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INTRODUCTION: The aim of this study was to evaluate and compare the effects of class II fixed functional treatment with a cast splint Herbst appliance (HA; Herbst Set I, Dentaurum, Ispringen, Germany) and Forsus fatigue resistant device (FRD; 3M Unitek Corp., Monrovia, CA, USA) on external apical root resorption (EARR) in posterior teeth. METHODS: In all, 40 patients (15 male and 25 female) with class II division 1 malocclusion were treated with two fixed functional appliances: HA (20 patients, mean age 14.60⯱ 1.14 years) and FRD (20 patients, mean age 14.15⯱ 1.28 years). The vestibular lengths of the first molars and premolars were measured on panoramic radiographs and converted to actual tooth length using the magnification coefficient (MC), which was calculated using dental models. Intragroup comparisons of pre- and posttreatment tooth lengths were performed with the paired ttest and Wilcoxon signed-rank test, while intergroup comparisons were performed with the Mann-Whitney U test. RESULTS: Pretreatment tooth length values decreased significantly with HA and FRD therapies for all posterior teeth. The maximum resorption was observed in the mandibular first premolar with a mean of 0.81â¯mm following HA and 1.55â¯mm following FRD treatment. While no significant difference existed between the EARR values of the HA and FRD groups for maxillary teeth, the amount of EARR of mandibular posterior teeth in the FRD group was significantly higher than in the HA group. CONCLUSIONS: In patients treated with HA or FRD, the tooth length of posterior teeth decreased to a clinically minor but statistically significant degree. The root resorption effect of FRD therapy in mandibular posterior teeth was significantly higher than that of HA therapy.
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Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Reabsorção da Raiz , Adolescente , Criança , Feminino , Humanos , Masculino , Cefalometria , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/terapia , Aparelhos Ortodônticos Funcionais/efeitos adversos , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/etiologia , ContençõesRESUMO
INTRODUCTION: The purpose of this study was to assess the effects of orthodontically aimed low-magnitude, high-frequency mechanical vibration (OLMHFMV) on intact calvarial bone, specifically the parietal and temporal, and cranial sutures, including the sagittal and parietotemporal, of rats in differing stages of growth and development. METHODS: Forty Wistar rats were divided into 4 groups: 2 control groups and 2 OLMHFMV groups. Subsequently, 0.3 cN of force with a frequency of 30 Hz was applied as OLMHFMV on the temporomandibular joint region in the rats in the OLMHFMV-1 group, with the protocol of 20 min/d for 5 d/wk for 1 month, whereas the rats in the OLMHFMV-2 group received mechanical stimuli for 2 months with the same protocol. Morphometric and structural analyses, including suture width, cranial width and height, bone mineral density, bone volume/tissue volume, trabecular number, trabecular separation, and trabecular thickness analyses, were carried out using micro-computed tomography. RESULTS: The width of the parietotemporal and sagittal sutures and the cranial height and width increased significantly by OLMHFMV (P <0.021). The structural analysis revealed that trabecular number and trabecular separation increased, whereas trabecular thickness decreased in the OLMHFMV groups compared with the control groups (P <0.048). Bone volume/tissue volume remained unchanged despite reducing the bone mineral density of the OLMHFMV groups. CONCLUSIONS: OLMHFMV had a potential for modulating sutural and cranial growth in adolescent rats. OLMHFMV increased the structural quality of the temporal and parietal bones. These effects may have clinical implications as a treatment option for patients suffering from craniofacial anomalies such as craniosynostosis or a supportive approach for dentofacial orthodontic treatments.
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Suturas Cranianas , Vibração , Animais , Suturas Cranianas/diagnóstico por imagem , Ratos , Ratos Wistar , Crânio/diagnóstico por imagem , Vibração/uso terapêutico , Microtomografia por Raio-XRESUMO
PURPOSE: We aimed to evaluate and compare effects of photobiomodulation (PBM) and low-magnitude high-frequency mechanical vibration (HFMV) on orthodontic retention. METHODS: Sixty-four female Wistar albino rats were divided into 9 groups (2 negative and positive controls each, 3 PBM and 2 HFMV groups) and studied for 25 days. In the experimental groups, closed nickel-titanium closed coil springs with a 50â¯cN force were placed for 10 days between the maxillary incisor and molar. PBM and HFMV were applied daily over long- (15 days) and short-term (7 days) retention periods. The PBM groups received PBM with a single wavelength (650â¯nm) or higher wavelengths (532, 650, 940â¯nm) for 9â¯min per day. HFMV groups received HFMV of 10, 20, and 30â¯Hz for 10â¯min per day. Right and left maxilla were assessed using micro-computed tomography imaging and real-time polymerase chain reaction. The amount of tooth movement during the retention period, expression levels of cyclooxygenase2 (COX-2), osteoprotegerin (OPG), and receptor activator of nuclear factor-kappa B ligand (RANKL) mRNA gene expression levels, OPG/RANKL ratios, alveolar bone trabecular thickness (Tb.Th), trabecular number (Tb.N), and structure model index were analyzed. Kruskal-Wallis and Mann-Whitney U tests were used for multiple comparisons of the nonparametric distributed data and binary comparisons, respectively. RESULTS: When using the long-term retention protocol, PBM and HFMV treatment increased Tb.N (pâ¯< 0.05) and decreased COX2 mRNA gene expression levels (pâ¯< 0.05) and Tb.Th (pâ¯< 0.05) compared to controls. For short-term retention, PBM and HFMV decreased the amount of relapse tooth movement compared to controls. In addition, Tb.Th (pâ¯< 0.05) and the mRNA gene expression levels of COX2 and RANKL (pâ¯< 0.05) were decreased. CONCLUSION: PBM and HFMV might be able to support retention after orthodontic tooth movement by reducing bone resorption and increasing bone quality.
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Osteoprotegerina , Ligante RANK , Animais , Ciclo-Oxigenase 2/metabolismo , Feminino , Imageamento Tridimensional , Níquel , Contenções Ortodônticas , Osteoclastos , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Titânio , Técnicas de Movimentação Dentária/métodos , Vibração , Microtomografia por Raio-XRESUMO
OBJECTIVES: This controlled study aimed to evaluate the effects of Herbst therapy on the trabecular structure of the condyle and angulus mandible using fractal dimension analysis (FD-A) accompanied by skeletal cephalometric changes. MATERIAL AND METHOD: The panoramic and cephalometric radiographs of 30 patients with skeletal Class II malocclusion treated with the Herbst appliance (C II-H group, mean age: 15.23 ± 1.08), 30 patients with skeletal Class II malocclusion that received fixed orthodontic treatment (C II-C group, mean age: 15.73 ± 1.38), and 30 patients with skeletal Class I malocclusion (C I-C group, mean age: 15.90 ± 1.30) were selected. FD-A was performed on the superoposterior region (C-SP) and centre of the condyles (C-C) and the mandibular angulus (Ang) on the panoramic radiographs taken at the pretreatment (T0), intermediate stage of treatment (T1), and posttreatment (T2) timepoints just like cephalometric analysis. RESULTS: Herbst therapy provided a statistically significant increase in SNB, ANS-Me, Na-Me, S-Go, Co-Gn and a decrease in ANB and overjet (P < 0.05). All skeletal changes remained stable during the fixed appliance treatment after Herbst. The FD values in C-C increased (P < 0.05), and C-SP values decreased (P < 0.05) during Herbst therapy, while after removal of the Herbst appliance, no significant change was observed despite an increase in C-SP. The Ang value did not change during Herbst treatment, but then increased significantly (P < 0.05). There was no significant change in the FD values of the C I-C and C II-C groups at any stage of treatment. The C-C and C-SP changes at T1-T0 period, C-SP and Ang changes at T2-T1 period, and C-C, C-SP, and Ang values at T2-T0 period were found higher in C II-H group compared with the C II-C group significantly (P < 0.05). CONCLUSION: Herbst therapy changed the trabecular structure of the condyles in different directions at the superoposterior and central regions of the condyles, while the structural complexity of the angulus mandible, which did not change during the Herbst treatment, increased during the fixed orthodontic treatment after Herbst.
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Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Adolescente , Cefalometria/métodos , Fractais , Humanos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/terapia , Mandíbula/diagnóstico por imagemRESUMO
OBJECTIVES: This retrospective longitudinal study aimed to evaluate the factors that affect the orthodontic treatment duration (OTD) and external apical root resorption (EARR) of maxillary impacted canines (MIC) as root-cortex relationship, root shape, impaction side, and gender. MATERIAL AND METHOD: Thirty-eight patients (mean age 15.28 ± 1.48 years) who had unilateral MIC and undergone orthodontic treatment were included in this study. Root-cortex relationship, root-cortex intersection amount, root shape, impaction side, height, alpha angle, impaction zone, and length of the MIC were evaluated on cone-beam computed tomography images at the beginning of the treatment. Final assessments were performed on ortopantograms at the end of the treatment as canine angulation and tooth length. The sample was characterized by descriptive statistics; t-tests, Mann-Whitney U-test, ANOVA, and Kruskal-Wallis tests were used for the comparison of EARR and OTD values between the categorical groups. RESULTS: Root shape affected OTD, and the longest value was detected in MIC with bent root (P < 0.000). The presence of root-cortex relationship also prolonged OTD for approximately 3 months (P = 0.006). MIC with risk factors like positive root-cortex relationship and bent roots had higher EARR values than those with negative root-cortex relationship and normal roots (P = 0.042, P = 0.021, respectively). EARR of the palatal MIC was also higher than the buccal MIC (P = 0.009). OTD was significantly influenced by root-cortex intersection amount (P = 0.004). CONCLUSION: The presence of root-cortex relationship and abnormal root shape were risk factors for greater EARR of MIC along OTD, which was also significantly influenced by root shape and root-cortex relationship.
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Reabsorção da Raiz , Dente Impactado , Adolescente , Tomografia Computadorizada de Feixe Cônico , Dente Canino/diagnóstico por imagem , Duração da Terapia , Humanos , Incisivo , Estudos Longitudinais , Maxila , Estudos Retrospectivos , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/etiologia , Dente Impactado/diagnóstico por imagemRESUMO
The aim of this study was to evaluate and compare the reparative and inhibitory effects of single wavelength photobiomodulation (SW-PBM) and of cumulative increased wavelength photobiomodulation (CW-PBM) on orthodontically induced inflammatory root resorption (OIIRR). Thirty-three Wistar albino rats were divided into five groups: untreated group (negative control), only relapse group (positive control-1), only retention group (positive control-2), SW-PBM group (650 nm, 100 mW/cm2), and CW-PBM group (532-650-940 nm, 100 mW/cm2). Orthodontic tooth movement was induced experimentally in rats for 10 days with an applied force of 50 cN; retention and therapeutic approaches were performed concurrently. At the end of the experiment, maxillary quadrants were prepared for micro-CT analysis and real-time polymerase chain reaction (RT-PCR) analysis. After the Shapiro-Wilk normality test, Kruskal-Wallis test followed post hoc Bonferroni test and paired samples t test was used for statistical evaluation of the data. Resorption lacunae volume (p < 0.001), number of resorption lacunae (p < 0.05), and percentage of the resorption (PR) lacunae (p < 0.001) decreased with PBM applications when compared with the positive control groups, and the mean PR was similar in the negative control group when compared with SW-PBM group. Receptor activator of nuclear factor kappa B ligand (RANKL) levels of the PBM groups were lower (p < 0.05) than those of the positive control groups. Cyclooxygenase-2 (COX-2) expression levels significantly decreased with PBM administration (p < 0.05). No significant change was found in osteoprotegerin (OPG) expression levels and OPG/RANKL ratios (p > 0.05). PBM applications showed marked inhibitory and reparative effects on OIIRR by modulating the RANKL and COX-2 expression levels. However, the effects of the different wavelengths were similar to each other.Graphical abstract.
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Retenção em Prótese Dentária , Luz , Terapia com Luz de Baixa Intensidade , Ortodontia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Reabsorção da Raiz/radioterapia , Microtomografia por Raio-X , Animais , Ciclo-Oxigenase 2/metabolismo , Masculino , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Ratos Wistar , Técnicas de Movimentação DentáriaRESUMO
OBJECTIVES: The aim was to evaluate the effects of mesenchymal stem cell (MSC) transfer to periodontal ligament (PDL) on the inhibition and/or repair of orthodontically induced root resorption (OIRR) during and after arch expansion and on the orthodontic tooth movement (OTM) rate of the maxillary first molar teeth of rats. MATERIAL AND METHODS: Sixty Wistar rats were divided into three groups as the untreated group, MSC and control injections during the expansion period group (EMSC-EC), and MSC and control injections at the retention period group (RMSC-RC). Fifty grams of orthodontic force was applied to the maxillary first molar teeth of the rats for 14 days in the vestibular direction, and then, 20 days of retention was carried out. MSCs and control injections were performed every 3 days in the EC, RC, EMSC, and RMSC groups. At the end of the experiment, samples were prepared for OTM evaluation, mRNA expression analysis, micro-computed tomography measurements, cementum thickness calculations, and structural examinations. RESULTS: The amount of OTM in EMSC group was significantly higher than in EC group (P < 0.001). MSC transfer during the expansion and retention periods reduced the number of resorption lacunae, volumetric and linear resorptive measurements, and cyclooxygenase-2 and receptor activator of nuclear factor kappa B ligand (RANKL) mRNA expression levels, and increased the osteoprotegerin (OPG) expression levels, OPG/RANKL ratio, and cementum thickness in the EMSC and RMSC groups. CONCLUSIONS: MSC transfer to PDL during expansion increased the amount of OTM. Injection of MSC during the retention period was found to be slightly more effective in prevention and/or repair of OIRR than MSC transfer during the expansion period.
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Células-Tronco Mesenquimais , Reabsorção da Raiz/etiologia , Animais , Osteoclastos , Ratos , Ratos Wistar , Técnicas de Movimentação Dentária/efeitos adversos , Microtomografia por Raio-XRESUMO
PURPOSE: To investigate the temperature changes in pulp chamber of incisor and canine teeth during different stripping procedures with thermal imaging. MATERIALS AND METHODS: Intact and freshly extracted human permanent 40 maxillary lateral incisor, 40 mandibular canine and 40 mandibular incisor teeth were selected for this study. Diamond bur, tungsten carbide bur and perforated diamond-coated disc were used for interdental stripping in high and low speed handpieces by air and water cooling. Temperature changes and cooling time of the tooth groups were recorded by a thermal imaging system. Paired t test and one-way analysis of variance (ANOVA) tests were performed for intragroup and intergroup comparisons of temperature changes and cooling time values. RESULTS: Stripping procedures created a statistically significant temperature rise in all study groups (p < 0.05). For maxillary lateral incisors and mandibular incisors, the greatest temperature rise was calculated during stripping with tungsten bur and perforated disk under air cooling (p < 0.001), while no statistically significant difference was found between the temperature rise values of mandibular canine teeth during different stripping procedures (p = 0.053). The lowest temperature rise and cooling time values among all tooth groups were observed during stripping with diamond bur under water cooling and the longest cooling time values were detected during stripping with perforated disc under air cooling (maxillary incisor; p < 0.001, mandibular incisor; p < 0.05, mandibular canine; p < 0.05). CONCLUSION: For all tooth groups, stripping with diamond bur in a high speed handpiece under water cooling produced the lowest temperature rise in the pulp chamber and the shortest cooling time values among different stripping procedures.
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Temperatura Corporal , Polpa Dentária , Cavidade Pulpar , Humanos , Incisivo , TemperaturaRESUMO
OBJECTIVES: To evaluate the changes of psychologic parameters, such as self-esteem, sensitivity to criticism, and social appearance anxiety, in skeletal Class III patients undergoing orthognathic surgery and to compare the psychologic status of skeletal Class III patients with control subjects. METHODS: The first group consisted of 60 patients with a mean age of 22.07 ± 1.30 years who did not need orthognathic surgery. The second group comprised 45 patients with skeletal Class III malocclusion (mean age 21.40 ± 2.02 years) who were evaluated in terms of psychologic changes from before to after surgery. A third group consisted of 50 Class III patients (mean age 20.09 ± 2.59 years) who were evaluated before surgery and a different 50 Class III patients (mean age 22.15 ± 2.03 years) who were investigated after surgery. The Rosenberg Self-Esteem Scale and the Social Appearance Anxiety Scale were used to evaluate psychologic parameters both before and after surgery. Analysis was carried out with the use of independent- and dependent-sample t tests, 1-way analysis of variance, and post hoc Tukey test. RESULTS: Self-esteem of the patients with skeletal Class III malocclusion increased, and sensitivity to criticism and social appearance anxiety decreased significantly after the surgery (P <0.001). In the patients with Class III malocclusion, self-esteem was significantly lower and social appearance anxiety significantly higher before orthognathic surgery than in the control group, and at the postoperative evaluation Class III patients had significantly higher self-esteem than the control group (P <0.001). CONCLUSIONS: Through the improvement in facial appearance after surgery, patients' self-esteem increases and their sensitivity to criticism and social appearance anxiety decrease.
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Ansiedade/etiologia , Imagem Corporal/psicologia , Procedimentos Cirúrgicos Ortognáticos/psicologia , Autoimagem , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Má Oclusão Classe III de Angle/psicologia , Má Oclusão Classe III de Angle/cirurgia , Adulto JovemRESUMO
PURPOSE: The purpose of this study was to compare the sagittal tilt of the head in different head positioning techniques using an inclinometer and facial stereophotogrammetric measurements. MATERIALS AND METHODS: The study was carried out in 45 participants (26 female, 19 male). Participants' head positioning was obtained with dynamic walking, Frankfort horizontal plane (FHP'), self-balance plus mirror, and subjective photographic positioning methods. All pitch values were recorded by an inclinometer and stereophotogrammetric images were obtained. Facial analysis included distances of the glabella (G'), pronasale (Pn), soft tissue A point (A'), upper lip (Ls), lower lip (Li), soft tissue B point (B)', and soft tissue pogonion (Pog') to the true vertical line (TVL) and face height and lip length measurements. RESULTS: Participants' head positions were observed to be more forward in the FHP' head positioning technique compared with other methods, whereas a more backward head position was recorded with subjective head positioning, and the difference was significant (P < .001). There were no relevant differences in pitch values between the self-balance plus mirror and dynamic walking methods. G'-TVL (P < .000), Pn-TVL (P < .029), A'-TVL (P < .039), Ls-TVL (P < .001), Li-TVL (P < .037), B'-TVL (P < .003), and Pog'-TVL (P < .000) in the profile view and face height, lower face height, and lower lip length values in the frontal view (P < .001) differed significantly by head positioning method. CONCLUSIONS: The dynamic walking and self-balance plus mirror head positioning methods offered similar and advisable natural head position results, whereas FHP' head positioning was questionable for an accurate determination of natural head position. Facial soft tissue measurements, such as face height, lower face height, lower lip length, and projection of structures such as the G', Pn, lips, and chin, varied based on head positioning method.
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Face , Fotogrametria , Cefalometria , Queixo , Face/anatomia & histologia , Feminino , Humanos , Lábio , MasculinoRESUMO
OBJECTIVES: This was a parallel, assessor-blinded, randomized, non-controlled prospective trial with the objective to evaluate and compare the effects of maximum advancement (MA) and incremental advancement (IA) of mandible with cast-splint-type Herbst-rapid palatal expander (RPE) appliance on pharyngeal airway dimensions and hyoid bone position in skeletal Class II late adolescents and young adults. MATERIALS AND METHODS: A total of 48 patients (19 male and 29 female, mean age: 15.45 ± 1.42 years) with skeletal Class II malocclusion were treated with cast-splint Herbst-RPE appliance. Inclusion criteria were skeletal Class II malocclusion, mandibular retrognathia, bilateral Class II molar and canine relationship, increased overjet, normal or decreased vertical dimensions, minimal crowding, and no missing teeth. Enrolled subjects were randomly allocated into two groups according to mandibular advancement type: IA and MA Herbst-RPE therapy. The outcome assessor was blinded. Advancement in MA group was adjusted until tête-à-tête incisor relationship or super Class I molar relationship was obtained. Initial forward movement in IA group was 4-5 mm and followed by bimonthly 2 mm of subsequent advancements. Skeletal, pharyngeal airway, and hyoid measurements were performed using lateral cephalometric films. Statistical significance was set at P value of less than 0.05. RESULTS: Hypopharyngeal airway dimensions (P < 0.000), oropharyngeal airway dimensions (P < 0.001, P < 0.007), and PASmin values (P < 0.010, P < 0.009) were increased and soft palate angle (P < 0.018, P < 0.007) was decreased in MA and IA groups significantly. Hyoid bone measurements revealed a significant difference in H-Cv2 distance (MA: P < 0.002-P < 0.002; IA: P < 0.001-P < 0.043) and H-Cv3 distance (P < 0.005, P < 0.001) for both groups. However, all these changes did not differ among the MA and IA activation groups. ANB°, Wits, overjet, and overbite measurements decreased and SNB°, Co-Gn, Na-Me, ANS-Me, and S-Go increased with the treatment significantly in both mandibular advancement groups (P < 0.000-P < 0.040). CONCLUSIONS: Herbst-RPE appliance provided a similar improvement in the oropharyngeal and hypopharyngeal airway dimensions and similar changes in sagittal and vertical hyoid position for both maximum and IA protocols in patients with skeletal Class II malocclusion. TRIAL REGISTRATION: ISRCTN69743543.
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Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Adolescente , Cefalometria , Feminino , Humanos , Masculino , Mandíbula , Faringe , Estudos Prospectivos , Distribuição Aleatória , Método Simples-Cego , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: Comparison of dental measurements between conventional plaster models, digital models obtained by impression scanning and plaster model scanning. PURPOSE: To evaluate and to compare the accuracy and reliability of tooth size, arch width and Bolton tooth size discrepancy measurements on 3 Dimensional (3D) digital models obtained by plaster dental model scanning, dental impression scanning and conventional plaster models. MATERIAL AND METHODS: This study was carried out on the maxillary and mandibular dental models of 25 patients with Angle Class I molar relationship and minimal crowding. Mesio-distal dimensions of the teeth, intercanine and intermolar arch width, and Bolton tooth size discrepancy measurements were calculated by conventional methods on plaster models, digital methods and on 3D models obtained from plaster model scanning and impression scanning. All measurements were repeated after three weeks for each of the investigated methods. Reliability of measurements was evaluated by Dahlberg formula and Pearson Correlation Coefficient. Comparisons of dental measurements between three methods were achieved with ANOVA Test. RESULTS: The repeated measurements were highly correlated for all methods. Method error was found within clinically acceptable limits. There was no significant difference between dental measurements on plaster dental models, digital models obtained from plaster dental model scanning and dental impression scanning. Results showed the methods being highly reliable and accurate for tooth size, arch width and Bolton analysis at total and anterior proportion calculation. CONCLUSION: Digital measurements of tooth size, arch width and Bolton tooth size discrepancy on digital models obtained from plaster dental model scanning and dental impression scanning showed high accuracy and reliability. There was no significant difference between the three methods for dental measurements.
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Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Modelos Dentários , Odontometria/métodos , Arco Dental , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Má Oclusão/classificação , Má Oclusão/diagnóstico , Má Oclusão/patologia , Má Oclusão Classe I de Angle/diagnóstico , Má Oclusão Classe I de Angle/patologia , Mandíbula , Maxila , Ortodontia , Reprodutibilidade dos Testes , Dente/patologiaRESUMO
The aim of this study was to introduce a minimally invasive procedure for mesenchymal stem cell (MSC) transfer into the intact periodontal ligament (PDL) of the molar teeth in rats. Ten 12-week-old Wistar albino rats were used for this preliminary study. MSCs were obtained from bones of two animals and were labeled with green fluorescent protein (GFP). Four animals were randomly selected for MSC injection, while 4 animals served as a control group. Samples were prepared for histological analysis, Cox-2 mRNA expression polymerase chain reaction analysis, and fluorescent microscopy evaluation. The number of total cells, number of osteoclastic cells, and Cox-2 mRNA expression levels of the periodontal tissue of teeth were calculated. The number of total cells was increased with MSC injections in PDL significantly (P < 0.001). The number of osteoclastic cells and Cox-2 mRNA expression were found to be similar for the two groups. GFP-labeled MSCs were observed with an expected luminescence on the smear samples of the PDL with transferred MSCs. The results of this preliminary study demonstrate successful evidence of transferring MSCs to intact PDL in a nonsurgical way and offer a minimally invasive procedure for transfer of MSCs to periodontal tissues.
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Objective: The aim of this study was to evaluate and compare the reparative and inhibitory effects of a light-emitting diode-mediated photobiomodulation (PBM) and of a low-intensity pulsed ultrasound (LIPUS) on orthodontically induced inflammatory root resorption (OIIRR). Materials and methods: Forty-nine Wistar rats were divided into four groups: untreated group (negative control), group treated with orthodontic appliances (positive control), PBM-treated group (wavelength: 618 nm, output power density: 20 mW/cm2), and LIPUS-treated group (frequency: 1.5% ± 5% MHz, pulse repetition ratio: 1.0% ± 10% kHz, effect area: 3.88% ± 1% cm2 and intensity: 30% ± 30% mW/cm2). OIIRR was induced experimentally in rats for 14 days with an applied force of 100g, and therapeutic approaches were performed concurrently. At the end of the experiment, upper first molar teeth of rats were prepared for genetic analysis, scanning electron microscopy, hematoxylin and eosin staining, and tartrate-resistant acid phosphatase staining. Kruskal-Wallis and post hoc Dunn's tests were performed. Results: Number of osteoclasts (p < 0.01), number of resorption lacunae and resorption area ratio (p < 0.001) decreased and number of total cells (p < 0.001) increased with the PBM and LIPUS applications when compared with the positive control group. Receptor activator of nuclear factor kappa B ligand (RANKL) levels of PBM and LIPUS groups were lower (p < 0.001), and osteoprotegerin (OPG) levels were higher (p < 0.001) than the positive control group. Cyclooxygenase-2 (Cox-2) expression significantly decreased with LIPUS and PBM administrations (p < 0.05). No significant difference was observed among PBM and LIPUS groups. Conclusions: PBM and LIPUS applications showed marked inhibitory and reparative effects on OIIRR by modulating the OPG/RANKL ratio, Cox-2 expression, and cell differentiation of osteoblasts and osteoclasts.