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1.
J Clin Sleep Med ; 18(1): 57-66, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34170240

RESUMO

STUDY OBJECTIVES: To evaluate facial 3-dimensional (3D) stereophotogrammetry's effectiveness as a screening tool for pediatric obstructive sleep apnea (OSA) when used by dental specialists. METHODS: One hundred forty-four participants aged 2-17 years, including children fully diagnosed with pediatric OSA through nocturnal polysomnography or at high-risk or low-risk of pediatric OSA, participated in this study. 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire were obtained from all participants. Ten dental specialists with interest in pediatric sleep breathing disorders classified OSA severity twice, once based only on 3D stereophotogrammetry and then based on 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire. Intrarater and interrater reliability and diagnostic accuracy of pediatric OSA classification were calculated. A cluster analysis was performed to identify potential homogeneous pediatric OSA groups based on their craniofacial features classified through the Craniofacial Index . RESULTS: Intrarater and interrater agreement suggested a poor reproducibility when only 3D facial stereophotogrammetry was used and when all tools were assessed simultaneously. Sensitivity and specificity varied among clinicians, indicating a low screening ability for both 3D facial stereophotogrammetry, ranging from 0.36-0.90 and 0.10-0.70 and all tools ranging from 0.53-1.0 and 0.01-0.49, respectively. A high arched palate and reversed or increased overjet contributed to explaining how participating dental clinicians classified pediatric OSA. CONCLUSIONS: 3D stereophotogrammetry-based facial analysis does not seem predictive for pediatric OSA screening, alone or combined with the Pediatric Sleep Questionnaire and Craniofacial Index when used by dental specialists interested in sleep-disordered breathing. Some craniofacial traits, more specifically significant sagittal overjet discrepancies and an arched palate, seem to influence participating dental specialists' classification. CITATION: Fernandes Fagundes NC, Carlyle T, Dalci O, et al. Use of facial stereophotogrammetry as a screening tool for pediatric obstructive sleep apnea by dental specialists. J Clin Sleep Med. 2022;18(1):57-66.


Assuntos
Apneia Obstrutiva do Sono , Adolescente , Criança , Pré-Escolar , Humanos , Programas de Rastreamento , Fotogrametria , Polissonografia , Reprodutibilidade dos Testes , Apneia Obstrutiva do Sono/diagnóstico por imagem , Inquéritos e Questionários
2.
Am J Orthod Dentofacial Orthop ; 157(4): 444-453, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241351

RESUMO

INTRODUCTION: This split-mouth trial aimed to investigate the effect of low-level laser therapy (LLLT) on the amount of maxillary canine distalization when applied every 4 weeks over 12 weeks. METHODS: Twenty-two adolescents and young adults (15 female, 7 male; aged 13-25 years; n = 22) requiring bilateral maxillary first premolar extractions were recruited. After extractions and leveling-alignment, canines were retracted using closed-coil nickel-titanium springs delivering 150 g of force. LLLT was applied to 8 intraoral points on the buccal and palatal sides around the canine root for 10 seconds per point, on day 0, 28, and 56 with the control side receiving sham application. Alginate impressions were taken every 4 weeks on day 0, 28, 56, and 84. The amount of tooth movement, anchorage loss, and canine rotation were measured digitally. Randomization was generated using www.randomisation.com and allocation concealment through sequentially numbered, opaque, sealed envelopes. Participants, operator, and statistic assessor were blinded. Linear regression modeling accounting for clustering within each patient was used to identify differences between LLLT and control sides. RESULTS: Twenty-one patients completed the study. The total amount of tooth movement was similar in the LLLT (2.55 ± 0.73 mm) and control group (2.30 ± 0.86 mm), whereas 0.25 mm (95% confidence interval, -0.21, 0.71 mm) of difference was insignificant (P = 0.27). No significant differences were found for anchorage loss (P = 0.22) or canine rotation (P = 0.25). No harms were reported. CONCLUSIONS: Application of LLLT every 4 weeks did not result in differences in the amount of tooth movement, anchorage loss, and canine rotation during extraction space closure.


Assuntos
Terapia a Laser , Terapia com Luz de Baixa Intensidade , Adolescente , Adulto , Dente Pré-Molar , Dente Canino , Feminino , Humanos , Masculino , Fios Ortodônticos , Técnicas de Movimentação Dentária , Adulto Jovem
3.
Eur J Orthod ; 41(4): 360-369, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-30321328

RESUMO

OBJECTIVE: The aim of this study was to assess the potential of improving orthodontic miniscrews' (MSs) primary stability in vivo by evaluating the dispersion capacity of an injectable bone graft substitute (iBGS) through a newly designed hollow MS [The Sydney Mini Screw (SMS)] and its integration with the cortical and trabecular bone by using the femur and tibia in a New Zealand rabbit animal model. METHODS: In total, 24 MSs were randomly placed in each proximal tibia and femur of 6 New Zealand rabbits with an open surgery process. Aarhus MSs were used as controls and the effect of injection of iBGS was studied by implanting SMSs with and without iBGS injection. The dispersion of iBGS and the integration of the SMS were studied by using micro Computed Tomography (µCT) and histochemical analysis at two time points, 0 day and 8 weeks post-implantation. RESULTS: iBGS was successfully injected through the SMS and hardened in situ. After 8 weeks, µCT results revealed that the iBGS particles were resorbed and bone tissue was formed around the SMS and within its lateral exit holes. CONCLUSIONS: This pilot animal study showed the high potential of the combined use of iBGS and SMS as a newly developed technique to promote the primary stability of MSs.


Assuntos
Osseointegração , Titânio , Animais , Parafusos Ósseos , Coelhos , Tíbia/cirurgia , Microtomografia por Raio-X
4.
Am J Orthod Dentofacial Orthop ; 154(3): 326-336, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30173835

RESUMO

INTRODUCTION: The purpose of this 2-arm-parallel split-mouth trial was to investigate the effect of low-level laser therapy (LLLT) on the repair of orthodontically induced inflammatory root resorption (OIIRR). METHODS: Twenty patients were included in this study, with 1 side randomly assigned to receive LLLT, and the other side served as a sham. Eligibility criteria included need for bilateral maxillary first premolar extractions as part of fixed appliance treatment. OIIRR was generated by applying 150 g of buccal tipping force on the maxillary first premolars for 4 weeks. After the active force was removed, the teeth were retained for 6 weeks. LLLT commenced with weekly laser applications using a continuous beam 660-nm, 75-mW aluminum-gallium-indium-phosphorus laser with 1/e2 spot size of 0.260 cm2, power density of 0.245 W/cm2, and fluence of 3.6 J/cm2. Contact application was used at 8 points buccally and palatally above the mucosa over each tooth root for 15 seconds with a total treatment time of 2 minutes. After 6 weeks, the maxillary first premolars were extracted and scanned with microcomputed tomography for primary outcome OIIRR calculations. Subgroup analysis included assessment per root surface, per vertical third, and sites of heaviest compressive forces (buccal-cervical and palato-apical). Randomization was generated using www.randomization.com, and allocation was concealed in sequentially numbered, opaque, sealed envelopes. Blinding was used for treatment and outcome assessments. Two-tailed paired t tests were used to determine whether there were any statistically significant differences in total crater volumes of the laser vs the sham treated teeth. RESULTS: Total crater volumes were 0.746 mm3 for the laser treated teeth and 0.779 mm3 for the sham. There was a mean difference of 0.033 ± 0.39 mm3 (95% CI, -0.21 to 0.148 mm3) greater resorption crater volume in the sham group compared with the laser group; this was not statistically significant (P = 0.705). No harm was observed. CONCLUSIONS: No significant difference was found between LLLT and sham control groups in OIIRR repair.


Assuntos
Cemento Dentário/patologia , Cemento Dentário/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Reabsorção da Raiz/radioterapia , Técnicas de Movimentação Dentária/métodos , Raiz Dentária/patologia , Raiz Dentária/efeitos da radiação , Adolescente , Dente Pré-Molar/patologia , Dente Pré-Molar/efeitos da radiação , Método Duplo-Cego , Feminino , Humanos , Masculino , Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Fios Ortodônticos , Estresse Mecânico , Extração Dentária , Técnicas de Movimentação Dentária/instrumentação , Resultado do Tratamento , Microtomografia por Raio-X
5.
Am J Orthod Dentofacial Orthop ; 152(4): 471-476, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28962730

RESUMO

INTRODUCTION: Our objective was to study the perceptions of laypeople for digital alterations and the amount of nasolabial angle increase that is tolerable and how much chin-neck length increase is needed to achieve a desirable profile in Class II Division 1 women with mandibular retrognathia. METHODS: The profile image of a white woman with a Class II Division 1 mandibular rethrognatic profile was digitally modified to create 6 images: 3 with stepwise increased nasolabial angles of 113°, 121°, and 129°, and 3 with stepwise increased chin-neck distances of 51, 54, and 57 mm. These images were assessed and ranked by 155 white laypeople. RESULTS: The baseline profile was judged significantly as the least attractive. A nasolabial angle of 129° was judged as unattractive as the baseline profile. Profiles with a chin-neck length of 54 and 57 mm were equally judged as most attractive. CONCLUSIONS: The untreated (baseline) profile was found to be least esthetic, as well as the profile with the largest nasolabial angle. Nasolabial angle increases up to 121° seem to be acceptable. Profiles simulating a chin-neck length increase as produced by surgery seem to be most favored.


Assuntos
Beleza , Má Oclusão Classe II de Angle/cirurgia , Retrognatismo/cirurgia , Adolescente , Adulto , Queixo/anatomia & histologia , Feminino , Humanos , Masculino , Má Oclusão Classe II de Angle/patologia , Pescoço/anatomia & histologia , Retrognatismo/patologia , Adulto Jovem
6.
Prog Orthod ; 18(1): 23, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28762151

RESUMO

BACKGROUND: Orthodontically induced iatrogenic root resorption (OIIRR) is an unavoidable inflammatory process. Several factors claimed to be related to the severity of OIIRR. Orthodontic forces cause micro-trauma to the periodontal ligament and activate a cascade of cellular events associated with local periodontal inflammation. The purpose of this split-mouth study were (1) to investigate the changes in cytokine profile in the gingival crevicular fluid (GCF) secondary to heavy orthodontic forces and (2) to compare the cytokine expression between participants showing high and low root resorption. METHODS: Eight participants requiring maxillary first premolar extractions involved in this study. The teeth on the tested side (TS) received 225 g of controlled buccal tipping force for 28 days, while the contralateral teeth act as a control (CS). GCF was collected from both TS and CS teeth at 0 h (prior to application of force) and 3 h, 1 day, 3 days, 7 days and 28 days after the application of force, and analysed with multiplex bead immunoassay to determine the cytokine levels. RESULTS: Statistically significant temporal increase was found in the TS teeth for tumour necrosis factor alpha (TNF-α) at 3 h and 28 days (p = 0.01). Interleukin 7 (IL-7) significantly peaked at the 28th day. Comparing cytokine profile for participants with high and low root resorption (>0.35 and <0.15 mm3, respectively), the levels of GM-CSF was significantly greater in low root resorption cases (p < 0.05). The amounts of root resorption which craters on mesial, distal surfaces and middle third region were significant in the TS teeth (p < 0.05). CONCLUSIONS: IL-7 and TNF-α (pro-resorptive cytokine) increased significantly secondary to a high-level of orthodontic force application. Significantly high levels of granulocyte macrophage colony-stimulating factor (anti-resorptive cytokine) were detected in mild root resorption cases secondary to high-level orthodontic force application. A future long-term randomised clinical trial with larger sample taking in consideration gender, age and growth pattern distribution would be recommended.


Assuntos
Citocinas/análise , Ortodontia , Reabsorção da Raiz/fisiopatologia , Adolescente , Feminino , Gengiva/química , Humanos , Interleucina-7/análise , Masculino , Pescoço , Extração Dentária , Fatores de Necrose Tumoral
7.
Am J Orthod Dentofacial Orthop ; 151(1): 53-62, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28024782

RESUMO

INTRODUCTION: The purpose of this study was to investigate the effect of piezocision on orthodontically induced inflammatory root resorption. METHODS: Fourteen patients were included in this split-mouth study; 1 side was assigned to piezocision, and the other side served as the control. Vertical corticotomy cuts of 4 to 5 mm in length were performed on either side of each piezocision premolar, and 150-g buccal tipping forces were applied to the premolars. After 4 weeks, the maxillary first premolars were extracted and scanned with microcomputed tomography. RESULTS: There was a significantly greater total amount of root resorption seen on the piezocision sides when compared with the control sides (P = 0.029). The piezocision procedure resulted in a 44% average increase in root resorption. In 5 patients, there was noticeable piezocision-related iatrogenic root damage. When that was combined with the orthodontic root resorption found on the piezocision-treated teeth, there was a statistically significant 110% average increase in volumetric root loss when compared with the control side (P = 0.005). CONCLUSIONS: The piezocision procedure that initiates the regional acceleratory phenomenon may increase the iatrogenic root resorption when used in conjunction with orthodontic forces. Piezocision applied close to the roots may cause iatrogenic damage to the neighboring roots and should be used carefully.


Assuntos
Piezocirurgia/efeitos adversos , Reabsorção da Raiz/etiologia , Adolescente , Dente Pré-Molar/cirurgia , Força de Mordida , Feminino , Humanos , Masculino , Reabsorção da Raiz/diagnóstico por imagem , Extração Dentária/métodos , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/cirurgia , Microtomografia por Raio-X , Adulto Jovem
8.
J Oral Maxillofac Surg ; 74(5): 1025-43, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26778518

RESUMO

PURPOSE: Surgically assisted rapid maxillary expansion (SARME) is required in non-growing patients when maturity or resistance precludes desired sutural separation by noninvasive techniques. The aim of this review was to determine what volumetric changes occur in the upper airway spaces after SARME in adults. MATERIALS AND METHODS: A systematic review was performed with data assessed for suitability of meta-analysis. The primary outcome measurement of volumetric changes in an upper airway space was sought in non-growing patients undergoing SARME. Electronic database searches were performed for published literature in Medline (by Ovid), Pre-Medline, Old Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) spanning all available years to August 1, 2015. Unpublished literature was searched electronically through ClinicalTrials.gov and the National Research Register. Additional hand searching of reference lists of relevant articles, grey searching, and expert correspondence was conducted for any additional studies. Two authors independently screened search results, extracted data, and assessed the risk of bias of included studies. RESULTS: Twenty-one studies were located by initial screening; 10 were excluded after full-text review, leaving 11 studies eligible that met all inclusion criteria for this systematic review. In total, 204 treated patients (mean age, 18 to 31 yr) were included in the qualitative synthesis. Ten studies evaluated nasal cavity volume, 2 evaluated palatal volume, and 1 evaluated oropharyngeal volume. Appliances used included tooth-borne hyrax and transpalatal distractor devices. CONCLUSIONS: SARME was found to produce substantial short-term volume increases in the nasal cavity in non-growing patients that were maintained for at least 63 months. Evidence weakly suggested no effect on oropharyngeal volume. However, most studies were evaluated as having a high risk of bias. The effect of such volume changes on respiratory function still needs to be determined; thus, SARME cannot be recommended for respiratory purposes.


Assuntos
Nasofaringe/fisiopatologia , Técnica de Expansão Palatina , Adulto , Humanos , Nasofaringe/patologia , Técnica de Expansão Palatina/efeitos adversos , Fenômenos Fisiológicos Respiratórios
9.
J Oral Maxillofac Surg ; 74(3): 453-73, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26608454

RESUMO

PURPOSE: A systematic review was conducted to examine the evidence for the effectiveness and safety of corticotomy-facilitated orthodontics. MATERIALS AND METHODS: Electronic databases (Ovid Medline, EMBASE, Cochrane, SCOPUS, and Web of Science) were searched for articles that examined the rate of corticotomy-facilitated orthodontic tooth movement and its effects on the periodontium, root resorption, and tooth vitality. Unpublished literature was searched electronically through ClinicalTrials.gov (http://www.clinicaltrials.gov) and the ISRCTN registry (http://www.controlled-trials.com). Relevant orthodontic journals and reference lists also were checked for eligible studies. Randomized clinical trials (RCTs) and controlled clinical trials (CCTs) were considered. Two article reviewers independently assessed the search results, screened the relevant articles, performed data extraction, and evaluated the methodologic quality of the studies. RESULTS: Fourteen eligible articles (6 RCTs and 8 CCTs) were included in the review. There was a statistically meaningful increase in the rate of tooth movement compared with controls for all corticotomy techniques assessed. Some studies reported that acceleration in tooth movement was only temporary (lasting a few months). Corticotomy procedures did not seem to produce unwanted adverse effects on the periodontium, root resorption, and tooth vitality. The quality of the body of evidence was regarded as low owing to the presence of multiple methodologic issues, high risks of bias, and heterogeneity in the included articles. CONCLUSION: Corticotomy procedures can produce statistically and clinically meaningful temporary increases in the rate of orthodontic tooth movement with minimal side-effects. Additional high-quality randomized clinical trials are needed to allow more definitive conclusions.


Assuntos
Osteotomia/métodos , Técnicas de Movimentação Dentária/métodos , Polpa Dentária/fisiologia , Humanos , Periodonto/fisiologia , Reabsorção da Raiz/etiologia
10.
Angle Orthod ; 81(4): 570-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21361777

RESUMO

OBJECTIVE: To quantify the amount of tooth movement and orthodontically induced root resorption (OIRR) in ovariectomized rats. MATERIALS AND METHODS: Five 10-week-old female Wistar rats undergoing ovariectomy (OVX) were investigated as the experimental group, and the other five without ovariectomy served as the control group. Four weeks after ovariectomy, 25-g nickel-titanium closed-coil springs were applied mesially to the maxillary left first molars. Micro-computed tomography was taken at day 0, 1, 3, 7, 14, 21, and 28. At day 28, the molars were extracted. The surface area of root resorption craters, depth, and volume were measured using electron and laser scanning microscopes. RESULTS: Tooth movement gradually increased with time throughout 28 days. There was a significant difference in the amount of tooth movement between the control group and the OVX group. For OIRR, the OVX group showed wide and shallow root resorption craters scattered on the mesial root. The deep resorption craters were observed on the distal roots distributed in the cervical, middle, and apical thirds of the roots. Statistically significant differences were found between the control and the OVX groups in the depth and the volume of root resorption craters in the distal roots and the total volume of root resorption craters in all three roots. CONCLUSION: Ovariectomy affected not only tooth movement but also OIRR. Tooth movement in the OVX group was more rapid than the control group. Furthermore, the amount of OIRR in the OVX group was more severe than the control group.


Assuntos
Reabsorção da Raiz/etiologia , Técnicas de Movimentação Dentária/efeitos adversos , Animais , Remodelação Óssea , Análise do Estresse Dentário , Estrogênios/deficiência , Feminino , Processamento de Imagem Assistida por Computador , Dente Molar , Ovariectomia , Ovário/fisiologia , Ratos , Ratos Wistar , Reabsorção da Raiz/diagnóstico por imagem , Microtomografia por Raio-X/métodos
11.
Angle Orthod ; 81(1): 91-99, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20936960

RESUMO

OBJECTIVES: To histologically and immunohistochemically assess the pattern of expression of bone morphogenic proteins 2 and 4 (BMP2/4) and proliferating cell nuclear antigen (PCNA) in response to bite jumping appliances in the condylar cartilage and the glenoid fossa. MATERIALS AND METHODS: Fifty-five 4-week-old female Sprague-Dawley rats were randomly divided into four experimental and four control groups. Bite-jumping appliances were fitted to the experimental animals. The rats were sacrificed at 3, 14, 21, and 30 days, and the temporomandibular structures were analyzed histologically and immunohistochemically. RESULTS: The expression of BMP2/4 in response to bite-jumping appliances was statistically significant in the condylar cartilage and the glenoid fossa. Cell proliferation was not significant. CONCLUSION: BMP2/4 plays an important role in bone formation in response to mandibular advancement by accelerating and enhancing the differentiation of mesenchymal cells into bone-forming cells.


Assuntos
Proteína Morfogenética Óssea 2/biossíntese , Proteína Morfogenética Óssea 4/biossíntese , Remodelação Óssea/fisiologia , Avanço Mandibular/instrumentação , Aparelhos Ortodônticos Funcionais , Articulação Temporomandibular/fisiologia , Adaptação Fisiológica , Animais , Proteína Morfogenética Óssea 2/genética , Proteína Morfogenética Óssea 4/genética , Cartilagem Articular/metabolismo , Diferenciação Celular , Feminino , Expressão Gênica , Côndilo Mandibular/metabolismo , Côndilo Mandibular/fisiologia , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Antígeno Nuclear de Célula em Proliferação/biossíntese , Antígeno Nuclear de Célula em Proliferação/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Osso Temporal/metabolismo , Articulação Temporomandibular/metabolismo
12.
J Oral Maxillofac Surg ; 66(6): 1104-11, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18486774

RESUMO

PURPOSE: The aim of this investigation was to assess the effect of low magnitude high frequency (LMHF) mechanical vibrated stimulation on healing the defects surgically imposed on craniofacial bones. MATERIALS AND METHODS: Forty 12-week-old C3H strain mice were separated into surgical and non-surgical groups. The surgical groups had a reproducible surgical bony lesion prepared in their right parietal bone. Both groups were further subdivided into vibration (experimental) and non-vibration (control) groups at 3 time points (zero hours, 2 weeks, and 4 weeks). The vibration groups were subjected to LMHF mechanical stimuli (30 Hz with peak strain 5 microepsilon) via a vibration machine for 20 minutes a day for 5 days a week for a total of 28 days. The specimens were analyzed using micro-computer tomography (micro-CT). RESULTS: Micro-CT volumetric measurement showed that in the surgical defects groups there was a significant decrease in the volume of the healing lesion with time (P < .001) and the linear decrease was significantly more pronounced in the vibration-treated group than the nontreated group (P < .001). Micro-CT histomorphometric measurement showed that in the nonsurgical groups there was no significant difference in microstructures of bony trabeculae between vibration-treated and nontreated groups. CONCLUSION: It is suggested that the introduction of LMHF mechanical stimuli in a healing bony lesion in the non-weight bearing bone significantly increases its healing capacity.


Assuntos
Regeneração Óssea/fisiologia , Osso Parietal/lesões , Cicatrização/fisiologia , Análise de Variância , Animais , Feminino , Camundongos , Camundongos Endogâmicos C3H , Osso Parietal/cirurgia , Estimulação Física , Distribuição Aleatória , Análise de Regressão , Tomografia Computadorizada por Raios X , Vibração
13.
Arch Oral Biol ; 52(2): 182-8, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17049482

RESUMO

OBJECTIVE: The aim of this study was to determine the response of the residual epithelial network following traumatic breakdown of the periodontal ligament (PDL). METHODS: Mandibular incisor sections with PDL (experimental) and sections denuded of PDL (control) from 4- to 6-week-old Wistar-Furth rats were transplanted into the defects created in the frontal bone of the recipient syngeneic rats. At intervals, the defects with implanted teeth roots were collected and processed for histological and biochemical examination. Immunolocalization of epithelial cells was performed to monitor their phenotypic changes during transplantation healing period. RESULTS: (1) Histological observation of the experimental sample revealed the sequence of cellular response characterized by an initial degeneration of PDL followed by a proliferation of granulation tissue. There was also a marked odontoblastic reaction with extensive deposition of regular dentine within the pulp chambers. In the control group, initial signs of bony fusion with dentine led to an extensive ankylosis and bone replacement between roots and defects. (2) Immunostaining indicated that, in experimental groups, the pattern of regularly spaced epithelial cells lying in close approximation to the root surface was distinct 10 days post-transplantation but became diminished afterwards. The immunoreaction against epithelial cells was negative in the control. CONCLUSION: Residual PDL is essential to prevent ankylosis after trauma and epithelial cells may facilitate the re-establishment of root-PDL-bone complex by transforming into mesenchymal cells.


Assuntos
Células Epiteliais/fisiologia , Odontogênese/fisiologia , Ligamento Periodontal/citologia , Reabsorção da Raiz/patologia , Reimplante Dentário , Raiz Dentária/fisiologia , Animais , Anquilose/prevenção & controle , Proliferação de Células , Feminino , Ligamento Periodontal/fisiologia , Ratos , Ratos Endogâmicos WF , Regeneração/fisiologia , Raiz Dentária/citologia
14.
Am J Orthod Dentofacial Orthop ; 128(4): 497-503, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16214633

RESUMO

INTRODUCTION: Receptor activator of nuclear factor kappa beta ligand (RANKL) activates osteoclast differentiation, whereas this activity is blocked by osteoprotegrin (OPG), so that the relative expression of these 2 proteins might contribute to bone and root resorption during orthodontic tooth movement. We describe experiments with RANKL and OPG mRNA expression in rats subjected to orthodontic forces. It was hypothesized that the ratios of RANKL to OPG expression would increase during root resorption processes. METHODS: Fixed Sentalloy (GAC, Bohemia, NY) closed-coil springs capable of delivering approximately 100 g of force were applied for mesial movement of the mandibular left first molar in 9 male, 7-week-old Wistar rats; the right mandibular molar was used as an internal control for each animal. After 14 days, the rats were killed; tissues from 2 rats were examined by paraffin histology, and high-quality messenger ribonucleic acid (mRNA) was extracted from 4-mm widths of the mesial bony tissues in the remaining animals. RESULTS: Paraffin sections showed osteoclastic resorption of roots on the mesial surfaces of teeth subjected to orthodontic forces. The integrity of mRNA was confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) for the housekeeping gene GAPDH, and that of primers specific for OPG and RANKL was determined by RT-PCR for these genes in material isolated from the UM106 rat cell line known to express both proteins. Densitometric analysis of the RT-PCR OPG product showed an increase in background levels of OPG mRNA in bony tissues subjected to orthodontic forces in all animals studied (P < .05). In contrast, low levels of mRNA for RANKL were detected in only 5 animals and only in association with orthodontic forces. CONCLUSIONS: Data are consistent with changes in levels of OPG and RANKL in tissues subjected to orthodontic forces and experiencing root resorption.


Assuntos
Proteínas de Transporte/metabolismo , Glicoproteínas/metabolismo , Glicoproteínas de Membrana/metabolismo , RNA Mensageiro/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Reabsorção da Raiz/metabolismo , Técnicas de Movimentação Dentária , Animais , Proteínas de Transporte/genética , Glicoproteínas/genética , Masculino , Mandíbula/citologia , Mandíbula/metabolismo , Glicoproteínas de Membrana/genética , Dente Molar/citologia , Dente Molar/metabolismo , Osteoclastos/metabolismo , Osteoprotegerina , Ligante RANK , Ratos , Ratos Wistar , Receptores Citoplasmáticos e Nucleares/genética , Receptores do Fator de Necrose Tumoral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Aust Orthod J ; 19(2): 67-75, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14703331

RESUMO

BACKGROUND: With the increasing use of computed tomography (CT) in oral diagnosis and treatment planning, concern has been expressed about the high levels of radiation used, and the associated risks. OBJECTIVES: The purpose of this study was to compare the radiation doses of facial CT scans with the radiation doses taking a lateral cephalometric radiograph, a panoramic radiograph (OPG), an occlusal film, and an intra-oral periapical radiograph. METHODS: An Alderson-Rando anthropomorphic phantom head was used for the analysis. Thirty-six lithium fluoride thermoluminescent dosimeters were placed in the phantom head in locations representing radiosensitive sites. Standard facial CT scans and conventional radiographs (lateral cephalometric, OPG, maxillary occlusal, intra-oral periapical) were then taken of the phantom head. RESULTS: The following radiation doses were measured: maxillo-mandibular CT scan, 2.1 mSv; maxillary CT scan, 1.40 mSv; mandibular CT scan, 1.32 mSv; lateral cephalometric radiograph, 0.005 mSv; OPG, 0.010 mSv; maxillary occlusal, 0.007 mSv; intra-oral periapical radiograph, 0.005 mSv. CONCLUSIONS: CT scans produce significantly more ionising radiation than conventional radiographs. This factor should be taken into account when considering a CT scan as an alternative to a survey with conventional radiographs. While CT scans offer many advantages over conventional radiography the high radiation dose to patients, and the cost of this procedure should be considered.


Assuntos
Doses de Radiação , Radiografia Dentária , Tomografia Computadorizada por Raios X , Encéfalo/efeitos da radiação , Cefalometria , Fluoretos , Humanos , Cristalino/efeitos da radiação , Compostos de Lítio , Mandíbula/efeitos da radiação , Maxila/efeitos da radiação , Glândula Parótida/efeitos da radiação , Imagens de Fantasmas , Radiografia Dentária/classificação , Radiografia Panorâmica , Pele/efeitos da radiação , Dosimetria Termoluminescente , Glândula Tireoide/efeitos da radiação
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