[Case report on bilateral absence of upper bicuspid of primary and permanent dentition correlated with upper permanent bicuspid].
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We studied the conditions of the aortic and pulmonary valves of 153 Syrian hamsters belonging to a single family subjected to high endogamous pressure. Semilunar valves of 143 specimens were examined using a stereomicroscope, and in 5 of these cases a histologic study was also performed. The remaining 10 specimens were studied by means of scanning electron microscopy. In 77 specimens both semilunar valves were normal. The aortic valve was bicuspid and the pulmonary valve was normal in 46 animals, while a normal aortic valve and a bicuspid pulmonary valve occurred in 24. In the remaining 6 specimens both semilunar valves were bicuspid. All bicuspid semilunar valves detected herein showed the same morphotype, namely with the leaflets oriented ventrodorsally. The incidence of these anomalous valves did not significantly differ between sexes. Results of a chi 2-test substantiate that conditions of both outflow tract semilunar valves are independent traits. Thus, concurrence of a bicuspid aortic valve and a bicuspid pulmonary valve in an individual is a random event. The present findings support the assumption that bicuspid aortic and pulmonary valves have different morphogenetic origin, although factors producing a bicuspid aortic valve and those leading to a bicuspid pulmonary valve are not mutually exclusive.
The bicuspid aortic valve is the most frequent congenital cardiac malformation; it may be isolated or associated with other congenital heart disease. The present investigation consists of a study of bicuspid aortic valves in 1022 heart specimens belonging to the anatomical collection of the Institute of Pathological Anatomy of the University of Padua. A bicuspid aortic valve was observed in 95 specimens. It occurred as an isolated congenital cardiac defect in 28 cases, seven of which had spontaneous laceration of the aortic valve (aortic dissection). It was associated with other congenital cardiac malformations in 67 out of the remaining 994 specimens (6.7%), 41 of which (61.2%) showed obstruction of the aortic arch. The frequency of bicuspid aortic valve in specimens with complete transposition of great arteries was only 1%. Bicuspid aortic valve was particularly frequent in association with ventricular septal defect and was significantly more frequent in cases with (51.1%) than in cases without (20.5%) aortic arch obstruction (p < 0.001). There was no significant relationship between the occurrence of bicuspid aortic valves and left ventricular outflow tract obstructions or mitral valve malformations. The morphology of the pulmonary valve was also examined. Concurrence of a bicuspid aortic and pulmonary valve was detected in 11 specimens, five of these had trisomy-18. Our findings cast doubt on the assumption that altered fetal blood flow through the aortic valve may be the main factor producing the bicuspid condition. Indeed, they rather support the hypothesis that most bicuspid aortic valves are expressions of a developmental complex that affects the aortic arch and the wall of the ascending aorta as well as the aorta valve.
BACKGROUND: Bicuspid aortic valve is the most frequent congenital cardiac malformation in humans. However, the morphogenesis of the defect is still unknown. Previous work showed that, in the Syrian hamster, congenital bicuspid aortic valves with the aortic sinuses arranged in ventrodorsal orientation are expressions of a trait the variation of which takes the form of a continuous phenotypic spectrum, ranging from a tricuspid aortic valve with no fusion of the ventral commissure to a bicuspid aortic valve devoid of any raphe. The present study was designed to elucidate the mechanism involved in the formation of bicuspid aortic valves in Syrian hamsters as a possible starting point for further investigation of this process in humans. METHODS: The sample examined consisted of 80 embryos, aged between 10 days, 16 hours and 13 days, 1 hour postcoitum. Most (n = 59) of the embryos belonged to a laboratory-inbred family of Syrian hamsters with a high incidence of bicuspid aortic valves. The study was carried out using scanning electron microscopy and histological techniques for light microscopy. RESULTS: Twenty-three embryos showed a still undivided conotruncus. In all of these cases there were six mesenchymal semilunar valve primordia protruding into the lumen of the conotruncus. In a further 29 embryos, the conotruncus had just divided into the aortic and pulmonary channels; the embryos were at the beginning of the valvulogenesis. In 13 of these 29 embryos there were three well-defined aortic valve cushions, right, left, and dorsal, whereas in the other 16, the right and left valve cushions were more or less fused toward the lumen of the aorta; when they were completely fused, only two aortic valve cushions, a ventral and a dorsal, could be identified. In the remaining 28 embryos, the aortic valve cushions showed a marked degree of excavation. In 23 of these cases, the valve exhibited a basically tricuspid architecture, whereas it was unequivocally bicuspid in the other five. CONCLUSIONS: All variants of the aortic valve morphologic spectrum occurring in the Syrian hamster develop from three mesenchymal valve cushions, right, left, and dorsal, after normal septation of the conotruncus. The bicuspid condition of the aortic valve is not the consequence of improper development of the conotruncal ridges, conotruncal malseptation, valve cushion agenesis, or lesions acquired after a normal valvulogenesis. Fusion of the right and left valve cushions at the beginning of the valvulogenesis appears to be a key factor in the formation of bicuspid aortic valves. Each aortic valve acquires its specific morphology prior to the end of the valvulogenetic process.
BACKGROUND: Bicuspid aortic valve is the most common congenital anomaly, occurring in 1% to 2% of the population. It is the most common reason for aortic valve replacement, and such individuals are at significantly increased risk of aortic complications. Despite the clinical significance of bicuspid aortic valve, its genetic basis remains unclear. The homeobox gene NKX2-5 occupies a central position in the hierarchy of cardiac determinants, and mutations in this gene are associated with bicuspid aortic valve in mice. We therefore investigated the presence of mutations in NKX2-5 among patients with bicuspid aortic valve and associated aneurysm. METHODS: Germline DNA was extracted from peripheral blood leukocytes and somatic DNA from diseased aortic tissues of 19 patients with bicuspid aortic valve and associated aortic aneurysm. Three patients with trileaflet aortic valve and aneurysm served as control subjects. The entire NKX2-5 coding sequence, including intron-exon boundaries, was screened for mutation by means of polymerase chain reaction, followed by DNA sequencing. RESULTS: Direct sequencing revealed a change in somatic (aortic) DNA 239A-->G, leading to synonymous amino acid alteration of Glu21Glu in one patient with bicuspid aortic valve and 1 control subject. There were no other alterations detected in the coding regions of germline or somatic genes. A known polymorphic change in the 3' untranslated region adjacent to exon 2 was detected in both bicuspid aortic valve and control samples. Discrepancies between germline and somatic DNA sequences were observed. CONCLUSION: Our study fails to demonstrate an association between bicuspid aortic valve and NKX2-5 mutation, as has been seen in mice. Our findings support the importance of sequencing somatic, as well as germline, DNA.
BACKGROUND: A bicuspid aortic valve is commonly associated with other levels of left ventricular outflow tract obstruction. Providing the bicuspid aortic valve is competent and nonobstructive, repair of subvalvar or supravalvar stenosis usually focuses on the obstructive lesions, leaving the valve in situ. The aim of this report was to examine the impact of a bicuspid aortic valve on the risk of reoperation for patients undergoing operation for subvalvar or supravalvar aortic stenosis. METHODS: Since 1976, 47 patients with supravalvar or subvalvar aortic stenosis have undergone repair. The median follow-up is 5.1 years (range, 2 months to 20.1 years). Sixteen patients (34%) had a bicuspid aortic valve that was competent and nonobstructive, and 31 (66%) had a tricuspid aortic valve. RESULTS: Reoperation was required in 9 patients (56%) with a bicuspid aortic valve, in each involving aortic valve replacement with an autograft (3), homograft (2), or prosthesis (4). Six patients (19%) with a tricuspid aortic valve required reoperation, yet only 1 required aortic valve replacement. The freedom from valve replacement was 43% (70% confidence interval, 31% to 55%) in the bicuspid aortic valve group versus 100% (70% confidence interval, 94% to 99.5%) in the tricuspid group at 5 years (p = 0.0001). The freedom from any reoperation at 5 years was 43% (70% confidence interval, 31% to 55%) in patients with a bicuspid aortic valve versus 86% (70% confidence interval, 80% to 93%) in the tricuspid group (p = 0.02). CONCLUSIONS: The data suggest that patients with subvalvar or supravalvar aortic stenosis and a bicuspid valve may be better palliated with a more definitive operation such as the Ross or Ross-Konno procedure.
BACKGROUND: Patients with bicuspid aortic valve malformations are at an increased risk of aortic dilatation, aneurysm formation, and dissection. Vascular tissues with deficient fibrillin-1 microfibrils release matrix metalloproteinases, enzymes that weaken the vessel wall by degrading elastic matrix components. In bicuspid aortic valve disease a deficiency of fibrillin-1 and increased matrix metalloproteinase matrix degradation might result in aortic degeneration and dilatation. METHODS: Samples of the pulmonary artery and aorta were obtained from surgical patients with bicuspid aortic valves (n = 21) and tricuspid aortic valves (n = 16). RESULTS: Fibrillin-1 content was reduced in bicuspid aortic valve aortas compared with that seen in tricuspid aortic valve aortas (P =.001), whereas the associated matrix components, elastin and collagen, were unchanged (P =.51 and P =.21). Reductions of aortic fibrillin-1 content were independent of valve function and patient age. Compared with tricuspid aortic valve aorta, matrix metalloproteinase 2 activity was increased more than 2-fold in bicuspid aortic valve aortas (P =.04) and correlated positively with aortic diameter (r = 0.74, P =.05). Matrix metalloproteinase 9 activity was not significantly different. Fibrillin-1 content was also reduced in the pulmonary arteries of patients with bicuspid aortic valves (P =.06), suggesting a systemic deficiency of fibrillin-1. Promatrix metalloproteinase 2 was increased (P =.04), reflecting an increased production of matrix metalloproteinase 2 in these fibrillin-1-deficient tissues, whereas active matrix metalloproteinase 2 and matrix metalloproteinase 9 species were unchanged, and correspondingly, the pulmonary arteries were not dilated. CONCLUSIONS: Deficient fibrillin-1 content in the vasculature of patients with bicuspid aortic valves might trigger matrix metalloproteinase production, leading to matrix disruption and dilatation. This process of vascular matrix remodeling in patients with bicuspid aortic valves offers novel therapeutic targets to prevent the aortic degeneration and dilatation characteristic of this disease.
OBJECTIVE: Bicuspid aortic valve disease has been associated with histologic abnormalities of the aortic root. Recent reports have suggested similar alterations may exist in the pulmonary artery of patients with bicuspid aortic valve. The present study was undertaken to define the histologic condition of the aortic and pulmonary artery root in bicuspid aortic valve disease and the relationship with pulmonary autograft root dilatation after the Ross procedure. METHODS: In 17 patients undergoing aortic root replacement with the pulmonary autograft, biopsy specimens of the aortic root and pulmonary artery trunk were collected. Clinical and histologic findings of patients with bicuspid aortic valves were compared with those with tricuspid aortic valves. RESULTS: There were 9 patients (8 male, 1 female) with bicuspid aortic valve (group 1) and 8 (all male) with tricuspid aortic valve (group 2). Mean age was comparable (24.4 +/- 9.8 vs 23.6 +/- 10.8 years, P =.9). Aortic insufficiency as an indication for operation was more common in group 1 (9/9 vs 5/8, P =.007), whereas preoperative aortic root dilatation was equally prevalent (4/9 vs 1/8, P =.1). Prior aortic valve repair had been performed in 2 patients (1/9 vs 1/8, P =.9). Prevalence of cystic medionecrosis of the aortic wall was similar in the 2 groups (4/9 vs 3/8, P =.6). Cystic medionecrosis of the pulmonary artery trunk was found only in 1 patient with tricuspid aortic valve (0/9 vs 1/8, P =.3). During a mean follow-up of 26.5 +/- 12.2 months (32.1 +/- 12.7 vs 20.1 +/- 7.4 months, P =.04), prevalence of pulmonary autograft root dilatation (greater than 4.0 cm) was equally represented in patients with native bicuspid or tricuspid aortic valve (3/9 vs 2/8, P =.6). CONCLUSIONS: Histologic abnormalities of the pulmonary artery root are rare and equally prevalent in young patients with bicuspid and tricuspid aortic valves. On the contrary, root dilatation is relatively common late after autograft root replacement but appears unrelated to bicuspid aortic valve disease or to pre-existing degenerative changes of the pulmonary artery root.
BACKGROUND AND AIM OF THE STUDY: The feasibility of the Ross procedure, and which patients benefit most from its performance, have not yet been fully established. The study aim was to analyze the relationship between the etiology of aortic valve disease, the feasibility of performing the Ross procedure, and late pulmonary autograft performance. METHODS: Between June 1995 and June 2001, 117 patients (77 males, 40 females; mean age 37+/-12 years) underwent the Ross procedure at the authors' institution. Of these patients, 53 (45.3%) had severe aortic stenosis, 53 (45.3%) had significant aortic insufficiency, four (3.4%) had active endocarditis, two (1.7%) had subaortic stenosis, and five (4.3%) had prosthesis dysfunction. Eighty-one patients (69%) had a bicuspid aortic valve. Pulmonary autograft dysfunction was defined as regurgitation grade > or =2, as registered by Doppler echocardiography. RESULTS: The Ross procedure was successful in 100 patients (85.5%); hospital mortality was 2.6% (n = 3). The procedure was not feasible in 17 patients (14.5%); of these, seven had bicuspid pulmonary valve, six had >3 mm multiple pulmonary valve fenestrations, three had severe pulmonary insufficiency, and one patient had dissection-related pulmonary valve injury. Twelve of 16 patients presenting with pulmonary valve defects had bicuspid aortic valve (p = 0.04). At six-year follow up, the probability of not requiring reoperation was 93% (confidence interval 86-100%). During follow up (30+/-14 months; range: 2-72 months), six patients presented with grade 2 pulmonary autograft insufficiency, three with grade 3, and two with grade 4. Six of the latter 11 patients (p = 0.03) had a history of bicuspid aortic valve with aortic regurgitation. Freedom from autograft dysfunction was 87% (confidence interval 82-92%). Patients with bicuspid aortic valve and aortic valve regurgitation had a higher tendency towards autograft dysfunction than those with bicuspid aortic valve and aortic stenosis (65% versus 100%, p = 0.004). CONCLUSION: The feasibility of performing the Ross procedure is high, unless there is presence of bicuspid aortic valve. Patients with bicuspid aortic valve and a history of aortic insufficiency tend to develop moderate autograft dysfunction during long-term follow up.
In an experimental study in pigs, the function of monocuspid and bicuspid patches was compared to improve surgical reconstruction of a hypoplastic pulmonary root. Segments from glutaraldehyde-treated porcine aortic roots served as monocuspid and bicuspid patches. Their leaflets and commissures were marked with radiopaque metal clips. Marker movements were recorded at 100 frames/sec. Quantification of pulmonary insufficiency, right ventricular stroke volume, as well as pressures in the right ventricle, pulmonary artery, and aorta was performed before and after patch plasty. The cyclic motion of the leaflets showed a three-phase pattern in monocuspid and bicuspid patches: (1) a rapid opening motion with a significantly longer distance to be covered in monocuspid patches (7.5 mm in monocuspid versus 4.9 mm in bicuspid patches); (2) a slow closing motion that was significantly greater in monocuspid patches (31.5% of maximal displacement in monocuspid versus 18.2% and 23.8% in bicuspid patches); (3) a similar rapid closure motion in both types of patches. The commissural expansion was less than 6% for monocuspid and bicuspid patches and began 10 to 20 msec before valve opening. Considerable irregularities in the movement of the different leaflet markers, especially in monocuspid patches, indicated leaflet buckling as a result of redundant leaflet tissue. There was a significant pulmonary regurgitant fraction only in monocuspid patches (19% in monocuspid versus 7% in bicuspid patches) that occurred during early diastole. No pressure gradients were observed across either type of patch. In monocuspid patches, a greater leaflet displacement during rapid closure was correlated with an increased pulmonary insufficiency (r = 0.8875). In conclusion, the function of a bicuspid patch is superior to that of a monocuspid patch for repair of a hypoplastic pulmonary root and allows the construction of a competent and stenosis-free valve mechanism.
BACKGROUND: Congenital bicuspid and quadricuspid pulmonary valves have received little attention because of their limited clinical relevance. However, knowledge of the mechanisms by which these anomalous valves develop is essential to obtain a more accurate survey of the etiological factors implicated in the malformations of the cardiac outflow tract in mammals. The present study was designed to assess the anatomical features of bicuspid and quadricuspid pulmonary valves in Syrian hamsters as well as to elucidate the mechanisms involved in the formation of these defective valves. METHODS: The sample examined consisted of 206 adults and 28 embryos belonging to a laboratory-inbred family of Syrian hamsters with a high incidence of congenital anomalies of the pulmonary and aortic valves. The study was carried out using histological techniques for light microscopy, semithin sections, and scanning electron microscopy. RESULTS: The pulmonary valve was tricuspid in 140 of the 206 adult hamsters, and in 124 of these tricuspid valves the dorsal commissure was more or less extensively fused. Another 45 hamsters possessed a bicuspid pulmonary valve with the sinuses oriented ventrodorsally. In 43 of these bicuspid valves, a raphe was located in the dorsal pulmonary sinus. The pulmonary valve was quadricuspid in a further nine specimens. The remaining 12 hamsters had a tricuspid pulmonary valve with a raphe-like ridge located in the right pulmonary sinus. In seven of these valves, the dorsal commissure showed a more or less extensive fusion. The embryos examined, aged between 11 days, 3 hours and 12 days, 6 hours postcoitum, were at the beginning of the valvulogenesis. In five of the 28 embryos, the pulmonary valve consisted of three mesenchymal valve cushions, right, left, and dorsal. In a further 17 embryos, the right and left valve cushions were more or less fused toward the lumen of the pulmonary artery. In the remaining six embryos, the left and dorsal valve cushions were normal, whereas the right cushion was divided into two lobes. CONCLUSIONS: The present findings suggest that in the Syrian hamster: (1) bicuspid pulmonary valves result from the extensive fusion of the right and left pulmonary valve cushions at the beginning of the valvulogenesis, (2) the partial fusion of the right and left pulmonary valve cushions leads to the formation of tricuspid pulmonary valves with a more or less extensive fusion of the dorsal commissure, (3) quadricuspid pulmonary valves result from the partition of one of the three valve cushions at a very early stage of the valvulogenesis, and (4) the partial division of the right pulmonary valve cushion may lead to the development of tricupsid pulmonary valves with a raphe-like ridge located in the right pulmonary sinus. In addition, the present findings, together with previous observations in Syrian hamsters, indicate that in this species the mechanisms by which bicuspid and quadricuspid pulmonary valves develop are similar to those by which bicuspid and quadricuspid aortic valves form, respectively. However, the primary factor or factors that induce the malformations of the pulmonary valve operate independently from those inducing the malformations of the aortic valve.
OBJECTIVE: To assess the utility of transthoracic echocardiography (TTE) with second harmonic combined with transesophageal echocardiography (TEE) in defining aortic valve morphology in a subset of patients with a high prevalence of bicuspid aortic valve. METHODS AND MATERIALS: Patients (n = 174) with dilated aortic root were consecutively evaluated using, initially, TTE. The aortic valve structure was assigned as tricuspid, bicuspid or undefined. In those assigned as bicuspid or undefined, TEE was performed. Other factors that could affect valve morphology assignment were recorded and evaluated in multivariate analysis. RESULTS: TTE was able to characterise 89% of the tricuspid valves and 56% of the bicuspid. Bicuspid structure was the only variable that, in the multivariate analysis, was related to the inability to definitively assign aortic valve morphology (OR = 0.13). TEE was performed in 59 patients and the morphology was definitively assigned in 56 of them (95%). TEE diagnosed 15 bicuspid valves in addition to confirming the 17 identified by TTE. Overall, using TTE combined with TEE we were able to correctly assign valvular morphology in 98% of patients. CONCLUSION: In a subset of patients with a high prevalence of bicuspid aortic valve, combination of TTE and TEE should be considered to define aortic valve morphology. TEE identifies an important number of patients with BAV.
BACKGROUND: Recently, bicuspid aortic valve disease is posed to be a possible risk factor for dilatation of the pulmonary autograft. METHODS: Analysis of all 123 patients in our prospective cohort with their native aortic valve in situ at the autograft procedure. RESULTS: The bicuspid aortic valve group (n = 81) had more males (p = 0.05), prior cardiac surgery (p = 0.02), prior aortic valve balloon dilatation (p = 0.01), aortic stenosis (p = 0.03), and less deterioration of left ventricular function (p = 0.02) than the tricuspid group (n = 42). Hospital mortality occurred in 3 patients (bicuspid 2, tricuspid 1). The follow-up was 99% complete (median, 5.3 years; SD, 3.5; range, 0.1 to 13.4) with a total of 674 patient years. During follow-up 4 patients died (bicuspid 2, tricuspid 2). Overall survival was 95% (95% confidence interval [CI], 89% to 98%) at 5 and 10 years. Seven patients required reoperation for autograft failure, all structural. Freedom from autograft reintervention was 97% (95% CI, 92% to 100%) at 5 years and 89% (95% CI, 79% to 98%) at 10 years. There were no differences in outcome between the groups. Four patients required reoperation for allograft failure, all structural. Freedom from allograft reoperation was 99% (95% CI, 97% to 100%) at 5 years and 91% (95% CI, 82% to 100%) at 10 years. There was no difference between the groups. CONCLUSIONS: An autograft procedure in patients with a bicuspid aortic valve is justified. Bicuspid aortic valve disease is not a contraindication for an autograft procedure. Patients with a bicuspid aortic valve will meet the limitations of the autograft procedure in the same frequency as the overall autograft population.
The bicuspid aortic valve affects 1 to 2% of the population and may be complicated by aortic stenosis or aortic insufficiency and infective endocarditis. The bicuspid aortic valve is associated with abnormalities of the aortic wall such as coarctation of the aorta, aortic dissection, and aortic aneurysm. Most patients with a bicuspid aortic valve will develop some complication during life. Individuals with a bicuspid valve may be unaware of its presence and are at risk for unsuspected complications. Aortic wall abnormalities associated with bicuspid aortic valve are due to cystic medial necrosis. This process is associated with increased metalloproteinase activity and apoptosis of vascular smooth muscle cells. The clinical correlates of aortopathy in the bicuspid aortic valve include significant enlargement of the ascending aorta with aneurysm formation and dissection. This process continues after valve replacement. The person with bicuspid aortic valve requires continuous surveillance to treat associated lesions and prevent complications.
OBJECTIVE: The degeneration of bicuspid aortic valve and its frequent association with ascending aortic pathology, point to a still unidentified genetic tissue defect with unknown mediators. Metalloproteinases (MMPs) are lytic enzymes that have been strongly implicated in aneurysm formation. The purpose of this study was to detect the presence of these enzymes in aortic valvular tissue in healthy and diseased aortic valves with or without the presence of synchronous ascending aortic pathology. METHODS: Aortic valve specimens from 26 aortic valve replacement patients as well as 4 healthy control tricuspid aortic valves were included. 10 patients had bicuspid aortic valves, and 16 had tricuspid aortic valves. Half of our patient population had a concomitant aortic procedure for aortic pathology. The study detected MMPs 1,2 and 9 as well as their Tissue inhibitors (TIMPs) 1 and 2. MMP and TIMP detection was accomplished with the construction of a tissue micro array and immunohistochemistry. CONCLUSIONS: MMP-9 expression was significantly higher in bicuspid aortic valves compared to normal valves (P<0.05). When compared to the tricuspid valve group, MMP-9 mean value was significantly higher in bicuspid valves (P<0.05). When the entire rest of the valve group (n=4+16, i.e. control and tricuspid valve groups) was compared to the bicuspid valve group, bicuspid valves had significantly higher MMP-2, and MMP-9 (P<0.01) expression. TIMP expression also changed in diseased valves, among different patient groups. This increased proteolytic presence in bicuspid aortic valves may attribute to the observed decreased elastin and collagen content, and their resultant functional failure.
OBJECTIVE: Bicuspid aortic valve disease is often associated with dilation of the aortic root and ascending aorta. This study examines the histologic features of the ascending aorta and main pulmonary artery of patients with and without aortic valve disease. METHODS: Samples from ascending aorta and main pulmonary artery were obtained at the time of the operation from 20 patients with bicuspid aortic valve and 11 patients with tricuspid aortic valve disease. In addition, samples were also obtained from autopsy cases with normal aortic valve. The histologic changes were graded from 1 to 3 according to severity of degenerative changes. RESULTS: In the ascending aorta, the severity of cystic medial necrosis (P =.001), elastic fragmentation (P =.002), and changes in the smooth muscle cell orientation (P =.002) were significantly more severe in patients with bicuspid than in those with tricuspid aortic valve disease. In the pulmonary trunk specimens, those 3 histologic features were also significantly more severe in patients with bicuspid than those with tricuspid valves (P =.001, P =.01, and P =.04, respectively). Seventy-five percent of patients with bicuspid aortic valve disease had grade 3 degenerative changes, whereas only 14% of those patients with tricuspid aortic valve disease had similar degrees of degenerative changes. CONCLUSION: Patients with bicuspid aortic valve disease have more severe degenerative changes in the media of the ascending aorta and main pulmonary artery than patients with tricuspid aortic valve disease. These findings may explain root and ascending aortic dilation in patients with bicuspid aortic valve disease and pulmonary autograft dilation in certain patients after the Ross procedure.
Treating periodontitis which involves the mesial concavity of the maxillary first bicuspid can be very challenging. Fifty extracted adolescent maxillary first bicuspids were sectioned in 2-mm thick sections apical to the cementoenamel junction (CEJ). The mesial concavity depth and the cementum and dentin thickness were measured in the sections. The single-rooted bicuspids have a concavity 0.35 mm deep at the CEJ and a concavity 0.59 mm deep 4.7 mm apical to the CEJ. Two-rooted bicuspids furcate at 7.9 mm and have a concavity 0.44 mm deep at the CEJ which increases to 1.08 mm at the 4.7 mm level. Cementum thickness averages from 0.9 mm at the CEJ to 1.1 mm at the 9.4-mm level. Most bicuspids also have a distal concavity which is deepest at the 4.7-mm level. The results imply that any attachment loss around the maxillary first bicuspid involves surfaces which are most likely concave. These concave surfaces make both plaque removal and various periodontal therapeutic procedures difficult.