutions that will have long-lasting effects. Our students face disruption to their education and career; our professional colleagues will be challenged rebuilding their practices, while staff at all Dental Schools are experiencing various hardships.

Abstract Objectives To determine whether Tumor Necrosis Factor alpha (TNFα) –308 G/A polymorphism is associated with oral lichen planus (OLP). Material and Methods A systematic electronic search of the literature was conducted to identify all published studies on the association between TNFα –308 G/A polymorphism and OLP. All case-control studies evaluating the TNFα –308 G/A polymorphisms in OLP were selected. A meta-analysis of the studies that fulfilled the inclusion criteria was performed. Odds ratios (OR) with 95% confidence intervals (CI) were also calculated. Results Seven studies comprising 450 OLP cases and 867 controls were included in the meta-analysis. In the pooled analysis, TNFα –308 G/A polymorphism was associated with OLP with random effects and OR of 2.33 (95%CI=1.07-5.11; p=0.03), assuming a dominant mode of inheritance (AA+GA vs. GG). In the subgroup analysis by ethnicity, TNFα –308 G/A was associated with a significantly increased odds ratio of OLP in mixed ethnicity (OR=5.22; 95%CI=1.93-14.15; p=0.001), but not in Asians (OR=1.57; 95%CI=0.54-4.54; p=0.41) or Caucasians (OR=1.45; 95%CI=0.19-11.22; p=0.72). For subgroup analysis based on HCV (hepatitis C virus) infection status, significant increased risk of OLP was found among patients with mixed HCV infection status (OR=3.77; 95%CI=1.07-13.2; p=0.038), but not in patients without HCV infection (OR=2.09; 95%CI=0.63-6.91; p=0.22) and patients with HCV infection (OR=0.48; 95%CI=0.13-1.69; p=0.25). Conclusion Our results suggest that –308 G/A polymorphism in TNFα is a potential genetic marker for OLP.

Resumo Indivíduos susceptíveis à periodontite crônica (CP) apresentam alto risco para o desenvolvimento de periimplantite (PI). Ambas doenças são multifatoriais e apresentam similaridades na patofisiologia e perfil poligênico. A MMP-13 (metaloproteinase da matriz tipo 13) é uma enzima colagenolítica cuja expressão é induzida por TGF beta 3 (fator transformador do crescimento tipo 3) nos fibroblastos gengivais humanos e inibida por TIMP-2 (inibidor tecidual de metaloproteinase tipo 2). O objetivo deste estudo foi investigar a ocorrência de periimplantite em sujeitos com periodontite crônica e a frequência dos polimorfismos nos genes MMP13, TIMP2 e TGFB3. Cento e sessenta e três voluntários submetidos à instalação de implantes endósseos foram analisados clínica e radiograficamente quanto à presença de histórico de CP e PI, sendo divididos em 4 grupos: Controle (sem história de CP e PI, n=72), CP (com CP e sem PI, n=28), PI (com PI e sem CP, n=28) e Doentes (com CP e PI, n=35). O teste do qui-quadrado correlacionou os genótipos nas regiões dos genes MMP13 (rs2252070), TIMP2 (rs7501477) e TGFB3 (rs2268626), considerando a interação entre CP e PI. Os resultados mostraram que voluntários com CP possuem 3.2 vezes mais chances de desenvolver PI (p=0.0004) comparados aos sem CP. Nenhuma associação significativa foi observada entre os genes MMP13, TIMP2 e TGFB3 e CP ou PI. A CP é um fator de risco ao desenvolvimento de PI, no entanto, não há associação entre ambas as doenças com polimorfismos nos genes MMP13, TIMP2 e TGFB3.

Abstract Subjects susceptible to chronic periodontitis (CP) show a high risk for the development of peiimplantitis (PI). Both diseases are multifactorial, presenting similarities in their pathophysiology and polygenic profile. MMP-13 (matrix metalloproteinases 13/ collagenase 3) is a collagenolytic enzyme, which expression is induced by TGF beta 3 (transforming growth factor type 3) in human gingival fibroblasts and inhibited by TIMP-2 (tissue inhibitor of metalloproteinase type 2). The aim of this study was to investigate the occurrence of peiimplantitis (PI) in subjects with history of chronic periodontitis (CP) and polymorphisms frequency in MMP13, TIMP2 and TGFB3 genes. One hundred and sixty-three volunteers received dental implant placement were submitted to oral and radiographic examination in order to identify past history of CP or presence of PI. Volunteers were divided into 4 groups: Control (without PI and CP, n=72), CP (with CP and without PI, n=28), PI (with PI and without CP, n=28) and diseased (with CP and PI, n=35). The chi-square test correlated genotypes in specific regions of MMP13 (rs2252070), TIMP2 (rs7501477) and TGFB3 (rs2268626) genes, considering the interaction between CP and PI. The results showed that volunteers with CP had 3.2 times more susceptibility to develop PI (p=0.0004) compared to those without CP. No significant association was observed in MMP13, TIMP2 and TGFB3 genes with CP or PI. CP is a risk factor to develop PI, however, there is no association of both diseases with polymorphisms in the MMP13, TIMP2 and TGFB3 genes.

The aim of this study was to determine the frequency of leukemia in parents of patients with nonsyndromic cleft lip and/or cleft palate (NSCL/P). This case-control study evaluated first-degree family members of 358 patients with NSCL/P and 1,432 subjects without craniofacial alterations or syndromes. Statistical analysis was carried out using Fisher’s test. From the 358 subjects with NSCL/P, 3 first-degree parents had history of leukemia, while 2 out of 1,432 subjects from the unaffected group had a family history of leukemia. The frequency of positive family history of leukemia was not significantly increased in first-degree relatives of patients with NSCL/P.