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1.
Eur J Pediatr Surg ; 16(6): 415-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17211790

RESUMO

PURPOSE: Nonparasitic splenic cysts (NPSCs) are uncommon in children. The aim of this multinational and multicentric study was to present the authors' experience as well as the changing trends in the management of NPSCs over the last 25 years. MATERIAL AND METHODS: From 1981 to 2005, 50 children or adolescents were surgically treated for NPSCs in 6 paediatric surgical centres in four European countries. The medical records of these 50 patients with NPSCs were reviewed retrospectively. RESULTS: Twenty-six male and 24 female patients were operated on. Age at surgery ranged from 1 to 17 years (mean 11.9). Seventeen patients were symptomatic. Six total (4 open and 2 laparoscopic) and 26 partial (22 open and 4 laparoscopic) splenectomies were performed. Laparoscopic fenestration or deroofing and open cystectomy was carried out in 9 patients, respectively. Histological findings revealed the lesion to be an epidermoid cyst (n = 28), a pseudocyst (n = 15) or a mesothelial cyst (n = 2). In 5 patients haemangioma or lymphangioma was the pathological diagnosis. At a mean follow-up of 2.9 years, residual cysts were found in 8 laparoscopically treated patients, 4 of whom required re-do laparoscopy or open surgery. CONCLUSIONS: Over the last two decades, the surgical treatment of NPSCs has changed from a formerly customary total splenectomy to spleen-conserving procedures, such as total cystectomy with or without partial splenectomy or partial cystectomy. These therapeutic modalities can be performed laparoscopically, if technically possible. Fenestration or deroofing of the cyst resulted in a high recurrence rate (7/9).


Assuntos
Cistos/cirurgia , Esplenopatias/cirurgia , Adolescente , Criança , Pré-Escolar , Cistos/diagnóstico , Feminino , Humanos , Achados Incidentais , Lactente , Masculino , Estudos Retrospectivos , Esplenopatias/diagnóstico
2.
Pediatr Surg Int ; 21(10): 806-8, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16142486

RESUMO

Elective endoscopic diaphragmatic hernia repairs have been reported. But endoscopic surgery was regarded unsuitable for emergency repair of diaphragmatic hernia in ventilated newborn children in bad general condition. We report a new method for inflation-assisted reduction and thoracoscopic repair of congenital diaphragmatic hernia diaphragmatic in a vitally endangered neonate. From three 2.7 mm to 5 mm accesses warmed low-pressure, low-volume CO2 was inflated into the thorax at 100 ml/min and 2 mm mercury. This allowed spontaneous reduction of the thoracic viscera into the abdomen and diaphragmatic suture with minimal handling. The 65-min procedure was tolerated well without perioperative deterioration. The baby was weaned off the respirator and breast-fed within 2 days, mediastinal shift normalized in 6 days. In suitable infants thoracoscopic repair and inflation-assisted reduction of thoracic contents is a more physiological access to congenital diaphragmatic hernia than laparoscopy or laparotomy.


Assuntos
Hérnia Diafragmática/cirurgia , Hérnias Diafragmáticas Congênitas , Ressuscitação , Toracoscopia , Humanos , Recém-Nascido , Pneumotórax Artificial , Respiração Artificial
3.
Surg Endosc ; 18(4): 626-8, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15026897

RESUMO

BACKGROUND: In children, laparoscopic decapsulation of large congenital splenic cysts has occasionally been advocated, but substantial series focusing on its long-term success are still lacking. We report the follow-up experiences from two pediatric surgical centers. METHODS: The decision to proceed to surgery was based on patient symptoms and cyst size (>4 cm and/or progression), after strictly exclusion of a parasitic cause (by serology and CT scan). With the use of three ports (5-10-mm) and a Harmonic Scalpel, the epithelial portion of the cyst was radically excised. The remaining hilar epithelium was coagulated carefully. After discharge, the children were examined regularly by ultrasound to detect recurrences. RESULTS: From 1998 until 2002, eight children (mean age, 11.1 years; range, 3.1-16.4) were treated for cysts ranging from 4 to 15 cm in diameter. All procedures were completed without significant intraoperative complications (no major bleeding, no conversions). The mean operating time was 75 min (range, 56-184). Postoperatively, one child developed a cystic remnant (2 cm), which remained unchanged during 30 months of observation. After a mean follow-up of 2.2 years (range, 13-38 months), none of the patients showed any evidence of recurrent growth, and all of them had healthy splenic remnants. CONCLUSION: Partial laparoscopic decapsulation is an advantageous approach to large splenic cysts in children, because it is effective, preserves splenic tissue, and provides good medium-term results.


Assuntos
Cistos/cirurgia , Laparoscopia/métodos , Esplenopatias/cirurgia , Adolescente , Criança , Pré-Escolar , Cistos/congênito , Cisto Epidérmico/congênito , Cisto Epidérmico/cirurgia , Feminino , Seguimentos , Humanos , Laparoscopia/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Masculino , Recidiva , Esplenopatias/congênito , Resultado do Tratamento
4.
Eur J Pediatr Surg ; 13(3): 187-94, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12939704

RESUMO

AIM: In contrast to other countries, no collective study of Rehbein's procedure in German-speaking nations has been performed. Therefore, our intention was, analogously to Goto and Ikeda's (10) Japanese study in 1984, Kleinhaus's (13) study on Swenson's procedure in 1979, Bourdelat's (2) French-Canadian investigation into Duhamel's technique in 1997 and Martuciello's (11) and Teitelbaum's (16) follow-up in the year 2000, to perform a follow-up study of Rehbein's technique of deep anterior resection. METHODS: The data of 200 patients from 22 German-speaking centers in Switzerland, Austria and Germany were collected. These data were gathered by questionnaire and the children were followed up in the individual participating hospitals for at least 3.5 years after the procedure. The procedure was performed between 1993 and 1997, over a 5-year period. The questionnaire contained 74 items including anamnestic data, diagnostic postoperative treatment and reoperations. RESULTS: Concerning the incidence of anastomotic leaks and resolving anastomotic strictures there was no significant difference between the results in our series and those of the collective analyses made by Hofmann von Kap-herr (7), Holschneider (9) and Sherman (18). In 6.6 % of the 191 patients an anastomotic leak and in 9.9 % a rectal stricture, which had to be dilated, was observed. Concerning late complications, 22.8 % of the children suffered from constipation, 4.3 % from encopresis, 10.6 % from enterocolitis and only 0.5 % from enuresis. The frequency of constipation diminishes over the years. A comparison of the different large series in the literature clearly shows that the incidence of constipation is higher after Rehbein's procedure and the frequency of urinary incontinence and encopresis higher following Swenson's, Soave's and Duhamel's techniques. The incidence of enterocolitis is less after Rehbein's procedure than after Swenson's, Soave's and Duhamel's techniques. CONCLUSIONS: The different results in the literature are due to the individual experience of the author, the very different follow-up methods and the date of follow-up. Therefore, the different results are hard to compare with our study. Nevertheless, Rehbein's anterior resection still could be presented as an adequate and important method to treat Hirschsprung's disease.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Doença de Hirschsprung/cirurgia , Áustria , Criança , Colo/cirurgia , Constipação Intestinal/etiologia , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Enterocolite/etiologia , Feminino , Seguimentos , Alemanha , Humanos , Masculino , Estudos Retrospectivos , Inquéritos e Questionários , Suíça
5.
Eur J Pediatr Surg ; 12(4): 235-8, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12368999

RESUMO

Since the first description in 1998, the minimally invasive repair of pectus excavatum has gained increasing acceptance. The aim of this survey is to report on the experiences of eight European centres with this technique. 172 patients with a mean age of 15.1 (+/- 4.6) years were treated and evaluated, 35.5 % were symptomatic. 45.3 % of the patients had an asymmetric configuration of the chest, 74.3 % had a CT index above 3.25. Mean duration of the operative procedure was 76 minutes. Major complications, including dislocation of the bar or stabiliser, pneumonia, atelectasis, local infection, pleural and pericardial effusion and liver injury occurred in 11.1 % of the patients. Minor complications, such as self-resolving pneumothorax, atelectasis and subcutaneous emphysema were reported in another 8.1 %. Early cosmetic results were excellent or good in 81.5 %. Although the surgical procedure is simple, blood-sparing and short, consideration of some important technical details, proper patient selection and knowledge of the limitations is of vital importance. Long-term results are still lacking.


Assuntos
Tórax em Funil/cirurgia , Toracoscopia/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Coleta de Dados , Desenho de Equipamento , Europa (Continente) , Feminino , Humanos , Lactente , Masculino , Complicações Pós-Operatórias , Inquéritos e Questionários , Resultado do Tratamento
6.
Surg Endosc ; 16(11): 1639, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12072989

RESUMO

BACKGROUND: A left thoracotomy is the standard access for aortosternopexy in severe tracheomalacia. We report a modified technique for thoracoscopic aortopericardiosternopexy. METHODS: The thymus is mobilized, and the needle is passed through the sternum and back. In extensive or recurrent tracheomalacia, not only the ascending aorta but also the innominate artery and pericardial base are fixed to the sternum. The effect is monitored bronchoscopically. RESULTS: This technique showed dramatic success in two children, one 4-year-old and a 2-year-old. In the younger child, the thoracoscopy was a redo procedure after a previous open aortosternopexy. CONCLUSIONS: Thoracoscopic aortopericardiosternopexy is an effective procedure that does not impair postoperative respiration. It should therefore be considered for severe tracheomalacia or even redo operations.


Assuntos
Aorta/cirurgia , Pericárdio/cirurgia , Esterno/cirurgia , Toracoscopia/métodos , Apneia/cirurgia , Cartilagem/anormalidades , Cartilagem/cirurgia , Pré-Escolar , Atresia Esofágica/cirurgia , Feminino , Humanos , Masculino , Procedimentos Cirúrgicos Torácicos/instrumentação , Procedimentos Cirúrgicos Torácicos/métodos , Doenças da Traqueia/congênito , Doenças da Traqueia/cirurgia
7.
Minim Invasive Ther Allied Technol ; 11(5-6): 231-236, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28561601

RESUMO

Technical principles and physical action mechanisms of ultrasonic dissection are introduced. We list various indications for using the BERCHTOLD SONO-CUT scissors and describe early clinical experiences, e.g. in pediatric laparoscopic surgery.

8.
J Pediatr Surg ; 36(2): 309-11, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11172422

RESUMO

BACKGROUND/PURPOSE: The laparoscopic splenectomy (LS) often is adopted to treat children affected by hematologic diseases. Many of the pitfalls of LS are related to the 2 steps-dissection and extraction. Although various methods have been adopted, the conversion rate still is too high during the learning curve period. The authors analyse their experience in 54 laparoscopic splenectomies performed by their teams in 3 European countries. METHODS: From 1995 to 1999, 54 children underwent laparoscopic splenectomy, 4 of whom also underwent a concomitant cholecystectomy. There were 29 girls and 25 boys with ages ranging between 4 and 19 years (median, 8.1 years). All patients underwent an elective laparoscopic splenectomy: Thirty children had hereditary spherocytosis, 13 had an idiopathic thrombocytopenic purpura, 10 were affected by a beta thalassemia, and 1 child had sickle cell disease. RESULTS: Mean operating time was 140 minutes (range, 100 to 250 minutes). Hospital stay ranged from 2 to 6 days (median, 3 days). In 7 patients the spleen was removed through a 7-cm minilaparotomy; in another 46 cases the spleen was captured into an extraction bag, fragmented, and then removed through the umbilical or left orifice. There was one conversion to open surgery because of a camera failure during the operation. CONCLUSIONS: On the basis of our experience we believe that the operating time of LS is still too long compared with open surgery, and the extraction phase still not simple enough. A perfect control of hemostasis is fundamental because severe complications can arise from even a slight bleeding episode. It also is very important to search for and remove any accessory spleens. In our series this occurred in 7 patients, one of whom had 3 accessory spleens. The laparoscopic approach is today a good alternative to open splenectomy.


Assuntos
Laparoscopia , Esplenectomia/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Complicações Intraoperatórias , Laparoscopia/efeitos adversos , Laparoscopia/métodos , Tempo de Internação , Masculino , Complicações Pós-Operatórias , Esplenectomia/efeitos adversos , Fatores de Tempo , Resultado do Tratamento
9.
Int Surg ; 85(2): 180-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11071339

RESUMO

BACKGROUND: Non-retractile foreskin comprise a significant number of referrals by pediatricians and general practitioners to pediatric surgical centers. In attempts to find alternatives to widely practised circumcision, various procedures have been developed over the years in order to relieve the non-fibrotic narrowing of the foreskin. PATIENTS AND METHODS: In a 13-year period from 1984-1997, we treated 2554 patients with non-retractile foreskin at our center. Dorsal relieving incision was the technique of choice and was performed in 2177 patients, circumcision in 73 patients and preputial adhesiolysis was sufficient to retract the foreskin in 284 patients. RESULTS: Satisfactory esthetic results, an extremely low rate of postoperative complications (1.8%) with a recurrence rate of only 0.8% (18 patients) was observed in our series with dorsal relieving incision. CONCLUSIONS: Dorsal relieving incision operation was found to be a less invasive, safe and effective procedure for non-retractile foreskin not affected by extensive secondary scarring. This technique has fewer complications in comparison to circumcision and can be performed as an ambulatory procedure.


Assuntos
Circuncisão Masculina/métodos , Fimose/cirurgia , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Adolescente , Procedimentos Cirúrgicos Ambulatórios/métodos , Criança , Pré-Escolar , Circuncisão Masculina/efeitos adversos , Humanos , Lactente , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Pomadas/uso terapêutico , Ácido Pantotênico/análogos & derivados , Ácido Pantotênico/uso terapêutico , Recidiva , Estudos Retrospectivos , Aderências Teciduais/prevenção & controle , Resultado do Tratamento
10.
Pediatr Surg Int ; 15(5-6): 431-4, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10415312

RESUMO

Tumors of the ovary in girls represent about 80% of pediatric genital tumors; approximately 30% of these tumors are malignant. The risk of malignancy increases with decreasing age. The most frequent finding is a teratoma; other tumors are rare. Small-cell carcinoma (SCCO) of the ovary is extremely rare, occurring mostly in young women. We present an 8-year-old girl with a SCCO of the hypercalcemic type. The findings and treatment are discussed with emphasis on the poor prognosis in these patients, even in stage 1 disease. The current literature is reviewed.


Assuntos
Carcinoma de Células Pequenas/diagnóstico , Carcinoma de Células Pequenas/cirurgia , Hipercalcemia/etiologia , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/cirurgia , Dor Abdominal/etiologia , Distribuição por Idade , Biópsia , Carcinoma de Células Pequenas/complicações , Criança , Diagnóstico Diferencial , Fadiga/etiologia , Feminino , Cefaleia/etiologia , Humanos , Hipercalcemia/sangue , Imageamento por Ressonância Magnética , Neoplasias Ovarianas/complicações , Ovariectomia , Prognóstico , Tomografia Computadorizada por Raios X
11.
Langenbecks Arch Surg ; 384(2): 187-93, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10328173

RESUMO

OBJECTIVES: Pectus excavatum is the most common congenital hereditary chest-wall deformity. This study analyses a single-center experience of pectus excavatum-thoracic wall reconstruction using a uniform technique of internal stabilization employing stainless steel struts. METHODS: From June 1984 to December 1997, we performed correction operations on 777 patients with pectus excavatum. The condition occurred more frequently in boys (621 patients) than girls (156 patients). Surgical repair was performed using a standard method of double bilateral chondrotomy parasternally and at points of transition to normal ribs. This was followed by detorsion of the sternum, retrosternal mobilization and correction of the inverted ribs. The anteriorly displaced sternum was stabilized by one trans-sternal and two bilateral parasternal metal struts. RESULTS: The corrections were completed with successful repair in 765 patients (98.5%) with a low complication rate of 6.7%. The follow-up period ranged from 4 weeks to 12 years, mean 6.4 years. Major recurrences were observed in 12 patients (1.5%) and mild recurrence were observed in 35 patients (4.5%). CONCLUSION: Significant reduction in postoperative cardiorespiratory disorders, low lethality, improvement of subjective complaints, satisfactory long-term results and improvement in psychological problems indicate the need to offer this method of surgical correction to low-risk children.


Assuntos
Tórax em Funil/cirurgia , Adolescente , Criança , Desenho de Equipamento , Feminino , Seguimentos , Tórax em Funil/classificação , Tórax em Funil/psicologia , Alemanha , Humanos , Fixadores Internos/efeitos adversos , Estudos Longitudinais , Masculino , Satisfação do Paciente , Complicações Pós-Operatórias , Recidiva , Costelas/cirurgia , Fatores Sexuais , Aço Inoxidável , Esterno/cirurgia , Taxa de Sobrevida , Resultado do Tratamento
12.
Pediatr Surg Int ; 15(1): 75-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-9914364

RESUMO

Gas gangrene is not a frequently encountered toxic wound infection in childhood. We present a case of postoperative Clostridium perfringens infection with proximal forearm myonecrosis. In order to reveal the full extent of tissue viability in the right upper extremity, infrared thermography was performed. Although dyschromia was evident in the proximal forearm, thermographs revealed viable tissue only up to the supracondylar region. Angiography, which provided valuable clues to the patency of the vascular supply, and subsequent intraoperative findings confirmed the extent of tissue perfusion as revealed by infrared thermography.


Assuntos
Clostridium perfringens , Antebraço/patologia , Gangrena Gasosa/patologia , Termografia , Amputação Cirúrgica , Pré-Escolar , Feminino , Antebraço/cirurgia , Gangrena Gasosa/cirurgia , Humanos
14.
Artigo em Alemão | MEDLINE | ID: mdl-9931825

RESUMO

The perinatal treatment of 23 infants with sacrococcygeal teratomas was recorded prospectively from 1990 to 1997, during which period 14 children (teratomas 6.9-18 cm) could be followed throughout the whole pregnancy at our own perinatal department. There were three prenatal deaths (21 h-27 week of gestation) and two peripartal deaths (1 hydrops and 1 ruptured teratoma). Prenatal Doppler sonography allows appropriate selection of high-risk fetuses. The vital prognostic sign was developing fetal hydrops with associated umbilical vein pulsations, increased aortal flow and an increasing pulsatility index in der venous duct.


Assuntos
Equipe de Assistência ao Paciente , Sacro/anormalidades , Neoplasias da Coluna Vertebral/congênito , Teratoma/congênito , Ultrassonografia Pré-Natal , Aborto Induzido , Feminino , Morte Fetal/etiologia , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Gravidez , Estudos Prospectivos , Sacro/diagnóstico por imagem , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Teratoma/diagnóstico por imagem
15.
Methods Inf Med ; 36(3): 207-13, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9293720

RESUMO

A one-hundred percent documentation rate of diagnoses and patient data is unfeasible and should not be pursued. Therefore, a "lean documentation" of diagnoses and basic patient data was introduced. Coding is done by a clinic-specific list of diagnoses (thesaurus) with a minimum of diagnostic codes, combined with optional free text. By recording the frequency of diagnoses for two years, a thesaurus of 188 diagnostic codes was developed. Bedside coding by treating physicians reduced medical and semantic mistakes of documentation. Cooperation of the clinicians was obtained by shortening the time required for coding to less than two minutes per patient. A documentation assistant supplemented incomplete data in collaboration with the treating surgeons. During a ten-year testing period 93.7% of the hospital-specific codes of our thesaurus were required for documentation, as compared to 13.1% if the same patients were coded by ICD-9. Consequently, coding by a clinic-specific code thesaurus is quick flexible and accurate.


Assuntos
Sistemas Computadorizados de Registros Médicos , Pediatria , Sistemas Automatizados de Assistência Junto ao Leito , Centro Cirúrgico Hospitalar , Vocabulário Controlado , Criança , Controle de Formulários e Registros , Alemanha , Humanos , Recém-Nascido
16.
Anat Embryol (Berl) ; 195(3): 289-97, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9084827

RESUMO

The purpose of this study was to compare the biomineralization of circumpulpal dentine with that of mantle dentine by ultrastructural and element-analytical techniques. Forty upper second molar germs of 10-day-old albino rats were cryofixed in liquid nitrogen-cooled propane and embedded in resin after freeze drying. Semithin dry sections were cut for analyzing the calcium and phosphorous concentration in initial mantle dentine, at the mineralization front of circumpulpal dentine, in the middle region of circumpulpal dentine and in mantle dentine peripheral to circumpulpal dentine. For the morphological evaluation of mineral deposits we compared ultrathin and unstained sections of cryofixed molars with chemically fixed molars. For both dentine types it was found that they develop via identical steps of mineral formation at collagen fibrils and non-collagenous matrix molecules. In circumpulpal dentine no globular mineral protrusions along the mineralization front (i.e. calcospherites) and no indications of interglobular dentine at the transition from circumpulpal dentine to mantle dentine were present. Two von Korff fibres were not only visible in mantle dentine but also in circumpulpal dentine. Matrix vesicles were present only during the formation of an initial coherent layer of mantle dentine and could not be observed during successive formation of mantle dentine and circumpulpal dentine. The element-analytical data did not demonstrate any difference in the mineral content between the two dentine types. Therefore, we conclude that mantle dentine and circumpulpal dentine in the rat molar possess a high degree of structural and chemical similarity and that only the extent of terminal branching of the odontoblast processes gives an approximate estimation of the thickness of mantle dentine.


Assuntos
Cálcio/análise , Dentina/química , Dentina/ultraestrutura , Fósforo/análise , Dente/química , Dente/ultraestrutura , Animais , Animais Recém-Nascidos , Calcificação Fisiológica , Colágeno/ultraestrutura , Microscopia Eletrônica , Ratos
17.
Artigo em Alemão | MEDLINE | ID: mdl-9574424

RESUMO

A total of 128 pediatric pyogenic perianal infections were recorded prospectively in 1984-1995; over 70% arose in children below the age of 2 years. A quarter of all perianal abscesses developed a recurrence between 3 weeks and 3 years after the initial operation, while five children had an anal fistula after deroofing of anal abscesses. The early age of onset and frequent anomaly of anal crypts (12%) suggests a partly congenital etiology due to impaired fusion of the proctodaeal membrane or rudimentary anorectal duplications for both conditions.


Assuntos
Abscesso/cirurgia , Infecções Bacterianas/cirurgia , Proctite/cirurgia , Fístula Retal/cirurgia , Abscesso/etiologia , Adolescente , Canal Anal/anormalidades , Infecções Bacterianas/etiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Proctite/etiologia , Estudos Prospectivos , Fístula Retal/complicações , Reto/anormalidades , Recidiva
18.
Eur J Orthod ; 18(6): 655-62, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9009430

RESUMO

This clinical study investigated the practical value of two methods for debonding brackets attached by the adhesive Concise to acid-etched enamel surfaces. Forty-two Ultratrimm Standard metal brackets and 42 Fascination ceramic brackets were collected from juvenile patients undergoing orthodontic treatment. All metal brackets were mechanically debonded by a conventional bracket removal plier, whereas the ceramic brackets were thermally debonded by a commercial Dentaurum ceramic debonding unit. All brackets were evaluated by scanning electron microscopy for the morphology of their adhesive fracture surfaces and for the occurrence of mineral-like particles attached to the adhesive fracture surfaces. These particles were analysed by an energy dispersive X-ray microprobe for their Ca/P ratios and by image analysis of scanning electron micrographs for measurement of their areas. The scanning electron micrographs showed 4 types of debonding fractures. The most frequent fracture was type 1 (between adhesive and bracket base) and type 2 (between adhesive and enamel surface). In the group of mechanically debonded metal brackets type 1 (38 per cent) and type 2 (45 per cent) showed a similar frequency, whereas thermally debonded ceramic brackets predominantly showed fracture type 1 (79 per cent) and only a minor percentage of type 2 (11 per cent). A statistical evaluation was applied to estimate the range of reproducibility of fracture types with a 95 per cent confidence interval (level of significance alpha = 5 per cent). In both groups the microprobe analysis of fracture surfaces lying completely or partly between adhesive and enamel surface identified the mineral-like particles as enamel mineral. They occurred partly as single particles (range of thickness: 5-25 microns, mean area: 3500 microns2) and partly as a coherent covering with a total area of 1.9-5.8 mm2. It is concluded that the thermodebonding technique is superior to conventional mechanical debonding, because the frequent occurrence of fracture type 1 after thermodebonding affords a protection for the enamel surface, whereas mechanical debonding entails a comparatively high risk of enamel fractures.


Assuntos
Cerâmica , Ligas Dentárias , Descolagem Dentária/métodos , Esmalte Dentário/ultraestrutura , Braquetes Ortodônticos , Condicionamento Ácido do Dente , Adesivos/química , Adolescente , Bis-Fenol A-Glicidil Metacrilato/química , Cálcio/análise , Cálcio/química , Cerâmica/química , Criança , Intervalos de Confiança , Ligas Dentárias/química , Descolagem Dentária/efeitos adversos , Descolagem Dentária/instrumentação , Esmalte Dentário/lesões , Microanálise por Sonda Eletrônica , Temperatura Alta , Humanos , Processamento de Imagem Assistida por Computador , Microscopia Eletrônica de Varredura , Fósforo/análise , Fósforo/química , Reprodutibilidade dos Testes , Propriedades de Superfície , Fraturas dos Dentes/etiologia , Fraturas dos Dentes/patologia
19.
Cell Tissue Res ; 284(2): 223-30, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8625389

RESUMO

The purpose of this study was to elucidate the mineralization process of mantle dentine by ultrastructural and element-analytical investigation of matrix vesicles and successive stages. Upper second molars of albino rats were cryofixed and embedded in resin after freeze drying. Semithin dry sections were prepared for analyzing the calcium and phosphorus concentrations in the mineralized matrix vesicles or noduli, larger mineralized islands, and the mantle dentine. For ultrastructural studies, it was necessary to reduce section contact with hydrous fluids to a minimum in order to avoid preparation artifacts. The first mineral deposits were recognized as dot-like formations both in the interior of matrix vesicles and in association with the inner vesicle membrane. This indicated the existence of mineral nucleating sites located both at the inner membrane and at calcium-phosphate-binding macromolecules in the interior of the matrix vesicles. A significantly higher mineral content was found in mineralized matrix vesicles than in the mineralized extravesicular regions of the mineralized islands, suggesting the existence of a rapidly and densely mineralized matrix in the matrix vesicles. A significant increase in mineral content per volume proceeding from the mineralized islands to mantle dentine suggested a further increase in the density of mineral.


Assuntos
Dentinogênese , Minerais/metabolismo , Animais , Cálcio/análise , Dentina/ultraestrutura , Dentinogênese/fisiologia , Microanálise por Sonda Eletrônica , Dente Molar/química , Fósforo/análise , Ratos
20.
J Oral Pathol Med ; 25(5): 200-5, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8835815

RESUMO

106 human TMJ specimens from 53 individuals (age: 65-85 years) were examined macro- and microscopically and measured for discal and condylar cartilage thickness at five points defined on a mediolateral axis along the middle dense part of the disc. 27% of the discs showed lateral and laterocentral perforations. In 8% the lateral portion was thinned down to a translucent layer. 62% showed no gross destruction or deviation in shape and thickness. The remaining 3% displayed extensive destruction and their condyles were osteoarthritic. All discs showed a significant decrease in thickness from their medial towards their lateral portions. The condyles displayed either a smooth articular surface (16%) or an irregular and progressively remodelled surface (81%) with histologically normal fibrocartilage. The condylar cartilage did not show a significant gradient of thickness in amediolateral direction. The results support our previously developed working hypothesis, that the joint is seemingly loaded along its entire articular surface and that a lateral disc perforation in older individuals can be due to a physiological process of wearing rather than to a pathological sequel of functional disorders.


Assuntos
Cartilagem Articular/anatomia & histologia , Côndilo Mandibular/anatomia & histologia , Osteoartrite/patologia , Disco da Articulação Temporomandibular/anatomia & histologia , Articulação Temporomandibular/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Doenças das Cartilagens/patologia , Cartilagem Articular/patologia , Colágeno , Tecido Conjuntivo/patologia , Feminino , Humanos , Masculino , Côndilo Mandibular/patologia , Estresse Mecânico , Articulação Temporomandibular/patologia , Disco da Articulação Temporomandibular/patologia
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