Assuntos
Fibroma Ossificante , Neoplasias Mandibulares , Dente Impactado , Humanos , Neoplasias Mandibulares/complicações , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Mandibulares/patologia , Fibroma Ossificante/diagnóstico , Fibroma Ossificante/complicações , Fibroma Ossificante/diagnóstico por imagem , Dente Impactado/diagnóstico por imagem , Dente Impactado/complicações , Dente Canino/diagnóstico por imagem , Masculino , Feminino , Radiografia Panorâmica , Mandíbula/diagnóstico por imagemRESUMO
OBJECTIVE: The demand for esthetics has increased in today's world and most parents prefer to preserve their children's primary anterior teeth until their natural exfoliation. However, an intracanal post is required to provide retention for reconstruction of severely damaged anterior teeth due to caries or trauma. Various materials and methods may be used for the fabrication of intracanal posts. This study assessed the fracture strength and fracture mode of primary canine teeth reconstructed with prefabricated and customized polyethylene and glass fiber posts. MATERIALS AND METHODS: This in vitro study evaluated 60 extracted primary canine teeth in four groups (n = 15). After pulpectomy and post space preparation with 4 mm depth, composite resin post, prefabricated glass fiber post (Whitepost), customized glass fiber post (Interlig), or customized polyethylene fiber post (Ribbond) were placed in the root canals to provide retention, and the tooth crown was restored with bulk-fill composite resin. The fracture strength was then measured in a universal testing machine. The fracture mode was also evaluated visually. RESULTS: The mean fracture strength was 22.45 ± 5.06, 33.10 ± 8.5, 30.20 ± 7.33, and 32.61 ± 5.73 N/mm2 in the composite resin post, Whitepost, Interlig, and Ribbond groups, respectively. The fracture strength was significantly lower in the composite group than in the remaining three groups (p = 0.000). No other significant differences were found (p > 0.05). Also, no significant difference was observed among the study groups in the fracture mode (p = 0.241). CONCLUSION: The composite resin post yielded a significantly lower fracture strength than the prefabricated and customized glass and polyethylene fiber posts, but the fracture mode was not significantly different among the four groups.
Assuntos
Resinas Compostas , Dente Canino , Análise do Estresse Dentário , Vidro , Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente Decíduo , Resinas Compostas/química , Fraturas dos Dentes/prevenção & controle , Vidro/química , Técnica para Retentor Intrarradicular/instrumentação , Humanos , Técnicas In Vitro , Planejamento de Prótese Dentária , Teste de Materiais , Materiais Dentários/química , Polietileno/química , Pulpectomia/métodos , Pulpectomia/instrumentação , PolietilenosRESUMO
BACKGROUND: Skin tones may be predictive of anterior tooth shade. An analysis of the relationship of skin tone to anterior tooth shade within a population may facilitate the prescription of complete dentures with optimal esthetics and realism. AIM: This study aimed to assess the relationship between skin tones and shades of upper anterior teeth among a diverse Nigerian adult population. METHODS: The study was conducted between February and December 2022 among consecutive healthy adults recruited from dental clinics of five teaching hospitals in four cities located across four geopolitical zones of Nigeria. Skin tones were recorded using the National Immigration Service (NIS) Skin Color scale. The Vitapan Classic® shade guide was used to record the tooth shade of the upper central incisors and canines. Bivariate and multivariate tests of associations were performed, and predictive probabilities were developed. RESULTS: A total of 1070 adults with a mean age of 30.8 ± 10 years participated in the study. NIS skin tones 6 (29.8%) and 5 (27.7%) were the most common, while hues A (48.7% in incisors and 48.4 % in canines) and B (41.1% in incisors and 40.1% in canines) were predominant. The values of the incisors and canines were positively related to skin tone (P = 0.001) and age (P = 0.001 for incisors and P = 0.003 for canines). Hue was also significantly associated with skin tone for canines (P = 0.01) and gender (P = 0.001). Regression models showed increasingly darker skin tones were positively related to duller values for incisor teeth (ß = 0.173, OR =1.19, P < 0.001). The values for canines were more likely to be >2 (ß = 0.118, OR =1.12, P = 0.01), but without significant positive relationship to increasingly darker skin tones (ß = -0.99, OR =0.91, P = 0.22). CONCLUSION: Skin tones were associated with upper anterior tooth shade. There was a positive relationship between skin tones and the shades of upper anterior teeth. Skin tones could guide the clinician in shade selection during complete denture prescriptions.
Assuntos
Incisivo , Pigmentação da Pele , Humanos , Masculino , Feminino , Adulto , Nigéria , Incisivo/anatomia & histologia , Pigmentação da Pele/fisiologia , Adulto Jovem , Pessoa de Meia-Idade , Dente Canino/anatomia & histologia , Cor , Estudos TransversaisRESUMO
Background A thorough knowledge of the root and canal morphology and their possible variations are essential for successful endodontic treatment. Methods like staining and clearing techniques, cross sectional method can provide precise information on root canal systems, however, these methods are invasive. Cone-beam computed tomography (CBCT) is the 3-dimensional scans of the maxillofacial skeleton that best visualizes canal morphology and helps in identifying additional canals and roots in vivo. Objective To investigate the root canal configuration of mandibular anterior teeth using Conebeam computed tomography. Method A total of 2910 CBCT images, comprising 970 central incisors, lateral incisors, and canines each from 485 patients were assessed. The following assessments were made: (1) The number of roots and root canals (2) Canal configuration according to Vertucci's classification (3) Bilateral occurrences for variations. Also, the gender and age of patients were noted. Result The study revealed mandibular anterior teeth predominantly had 1 root with Type I (79.79%, 77.11%, 91.34%) canal configuration followed by type III (20.2%, 22.67%, 5.15%) in central, lateral and canine respectively. Almost 90% incisors had symmetry in the canal configurations. No statistical correlation was found between the gender and root canal configurations. Type III canal configurations in canines were present more in elder age group. Conclusion Clinicians must be aware that each tooth may display a different number of roots and types of canal configurations. During endodontic treatment, presuming lower anterior teeth with single root and single canal may lead to missed canals and consequently, treatment failure.
Assuntos
Tomografia Computadorizada de Feixe Cônico , Mandíbula , Humanos , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Masculino , Adulto , Mandíbula/diagnóstico por imagem , Mandíbula/anatomia & histologia , Incisivo/diagnóstico por imagem , Incisivo/anatomia & histologia , Pessoa de Meia-Idade , Adolescente , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/anatomia & histologia , Dente Canino/diagnóstico por imagem , Dente Canino/anatomia & histologia , Idoso , Imageamento TridimensionalRESUMO
Objectives: To analyse and document internal root morphological variations in permanent anterior teeth using conebeam computed tomography. METHODS: The cross-sectional, retrospective study was conducted from January 21 to June 19, 2021, at Jinnah Magnetic Resonance Imaging and Body Scan, and comprised data from July to December 2020 related to all the patients who had been referred to the centre for dental cone-beam computed tomography scan. The scans were evaluated at the Radiology Department of the School of Dentistry at Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan. The morphology of the roots and root canals in all permanent anterior teeth was examined. Root canal configuration was categorised using Vertucci's classification. Data was analysed using SPSS 20. RESULTS: Of the 211 patients, 116(55%) were females and 95(45%) were males. The overall mean age was 39.9±1.02 years (range: 15-65 years). All the permanent anterior teeth exhibited a single root, with the exception 2(0.9%) mandibular right and 4(1.9%) left canines which had double roots. Type I root canals were observed in all 211 (100%) maxillary right central incisors, maxillary left central incisors and maxillary left canines. Among maxillary right canines, 208(98.6%) had type-I root canals, and the corresponding value for maxillary right lateral incisors was 209(99.1%), and for maxillary left lateral incisors, the value was 210(99.5%). Root canal polymorphism had no significant association with gender (p>0.05). CONCLUSIONS: The presence of type-I root canal was common in permanent anterior teeth, and there was significant association of root canal polymorphism with gender.
Assuntos
Tomografia Computadorizada de Feixe Cônico , Cavidade Pulpar , Humanos , Masculino , Feminino , Tomografia Computadorizada de Feixe Cônico/métodos , Estudos Transversais , Paquistão , Adulto , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/anatomia & histologia , Estudos Retrospectivos , Idoso , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/anatomia & histologia , Incisivo/diagnóstico por imagem , Incisivo/anatomia & histologia , Dente Canino/diagnóstico por imagem , Dente Canino/anatomia & histologia , Dentição PermanenteRESUMO
OBJECTIVES: To detect any association between palatally displaced canine (PDC) and nasal septal deviation (NSD), palatal bone thickness and volume, and nasal airway dimensions and volume. MATERIALS AND METHODS: A total of 92 patients were included and subdivided into two groups: group 1, unilateral PDCs (44 patients), and group 2, normally erupted canines (NDCs) (48 subjects). The following variables were measured using cone-beam computed tomography: presence and type of NSD, nasal width, inferior conchae, hard palate and nasal septum thickness, maxillary bone and nasal airway volumes. RESULTS: NSD was detected in 77% and 50% of PDC and NDC subjects, respectively. Within the PDC subjects, significant differences between the displaced and nondisplaced sides were detected. Palate thickness was increased in the canine region and reduced in the molar region. Compared with the control group, PDC subjects had reduced palate thickness and lower nasal airway volume. Two predictors were significant for predicting the odds of PDC occurrence: NSD and maxillary bone volume. CONCLUSIONS: NSD is more frequent in PDC subjects. PDC subjects have reduced palate thickness and decreased nasal airway volume. In the presence of NSD, the odds of developing PDC increase by 3.35 times, and for each one-unit increase in the maxillary bone volume, the odds of developing PDC decrease by 20%.
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Tomografia Computadorizada de Feixe Cônico , Dente Canino , Maxila , Septo Nasal , Humanos , Tomografia Computadorizada de Feixe Cônico/métodos , Estudos Retrospectivos , Masculino , Feminino , Septo Nasal/diagnóstico por imagem , Dente Canino/diagnóstico por imagem , Adolescente , Maxila/diagnóstico por imagem , Criança , Palato Duro/diagnóstico por imagem , Erupção Ectópica de Dente/diagnóstico por imagem , Cavidade Nasal/diagnóstico por imagem , Cavidade Nasal/anatomia & histologia , Adulto JovemRESUMO
OBJECTIVES: To determine the prevalence of root resorption of teeth adjacent to permanent maxillary canines on both sides, by cone-beam computed tomography (CBCT), in pretreatment adolescent subjects with unilaterally impacted maxillary canines, and to define predictive factors for the root resorption. MATERIALS AND METHODS: This retrospective sample included 76 adolescents (38 boys, 38 girls, mean age 12.3 ± 2.1 years; range 8-17 years) who had CBCT after detection of a unilateral impacted maxillary canine before any active orthodontic treatment. Both ipsilateral and contralateral sides were examined, and 14 qualitative and quantitative variables were collected. Descriptive statistics were calculated, and multiple logistic regression was used to predict root resorption. RESULTS: On the impaction side, 57.9% of canines resorbed at least one adjacent tooth compared with 13.2% on the contralateral side (P < .001). On the impaction side, resorption was slight in 59.6%, moderate in 5.8%, and severe in 34.6% of the cases. On the contralateral side, resorption was slight in 91.7%, moderate in 0%, and severe in 8.3% of the cases. On both sides, upper lateral incisors were the teeth most frequently resorbed, followed by the upper first premolars and upper central incisors. The presence of contact between the canine and the adjacent roots was the only statistically significant risk factor for resorption for both ipsilateral and contralateral sides. CONCLUSIONS: Orthodontists should look for root resorption on both sides in cases of unilaterally impacted maxillary canines.
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Tomografia Computadorizada de Feixe Cônico , Dente Canino , Maxila , Reabsorção da Raiz , Dente Impactado , Humanos , Adolescente , Feminino , Dente Impactado/diagnóstico por imagem , Masculino , Dente Canino/diagnóstico por imagem , Criança , Tomografia Computadorizada de Feixe Cônico/métodos , Estudos Retrospectivos , Reabsorção da Raiz/etiologia , Reabsorção da Raiz/diagnóstico por imagem , Maxila/diagnóstico por imagem , Erupção DentáriaRESUMO
INTRODUCTION: Symmetry is balance, some correspondence in the size, form, and arrangements of parts on opposite sides of a plane, line, or point. The opposite of this concept is asymmetry, or imbalance. OBJECTIVE: This retrospective study compared two methods for assessing arch symmetry with linear measurements based on triangles, to determine their applicability and efficiency. METHODS: Two groups were enrolled: children (n=20) and adults (n=20), and the arch symmetry was assessed from linear measurements. Method 1: the incisor-canine (INC), canine-molar (CM), and incisor-molar (INM) distances (paired t-test and Pearson correlation). Method 2: a mathematical equation between the cusps measurements of the canines and the distobuccal of the first molars leading to result 1 (t-test for one sample and bootstrapping analysis). Dental casts were digitized and analyzed using a software program. The Bland-Altman test compared the methods (α=0.05). RESULTS: The Bland-Altman test revealed concordance between the methods; however, separately the results were different: In method 1, the mandibular arch did not demonstrate correlation (children, INC r=0.33; CM r=0.45; INM r=0.51; adults, CM r=0.46; INM r=0.35), however, the maxilla revealed a strong correlation in children and a strong/moderate correlation in adults. In method 2, both arches were symmetrical (p>0.05). CONCLUSION: Method 1 may be appropriate during orthodontic treatment, and method 2 may be indicated for final treatment. These methods are useful; however, only method 1 identified the side of asymmetry. The methods can contribute to future studies in syndromic and non-syndromic patients, before and after orthognathic surgeries and orthodontic treatment, comparing results.
Assuntos
Dente Canino , Arco Dental , Incisivo , Dente Molar , Humanos , Arco Dental/anatomia & histologia , Estudos Retrospectivos , Criança , Adulto , Dente Canino/anatomia & histologia , Dente Canino/diagnóstico por imagem , Feminino , Dente Molar/anatomia & histologia , Incisivo/anatomia & histologia , Masculino , Modelos Dentários , Mandíbula/anatomia & histologia , Maxila/anatomia & histologia , Cefalometria/métodos , Adolescente , Adulto JovemRESUMO
OBJECTIVE: This study aimed to assess root volumes of maxillary canines and adjacent lateral incisors in patients with unilateral maxillary canine impaction. METHODS: This cross-sectional study was performed on cone-beam computed tomography (CBCT) scans of 100 patients (49 females and 51 males) with unilateral maxillary canine impaction. The images were loaded in Planmeca Romexis Viewer, and root layers between the cementoenamel junction and apex were reconstructed at 600-µm intervals. At each layer, the root boundary was marked, and finally, the root volume was calculated by multiplying the layers' area by the thickness of 600 µm. The root size of canines and lateral incisors was compared between the impaction and normal eruption sides. RESULTS: Sixty-two patients showed buccal canine impaction, and 38 presented palatal impaction. The mean root volume of canines on the impaction side was significantly greater than that on the normal eruption side; either the tooth was buccally or palatally impacted (p<0.001). The lateral incisors on the side of buccally-impacted canines showed a significantly smaller root volume than that of the contralateral side (p<0.001). However, there was no significant difference in the root size of lateral incisors between the two sides in cases presenting palatal canine impaction (p=0.177). CONCLUSION: The difference in root volume of canines between the two sides can serve as an indicator of canine impaction. The reduction in the root size of the lateral incisor on the side of the buccally impacted canine may be due to root resorption created by pressure from the canine's crown.
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Tomografia Computadorizada de Feixe Cônico , Dente Canino , Incisivo , Maxila , Raiz Dentária , Dente Impactado , Humanos , Dente Impactado/diagnóstico por imagem , Masculino , Dente Canino/diagnóstico por imagem , Feminino , Incisivo/diagnóstico por imagem , Estudos Transversais , Maxila/diagnóstico por imagem , Raiz Dentária/diagnóstico por imagem , Adolescente , Adulto Jovem , Adulto , CriançaAssuntos
Dente Canino , Cimentos de Ionômeros de Vidro , Dente Impactado , Humanos , Dente Impactado/terapia , Dente Impactado/diagnóstico por imagem , Dente Canino/diagnóstico por imagem , Dente Canino/patologia , Feminino , Extrusão Ortodôntica/instrumentação , Extrusão Ortodôntica/métodos , Adolescente , Criança , MasculinoRESUMO
BACKGROUND: This study assessed the internal morphology of maxillary canines (MxC) through a systematic review of existing literature. METHODS: Research articles up to June 2024 were retrieved from five electronic databases (MEDLINE via PubMed, Embase, Scopus, LILACS, and Cochrane). Predefined search terms and keywords were used, and potential studies were identified by cross-referencing and bibliographies of the selected articles reviewed. RESULTS: Two hundred studies were identified, 73 duplicates were removed, 127 records were screened, and 113 were removed after consultation of title and abstract. After full-text consultation and hand searching, finally 22 studies were included. Using the method for describing the root canal configuration (RCC) of Briseño Marroquín et al. (2015) and Vertucci (Ve) (1984), the most frequently reported RCC of MxC were 1-1-1/1 (Ve I, 75.4-100%), 2-2-1/1 (Ve II, 0.1-20%), 1-2-1/1 (Ve III, 0.1-11.6%), 2-2-2/2 (Ve IV, 0.1-0.4%), 1-1-2/2 (Ve V, 0.1-2.4%), 2-1-2/2 (Ve VI, 0.5-1.2%), and 1-2-1/2 (Ve VII, 0.1-0.2%). The meta-analysis of six studies (Europe/Asia) showed that a significantly higher number of RCC of 2-2-1/1 (Ve II) (OR [95%CI] = 1.34 [0.53, 3.41]), 1-2-1/1 (Ve III) (OR [95%CI] = 2.07 [1.01, 4.26]), and 1-1-2/2 (Ve V) (OR [95%CI] = 2.93 [1.07, 8.07]), were observed in males, and 2-2-2/2 (Ve IV) (OR [95%CI] = 0.08 [0.00, 4.00]) in females. No sex differences in the RCC of 1-1-1/1 (Ve I) and 1-2-1/2 (Ve VII) were observed. CONCLUSIONS: Cone beam computed tomography is the most frequently used method for research on the RCC of MxC. Despite the high prevalence of type 1-1-1/1 (Ve I) RCC in MxC, clinicians should remain vigilant for more complex and sex-differentiated patterns in up to 25% of cases to prevent endodontic treatment complications or failures.
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Dente Canino , Cavidade Pulpar , Maxila , Humanos , Dente Canino/anatomia & histologia , Dente Canino/diagnóstico por imagem , Maxila/anatomia & histologia , Cavidade Pulpar/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagemRESUMO
INTRODUCTION: Variation in the thickness of commercially available preformed rectangular archwires at the bracket positions has not been thoroughly studied. Therefore, this study measured the edgewise (height) and flatwise (width) dimensions of preformed rectangular nickel-titanium (NiTi) archwires at bracket positions corresponding to the central incisor, canine, and first molar and compared them among bracket positions. METHODS: Sixty types of preformed rectangular NiTi mandibular archwires indicated as 0.019 × 0.025-in were obtained from 14 manufacturers. The height and width dimensions of archwires were measured at 4 points (3 bracket positions corresponding to the central incisor, canine, and first molar, and 1 terminal end) of each side of each archwire using a micrometer and compared with the indicated dimensions using 1-sample t tests. Furthermore, the measured dimensions were compared among the 3 bracket positions using a 1-way analysis of variance and Bonferroni post-hoc test. RESULTS: The measured dimensions were significantly smaller than the indicated dimensions for all points except the central incisor point for height and significantly smaller than the indicated dimensions for all points for width. Comparisons among points showed that for height, the central incisor point was significantly larger than the first molar and terminal points. However, no significant differences were found for width at any point. CONCLUSIONS: The measured dimensions of preformed NiTi archwires at the bracket positions were generally smaller than the indicated dimensions, with variations observed not only among products but also among manufacturers.
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Incisivo , Dente Molar , Níquel , Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Fios Ortodônticos , Titânio , Incisivo/anatomia & histologia , Humanos , Dente Canino/anatomia & histologia , Ligas DentáriasRESUMO
BACKGROUND: The aim of this study was to assess factors associated with higher odds of undergoing repeat general anesthesia (GA2) for dental treatments. METHODS: The authors studied children up to age 48 months of age enrolled in Medicaid who underwent dental treatment under first general anesthesia (GA1). The authors used a case-control design to compare children who had a GA2 within 48 months of GA1 (case patients) with those who did not (control patients). RESULTS: In total, 60 case patients were age and sex matched to 120 control patients. Mean (SD) age at GA1 was 38 (5.2) months for case participants and 40 (4.7) months for control participants (P = .08). Higher caries involvement of maxillary incisors (P = .04), and lower caries involvment of canines (P = .003), first molars (P = .012), and second molars (P < .001) at GA1 was associated with higher odds of occurrence of GA2. There was a significant inverse association between full-coverage restoration on canines (P = .003), first molars (P = .001), and second molars (P = .002) at GA1 and occurrence of GA2. There was a significant direct association between the use of composites or sealants on second molars in GA1 and occurrence of GA2 (P = .02). The number of extractions at GA1 was not associated significantly with the occurrence of GA2. CONCLUSIONS: The use of full-coverage restorations on primary molars and canines under general anesthesia (GA) was associated with lower odds of occurrence of GA2. Resin restorations and sealants on primary second molars were associated with higher odds of occurrence repeat GA. The findings support preferential use of full-coverage restorations for young children undergoing dental GA. PRACTICAL IMPLICATIONS: Full-coverage restorations should be considered strongly for young children undergoing GA for dental treatments to reduce the risk of requiring GA2.
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Anestesia Dentária , Anestesia Geral , Cárie Dentária , Restauração Dentária Permanente , Humanos , Estudos de Casos e Controles , Anestesia Geral/estatística & dados numéricos , Masculino , Feminino , Pré-Escolar , Restauração Dentária Permanente/métodos , Restauração Dentária Permanente/estatística & dados numéricos , Anestesia Dentária/métodos , Lactente , Dente Decíduo , Dente Molar , Dente Canino , Estados Unidos , Medicaid , Incisivo , Assistência Odontológica para Crianças/métodos , Fatores de Risco , Resinas Compostas/uso terapêuticoRESUMO
OBJECTIVES: Canine-induced root resorption (CIRR) is caused by impacted canines and CBCT images have shown to be more accurate in diagnosing CIRR than panoramic and periapical radiographs with the reported AUCs being 0.95, 0.49, and 0.57, respectively. The aim of this study was to use deep learning to automatically evaluate the diagnosis of CIRR in maxillary incisors using CBCT images. METHODS: A total of 50 cone beam computed tomography (CBCT) images and 176 incisors were selected for the present study. The maxillary incisors were manually segmented and labeled from the CBCT images by two independent radiologists as either healthy or affected by root resorption induced by the impacted canines. We used five different strategies for training the model: (A) classification using 3D ResNet50 (Baseline), (B) classification of the segmented masks using the outcome of a 3D U-Net pretrained on the 3D MNIST, (C) training a 3D U-Net for the segmentation task and use its outputs for classification, (D) pretraining a 3D U-Net for the segmentation and transfer of the model, and (E) pretraining a 3D U-Net for the segmentation and fine-tuning the model with only the model encoder. The segmentation models were evaluated using the mean intersection over union (mIoU) and Dice coefficient (DSC). The classification models were evaluated in terms of classification accuracy, precision, recall, and F1 score. RESULTS: The segmentation model achieved a mean intersection over union (mIoU) of 0.641 and a DSC of 0.901, indicating good performance in segmenting the tooth structures from the CBCT images. For the main classification task of detecting CIRR, Model C (classification of the segmented masks using 3D ResNet) and Model E (pretraining on segmentation followed by fine-tuning for classification) performed the best, both achieving 82% classification accuracy and 0.62 F1-scores on the test set. These results demonstrate the effectiveness of the proposed hierarchical, data-efficient deep learning approaches in improving the accuracy of automated CIRR diagnosis from limited CBCT data compared to the 3D ResNet baseline model. CONCLUSION: The proposed approaches are effective at improving the accuracy of classification tasks and are helpful when the diagnosis is based on the volume and boundaries of an object. While the study demonstrated promising results, future studies with larger sample size are required to validate the effectiveness of the proposed method in enhancing the medical image classification tasks.
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Tomografia Computadorizada de Feixe Cônico , Dente Canino , Aprendizado Profundo , Reabsorção da Raiz , Dente Impactado , Tomografia Computadorizada de Feixe Cônico/métodos , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/classificação , Humanos , Dente Impactado/diagnóstico por imagem , Dente Canino/diagnóstico por imagem , Incisivo/diagnóstico por imagemRESUMO
BACKGROUND: Posttreatment changes after orthodontic treatment are challenging. One of the main reasons for such a phenomenon is the lack of patient compliance with removable retainers especially in the maxillary arch, due to palatal coverage, deterioration of speech, decreased masticatory efficiency, and loss of retainers. Fixed retainers have been introduced to overcome patient compliance and provide longer stable results. However, teeth still show movements when a six-unit fixed retainer is in place. Thus, in this study, an eight-unit fixed retainer was evaluated in an attempt to eliminate unwanted movements. THE AIM OF THIS RESEARCH: was to assess short-term positional changes associated with an eight-unit extended maxillary fixed retainer. MATERIALS AND METHODS: A single-arm clinical trial was conducted to address the aim of the study. This research was approved by the institutional review board of the Faculty of Dentistry, Alexandria University (IORG:0008839, No-0479-8/2022). The registration date of this study was 5/06/2023. Twenty-eight patients (19.8 ± 4.5 years) who had finished the active orthodontic phase and started retention had an eight-unit extended maxillary fixed retainer that was bonded to the palatal surface of the maxillary incisors, canines, and the first premolars or the second premolars. Pre-retention and one-year post-retention intra-oral scans were made to produce STL files that were superimposed to determine the amount of tooth change. Additionally, analysis of digital casts and lateral cephalometric radiographs was performed. RESULTS: Statistically significant changes in all planes and the rotation of teeth after one year of retention were found. The upper right lateral incisor exhibited the most evident change in the vertical plane, while the upper right central incisor exhibited the greatest change overall. Minimal changes in the cast measurements were observed. Lateral cephalometric measurements showed minimal changes after one year of retention, and these changes were not statistically significant except in the interincisal angle and the angle between the upper incisor and the line connecting the A-point to the pogonion. CONCLUSION: Increasing the extension of maxillary fixed retainers did not eliminate unwanted tooth movement in the first year of retention.
Assuntos
Maxila , Desenho de Aparelho Ortodôntico , Contenções Ortodônticas , Técnicas de Movimentação Dentária , Humanos , Maxila/diagnóstico por imagem , Feminino , Adulto Jovem , Masculino , Técnicas de Movimentação Dentária/métodos , Técnicas de Movimentação Dentária/instrumentação , Incisivo/diagnóstico por imagem , Imageamento Tridimensional/métodos , Adolescente , Cefalometria , Dente Canino/diagnóstico por imagem , AdultoRESUMO
BACKGROUND: This 20-year retrospective study aimed to evaluate the treatment methods used in patients with impacted maxillary permanent canines and to determine the occurrence of ankylotic and resorptive processes and their association with potential risk factors. METHODS: The cohort consisted of 351 consecutive Caucasian patients (120 males and 231 females, mean age 18.4 and 19.9 years, respectively) with 420 impacted maxillary permanent canines. CT and CBCT findings were subsequently confirmed during surgery. Statistical analyses were performed by the generalized linear models, Pearson x2 and Fisher exact tests using the statistical programs R and Statistica v. 14. RESULTS: A total of 273 (65.0%) impacted canines were aligned in the dental arch by orthodontic traction after surgical exposure, this treatment was predominant in patients under 20 years of age. Surgical extraction was performed in 115 (27.2%) impacted canines and was more common in older patients. Ankylotic changes were recorded in 61 (14.5%) impacted canines. The probability of ankylosis increased with age, particularly after the patient's 20th year of life (p < 0.001). Patients were 1.2% likely to develop ankylosis at age 15 years, 4.3% at age 20 years, 14.1% at age 25 years, and 96.8% at age 45 years. Invasive cervical root resorption (ICRR) was found in 8 (1.9%) canines. In 4 canines (1.0%), root ankylosis in addition to ICRR was observed. In contrast to ankylosis, whose frequency of occurrence increased with age, the occurrence of ICRR resulting from PDL damage during surgery was more typical in younger patients. Canines in a high position above the root apices of the adjacent teeth, with a horizontal inclination of the longitudinal axis, with the crown located deep in the center of the alveolar bone and with labiopalatal position, should be considered critically impacted canines with a high risk to failure of orthodontic traction. CONCLUSION: In conclusion, the treatment of impacted canines depends mainly on the age of the patient, and the position and inclination of the longitudinal axis of the impacted tooth. To select an adequate treatment method, we recommend CBCT examination, which allows a precise analysis of the position of impacted canines.
Assuntos
Tomografia Computadorizada de Feixe Cônico , Dente Canino , Maxila , Anquilose Dental , Dente Impactado , Humanos , Dente Impactado/cirurgia , Dente Impactado/diagnóstico por imagem , Dente Canino/diagnóstico por imagem , Estudos Retrospectivos , Masculino , Feminino , Adolescente , Anquilose Dental/diagnóstico por imagem , Adulto Jovem , Maxila/cirurgia , Fatores Etários , Criança , Adulto , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/etiologia , Extração Dentária , Fatores de Risco , Tomografia Computadorizada por Raios X , Extrusão Ortodôntica/métodos , Estudos de CoortesRESUMO
PURPOSE: This study aimed to measure and analyze the transverse indicators of normodivergent patients with different sagittal skeletal malocclusions, to explore the transverse characteristics of different sagittal skeletal malocclusions. METHODS: Lateral cephalograms and CBCT of 90 normodivergent patients with skeletal Class â , â ¡ and â ¢ in their permanent dentition were collected. Dolphin software was applied to measure the widths of the basal bone, alveolar bone, dental arch and buccolingual inclination angle of the corresponding teeth in the maxillary and mandibular canine, premolar and molar areas. SPSS 22.0 software package was applied for statistical analysis of the data. RESULTS: The widths of the mandibular basal bone in canine, premolar and molar areas of skeletal Class â ¢ were (27.15±2.74), (39.30±2.82) and (59.97±2.93) mm, respectively. The widths of the mandibular alveolar bone of skeletal Class â ¢ were (25.38±1.78), (34.51±2.28) and (47.72±2.73) mm, respectively. The dental arch widths of the maxillary premolar and mandibular canine areas of skeletal Class â ¢ were (48.70±2.35) and (30.69±2.31)mm, respectively. The above data of skeletal Class â ¢ were significantly larger than those of skeletal Class â and â ¡(Pï¼0.01). The dental arch widths of the maxillary canine, maxillary molar and mandibular molar areas of skeletal Class â ¢ were (38.88±1.90), (59.51±3.40) and (56.01±2.86)mm, respectively, which were significantly larger than those of skeletal Class â ¡(Pï¼0.05). The maxillomandibular width difference of basal bone in the canine, premolar and molar areas of skeletal Class â ¢ were (4.69±2.84), (2.31±2.39) and (3.27±2.05) mm, respectively, which were significantly less than that of skeletal Class â and â ¡(Pï¼0.01). Compared with skeletal Class â , the maxillary canines and first molars of skeletal Class â ¡ had larger lingual inclination level, while the maxillary first premolars and first molars of skeletal Class â ¢ had larger buccal inclination level, the mandibular canines and the mandibular first premolars of skeletal Class â ¢ had larger lingual inclination level(Pï¼0.01). CONCLUSIONS: For normodivergent patients, the width of the mandibular base bone, alveolar bone, and maxillary and mandibular dental arch in skeletal Class â ¢ is the widest, which is more likely to have width discrepancy in basal bone. In skeletal Class â ¢, the maxillary teeth are buccally inclined, and the mandibular teeth are ingually inclined. In skeletal Class â ¡, the maxillary teeth are lingually inclined, and the mandibular teeth are compensatory upright.
Assuntos
Cefalometria , Arco Dental , Mandíbula , Maxila , Humanos , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Cefalometria/métodos , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Arco Dental/anatomia & histologia , Má Oclusão/patologia , Tomografia Computadorizada de Feixe Cônico/métodos , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Dente Canino/anatomia & histologia , Dente Canino/diagnóstico por imagem , Dente Pré-Molar/anatomia & histologia , Dente Pré-Molar/diagnóstico por imagem , Má Oclusão Classe III de Angle , Processo Alveolar/anatomia & histologia , Processo Alveolar/diagnóstico por imagem , Dentição PermanenteRESUMO
Purpose: Although gingival thickness has been extensively studied in permanent dentition, the literature regarding marginal gingival thickness in primary dentition is insufficient. The purpose of this study was to assess the variations in marginal gingival thickness in preschool-age children. Methods: A cross-sectional study of 4,109 primary teeth was conducted. Using a reamer, the transgingival probing method was employed to assess marginal gingival thickness in healthy preschoolers. Inter-examiner and intra-examiner reproducibility were assessed via the intraclass correlation coefficient. Results: Descriptive statistics revealed that primary maxillary left second molars had the highest mean marginal gingival thickness (1.06 mm), whereas primary mandibular right central incisors had the lowest mean marginal gingival thickness (0.74 mm). Gender-based independent sample t-tests revealed significant differences in the values of primary maxillary right canines (females had greater values than males; P=0.03) and primary mandibular right first molars (males had greater values than females; P=0.01). An inter-arch comparison revealed significant differences between the primary second molars (maxillary more than mandibular; P=0.001). Conclusions: This study reports the first documented marginal gingival thicknesses of primary dentition. It reveals substantial variations in the values of primary maxillary right canines and primary mandibular right first molars and between primary maxillary and mandibular second molars.
Assuntos
Gengiva , Dente Decíduo , Humanos , Estudos Transversais , Feminino , Pré-Escolar , Masculino , Gengiva/anatomia & histologia , Gengiva/diagnóstico por imagem , Dente Decíduo/anatomia & histologia , Dente Decíduo/diagnóstico por imagem , Criança , Dente Canino/anatomia & histologia , Dente Canino/diagnóstico por imagem , Reprodutibilidade dos Testes , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Incisivo/anatomia & histologia , Incisivo/diagnóstico por imagem , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagemRESUMO
AIM: The objective of the present study was to investigate the association between the anatomical characteristics of different tooth groups and the diffusion and bleaching effect of hydrogen peroxide (H2O2). MATERIALS AND METHODS: Computed tomography (CT) images from five patients were used to assess the hard tissue thickness and pulp volume (PV) of four tooth groups: lower (mandibular) incisors (LI), upper (maxillary) incisors (UI), canines (C), and premolars (PM). Additionally, 80 bovine tooth disks were divided into four groups (n = 20) to match the thickness of each tooth group studied. All the specimens were exposed to a 35% H2O2 bleaching gel, with 50 µL applied for 45 min during the first, second, and third sessions. Diffusion was evaluated using the peroxidase enzyme method. Color change analyses (∆E, ∆E00, and ∆WID) were performed after the three application sessions and 7 days after the bleaching treatment using a spectrophotometer. RESULTS: The PM group showed greater thickness and PV, followed by the C, UI, and LI groups (P 0.001). The LI group had six times greater H2O2 diffusion compared with the PM group (P 0.001), while the PM group exhibited a PV nine times larger than the LI group. Furthermore, the LI and UI groups achieved color saturation with one fewer session than the C and PM groups. CONCLUSIONS: Specific tooth groups have anatomical characteristics that interfere with bleaching treatment in terms of the diffusion and whitening effect of H2O2. Furthermore, the diffusion capacity of H2O2 was inversely proportional to the thickness of the tooth groups.