Comparison of Chu's Proportion Gauge with a T-bar Tip and a Two-Tip Compass in the Determination of Anterior Dentition Tooth Size in a Group of Puerto Ricans.

OBJECTIVE: Compare maxillary anterior dentition measurements, using Chu's proportion gauge with a T-bar tip (PG-TT) and a Two-Tip Compass (T-TC), in a group of Puerto Ricans, to determine the reliability of the PG-TT. METHODS: This cross-sectional study was conducted at the University of Puerto Rico, School of Dental Medicine, Medical Sciences Campus. The participants (18-35 years old) were dental students or employees of the university. Previously, the examiner had been trained and calibrated in instrument usage. Calibration participants (n = 16) received an oral exam, prophylaxis, and a chlorhexidine mouthwash for home use. After 3 days, the upper-anterior teeth were measured using the 2 instruments. The agreement was determined using weighted kappa statistics (Kw), and 0.80 was the minimum acceptable level. The examiner achieved almost perfect agreement (inter-examiner KwT-TC = 0.95 [0.96-0.93]; KwPG-TT = 0.82 [0.81-0.87]) with a reference examiner. RESULTS: Fifty participants (25 women and 25 men) were evaluated. Length: The teeth of the men presented an unacceptable level of agreement, except for in the right central incisors. For the women, a strong level of agreement was observed only in the lateral incisors and left canines. When the teeth of both sexes were considered, a strong level of agreement was detected, except for in the right canines and left central incisors. Width: The level of agreement was unacceptable, except for in the right canines (distal). CONCLUSION: T-TC is a more reliable instrument to measure tooth dimensions as compared to the PG-TT.

Prevalence of gingivitis and calculus in 12-year-old Puerto Ricans: a cross-sectional study.

BACKGROUND: Gingivitis is a common oral health problem. Untreated gingivitis may progress to periodontitis, a common cause of tooth loss. The prevalence of gingivitis and calculus among Puerto Rican children is unknown. Understanding this prevalence can support early public health preventative strategies. This study aims to estimate the prevalence of gingivitis and calculus among 12-year-old Puerto Ricans by health region and to explore differences in distribution by school type (proxy for socio-economic status) and gender. METHODS: A probability-based sample of 113 schools was selected proportional to enrollment size and stratified by health region, school type, and gender. Two trained examiners evaluated the presence of gingivitis and both supragingival and subgingival dental calculus. Gingivitis was defined as the presence of gingival bleeding upon gentle probing (BOP) in at least one site, and the extent of the problem was classified according to the percentage of teeth whose gingiva presented BOP (limited: 25-49% of the teeth tested; extensive: >50% of teeth tested). Logistic and linear regression models, adjusted for health regions, were used to compare gingivitis and calculus prevalence and extent between genders and school types. RESULTS: Gingivitis was found in 80.41% of the 1586 children evaluated. Urban-public schoolchildren had a slightly higher prevalence (83.24%) compared to private (79.15%, p = 0.16); those in rural-public (77.59%) and private schools had similar prevalence (p = 0.15). Extensive gingivitis was present in 60.81% of all children. The mean percentage of sites presenting BOP (BOP%) was 17.79%. Rural and urban public schoolchildren presented significantly higher BOP% compared to children from private schools (p = 0.0005, p = 0.002, respectively). Dental calculus was detected in 61.59% of the sample, boys presenting significantly higher (p = 0.005) total and supragingival calculus. Rural-public schoolchildren had a significantly higher prevalence of subgingival calculus compared to private schoolchildren (p = 0.02). CONCLUSIONS: Gingivitis prevalence is higher among 12-year-old Puerto Ricans compared to data reported for U.S. adolescents. Public schoolchildren presented significantly higher BOP% sites compared to private schoolchildren. Boys presented a significantly higher total and supragingival calculus prevalence than girls. Oral health disparities related to gender and school type were identified by this study. Studies exploring the reasons for these disparities are recommended.

Prevalence of Gingivitis in a Group of 35- to 70-Year-Olds Residing in Puerto Rico.

OBJECTIVE: Gingivitis, an inflammation of the gingival tissues, typically progresses to periodontitis. The objective of this study is to estimate the prevalence of gingivitis in 35- to 70-year-olds residing in San Juan, Puerto Rico, and assess the differences in gingivitis distribution between age and gender groups. METHODS: A cross-sectional epidemiological study was conducted with a sample of patients from a private practice and patients/employees of the Puerto Rico Medical Center. Participants completed a medical history questionnaire and received soft/hard tissue and gingival assessments based on a modified Löe-Silness index. Descriptive statistics were employed to estimate the overall gingivitis prevalence, severity (mild, moderate, severe), and mean gingival index (GI). Bleeding on probing (BOP) prevalence and the mean percentage of BOP sites were calculated by gender and age. Multinomial logistic regression was used to evaluate the associations between age, gender, and severity in 3 categories; multivariate logistic regression was used for having >=40% sites with BOP (vs. having <40% sites with BOP as reference). Odds ratios were also estimated. RESULTS: All 300 participants (52% women; 48% men) had gingivitis. The mean GI was 1.38. Moderate gingivitis was detected in 83% of the participants, mild in 7.3%, and severe in 9.3%. BOP was observed in 99% of the subjects (mean % BOP sites = 34%). After adjusting for age, men had significantly higher odds of moderate (OR = 4.66) and severe gingivitis (OR =10.06), compared to women, as well as 1.76 times higher odds of having 40% or more sites with BOP. CONCLUSION: Gingivitis was observed in all participants. Men had significantly higher GI, compared to women. The prevalence of gingivitis was higher in Puerto Rico than in the US.

Persistent oral health disparity in 12-year-old Hispanics: a cross-sectional study.

BACKGROUND: Dental caries is the most prevalent chronic illness worldwide. In the US dental caries has been described as a "silent epidemic", affecting 58.2 % of 12-15 year-olds, particularly in minority and immigrant groups. Caries is associated with complex yet preventable biological and behavioral factors such as dental plaque and diet, as well as social determinants of health. In developed nations, a higher risk caries has been associated with populations of low socio-economic status (SES), especially in areas with greater income disparity. An island-wide study conducted in Puerto Rico in 1997 revealed a high prevalence of dental caries in 12-year-olds and a significant health disparity between children attending private and public schools. The purpose of the present study was twofold: 1) to estimate caries levels of 12-year-old school Puerto Ricans in 2011; and 2) compare results to data obtained in 1997 to explore any possible change in caries outcomes after a government health insurance (GHI) reform was implemented. METHODS: In this cross-sectional study, a probability sample of 133 out of 1,843 schools was selected proportional to enrollment size, and stratified by 1997 GHI regions, school type, and gender. Calibrated examiners conducted oral soft tissue and caries examinations. Dental caries prevalence was estimated. Mean Decayed Missing Filled Tooth/Surface (DMFT/S) indices and mean Significant Caries Index (SiC) were calculated and compared retrospectively to data obtained in 1997. RESULTS: The final sample included 1,587 school-enrolled children. About 53 % of participants were female and 77 % attended public schools. Between 1997 and 2011, reductions were observed in caries prevalence (81 to 69 %), mean DMFT scores (3.8 to 2.5), mean DMFS scores (6.5 to 3.9), and mean SiC index (7.3 to 5.6) in both private and public schools, with a more prominent decrease in private schools. Between 1997 and 2011, overall the filled component increased (50 to 67 %), while decayed and missing component decreased (42 to 30 %) and (8 to 3 %), respectively. CONCLUSIONS: Among 12-year-old schoolchildren in Puerto Rico between 1997 and 2011, caries prevalence, extent, and severity decreased as well as the DMFT missing component, while the filled component increased. Dental caries prevalence was high and the health disparity persists between children enrolled in public and private schools after more than a decade of the GHI implementation. The relationship between GHI implementation and other potentially relevant co-factors for caries warrants further research, as does the seemingly entrenched disparity across groups.

Models of ventricular structure and function reviewed for clinical cardiologists.

The architectural arrangement of cardiomyocytes aggregated together within the ventricular walls remains controversial. Two models currently attract clinical attention, with neither model standing rigorous anatomical scrutiny. The first is based on the notion that ventricular mass can be unraveled consistently to produce a unique myocardial band. The second model was initially based on the notion that cardiomyocytes were bundled together in uniform fashion, with fibrous shelves interposed in transmural fashion. This concept was subsequently modified to accept the fact that the fibrous matrix supporting the cardiomyocytes within the ventricular walls does not form transmural sheets. Current observations demonstrate that not all cardiomyocytes are aggregated together in tangential fashion. A significant netting component is aligned in obliquely intruding and transversal fashion. The interaction between the tangential and transversal chains of cardiomyocytes with the fibrous matrix produces antagonistic forces, with both unloading and auxotonic forces necessary to explain normal and abnormal cardiodynamics. This article is part of a JCTR special issue on Cardiac Anatomy.

Triggers and anatomical substrates in the genesis and perpetuation of atrial fibrillation.

The definition of atrial fibrillation (AF) as a functional electrical disorder does not reflect the significant underlying structural abnormalities. Atrial and Pulmonary Vein (PV) muscle sleeve microstructural remodeling is present, and establishes a vulnerable substrate for AF maintenance. In spite of an incomplete understanding of the anatomo-functional basis for AF, current evidence demonstrates that this arrhythmia usually requires a trigger for initiation and a vulnerable electrophysiological and/or anatomical substrate for maintenance. It is still unclear whether the trigger mechanisms include focal enhanced automaticity, triggered activity and/or micro re-entry from myocardial tissue. Initiation of AF can be favored by both parasympathetic and sympathetic stimulation, which also seem to play a role in maintaining AF. Finally, evolving clinical evidence demonstrates that inflammation is associated with new-onset and recurrent AF through a mechanism that possibly involves cellular degeneration, apoptosis, and subsequent atrial fibrosis.

Anatomical bases of supraventricular arrhythmias

The adoption of catheter ablation techniques for the treatment of tachyarrhythmias in humans has increased the interest in cardiac anatomy. Interventional arrhythmologists have had to study the gross morphologic and architectural features of the heart. In addition, a new investigational wave has emerged to revisit cardiac anatomic topics for which the information was incomplete or simply wrong. As a result, recent studies have unraveled anatomic features, architectural aspects, and histologic details of certain components of the heart that are of interest to understand the substrates of tachycardias and their ablation. The purpose of this study was to review the gross morphological band structural details of the right and left atria such as the terminal crest (crista terminalis), cavotricuspid isthmus, Koch´s triangle, and its content, the Eustachian ridge or valve, the sub-Thebesian recess, the PV orifices and their neighboring left atrial landmarks and the architecture of the venoatrial junction. In addition, we describe the anatomy of the left atrial isthmus and, the oblique vein of Marshall. The relationship of the important structures in the neighborhood of the left atrium and the pulmonary veins as the oesophagus and phrenic nerves are also described (AU)

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Koch's triangle and the atrioventricular node in Ebstein's anomaly: implications for catheter ablation.

INTRODUCTION AND OBJECTIVES: The development of ablation techniques for supraventricular arrhythmias in patients with Ebstein's anomaly have led to a need for better understanding of the morphology of the triangle of Koch and the position of the atrioventricular (AV) node in this structure. METHODS: The study involved 17 human hearts: 11 with Ebstein's anomaly (age range: 37 weeks' gestation to 1 week after birth) and 6 structurally normal hearts (age range: 35 weeks' gestation to 2 days after birth). The area of the triangle of Koch was calculated and the length of the AV node and the bundle of His were measured. RESULTS: The area of the triangle of Koch was significantly smaller in specimens with Ebstein's anomaly than in control specimens (17.5+/-4.5 mm2 vs. 25.5+/-6.5 mm2; P< .05). The length of the AV node and its extensions were similar in hearts with Ebstein's anomaly and normal hearts. The AV node was displaced towards the base of the triangle in 73% of specimens with Ebstein's anomaly, and the inferior extensions reached the level of the cavotricuspid isthmus. In 91% of specimens with Ebstein's anomaly, the entry of the His bundle occurred before the apex of the triangle was reached and its length was shorter. CONCLUSIONS: Morphologic findings in this study indicate that performing an ablation procedure close to the base of the triangle of Koch in patients with Ebstein's anomaly could result in AV nodal block.

El triángulo de Koch y el nodo AV en la anomalía de Ebstein: implicaciones en la ablación con catéter / Koch’s triangle and the atrioventricular node in Ebstein’s anomaly: implications for catheter ablation

Introducción y objetivos. Los avances realizados en los procedimientos de ablación de arritmias supraventriculares en la anomalía de Ebstein (AE) han creado la necesidad de un mejor entendimiento de la morfología del triángulo de Koch (TK) y disposición en dicha estructura del nodo auriculoventricular (AV). Métodos. Se han estudiado 17 corazones humanos, 11 con AE (intervalo de edades, 37 semanas a 1 semana después de nacer) y 6 estructuralmente normales (intervalo de edades, 35 semanas a 2 días después de nacer). Se calculó el área del TK y se midió la longitud del nodo AV y el haz de His. Resultados. El área del TK es significativamente más pequeña en los especímenes con AE que en los controles (17,5 ± 4,5 mm2 frente a 25,5 ± 6,5 mm2; p < 0,05). En los corazones con AE, el nodo AV y sus extensiones son similares en longitud a los corazones normales. El nodo AV en los especímenes con AE se desplaza hacia la base del triángulo en el 73% y las extensiones inferiores llegan al nivel del istmo cavotricuspídeo (ICT). En el 91% de los especímenes con AE, la entrada del haz de His se produce antes de llegar al ápex del triángulo, y su longitud es más corta. Conclusiones. Con base en los hallazgos morfológicos obtenidos en este estudio, se puede deducir su utilidad en los procedimientos de ablación en las proximidades de la base del TK por la posibilidad de producir un bloqueo del nodo AV en pacientes con AE (AU)

Introduction and objectives. The development of ablation techniques for supraventricular arrhythmias in patients with Ebstein’s anomaly have led to a need for better understanding of the morphology of the triangle of Koch and the position of the atrioventricular (AV) node in this structure. Methods. The study involved 17 human hearts: 11 with Ebstein’s anomaly (age range: 37 weeks’ gestation to 1 week after birth) and 6 structurally normal hearts (age range: 35 weeks’ gestation to 2 days after birth). The area of the triangle of Koch was calculated and the length of the AV node and the bundle of His were measured. Results. The area of the triangle of Koch was significantly smaller in specimens with Ebstein’s anomaly than in control specimens (17.5±4.5 mm2 vs. 25.5±6.5 mm2; P < .05). The length of the AV node and its extensions were similar in hearts with Ebstein’s anomaly and normal hearts. The AV node was displaced towards the base of the triangle in 73% of specimens with Ebstein’s anomaly, and the inferior extensions reached the level of the cavotricuspid isthmus. In 91% of specimens with Ebstein’s anomaly, the entry of the His bundle occurred before the apex of the triangle was reached and its length was shorter. Conclusions. Morphologic findings in this study indicate that performing an ablation procedure close to the base of the triangle of Koch in patients with Ebstein’s anomaly could result in AV nodal block (AU)

Capillary supply to the sinus node in subjects with long-term atrial fibrillation.

BACKGROUND: Atrial ischemia, and sinus node ischemia in particular, may be involved in the pathogenesis of atrial fibrillation. In this study we compared the sinus node blood capillary content in normal hearts in sinus rhythm and in pathologic hearts with chronic atrial fibrillation and we analyzed the ultrastructural features of such capillaries. METHODS: Sinus node biopsy specimens were obtained from 16 patients in chronic atrial fibrillation undergoing open heart surgery. Control sinus node specimens of normal hearts were obtained at autopsy from 7 subjects. Specimens were processed for immunohistochemical, light microscopy and transmission electron microscopy analysis and compared grossly and with morphometric techniques. RESULTS: The proportion of sinus node tissue corresponding to capillaries, defined as blood vessel density (or BVD), was estimated as 1.06 +/- 1.47% for the atrial fibrillation group versus 2.12 +/- 2.0% for controls (p < 0001). Internal capillary diameter averaged 21.6 microm in the atrial fibrillation group and 24.2 microm in controls (p = 0.175), whereas external diameter averaged 32.2 microm in the atrial fibrillation group and 38.9 microm in controls (p = 0.052). Ultrastructural analysis demonstrated scarce and interrupted myoendocardial bridges and abnormal deposits of elastic fibers under the endothelial basal membrane at the level of precapillary sphincters and metaarterioles of atrial fibrillation specimens. CONCLUSIONS: There is a significant reduction in the amount of capillaries in the sinus node of hearts in chronic atrial fibrillation. Our findings would support a potential association between sinus node tissue ischemia and chronic atrial fibrillation.

Cryoablation time-dependent dose-response effect at minimal temperatures (-80 degrees C): an experimental study.

AIMS: To establish a temporal safety window for cryoablation at minimal temperatures and to assess the electrophysiological and histological changes as a function of the application duration. METHODS AND RESULTS: Twenty mini-pigs underwent AV nodal cryoablation at -80 degrees C without prior cryomapping. The duration of the cryoapplication following atrioventricular block (AVB) was randomized to 0, 10, 20, 40, or 60 s. Atrioventricular block was obtained in all animals after a median of 3 (1-8 interquartile range) applications. One week later, AV nodal conduction fully recovered in animals with application duration <10 s, whereas persistent AVB incidence increased as a function of time in animals with longer applications duration. Cryoablation application duration following AVB was the only independent predictor of persistent AVB (OR, 1.116; 95% CI, 1.013-1.229; P = 0.026). There was no difference in lesion location or size between animals with vs. those without persistent AVB at 1 week. However, animals randomized to longer application duration demonstrated higher degree of cell destruction and fibrotic content. CONCLUSION: In this closed-chest pig model, there was a relation between cryoapplication duration following AVB at -80 degrees C and recovery of conduction. A safety window of at least 10 s was observed in all cases.

Morphological evidence of muscular connections between contiguous pulmonary venous orifices: relevance of the interpulmonary isthmus for catheter ablation in atrial fibrillation.

BACKGROUND: Electrophysiological studies in patients with atrial fibrillation demonstrated the presence of electrical conduction between superior and inferior left pulmonary veins (PVs) that makes electrical disconnection of individual PVs difficult. Anatomically, the prevalence, sizes, and locations of the interpulmonary connections have not been investigated systematically. METHODS: We retrieved 112 PVs from 28 patients who died from noncardiac causes (43 +/- 13 years, 17 males). Dissections of subepicardial myocardial strands at the venoatrial junctions were made in 10 hearts, and histological sections were made in the remaining 18 hearts. RESULTS: We found histological variations in the muscular width of the interpulmonary isthmus between ipsilateral left and right PVs (2.7 +/- 0.5 mm vs 1.7 +/- 0.5 mm; P <.05). Histologic sections of 15 hearts revealed myocardial strands 0.2-3.5 mm thick crossing obliquely at the left isthmus in 53%, at the right isthmus in 33%, and at both isthmuses in 14% of hearts to connect with the myocardial sleeves of adjacent veins. In 40% of hearts there were additional direct bridges connecting the anterior or posterior walls of the veins. The crossing myocardial strands were at the epicardial (27% of hearts), subendocardial (53% of hearts), and both (20%) aspects of the PV wall. The mean distance between the endocardium of the interpulmonary isthmus to the muscular connections was 2.5 +/- 0.5 mm in the left-sided PVs and 1.5 +/- 0.5 mm in the right-sided PVs. CONCLUSIONS: Crossing myocardial strands and bridges at the interpulmonary isthmus may be the anatomical substrate for electrical connection between superior and inferior PVs and may have implications for local PV isolation in patients with atrial fibrillation.

Anatomic evaluation of the left phrenic nerve relevant to epicardial and endocardial catheter ablation: implications for phrenic nerve injury.

BACKGROUND/OBJECTIVE: The purpose of this study was to clarify the spatial relationship between the left phrenic nerve (LPN) and key cardiac structures in order to minimize the risk of phrenic nerve injury during interventions. METHODS: The course and relationship of the LPN to various cardiac structures were examined by gross dissection and histologic sections of 22 human cadavers. RESULTS: The nerve descended on the fibrous pericardium along one of three courses: over the anterior surface of the left ventricle (18%), over the lateral margin of the left ventricle (59%), and in a posteroinferior direction (23%). The endocardium of the roof of the left atrial appendage was <4 mm from the LPN in 2 (9%) specimens. The nerve passed <2.5 mm from the epicardium of the apex of the left atrial appendage in 7 (31%) specimens. Regardless of the position of the nerve in relation to the high left ventricular wall, the nerve was <3 mm from the epicardial surface in 8 (36%) specimens and passed <6 mm from the epicardium of the right ventricular outflow tract in 2 (9%) specimens. CONCLUSION: During electrophysiologic interventions, the LPN is especially at risk when procedures are performed in the vicinity of the left atrial appendage and high left ventricular wall.