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1.
J Appl Oral Sci ; 29: e20200734, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33825762

RESUMEN

OBJECTIVE: To compare tooth movement rate and histological responses with three different force magnitude designs under osteoperforation in rabbit models. METHODOLOGY: 48 rabbits were divided into three groups: Group A, Group B, and Group C, with traction force of 50 g, 100 g, 150 g, respectively. Osteoperforation was performed at the mesial of the right mandibular first premolar, the left side was not affected. One mini-screw was inserted into bones between two central incisors. Coil springs were fixed to the first premolars and the mini-screw. Tooth movement distance was calculated, and immunohistochemical staining of PCNA, OCN, VEGF, and TGF-ß1 was analyzed. RESULTS: The tooth movement distance on the surgical side was larger than the control side in all groups (P<0.01). No significant intergroup difference was observed for the surgical side in tooth movement distance among the three groups (P>0.05). For the control side, tooth movement distance in Group A was significantly smaller than Groups B and C (P<0.001); no significant difference in tooth movement distance between Group B and Group C was observed (P>0.05). On the tension area of the moving premolar, labeling of PCNA, OCN, VEGF and TGF-ß1 were confirmed in alveolar bone and periodontal ligament in all groups. PCNA, OCN, VEGF and TGF-ß1 on the surgical side was larger than the control side in all groups (P<0.001). CONCLUSION: Osteoperforation could accelerate orthodontic tooth movement rate in rabbits. Fast osteoperforation-assisted tooth movement in rabbits was achieve with light 50 g traction.


Asunto(s)
Ligamento Periodontal , Técnicas de Movimiento Dental , Animales , Diente Premolar , Conejos
2.
J Clin Pediatr Dent ; 45(1): 54-57, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690829

RESUMEN

OBJECTIVES: This study examines how accurate pediatric dentists are at estimating dental arch lengths by comparing their model estimations (guesstimating the arch length without measuring) to the Tanaka and Johnston mixed dentition arch length analysis. STUDY DESIGN: This study consisted of two parts, a survey of practitioners and a model estimating and measuring component. The survey was designed and given to 44 pediatric dentists to determine how many were practicing orthodontics and using arch length analyses routinely. Then 18 pediatric dentists and 13 pediatric dental residents examined 20 sets of mixed dentition models and estimated how much space was available. These estimations were compared to the calculated gold standard, the Tanaka and Johnston arch length analysis of the same models. RESULTS AND CONCLUSIONS: More than half of the dentists surveyed that practice comprehensive orthodontics use arch length estimates. Pediatric dentists and pediatric dental residents are just as good as each other at estimating arch length. Pediatric dentists and pediatric dental residents underestimated arch length by -3.6 and -3.1 mm, respectively. More research needs to be done to determine if model estimation is a clinically acceptable way to judge arch length.


Asunto(s)
Dentición Mixta , Ortodoncia , Diente Premolar , Niño , Arco Dental , Humanos , Odontometría
3.
J Clin Pediatr Dent ; 45(1): 58-62, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690831

RESUMEN

OBJECTIVE: To determine the prevalence and distribution of premature eruption and agenesis of premolars in a sample of Turkish children. STUDY DESIGN: A sample of 1715 patients aged 5 to 11 years was selected. Panoramic radiographs were used to assess premature eruption and agenesis of premolars. Developmental stage of erupted premolars was assessed using Demirjian's method and selecting prematurely erupted premolars on the basis of clinical eruption with a root length less than half of their final expected root lengths. Statistical analysis was performed using chi-square test (p <.05). RESULTS: One hundred fifteen (6.7%) of 1715 patients presented at least one premolar agenesis with no significant sex difference (56 boys, 59 girls). Mandibular second premolars were the most absent teeth. Multiple agenesis of premolars (3.4%) was more common than single agenesis (3.3%). A total of 85 (5.0%) patients (51 boys, 34 girls; no significant sex difference) had at least one prematurely erupted premolar, and maxillary first premolars were most commonly affected. Early erupted premolars were in stage D or E based on Demirjian's dental formation scale. CONCLUSIONS: The prevalence of premature eruption and agenesis of premolars in Turkish children were 5.0% and 6.7%, respectively. Both conditions are not uncommon and may highlight the need for early diagnosis to prevent subsequent clinical problems.


Asunto(s)
Anodoncia , Odontogénesis , Anodoncia/epidemiología , Diente Premolar , Niño , Preescolar , Femenino , Humanos , Masculino , Prevalencia , Radiografía Panorámica , Estudios Retrospectivos
4.
J Clin Pediatr Dent ; 45(1): 63-65, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690832

RESUMEN

Delayed tooth development (DTD) is the development progress of a tooth germ that takes place later due to local or general causes. This case report reviews a 16-year-old Asian adolescent whose bilateral upper second premolar germs were at Nolla's 6 stage as shown on a panoramic radiograph. It is unusual that tooth germs of the maxillary second premolar are developed after 11 years of age. To reduce the chance of misdiagnosis, clinicians should consider the possibility of DTD if a tooth germ does not present in radiographs.


Asunto(s)
Germen Dentario , Adolescente , Diente Premolar/diagnóstico por imagen , Humanos , Radiografía Panorámica
5.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(3): 256-262, 2021 Mar 09.
Artículo en Chino | MEDLINE | ID: mdl-33663155

RESUMEN

Objective: To explore the effect of extraction on upper airway in skeletal class Ⅰ adolescents. Methods: According to random number table method, 30 skeletal class Ⅰteenagers who underwent orthodontic straight wire treatment were selected randomly in Department of Orthodontics, School of Stomatology, The Fourth Military Medical University between January 2016 and December 2019. There were 13 males and 17 females, aged (13.7±1.5) years (12.2-15.7 years). In all patients, four first premolars were removed and the upper and lower anterior teeth were retracted under non-maximal anchorage (non-implant anchorage or face bow). The cone-beam CT (CBCT) data before and after orthodontic extraction treatments were studied. The three-dimensional model of the upper airway was reconstructed and segmented, and the relevant indexes of oropharyngeal volume and cross-sectional area were measured. Cephalograms was generated to measure tooth-jaw indexes and hyoid position. The changes of each index before and after orthodontic treatment were compared. The correlation between the changes in the volume or sectional area of the oropharyngeal airway and the changes in the dental and maxillary indexes and the hyoid position was tested. Results: Compared with those before treatment, palatopharyngeal volume, glossopharyngeal volume, oropharyngeal total volume, and minimum transection area increased by 632 (558) mm3, 758 (549) mm3, 1 454 (955) mm3 and 14 (29) mm2 respectively, and statistically significant differences were found (P<0.05). The minimum oropharyngeal area was mostly located in the glossopharynx. The cross-sectional area and the maximum anterior-posterior diameter of uvula tip decreased by (4±10) mm2 and (0.4±0.8) mm respectively, and the difference was statistically significant (P<0.05). There was no significant difference in the maximum lateral diameter before and after treatment (P>0.05). The ratio of the maximum antero-posterior diameter to the maximum lateral diameter at the uvula tip decreased from 0.589 (0.034) before treatment to 0.535 (0.047) after treatment (P<0.05), indicating that its shape tends to be more elliptic after treatment. In addition, the change of cross-sectional area at the apex of uvula was positively correlated with the changes of mandibular central incisor lip inclination and the distances from the upper and lower central incisor points to the Frankfort plane perpendicular to the sella point (UI-FHp and LI-FHp) (P<0.05). Conclusions: The impact of orthodontic extraction treatment on oropharyngeal airway was generally small in skeletal class Ⅰ adolescents. However, it could change the shape of the airway to some extent. The change of airway cross-sectional area at the uvula tip was positively correlated with the retraction of anterior teeth.


Asunto(s)
Mandíbula , Maxilar , Adolescente , Diente Premolar , Cefalometría , Niño , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Hueso Hioides , Masculino , Maxilar/diagnóstico por imagen
6.
Am J Orthod Dentofacial Orthop ; 159(2): 234-245, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33546828

RESUMEN

Autotransplantation of a mature premolar in adults can be a treatment of choice for tooth replacement when combined with well-planned orthodontic treatment. This case report describes the successful treatment of a 39-year-old patient with severe crowding and a hopelessly fractured tooth on the maxillary left side. Maxillary dental crowding was relieved by extraction of a premolar on the right side, and this extracted tooth was autotransplanted to replace the fractured tooth. A mandibular incisor was extracted to correct anterior crossbite. The total treatment period was 20 months. The treatment results showed a good long-term prognosis after transplantation of a mature premolar with normal surrounding alveolar bone level for over 6 years of follow-up. Occlusion and periodontal health were excellent in the long term.


Asunto(s)
Fracturas de los Dientes , Adulto , Diente Premolar/cirugía , Humanos , Incisivo , Mandíbula , Maxilar , Fracturas de los Dientes/diagnóstico por imagen , Fracturas de los Dientes/cirugía , Trasplante Autólogo
7.
Am J Orthod Dentofacial Orthop ; 159(3): 333-342, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33541786

RESUMEN

INTRODUCTION: The purpose of this study was to evaluate the effects of 2 extraction patterns on incisor and molar movements in patients with growing Class II Division 1. METHODS: The sample included 54 patients 10-17 years of age treated by 2 private practice orthodontists using Tweed directional force mechanics, 4 premolar extractions, J-hook headgears, and Class II elastics or Saif springs. The sample was divided on the basis of having maxillary and mandibular first premolars (4/4) or maxillary first and mandibular second premolars (4/5) extracted. Each group included 27 patients. Treatment lasted 2.8 ± 0.60 years and 2.6 ± 0.54 years for the 4/4 and 4/5 groups, respectively. Pretreatment (T1) and posttreatment lateral cephalograms and dental casts were evaluated. Cranial base, mandibular, and maxillary superimpositions were performed to quantify tooth movements and displacements. RESULTS: There were no statistically significant T1 between-group differences in crowding or in the SNA, SNB, ANB, and MPA angles. Analyses of covariance, controlling for statistically significant (P <0.05) differences in T1 mandibular incisor position, showed that mandibular first premolars extractions produced greater (1.6 mm) mandibular incisor retraction than second premolar extractions. The mandibular first molars were protracted significantly more (0.7 mm) after the second premolar than the first premolar extractions. Within-group changes of the MPA, between-group differences in the changes in MPA, and the amount of vertical eruption of the maxillary and mandibular molars were not significantly different between the 2 extraction patterns. CONCLUSIONS: Extraction of mandibular second premolars enhances Class II molar correction, with greater mesial first molar movement and less distal incisor movement. Neither extraction pattern has an effect on the MPA or the vertical dimension (ie, there was no "wedge effect").


Asunto(s)
Maloclusión de Angle Clase II , Mandíbula , Diente Premolar/cirugía , Cefalometría , Humanos , Maloclusión de Angle Clase II/terapia , Maxilar , Diente Molar , Extracción Dental , Técnicas de Movimiento Dental
8.
Ned Tijdschr Tandheelkd ; 128(1): 29-40, 2021 Jan.
Artículo en Holandés | MEDLINE | ID: mdl-33449054

RESUMEN

There aren't any generally accepted guidelines for the restoration of an endodontically treated tooth. With a questionnaire among dental general practitioners and endodontists, several restorative treatment options for endodontically treated molars and premolars were identified. The questionnaire inventoried the influence of various parameters on treatment preferences. For each case, additional questions were put about material choice, cuspal coverage and the use of root canal posts. Both groups identified the vertical root fracture as the most common reason for extraction. The dentist general practitioner waited longer than the endodontist to make a permanent restoration in the case of apical periodontitis. Treatment preferences were found to be the same for premolars and molars. In the case of premolars, a root canal post was indicated more often and the location of the wall (bearing/non-bearing) influenced the choice of cuspal coverage. Of the dentist general practitioners and endodontists, 51-53% and 75-94%, respectively, preferred a partial over a full crown preparation in the case of single-walled teeth.


Asunto(s)
Restauración Dental Permanente , Diente no Vital , Diente Premolar , Resinas Compuestas , Humanos , Diente Molar , Diente no Vital/terapia
9.
Arch Oral Biol ; 123: 105040, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33454421

RESUMEN

OBJECTIVE: To evaluate cone-beam computed tomography images in an Argentine population in order to determine the presence of mandibular premolars with C-shaped canal system and classify them. METHODS: 697 images were observed, 170 of them fulfilling the selection criteria. Once established the presence of a C-shaped canal system, premolars were classified using Fan's criteria. Data description was made by frequencies and percentages rates, with a 95% confidence interval according to the score method. Comparisons were assessed by means of the Chi-square test with a significance level equal to 5%. RESULTS: Of 269 first premolars, 27 teeth showed C-shaped canal system, i.e. 10%, and of 231 second premolars, 4 presented C-shaped canal system, i.e. 2%. Out of 17 patients presenting first premolars in both sides, 6 showed a bilateral C-shaped canal system pattern and 11 did not present this condition. When the condition was unilateral (n = 15), 7 patients showed C-shaped canal in the tooth 3.4 and 8 patients showed C-shaped canal in the tooth 4.4. The second premolars showed C-shaped canals unilaterally. Along the canal, configuration variations at the three-thirds have been observed for the first and second mandibular premolars. CONCLUSION: The C-shaped canal system pattern prevalence in mandibular first and second premolars was estimated for the first time in an Argentine population, in vivo. The present report contributes to the epidemiological understanding of the anatomical variable of the inner dental configuration and its extrapolation to the clinical practice.


Asunto(s)
Diente Premolar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Cavidad Pulpar , Raíz del Diente , Argentina , Cavidad Pulpar/diagnóstico por imagen , Humanos , Mandíbula/diagnóstico por imagen
10.
Mymensingh Med J ; 30(1): 214-219, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33397877

RESUMEN

In the dental specialty forensic odontology, dimensions of tooth structure is being used to predict gender of a particular population in case accidents and mass disasters. Therefore the aim of our study was to develop a modified based on the mesio-distal dimension of teeth in Saudi Arabian population. The pretreatment orthodontic cast models of patients reporting to Riyadh Elm University, Riyadh, Saudi Arabia to measure the mesio-distal dimensions of all the teeth from permanent second molar of right quadrant to second molar of the left quadrant for both maxillary and mandibular arch with the help of an electronic devices. A significant difference was observed in mesio-distal dimensions for between males and females for canines, premolars and first molars (p≥0.05) except for incisors and second molars. On multi-variate logistic regression analysis a final model was developed which included permanent maxillary right canine (13), permanent mandibular left lateral incisor (32) and permanent mandibular left canine (33). The current modified sex predictive model for Saudi Arabian population displayed 80% accuracy for sex prediction. Based on the specificity of the modified model it can be recapitulated the model has a potential for gender prediction of Saudi Arabian population.


Asunto(s)
Incisivo , Diente Molar , Diente Premolar , Femenino , Humanos , Masculino , Arabia Saudita/epidemiología , Corona del Diente
11.
Am J Orthod Dentofacial Orthop ; 159(2): e135-e147, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33388201

RESUMEN

INTRODUCTION: The purposes of this study were to characterize the 3-dimensional position of teeth adjacent to impacted canines and examine whether impaction affects canine development using cone-beam computed tomography. METHODS: Cone-beam computed tomography images of 34 unilateral maxillary impacted canines (12 males, 22 females; mean age, 16.5 years) were collected. Twenty-one canines were palatally impacted (PIC), and 13 were buccally impacted (BIC). Angular measurements of lateral incisors (LIs), first premolars, and the impacted canines positions relative to a 3-dimensional coordinate system and canines' volume, length, and shape of the roots, were compared between the affected and contralateral control sides. The influence of canine position and severity of impaction was examined. Statistics included the paired t test, Wilcoxon signed rank test, and McNemar test. RESULTS: In the PIC group, LIs showed significant mesiobuccal rotation (-17.1°), mesial angulation (8.4°), and buccal root torque (5°) and first premolars mesiobuccal rotation (6.1°). In the BIC group, LIs displayed mesiobuccal rotation (-18°) and significant palatal root torque (-5°). The canine volumes were similar in BICs and slightly smaller in PICs. The lengths were shorter in both, but root hooks were more prevalent in BICs. The severity of impaction affected the measured variables. CONCLUSIONS: The differential position of the adjacent teeth is pathognomonic for PIC vs BIC, and impaction seems to affect canine development. The findings provide evidence-based clinical and radiographical clues for early diagnosis of canine displacement and planning the most efficient treatment strategy. In addition, they support timely orthodontic eruption before the development of the apical third of the root.


Asunto(s)
Diente Canino , Diente Impactado , Adolescente , Diente Premolar , Tomografía Computarizada de Haz Cónico , Diente Canino/diagnóstico por imagen , Femenino , Humanos , Incisivo , Masculino , Maxilar/diagnóstico por imagen , Diente Impactado/diagnóstico por imagen
12.
Am J Orthod Dentofacial Orthop ; 159(2): e103-e111, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33390312

RESUMEN

INTRODUCTION: Our aim was to assess changes in the number of enamel microcracks (EMCs) after removing metal brackets in teeth with and without visible EMCs before the bonding procedure. METHODS: Before bonding, 13 patients having teeth with visible EMCs and 13 subjects whose teeth were free of EMCs were included in the study. All patients were asked to complete a questionnaire with a detailed medical history at the beginning of treatment and after removing metal brackets. The number of teeth with visible EMCs and the number of premolars without EMCs were recorded for each subject twice, that is, before bonding and after debonding, together with the tooth sensitivity assessments elicited by compressed air and cold testing. RESULTS: The number of visible EMCs in premolars increased after removing metal brackets. EMCs were recorded in at least 25.0% of all evaluated teeth for the patients having teeth with and without visible EMCs at the beginning of treatment. However, the changes in the number of visible EMCs were not significantly different (P = 0.619) between the groups. For the subjects with visible EMCs, tooth sensitivity caused by cold was registered nearly 3 times more often after removing brackets compared with the patients without EMCs prior bonding. CONCLUSIONS: Formation of EMCs was noticed after debonding. Changes in the number appeared to be similar for the subjects with and without visible EMCs before bonding. Higher incidence of EMCs was associated with more frequent tooth sensitivity perceptions after removing brackets.


Asunto(s)
Recubrimiento Dental Adhesivo , Soportes Ortodóncicos , Diente Premolar , Cerámica , Desconsolidación Dental/efectos adversos , Esmalte Dental , Humanos , Soportes Ortodóncicos/efectos adversos
13.
J Adhes Dent ; 23(1): 67-75, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33512117

RESUMEN

PURPOSE: To investigate the fatigue performance and stress distribution of endodontically treated maxillary premolars with occlusal (O), mesio-occlusal (MO), or mesio-occluso-distal (MOD) cavities filled directly with bulk-fill composite. Materials and Methods: Besides the intact teeth (control group), sixty sound maxillary first premolars, standardized by size and morphology, were subjected to root canal treatment and randomly allocated to three groups throughout cavity preparations (O/MO/MOD). All cavities were restored with a bulk-fill composite (Tetric N-Ceram Bulk fill) and universal adhesive (Tetric N-Bond Universal) using etch-and-rinse mode. Half of the specimens of each group underwent 20,000 thermocycles (5°C-55°C). All specimens were subjected to a 50-N load perpendicular to their buccal bevels on the palatal cusps for 1,200,000 cycles. The survival curve and fracture mode were analyzed by log-rank and Fisher's exact tests, respectively. Finite element analysis (FEA) was conducted to simulate the working condition of premolars with O/MO/MOD cavities. The von Mises stress and the first principal stress were calculated for three FEA models. Results: Premolars with O cavity restorations exhibited better stress distributions than did those with MO and MOD cavity restorations. Compared to the intact premolars, no significant difference was detected in the fatigue performance of O/MO/MOD restorations, regardless of whether they underwent thermocycling. Only one specimen presented unrestorable fracture, while the rest of the fractured premolars were restorable. Conclusion: The cavity design of endodontic premolars restored with a bulk-fill composite has no influence on the stress distribution or fatigue survival, with a biomechanical performance similar to that of an intact tooth.


Asunto(s)
Fracturas de los Dientes , Diente no Vital , Diente Premolar , Resinas Compuestas , Preparación de la Cavidad Dental , Restauración Dental Permanente , Análisis del Estrés Dental , Humanos
14.
Am J Orthod Dentofacial Orthop ; 159(2): 184-192, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33388202

RESUMEN

INTRODUCTION: This study aimed to evaluate the 3-dimensional (3D) mandibular dental changes over 42 years using the registration of digital models. METHODS: The sample comprised digital dental models of 8 untreated subjects (4 males and 4 females) with normal occlusion measured longitudinally at ages 17 years (T1) and 60 years (T2). Using 13 landmarks placed on the mucogingival junction, we registered the T2 model on the T1 model. Three-dimensional changes in the position of the landmarks on the buccal cusp tip of the posterior teeth and incisal edge of the central incisors were measured by 2 examiners. Registration and measurements were performed using SlicerCMF (version 3.1; http://www.slicer.org) software. Intra- and interrater agreements were evaluated using intraclass correlation coefficients and the Bland-Altman method. One-sample t tests were used for evaluating interphase 3D dental changes (P <0.05). RESULTS: Adequate intra- and interrater reproducibility was found. From T1 to T2, the mandibular teeth showed significant 3D positional changes. A significant dental eruption relative to the mucogingival junction was observed for the anterior and posterior teeth. Anteroposterior movements of mandibular teeth were not significant except for the right molar that drifted mesially. Transverse movements included slight lingual tipping at canines and premolars regions. CONCLUSIONS: Dental changes in untreated normal occlusion were very slight from early to mature adulthood. The eruption of the mandibular teeth was the most consistent finding. A tendency for mesial movement of molars and lingual movement of first premolars and canines was observed in the mandible during the aging process.


Asunto(s)
Mandíbula , Diente Molar , Adolescente , Adulto , Envejecimiento , Diente Premolar , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Reproducibilidad de los Resultados
15.
Am J Orthod Dentofacial Orthop ; 159(2): 167-174, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33342674

RESUMEN

INTRODUCTION: This research aimed to analyze the prevalence of root dilaceration in buccally impacted canines (BICs) and palatally impacted canines (PICs) with their adjacent teeth based on a retrospective cone-beam computed tomography (CBCT) investigation. METHODS: Pretreatment CBCT images of 145 subjects with unilateral maxillary canine impaction and 145 age- and sex-matched subjects without impaction were used. Prevalence of dilaceration (subclassified to root curvature and apical hook based on severity) in canines and adjacent teeth was determined in CBCT records. The root length of maxillary impacted canines was measured for further morphologic evaluations. RESULTS: Impacted canines had a significantly higher prevalence of root dilaceration than the control group and compared with the erupted contralateral canines in the experimental group (P < 0.001 for both). A significantly higher prevalence of root dilaceration was found in adjacent lateral incisors of the PICs subgroup than that of the control group (P < 0.001). Adjacent premolars had a higher prevalence of dilacerated roots in the PICs subgroup (P < 0.001) than the control group, but not for the BICs subgroup. Significantly higher prevalence of curvature (P < 0.001 for both) and hook (P = 0.008 and P < 0.001, respectively) were found in BICs and PICs roots compared with the control group. Both types of impacted canines had significantly shorter roots than the control group (P < 0.001 for both). CONCLUSIONS: BICs and PICs have a higher tendency to present root dilaceration and shorter roots. Unlike BICs, adjacent teeth to PICs were more frequently observed to have root dilaceration.


Asunto(s)
Diente Canino , Diente Impactado , Diente Premolar , Tomografía Computarizada de Haz Cónico , Diente Canino/diagnóstico por imagen , Humanos , Incisivo , Maxilar/diagnóstico por imagen , Estudios Retrospectivos , Diente Impactado/diagnóstico por imagen
16.
Angle Orthod ; 91(1): 61-66, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33339043

RESUMEN

OBJECTIVES: To investigate the correspondence between programmed interproximal reduction (p-IPR) and implemented interproximal reduction (i-IPR) in an everyday-practice scenario. The secondary objective was to estimate factors that might influence i-IPR to make the process more efficient. MATERIALS AND METHODS: Fifty patients treated with aligner therapy by six orthodontists were included in this prospective observational study. Impressions were taken at the beginning of treatment and after the first set of aligners. Data on p-IPR, i-IPR and technical aspects of IPR were gathered for 464 teeth. Statistical analyses included the Wilcoxon signed-rank test, Kruskal-Wallis, and multilevel mixed regression. RESULTS: Mean difference between p-IPR and i-IPR was 0.15 mm (SD: 0.14 mm; P = .0001), with lower canines showing the highest discrepancy. Use of burs and measuring gauges resulted in a smaller difference (respectively: coeff.: 0.09, P = .029; coeff.: -0.06, P = .013). IPR was performed more accurately on the mesial surface of teeth than on the distal surface. Round tripping before IPR resulted in a slightly more precise i-IPR compared to the previous alignment (coeff.: -0.021, P = .041). CONCLUSIONS: Implemented IPR tends to be less than p-IPR, especially for lower canines and distal surfaces of teeth. Burs tend to provide more precise i-IPR, especially compared to manual strips; however, there is variation between the techniques. Using a measuring gauge tends to increase the precision of i-iPR. As several factors influence the implementation of IPR, particular attention must be paid during the procedure to maximize its precision.


Asunto(s)
Esmalte Dental , Ortodoncistas , Diente Premolar , Humanos
17.
Braz. dent. sci ; 24(1): 1-6, 2021. tab
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1145511

RESUMEN

Objective: The present study aimed to assess theinfluence of vibration effect on microshear bond strength (µSBS) of flowable composite to enamel. Material and Methods: Sixty non-cariousextracted human premolar teeth were collected and randomly divided into six groups (n = 10) after being trimmed to produce a smooth flat surface: Flowable composites [Wave (SDI), Wave HV (SDI) and Grandioflow (Voco)] were used as bonding agents without or with vibration using an ultrasonic scaler (Mini Piezon, EMS, Switzerland). Composite resin, with an internal diameter of 0.7mm and height of 1mm, was cured on the substrate. The specimens' µSBS was tested by a microtensile tester (Bisco, USA) at a crosshead speed of 0.5 mm/min. The bond strength values were analyzed using one-way ANOVA and post hoc Tukey test (p < 0.05). Results:Vibrationdid not lead to any significant difference in the µSBS values of Wave, Wave HV, and Grandio Flow µSBS values (P=0.690, P=1.000 and P=0.947, respectively). No significant difference was found between flowable composites in terms of micro shear bond strength to enamel (p > 0.05). Conclusions: The application of ultrasonicvibration might not be advantageous in terms of improving the shear bond strength of flowable composites to enamel. (AU)


Objetivo: Este estudo teve como objetivo avaliar a influência de microcisalhamento com efeito de vibração na resistência de união (µSBS) de compósito fluido ao esmalte. Material e Métodos: Sessenta dentes pré-molares humanos extraídos não cariados foram coletados e divididos aleatoriamente em seis grupos (n = 10) após serem desgastados para produzir uma superfície lisa e plana: Compósitos fluidos [Wave (SDI), Wave HV (SDI) e Grandioflow (Voco)] foram usados como agentes adesivos sem e com vibração através de um aparelho ultrassônico (Mini Piezon, EMS, Switzerland). Uma resina composta, com diâmetro interno de 0,7 mm e peso de 1 mm, foi polimerizada no substrato. Os espécimes de µSBS foram submetidos a teste de microtração (Bisco, USA) em uma velocidade de 0.5 mm/min. Os valores de resistência adesiva foram analisados através de testes de ANOVA a um critério e de Tukey post hoc (p < 0.05). Resultados: A vibração não levou a nenhuma diferença significativa nos valores de µSBS entre Wave, Wave HV, e Grandio Flow (P=0.690, P=1.000 e P=0.947, respectivamente). Não foi encontrada nenhuma diferença significativa entre os compósitos fluidos quanto à resistência de união ao esmalte quando sob microcisalhamento (p >0.05). Conclusões: A aplicação de vibração ultrassônica pode não ser vantajosa para uma melhora na resistência adesiva de compósitos fluidos ao esmalte frente a cisalhamento. (AU)


Asunto(s)
Humanos , Vibración , Diente Premolar , Resinas Compuestas , Esmalte Dental
18.
Ned Tijdschr Tandheelkd ; 127(12): 671-676, 2020 Dec.
Artículo en Holandés | MEDLINE | ID: mdl-33367293

RESUMEN

In this article, the short- and long-term results of two types of functional appliances are discussed regarding their ability to stimulate the mandibular growth at mandibular retrognathia and reduce an increased overjet. Removable functional appliances, or activators, are compared to a fixed functional appliance, the Herbst appliance. The activator, often consisting of an acrylic base, is advised to be worn for 12 to 20 hours a day. The Herbst appliance consists of interconnected bands around the molar- and premolar bands, keeping the mandibula continuously positioned forward by means of hinges or telescopes. In the short-term, both appliances are effective in reducing the overjet, improving the molar-occlusion and reducing the mandibular retrognathia. The comparative literature is inconclusive as to which appliance is more effective on which level, skeletal or dentoalveolar. The removable appliances are more likely to be accepted at a younger age, whilst the fixed appliances are more suitable for the adolescents. The stability of the long-term treatment effects is minimally described in the existing literature. However, the highest stability rate seems to apply to the Herbst appliance. The impact of a widely applied second phase of treatment with fixed appliances, with possible use of intermaxillary class II elastics and retention using functional appliances is barely taken into account.


Asunto(s)
Maloclusión de Angle Clase II , Aparatos Ortodóncicos Funcionales , Adolescente , Diente Premolar , Cefalometría , Humanos , Mandíbula
19.
Ned Tijdschr Tandheelkd ; 127(12): 677-681, 2020 Dec.
Artículo en Holandés | MEDLINE | ID: mdl-33367294

RESUMEN

A healthy adult male patient presented himself, 11 days after a fixed orthodontic appliance was placed, with a sudden pink discoloration of the dental crown of tooth 21. The emergency dentist on call diagnosed the discoloration as non-painful peri-apical periodontitis, partly on the basis of a radiograph, and recommended endodontic treatment of tooth 21. Prior to endodontic treatment, the patient was first seen by the orthodontist who had initiated treatment. Tooth 21 was investigated and reacted normally to percussion and palpation but did not react to the cold test. The patient was referred to an endodontist who made the likely diagnosis: 'Transient apical breakdown'. No endodontic treatment was carried out and the orthodontic treatment was not interrupted. Six weeks after the discoloration appeared, visible recovery was evident.


Asunto(s)
Periodontitis Periapical , Decoloración de Dientes , Adulto , Diente Premolar , Humanos , Masculino , Decoloración de Dientes/diagnóstico , Decoloración de Dientes/etiología
20.
Angle Orthod ; 90(3): 457-466, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33378438

RESUMEN

Maxillary canine and first premolar transposition is a complicated dental anomaly to treat, especially if the clinician's goal is to orthodontically move the canine into its normal position. Early diagnosis with cone-beam computed tomography simplifies the treatment of this pathology. This case report describes a patient with bilateral transposition, one complete and the other incomplete, involving the maxillary canine and the first premolar (Mx.C.1P). The orthodontic treatment involved the correction of both transpositions. In the complete transposition, the traction was mesial and upward to move the canine into a more apical position with a wider dentoalveolar process for easier crown interchange.


Asunto(s)
Erupción Ectópica de Dientes , Diente Premolar/diagnóstico por imagen , Diente Premolar/cirugía , Tomografía Computarizada de Haz Cónico , Diente Canino/diagnóstico por imagen , Humanos , Maxilar/diagnóstico por imagen , Erupción Ectópica de Dientes/diagnóstico por imagen , Erupción Ectópica de Dientes/terapia
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