[Differences between laypersons and orthodontists in recognizing the light reflection zone on the maxillary central incisors crowns].

The light reflection zone (LRZ) is a new parameter that may serve as a tool for the diagnosis of smile esthetics. It is a bright white dot or area that appears on the surface of the maxillary central incisors and/or the gingiva of the front teeth, visible in intra-oral and smile extra-oral photographs. Recently it was found that the general population defines a nicer smile when the LRZ is located in the gingival area of the upper central incisors' surface rather than the incisal third. The aim of this study was to find out in two populations that are not aware of this new parameter, laypersons and orthodontists, whether there is a difference in the identification of the LRZ and the importance of the LRZ in determining the quality of the smile. Twelve pairs of facial photographs, including 10 of ordinary smiling persons and 2 of smiling models, were presented to 108 laypersons and 30 orthodontists. The only difference between each pair was the location of the LRZ that was moved, compared to the original photograph, gingivally or incisally respectively, using Photoshop (Adobe). Each participant was asked to mark whether he/she noticed a difference between the 2 pictures, and if so, to score the nicer smile. Data analysis was carried out using Chi square test and Fisher's exact test (SPSS v17). The results showed that both populations had difficulty in recognizing the differences between the pictures that were based solely on the LRZ parameter. However, when differences were recognized, most of the participants in both populations pointed on the smile where the LRZ was located gingivally as the nicer one. The orthodontic population recognized the difference between the two pictures, in which only the LRZ was changed, to a lesser extent compared to the laypersons populations. This result was with statistical significance (p = 0.007).

[Lip angle and the position of the maxillary lateral incisor--post orthodontics retention considerations].

The relations between the soft tissues draping, the dentoskeletal structure and teeth position have been thoroughly investigated. Nevertheless, it is still unclear to point on the primary underlying cause for pathology if exists, is it the frame or the content, the chicken or the egg. Those relations are of an utmost importance in the process of determining the retention procedure and length in post orthodontic treatment patients. This paper discusses the issue which, as far as we know, has never been examined - the upper lip angle, (the angle created by 3 points - the two intersections between the lip cupid arch and the lip philtrum columns and the lip commissural point in either side), as it related to the maxillary lateral incisors position. Long term clinical observations were behind our hypothesis that lips with acute angles go along with palatally positioned maxillary lateral incisors, one or two. The lips angel of both the study group (37 orthodontic patients ages 15.7+/-6.8, with at least one maxillary lateral incisor in palatal position), and the control group (37 orthodontic patients ages 16.5+/-8.7 with no mal-aligned maxillary teeth) were measured and compared. It was found that the lip angle of the control group was 152.256+/-5.52 degrees while for the study group it was 149.23+6.68. This result is with statistical difference (p=0.001). It was further found that the more acute the lip angle; the more the lateral maxillary tooth or teeth are palatally positioned. The results of this study and the clinical observations suggest long term fixed retention of the maxillary incisors, following orthodontic treatment especially in patients with acute lip angle.

[Light reflection zone on the incisors' surface--a new parameter for smile esthetics evaluation].

The light reflection zone (LRZ) is a bright white dot or area that appears on the surface of the maxillary central incisors and/or the gingiva of the front teeth, visible in intra-oral and smile extra-oral photographs. Previously, a positive correlation between the location of the LRZ as observed in intra-oral frontal photographs and the inclination of the upper central incisors as measured on lateral headfims was found. The purpose of this study was to find whether this LRZ location can serve as a new parameter influencing the level of smile esthetics. Twelve pairs of facial photographs, including 10 of ordinary smiling persons and 2 of smiling models, were presented to 138 participants. The only difference between each pair was the location of the LRZ that was moved, compared to the original photograph, gingivally or incisally respectively, using Photoshop (Adobe). Each participant was asked to mark whether he/she noticed a difference between the 2 pictures, and if so, to score the nicer smile. Data analysis was carried out using Chi square test and Fisher's exact test (SPSS v17). The results showed that most of the participants did not recognize the differences between the pairs however, when differences were recognized, most of the participants pointed on the smile where the LRZ was located gingivally as the nicer one. This result was with statistical significance for the 2 models (p < 0.05), In conclusion, the LRZ is a new, yet unrecognized, parameter that can serve as a tool for the diagnosis of esthetic smile. The general population defines a nicer smile when the LRZ is located in the gingival area of the upper central incisors' surface rather than the incisal third. The LRZ should probably be studied not only in Orthodontics but also in other branches of dentistry.

[The inaccuracy of the panoramic radiograph as a tool to determine tooth inclination].

The panoramic radiograph is one of the most common radiographs in orthodontics. It is sometimes used as an aid for the decision which teeth should be extracted as part of the individual treatment plan. When treating patients with clear plates (for example, Invisalign), it is very important to know the inclination direction of the involved teeth. Tipping is more predictable and it takes less time than bodily movement. The objective of this paper is to demonstrate the limitations of the panoramic radiograph in the decision making process related extraction in orthodontics. An eleven years old girl with lower anterior crowding of about 5 mm was examined prior to her orthodontic treatment. One possible treatment plan, in order to relieve the crowding, was to extract two lower bicuspids. The other treatment plan was to extract one lower incisor. Clinically, both cuspids were acutely tipped mesially, but were imaged uprighted and parallel to their adjacent teeth in the panoramic radiograph. In order to better understand the cuspids position, a model of the lower arch was prepared, with a similar malocclusion demonstrated by the patient. In the model, the cuspids' metal teeth, invested in wax, were mesially angulated. A panoramic radiograph of the model was then taken. The radiograph of the model shows a parallel position of the incisors, the cuspids and the bicuspids, exactly as was shown in the patient's radiograph. It has been demonstrated that there is a discrepancy between the actual position of the teeth and roots and their position in the panoramic radiograph, especially in the mesiodistal angulation. It was concluded that we should be very cautious when trying to interpret the panoramic radiograph as a tool for root parallelism, and remember the inherent image distortions. This is especially true before deciding which teeth will be extracted, on the basis of "incorrect" tooth angulation.

Preliminary observations of sildenafil treatment for erectile dysfunction in dialysis patients.

Erectile dysfunction is common in dialysis patients. We report our experience with sildenafil citrate in patients undergoing dialysis therapy. Male subjects attending the Outpatient Dialysis Unit at the University of Pennsylvania (Philadelphia, PA) who were prescribed sildenafil by their primary physician or nephrologist were asked to complete the International Index of Erectile Function before their first dose of sildenafil and after at least 4 weeks of therapy. Subjects' mean age was 50.3 +/- 14.63 (SD) years. Ninety-three percent of the subjects were black. Based on a global efficacy question, 66.7% of the subjects believed that treatment had improved their erections. Subjects reported no increase in the sexual desire domain despite experiencing a significant increase in erectile function, orgasmic function, and satisfaction with intercourse. Sildenafil was well tolerated in a selected group of patients who reported improved sexual function with no major adverse effects.

Outbreak of sterile peritonitis among continuous cycling peritoneal dialysis patients.

BACKGROUND: Approximately 30,000 patients receive peritoneal dialysis in the United States. In August 1996, several dialysis centers from different states reported sterile peritonitis among CCPD patients using sterile peritoneal dialysis solution (PDS) from a single manufacturer. The manufacturer recalled 53 lots of PDS that had passed established industry guidelines and Food and Drug Administration (FDA) approved quality control tests [including endotoxin levels <0.5 endotoxin units (EU)/ml], but had pre-sterilization bacterial colony counts >1 cfu/ml. METHODS: At one outpatient dialysis center, Hospital of the University of Pennsylvania (HUP), we conducted a retrospective cohort study of all CCPD patients treated during July 15 to August 30, 1996. A case-patient was defined as any HUP patient with culture-negative peritoneal fluid with a white blood cell count >100/mm3, cloudy peritoneal fluid, and/or abdominal pain. PDS and tubing were cultured for bacteria and assayed for endotoxin. RESULTS: Overall, 14 of 28 patients had sterile peritonitis. The only risk factor identified was exposure to > or =1 lot of recalled PDS (14 of 22 vs. 0/6, P = 0.02); the more recalled lots received, the higher the attack rate (P = 0.0001). Five of 47 PDS bags had detectable endotoxin; recalled lots were more likely to have measurable endotoxin than nonrecalled lots (5/19 vs. 0/17, P = 0.05). When case-patients resumed CCPD using PDS from non-recalled lots, no further cases were reported. CONCLUSIONS: Our results suggest that this outbreak was caused by intrinsic PDS contamination with endotoxin. Pre-sterilization colony counts may be an important quality control indicator for CCPD fluids in conjunction with endotoxin levels.

Nephrolithiasis: acute management and prevention.

The primary care physician has a responsibility not only to recognize and treat acute stone passage but to ensure that the patient with recurrent stones has metabolic evaluation and appropriate preventive care. Renal colic is typically severe, radiates to the groin, is associated with hematuria, and may cause ileus. About 90% of stones that cause renal colic pass spontaneously. The patient with acute renal colic should be treated with fluids and analgesics and should strain the urine to recover stone for analysis. Highgrade obstruction or failure of oral analgesics to relieve pain may require hospitalization; a urinary tract infection in the setting of an obstruction is a urologic emergency requiring immediate drainage, usually with a ureteral stent. Several approaches are available when stones do not pass spontaneously, including extracorporeal shock wave lithotripsy, percutaneous lithotripsy, and ureteroscopic laser lithotripsy. Calcium stone disease has a lifetime prevalence of 10% in men and causes significant morbidity. Renal failure is unusual. Stone types include calcium oxalate, uric acid, struvite, and cystine. Stone analysis is particularly important when a noncalcareous constituent is identified. The majority of patients with nephrolithiasis will have recurrence, so prevention is a high priority. High fluid intake is a mainstay of prevention. Metabolic evaluation will indicate other appropriate preventive measures, which may include dietary salt and protein restriction, and use of thiazide diuretics, neutral phosphate, potassium citrate, allopurinol, and magnesium salts. Dietary calcium restriction may worsen oxaluria and negative calcium balance (osteoporosis).

Hemodialysis vascular access morbidity.

Complications associated with hemodialysis vascular access represent one of the most important sources of morbidity among ESRD patients in the United States today. In this study, new data on the magnitude and growth of vascular access-related hospitalization in the United States is presented, demonstrating that the costs of this morbidity will soon exceed $1 billion per yr. This study also reviews published literature on the morbidity associated specifically with native arteriovenous fistulae, polytetrafluoroethylene bridge grafts, and permanent central venous catheters. Next, new information on the changing patterns of vascular access type in the United States is presented, demonstrating the continuing evolution of medical practice away from the use of arteriovenous fistulae in favor of more reliance on synthetic bridge grafts. Based on these data, a discussion is provided of the tradeoffs among the most commonly available modalities of vascular access today. Although radial arteriovenous fistulae continue to represent the optimal access modality, the appropriate roles for brachial arteriovenous fistulae, synthetic bridge grafts, and central venous catheters are less certain because of inadequate data on the long-term function of the first and the high rates of complications associated with the latter two. To reduce vascular access-related morbidity, strategies must be developed not only to prevent and detect appropriately early synthetic vascular access dysfunction, but to better identify the patients in a whom radial arteriovenous fistula is a viable clinical option.

Changing patterns of medical practice: protein restriction for chronic renal failure.

The use of dietary protein restriction for renal failure has fluctuated during the past 125 years. These fluctuations reflect not only the state of medical knowledge but also social, economic, and cultural factors. Factors inhibiting use of dietary treatment have been its status as an aspect of hygiene rather than as active therapy; the opinions of dominant practitioners and scientists around midcentury, including a presumption that renal adaptation to a high-protein diet must be appropriate; fear of malnutrition and a cultural belief in the virtue of dietary protein; unwillingness by physicians and patients to restrict consumption or lifestyle; and professional identification with the technologies of dialysis and renal transplantation. Factors promoting dietary treatment have been rediscovery of previous work on protein-induced renal injury; a sense that homeostatic compensations could have adverse consequences; federal incentives to curb consumption of scarce resources such as renal dialysis; and the integration of research on, and therapeutic use of diet into scientific medicine. A large ongoing study of dietary protein restriction to limit renal injury will add to our knowledge of this treatment; its application will surely be informed by social and cultural considerations.

Root resorption after orthodontic treatment: Part 2. Literature review.

All permanent teeth may show microscopic amounts of root resorption that are clinically insignificant and radiographically undetected. Root resorption of permanent teeth is a probable consequence of orthodontic treatment and active tooth movement. The incidence of reported root resorption during orthodontic treatment varies widely among investigators. Usually, extensive resorption does not affect the functional capacity or the effective life of the tooth. Most studies agree that the root resorption process ceases once the active treatment is terminated. Root resorption of the deciduous dentition is a normal, essential, and physiologic process. Permanent teeth have the potential to clinically undergo significant external root resorption when affected by several stimuli. This resorptive potential varies in persons and between different teeth in the same person. This throws doubt on the role of systemic factors as a primary cause of root resorption during orthodontic treatment. Tooth structure, alveolar bone structure at various locations, and types of movement may explain these variations. The extent of treatment duration and mechanical factors definitely influence root resorption. In most root resorption studies, it is not possible to compare the results and conclusions because of their different methods. Further research in this field is necessary to advance the service of the specialty. The question of whether there is an optimal force to move teeth without resorption or whether root resorption may be predictable remain unanswered. This review indicates the unpredictability and widespread incidence of the root resorption phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS)