A graftless maxillary sinus lifting approach with simultaneous dental implant placement: a prospective clinical study.

PURPOSE: This study aimed to introduce a graftless sinus lifting approach with simultaneous dental implant placement in the alveolus of the posterior maxilla and compare this approach's outcomes in freshly extracted sockets versus healed sockets. MATERIALS AND METHODS: A prospective study was conducted on 60 patients aged between 27 and 59 years old, requiring dental implants in the posterior maxilla, and diagnosed with reduced vertical bone height (30 with freshly extracted sockets (group A) and the remaining 30 with healed sockets (group B). Before the sinus lifting approach, a cone beam computed tomography (CBCT) was taken, followed by another CBCT at least one-year post-sinus lifting (range: 12-36 months). Biological and mechanical complications were assessed, and the primary implant stability was measured using the Implant Stability Quotient (ISQ). Parametric data were analyzed using an independent t-test for intergroup comparisons, with significance set at P < 0.05. RESULTS: No significant differences were found among groups concerning gender, placement side, and follow-up. All dental implants demonstrated high survival rates with no observed biological or mechanical complications. Moreover, the primary implant stability was satisfactory, and there was no statistically significant difference (P = 0.38). In terms of new intrasinus bone formation, both groups exhibited satisfactory and successful outcomes, with increased new bone formation in group A. However, there was no statistically significant difference (P = 0.26). Regarding the vertical sinus floor elevation without new bone formation, group B showed (0.11 ± 0.64) mm of intrasinus implant height without bone formation, while group A showed an increment of bone formation above the intrasinus implant (0.22 ± 0.33) mm, with no statistically significant difference between both groups (P = 0.30). CONCLUSION: Our approach proves to be predictable, low-cost, and efficient option for sinus lift procedures, demonstrating high survival rates with acceptable primary implant stability. Moreover, it yields satisfactory outcomes in terms of new intrasinus bone formation, both in freshly extracted and healed sockets. Consequently, our approach holds promise as a reliable procedure for sinus lifting with simultaneous dental implant placement.

Efficacy of lycopene for management of oral potentially malignant disorders: A systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to investigate the available evidence on the efficacy of lycopene in the management of oral potentially malignant disorders (OPMDs). STUDY DESIGN: PubMed, Scopus, Web of Science, Google Scholar, China National Knowledge Infrastructure, and ProQuest databases were searched up to April 20, 2022. All clinical trials that assessed the efficacy of lycopene (I) on the signs/symptoms (O) of patients with OPMDs (P) in comparison to either active control or placebo (C) were included. Meta-analysis was conducted using the RevMan software (Cochrane Collaboration, London, UK). RESULTS: A total of 27 clinical trials (20 on oral submucosa fibrosis [OSF], 5 on oral lichen planus [OLP], and 2 on leukoplakia) were included. Overall, lycopene was efficacious in reducing signs and symptoms of OSF, OLP, and leukoplakia. The pooled data revealed comparable efficacy of lycopene and prednisolone in reducing pain and promoting clinical resolution of OLP. Additionally, the pooled data reported comparable efficacy of lycopene and conventional controls in improving the mouth opening and tongue protrusion in patients with OSF. CONCLUSIONS: The results reveal promising effects of lycopene in alleviating signs and symptoms of OSF, OLP, and leukoplakia. However, owing to the observed heterogeneity and short follow-up periods, further well-designed studies with long-term therapy and follow-up are highly recommended.

Knowledge, beliefs, attitude, and practices of E-cigarette use among dental students: A multinational survey.

BACKGROUND: E-cigarette use is a trend worldwide nowadays with mounting evidence on associated morbidities and mortality. Dentists can modify the smoking behaviors of their patients. This study aimed to explore the knowledge, beliefs, attitude, and practice of E-cigarette use among dental students. MATERIALS AND METHODS: This multinational, cross-sectional, questionnaire-based study recruited undergraduate dental students from 20 dental schools in 11 countries. The outcome variable was current smoking status (non-smoker, E-cigarette user only, tobacco cigarette smoker only, dual user). The explanatory variables were country of residence, sex, age, marital status, and educational level. Multiple linear regression analysis was performed to explore the explanatory variables associated with E-cigarette smoking. RESULTS: Of the 5697 study participants, 5156 (90.8%) had heard about E-cigarette, and social media was the most reported source of information for 33.2% of the participants. For the 5676 current users of E-cigarette and/or tobacco smoking, 4.5% use E-cigarette, and 4.6% were dual users. There were significant associations between knowledge and country (P< 0.05), educational level (B = 0.12; 95% CI: 0.02, 0.21; P = 0.016) and smoking status (P< 0.05). The country of residence (P< 0.05) and smoking status (P< 0.05) were the only statistically significant factors associated with current smoking status. Similarly, there were statistically significant associations between attitude and country (P< 0.05 for one country only compared to the reference) and history of previous E-cigarette exposure (B = -0.52; 95% CI: -0.91, -0.13; P = 0.009). Also, the practice of E-cigarettes was significantly associated with country (P< 0.05 for two countries only compared to the reference) and gender (B = -0.33; 95% CI: -0.52, -0.13; P = 0.001). CONCLUSION: The knowledge of dental students about E-cigarette was unsatisfactory, yet their beliefs and attitudes were acceptable. Topics about E-cigarette should be implemented in the dental curriculum.

Analysis of Environmental Exposures for Nonsyndromic Cleft Lip and/or Palate: A Case-Control Study.

Background: Orofacial cleft is among the most common developmental malformations in humans. This study aimed to identify the relationship between environmental factors and nonsyndromic cleft lip and/or palate (NSCL/P) in Northwest China. Methods: This case-control study was conducted in Gansu Province, China over two years (Jan. 1, 2017-Jan. 1, 2019). Overall, 600 NSCL/P cases and 660 normal control cases were finally enrolled in the current study. Data were collected by conducting face-to-face interviews with both parents of each case. Results: Univariate (χ2) analysis revealed 22 factors as being significantly associated with NSCL/P. Multivariate (stepwise logistic regression) analysis identified that 14 factors had statistically significant association with NSCL/P. Male gender (OR=0.789), paternal age at childbirth of 25-29 yr (OR=0.690), and folic acid supplement (OR=0.197) were found to be protective factors against NSCL/P. On the other hand, blood A-type, multiple births, positive family history of NSCLP (OR=6.660), parental consanguinity (OR=6.107), positive abortion history, high or low maternal childbearing age, and maternal passive smoking (OR=4.349), malnutrition (OR=4.431), infections, and drug use (OR=2.188) during early gestation were significant risk factors for NSCL/P. Conclusion: Parental age at childbirth of 25-29 yr, and folic acid supplement can reduce the risk of NSCL/P. By contrast, maternal passive smoking, infections, and drug use during early gestation period, and multiple births, parental consanguinity, positive family history, and maternal abortion history can increase the risk of NSCL/P. Identification of risk factors is essential in minimizing the incidence of NSCL/P in a particular population.

Oral health practices and self-reported adverse effects of E-cigarette use among dental students in 11 countries: an online survey.

OBJECTIVES: E-cigarette use has become popular, particularly among the youth. Its use is associated with harmful general and oral health consequences. This survey aimed to assess self-reported oral hygiene practices, oral and general health events, and changes in physiological functions (including physical status, smell, taste, breathing, appetite, etc.) due to E-cigarette use among dental students. METHODS: This online, multicounty survey involved undergraduate dental students from 20 dental schools across 11 different countries. The questionnaire included demographic characteristics, E-cigarette practices, self-reported complaints, and associated physiological changes due to E-cigarette smoking. Data were descriptively presented as frequencies and percentages. A Chi-square test was used to assess the potential associations between the study group and sub-groups with the different factors. Statistical analysis was performed using SPSS at P < 0.05. RESULTS: Most respondents reported regular brushing of their teeth, whereas only 70% used additional oral hygiene aids. Reported frequencies of complaints ranged from as low as 3.3% for tongue inflammation to as high as 53.3% for headache, with significant differences between E-cigarette users and non-users. Compared to non-smokers, E-cigarette users reported significantly higher prevalence of dry mouth (33.1% vs. 23.4%; P < 0.001), black tongue (5.9% vs. 2.8%; P = 0.002), and heart palpitation (26.3%% vs. 22.8%; P = 0.001). Although two-thirds of the sample reported no change in their physiological functions, E-cigarette users reported significant improvement in their physiological functions compared to never smokers or tobacco users. CONCLUSION: Dental students showed good oral hygiene practices, but E-cigarette users showed a higher prevalence of health complications.

Zinc supplementation for prevention and management of recurrent aphthous stomatitis: a systematic review.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is a very common oral ulcerative disease with no definitive cure. Growing evidence suggests a significant association between zinc deficiency and RAS. OBJECTIVES: To assess the efficacy of systemic zinc supplementations in the prevention and management of RAS. METHODS: Five databases were searched for all English and Chinese studies published up to November 2020. All clinical trials that assessed the efficacy of zinc supplementations in the management and/or prevention of RAS were included. RESULTS: Seven clinical trials comprising 482 RAS patients (250 in zinc group) fulfilled the inclusion criteria. The follow-up period ranged from three months to one year. Five studies showed significantly better efficacy of zinc in reducing the recurrence rates of RAS, whereas two studies did not report any significant differences compared to the controls. Four studies reported on signs/symptoms of RAS, three of which showed superior outcomes in favour of zinc, while one study reported comparable results. CONCLUSION: Zinc supplementation seems to be efficacious in the management and prevention of RAS. However, further clinical trials with standardized methodologies and adequate follow-up periods are required to confirm the efficacy of zinc supplementations.

Cone beam computed tomography findings in the temporomandibular joints of chronic qat chewers: Radiographic bone density and trabecular microstructural analyses.

OBJECTIVES: This cross-sectional comparative study investigated the effects of qat chewing habit on the radiographic bone density (RBD) and trabecular microstructure of temporomandibular joint condyles using cone beam computed tomography (CBCT). STUDY DESIGN: In total, 85 systemically healthy Yemeni males were included and divided into qat chewers (QCs; n = 41); and non-qat chewers (NQCs; n = 44). The participants responded to a structured questionnaire and underwent standardized clinical examination and CBCT scanning of the temporomandibular joint. Measurements of RBD and trabecular microstructure (trabecular thickness, trabecular separation, bone volume fraction, and fractal dimension) were performed. Statistical significance was established at P ≤ .05. RESULTS: No statistically significant differences were found between QCs and NQCs in RBD or trabecular microstructure. The mean standard deviations and maximum values of trabecular separation on the nonchewing side for QCs were significantly lower compared to the corresponding values for NQCs (0.60 and 2.68 for QCs vs 0.72 and 3.05 for NQCs; P = .025 and .05, respectively). A comparison between chewing and nonchewing sides in QCs revealed no significant differences. CONCLUSIONS: Qat chewing habit induces insignificant changes in condylar RBD and trabecular microstructure as detected by CBCT. Further studies using advanced radiographic techniques are warranted.

Association between serum zinc levels and recurrent aphthous stomatitis: a meta-analysis with trial sequential analysis.

OBJECTIVES: The present meta-analysis sought to investigate the potential association between zinc levels and recurrent aphthous stomatitis (RAS). METHODS: A comprehensive search of online databases (PubMed, Scopus, Web of Science, and China National Knowledge Infrastructure (CNKI)) was conducted to identify all English and Chinese studies published up to August 2020. All case-control studies that assessed plasma/serum zinc levels were eligible for inclusion. Data were analyzed using Comprehensive Meta-Analysis software version 2.2.046 (Biostat, Englewood, NJ, USA). Trial sequential analysis (TSA) was conducted with the trial sequential analysis program. RESULTS: Nineteen case-control studies, involving 1079 RAS cases and 965 controls, were included in the meta-analysis. The pooled results of 19 studies showed that zinc level was significantly lower in RAS patients than in healthy controls (weighted difference in means = - 21.092, 95% CI - 26.695 to - 15.490, I2 = 95.375%, P < 0.001). Upon subgroup analysis by geographic distribution of the sample (Chinese vs. others), the association remained significant in each individual subgroup, although the association was more pronounced among Chinese populations. TSA indicated that the current studies surpassed the required information size, confirming that the differences were reliable. CONCLUSION: The results suggest a significant association between low serum zinc levels and the occurrence of RAS. Although TSA confirmed a solid conclusion, conducting large-scale studies with the highest standards of quality is encouraged. CLINICAL RELEVANCE: Determining zinc levels should be considered in diagnosis, management, and prevention of RAS.

Cone beam computed tomography findings in temporomandibular joint of chronic qat chewers: Dimensional and osteoarthritic changes.

The social habit of chewing qat (also known as khat) is widely practised in East Africa and the Arabian Peninsula. It has been linked with various oro-facial conditions, including temporomandibular joint disorders (TMD). This cross-sectional, comparative study sought to investigate the effects of qat chewing on temporomandibular joint (TMJ), using cone beam computed tomography (CBCT). A total of 85 Yemeni males were included. The participants were divided into two groups: Qat chewers (QC; n = 41) and non-qat chewers (NQC; n = 44). Relevant data were obtained using a structured questionnaire and standardised clinical examination. Additionally, CBCT images of the TMJs were obtained, and then, osteoarthritic changes and TMJ dimensions were analysed. SPSS 21 was used for statistical analyses, with a significant level was set at 0.05. Compared to NQC, a significantly higher proportion of QC presented with clinical signs of TMDs. The qualitative CBCT findings revealed significantly higher osteoarthritic changes in QC than in NQC: osteophyte (51.2% vs 22.7%; P = .008), subcortical sclerosis (48.8% vs 27.3%; P = .047), articular surface flattening (46.3% vs 6.8%; P = .009) and subcortical cysts (43.9% vs 4.5%; P < .001). However, CBCT quantitative findings (condylar dimensions) did not show significant differences between the two groups. The chewing side of the QC group showed slightly more changes compared to the non-chewing side. The results demonstrate that qat chewing has detrimental effects on TMJ manifested mainly as osteoarthritic changes. Further large-scale studies are recommended.

Efficacy of propolis-based mouthwashes on dental plaque and gingival inflammation: a systematic review.

BACKGROUND: This systematic review of randomized clinical trials aimed to evaluate the available evidence regarding the efficacy of propolis-based mouthwash on dental plaque and gingival inflammation. METHODS: PubMed, Scopus, and Web of Science databases were searched up to November 2019. Clinical trials that evaluated the efficacy of propolis mouthwashes compared with chlorhexidine (CHX) were included. The primary outcomes comprised dental plaque and/or gingival inflammation. Two authors assessed the risk of bias using the Cochrane tool. Due to marked heterogeneity of the available data, studies were assessed qualitatively, and no metaanalysis was performed. RESULTS: Nine clinical trials, comprising 333 subjects, fulfilled the eligibility criteria. Most of the included studies showed high risk of bias. Overall, propolis mouthwashes showed good efficacy on plaque and gingivitis in all of the included studies. Out of the eight studies that reported on plaque index, 5 studies found equal efficacy of propolis and CHX in reducing plaque, two studies found superior efficacy in favor of CHX, while one study found superior efficacy in favor of propolis. Six studies assessed gingival inflammation outcome, four of which reported better results with propolis, while two studies reported comparable results. CONCLUSIONS: The results suggest that propolis-based mouthwashes have potential benefits in reducing plaque and gingival inflammation. However, methodological limitations along with small sample sizes in some of the included studies weaken the strength of the evidence. Therefore, further well-designed clinical trials with large sample sizes and adequate follow-up period are recommended to discern the efficacy of propolis mouthwash on plaque and gingivitis.

Prevalence of impacted teeth among a sample of yemeni population and their association with sex and age / Prevalencia de dientes impactados entre una muestra de población yemení y su asociación con el sexo y la edad

Aim: the aim of the study was to assess the prevalence of impacted teeth and its association with sex and age among a sample of the Yemeni population. Materials and Methods: A cross sectional study design was employed. The study included 999 radiographical records of patients who had panoramic X- rays previously done. All radiographs were assessed for the number and type of impacted teeth, pathology-associated impaction, sex, age and location (mandible and/or maxilla). The collected data was analyzed using SPSS®version21 software. Results: The study sample comprised digital panoramic radiographs of Yemeni patients aged 17 to 54 years (mean 26.6 years). The present study found 542 patients (54.3%) presented with at least one impacted tooth. The 17 to 25 years age group of the study sample had the highest prevalence of tooth impaction (28.6%). Only 10 (1.0%) case presented pathologies associated with the impacted teeth. There was a significant difference in the number of male 203 (20.3%) and female 339 (33.9%) patients with impacted teeth (p=0.031). Impacted teeth occurred slightly more often in the mandible (42.8%) compared to the maxilla (42.4%). Conclusion: The prevalence of impacted teeth among a sample of Yemeni population was high. Third molars and canines were the most common impacted teeth. The prevalence of impacted teeth in females was higher than in males and it was higher in the mandible than in the maxilla, with the younger patients with a higher prevalence of impaction.

Objetivo: el objetivo del estudio fue evaluar la prevalencia de dientes impactados y su asociación con el sexo y la edad en una muestra de la población yemení. Material y Métodos: se empleó un diseño de estudio transversal. El estudio incluyó 999 registros radiográficos de pacientes con radiografías panorámicas realizadas previamente. Todas las radiografías fueron evaluadas en relación al número y tipo de dientes impactados, patología asociada a la impactación, sexo, edad y ubicación (mandíbula y/o maxilar). Los datos recopilados se analizaron utilizando el software SPSS® version 21. Resultados: La muestra del estudio comprendió radiografías panorámicas digitales de pacientes yemeníes entre 17 a 54 años (media 26,6 años). El presente estudio encontró que 542 pacientes (54,3%) presentaron al menos un diente impactado. El grupo de edad de 17 a 25 años de la muestra de estudio tuvo la mayor prevalencia de impactación dental (28,6%). Solo 10 casos (1,0%) presentaron patologías asociadas a los dientes impactados. Hubo una diferencia significativa en el número de pacientes masculinos 203 (20.3%) y femeninos 339 (33.9%) con dientes impactados (p=0.031). Los dientes impactados ocurrieron con un poco más de frecuencia en la mandíbula (42.8%) en comparación con el maxilar (42.4%). Conclusión: La prevalencia de dientes impactados entre una muestra de población yemení fue alta. Los terceros molares y caninos fueron los dientes más comúnmente impactados. La prevalencia de dientes impactados en las mujeres fue mayor que en los hombres y fue mayor en la mandíbula que en el maxilar, y los pacientes más jóvenes mostraron una mayor prevalencia de impactación.

Dental environment and war-related stress among dental students, Yemen.

BACKGROUND: Education related to health sciences appears to be the most stressful. AIMS: The aim of this study was to evaluate the perceived stress among Yemeni dental students and to explore the effect of the war circumstances on the perceived stress. METHODS: This cross-sectional study targeted all dental students at the two main dental faculties in Yemen. Dental environmental stress questionnaire was used. An extra 12 items (as one domain) were developed to reflect the stress resulting from the current war circumstances. RESULTS: A total of 1051 dental students participated in this study. The overall dental environmental stress was 1.63±0.45. The most significant stressor domain was "workload", followed by "war-related" along with "performance pressure". In general, females, married, and clinical students, and those with lower GPA scored significantly higher stress levels than their counterparts. Regression analysis revealed that the university, sex, and study level as the most significant determinants for most domains. CONCLUSIONS: The level of stress among Yemeni dental students can be considered as moderate to high. This stress was further exacerbated by the war circumstances present.

Management of temporomandibular joint ankylosis in yemeni children by metatarsal bone grafts

Aim: This study aimed to evaluate temporomandibular joint reconstruction in Yemeni children with metatarsal bone graft after release of ankylosis. Methodology: Ten patients ≤12 years of age, comprising eight unilateral and two bilaterally TMJ ankylosis, were selected for this study. These patients underwent reconstruction with 10 non-vascularized metatarsal grafts. The reconstructed joints were then followed for an average of 1 year. Measures of opening, symmetry, and clinical symptoms relating to the reconstructed joints were assessed. Results: Mean pre-operative interincisal aperture was 8.2mm, and immediate post-operative aperture 23.4mm. At the end of the follow-up period, acceptable results were achieved in 8 out of 10 cases, with adequate mouth opening of 35.6mm in 8 out of 10 patients and overall interincisal aperture of 30.3mm. Re-ankylosis occurred in two bilaterally-treated patients at the end of follow-up. Subjectively, 80 percent of the patients rated their function as satisfactory and were able to occlude and masticate without any difficulty. Conclusion: Reconstruction of TMJ after release of ankylosis utilizing metatarsal bone graft shows a satisfactory interincisal aperture in 80 percent of patients.

Risk factors for periodontal diseases among Yemeni type II diabetic patients: a case-control study

BACKGROUND: chronic periodontal diseases are one of diabetes mellitus complications. The present study aims to compare the periodontal status of type II diabetic patients to a control group and assess the role of risk factors in both groups. MATERIALS AND METHODS: A case-control study was conducted of 270 individuals (132 type II diabetics and 138 non-diabetics). Full mouth periodontal examination including plaque index, gingival bleeding, gingival recession, clinical attachment loss (CAL), tooth mobility, furcation involvement and the number of missing teeth. The case group was subdivided according to glycosylated hemoglobin (HbA1c) status (poorly controlled HbA1c >8 and well controlled HbA1c≤8) Likewise, the duration of diabetes mellitus as short or long duration (DM≤10 or >10). The diabetic group was also subdivided according to smoking and Khat chewing habits. RESULT: The severity of periodontal disease among type II diabetic patients were significantly higher compared to the control group regarding the plaque index 2.6 (1.6-4.3), bleeding on probing 3.5 (2.3-13.0), gingival recession 2.0 (1.2-3.4), furcation involvement 4.0 (2.3-6.7), clinical attachment loss 5.7 (3.1-10.5), tooth mobility 2.0 (1.2-3.4), and number of missing teeth 4.4 (2.3-8.5). In addition, poorly controlled type II DM and long duration had higher CAL and number of missing teeth than well-controlled DM and short duration. No significant differences were found between smokers/nonsmokers and Khat chewers/non-chewers among the diabetic group. CONCLUSION: Type II diabetic patients have severe periodontal destruction and tooth loss compared to non-diabetic people and there were no differences within the diabetic group in regards to smoking and Khat chewing habits.(

Tongue lesions and anomalies in a sample of Yemeni dental patients: a cross-sectional study

Background: Tongue examination helps considerably in diagnosing the underlying health state of the patient, especially in the cases of chronic diseases. The aim of this study is to determine the prevalence and association of tongue lesions with risk factors among Yemeni dental patients. Materials and methods: An oral medicine specialist examined all 713 patients attending the dental polyclinics at the University of Sciences and Technology (Sana’a, Yemen). The examination sheet was designed to include information related to patient characteristics, medical history, dental history, habits, and tongue lesions. Results: The prevalence of tongue lesions among the examined participants was 76.5 percent. The prevalence rate was 83.4 percent for males and 69.2 percent for females. Fissured tongue was the most common condition. Logistic regression analysis indicated that older age (p<0.001), gender (p=0.007), khat chewing (p<0.001), and smoking (p=0.001) were associated with fissured tongue; gender (p<0.001), khat chewing (p<0.001), and smoking (p<0.001) were associated with hairy tongue; and older age (p<0.001), khat chewing (p=0.001), and smoking (p=.021) were associated with coated tongue. Conclusion: The prevalence of tongue lesions among this sample of Yemeni population was 76.5 percent; fissured tongue and hairy tongue were the most prevalent lesions. Khat chewing, smoking, and older age were the associated risk factors for many of studied lesions and anomalies.

Self-Reported Oral Health Attitudes and Behavior of Dental and Medical students, Yemen.

OBJECTIVES: To assess self-reported oral health attitudes and behavior among undergraduate dental and medical students, and to analyze the variations in oral health attitudes based on gender, level of education, study discipline, academic average, and type of university. METHODS: A self-administered questionnaire based on the Hiroshima University-Dental Behavioural Inventory (HU-DBI) was distributed to 1269 undergraduate dental and medical students at two universities (one public and one private) in Sana'a, Yemen. RESULTS: Overall, the mean questionnaire score for the total sample was markedly low (4.91±1.58), with no significant difference between dental and medical students (P>0.05). Females had better oral health attitudes and behavior, especially towards visiting the dentist, tooth-brushing habits and oral hygiene practices (P<0.05). Students attending the public university had better oral health attitudes and behaviors than those attending the private university (P=0.049). On the other hand, no significant associations were observed between students' oral health attitudes/behavior and level of education and academic performance (P>0.05). CONCLUSION: Yemeni dental and medical students have shown markedly poor oral health attitude and behavior. Further studies are required to reveal possible shortcoming in these schools' education process. Dental and medical curricula should emphasize the importance of proper oral hygiene, and further participation of medical and dental students in oral hygiene seminars is highly encouraged.