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1.
Int J Oral Sci ; 15(1): 5, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36604408

RESUMO

Tooth number abnormality is one of the most common dental developmental diseases, which includes both tooth agenesis and supernumerary teeth. Tooth development is regulated by numerous developmental signals, such as the well-known Wnt, BMP, FGF, Shh and Eda pathways, which mediate the ongoing complex interactions between epithelium and mesenchyme. Abnormal expression of these crutial signalling during this process may eventually lead to the development of anomalies in tooth number; however, the underlying mechanisms remain elusive. In this review, we summarized the major process of tooth development, the latest progress of mechanism studies and newly reported clinical investigations of tooth number abnormality. In addition, potential treatment approaches for tooth number abnormality based on developmental biology are also discussed. This review not only provides a reference for the diagnosis and treatment of tooth number abnormality in clinical practice but also facilitates the translation of basic research to the clinical application.


Assuntos
Dente , Regulação da Expressão Gênica no Desenvolvimento , Odontogênese , Transdução de Sinais , Dente/metabolismo , Humanos
2.
Sci Rep ; 13(1): 384, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36611118

RESUMO

A finite element method (FEM) is presented to conduct loaded tooth contact analysis and strength calculations of involute spline couplings. Special FEM software has been developed. Contact, bending and shear stresses of the spline couplings are analyzed by the developed software and they are compared with results obtained by an approximation method. It is found that "Edge loads" exist at tooth tip and root contacts and also exist at two sides of the face width when the pair of teeth has different face widths. Effects of tooth profile deviations and pitch errors on tooth contacts are also investigated by the developed software respectively. It is found that tooth contact and stresses are affected by the tooth profile deviations and pitch errors greatly. Finally, reliability of the presented method and software are discussed.


Assuntos
Dente , Reprodutibilidade dos Testes , Análise de Elementos Finitos , Software , Estresse Mecânico
3.
Evol Dev ; 25(1): 54-72, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36594351

RESUMO

Vertebrate skin appendages are incredibly diverse. This diversity, which includes structures such as scales, feathers, and hair, likely evolved from a shared anatomical placode, suggesting broad conservation of the early development of these organs. Some of the earliest known skin appendages are dentine and enamel-rich tooth-like structures, collectively known as odontodes. These appendages evolved over 450 million years ago. Elasmobranchs (sharks, skates, and rays) have retained these ancient skin appendages in the form of both dermal denticles (scales) and oral teeth. Despite our knowledge of denticle function in adult sharks, our understanding of their development and morphogenesis is less advanced. Even though denticles in sharks appear structurally similar to oral teeth, there has been limited data directly comparing the molecular development of these distinct elements. Here, we chart the development of denticles in the embryonic small-spotted catshark (Scyliorhinus canicula) and characterize the expression of conserved genes known to mediate dental development. We find that shark denticle development shares a vast gene expression signature with developing teeth. However, denticles have restricted regenerative potential, as they lack a sox2+ stem cell niche associated with the maintenance of a dental lamina, an essential requirement for continuous tooth replacement. We compare developing denticles to other skin appendages, including both sensory skin appendages and avian feathers. This reveals that denticles are not only tooth-like in structure, but that they also share an ancient developmental gene set that is likely common to all epidermal appendages.


Assuntos
Calcificações da Polpa Dentária , Tubarões , Dente , Animais , Vertebrados , Odontogênese
4.
Evolution ; 77(1): 83-96, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36689235

RESUMO

Identifying the drivers of adaptation is key to understanding the origin and evolution of diversity. Here we study the morphological evolution of tooth morphology, a classic example of a conserved structure, to gain insights into the conditions that can overcome resistance to evolutionary change. We use geometric morphometrics of the occlusal surface outline of the fourth lower premolar (p4) of squirrels, a paradigm of a stable tooth morphology, to explore morphological adaptations to diet. Although a versatile generalist dental morphology favors the retention of the ancestral shape, the acquisition of diets that require strong mechanical processing drives morphological change. In particular, species that eat both grass and dry fruits evolved disparate tooth shape morphologies, related to trade-offs between feeding performance that lead to a more or less pronounced change depending on the proportion of those items in their diet. Also, some folivores develop relatively large p4s, and most bark gleaners have relatively small p4s. Ultimately, despite the role of diet shaping these patterns, we showed that diet is not the only factor driving the evolution of tooth morphology.


Assuntos
Sciuridae , Dente , Animais , Sciuridae/anatomia & histologia , Dente/anatomia & histologia , Dieta , Adaptação Fisiológica , Evolução Biológica , Filogenia
5.
J Indian Prosthodont Soc ; 23(1): 99-102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36588383

RESUMO

The importance of a judicious and unerring abutment tooth preparation in the field of prosthodontics has always been paramount. It is not uncommon for many clinicians to face challenges during laboratory fabrication of fixed prostheses, caused due to inappropriate occlusal clearance and over axial wall taper of the abutment tooth. With evolving technologies and methods, the modus operandi for attaining such tooth preparation is varying; however, every technique has its own shortcomings. The technique mentioned in the article is cost-effective as it uses modified Heister mouth gag forceps to achieve the desired objective of evaluating the prepared abutment morphology three-dimensionally with minimum chairside time.


Assuntos
Preparo do Dente , Dente , Prostodontia , Dente/cirurgia , Dente Suporte , Oclusão Dentária
6.
Nutrients ; 15(2)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36678235

RESUMO

Nutritional factors reflect the periodontal parameters accompanying periodontal status. In this study, the associations between nutritional factors, blood biochemical items, and clinical parameters were examined in patients with systemic diseases. The study participants were 94 patients with heart disease, dyslipidemia, kidney disease, or diabetes mellitus. Weak negative correlation coefficients were found between nine clinical parameters and ten nutritional factors. Stage, grade, mean probing depth (PD), rate of PD 4-5 mm, rate of PD ≥ 6 mm, mean clinical attachment level (CAL), and the bleeding on probing (BOP) rate were weakly correlated with various nutritional factors. The clinical parameters with coefficients of determinations (R2) > 0.1 were grade, number of teeth, PD, rate of PD 4-5 mm, CAL, and BOP rate. PD was explained by yogurt and cabbage with statistically significant standardized partial regression coefficients (yogurt: -0.2143; cabbage and napa cabbage: -0.2724). The mean CAL was explained by pork, beef, mutton, and dark green vegetables with statistically significant standardized partial regression coefficients (-0.2237 for pork, beef, and mutton; -0.2667 for dark green vegetables). These results raise the possibility that the frequency of intake of various vegetables can be used to evaluate periodontal stabilization in patients with systemic diseases.


Assuntos
Doenças Periodontais , Dente , Animais , Bovinos , Humanos
7.
J Biomech ; 147: 111434, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36638579

RESUMO

This study sought to 1) investigate the spatial distribution of mineral density of dog dentin using µ-CT and 2) characterize the relationship between the elastic modulus and mineral density of dog dentin using nanoindentation and µ-CT. Maxillary canine teeth of 10 mature dogs were scanned with a µ-CT then sectioned in the transverse and vertical planes and tested using nanoindentation. Spatial distribution of mineral density and elastic modulus was quantified. Results demonstrated significant spatial variation in mineral density and elastic modulus. Mineral density and elastic modulus generally increased from the dentin-pulp interface to the dentino-enamel junction and from the crown base to the crown tip. Significant site dependent correlations between mineral density and elastic modulus were determined (0.021 > R2 > 0.408). The results of this study suggest that while mineral density is a mediator of elastic modulus, other mediators such as collagen content may contribute to the mechanical behavior of dog dentin.


Assuntos
Dentina , Dente , Animais , Cães , Módulo de Elasticidade , Dentina/diagnóstico por imagem , Minerais , Tomografia Computadorizada por Raios X , Dureza
8.
BMC Vet Res ; 19(1): 12, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658593

RESUMO

Macrodontia is the enlargement of tooth dimensions of different ethologies. This work aims to show a histological evaluation of macrodontic teeth in guinea pigs. The material was obtained from animals postmortem. Ninety structural changes derived from 24 guinea pigs were evaluated. All teeth used in the study showed macrodontic changes. The samples were decalcified, dehydrated and embedded in paraffin. Material was cut in the transverse and longitudinal planes in relation to the alveolar bone. Histological evaluation included apical bud cells, pulp cavity cells, periodontium, dentin, enamel, cementum and alveolar bone tissue. Individual elements were evaluated with respect to their morphology and distribution. Moreover, the arrangement of the individual hard tooth structures was assessed on the teeth. No atypia was found among the cells that make up the apical bud, pulp or periodontal cavity. Displacement of periodontal cells or odontoblasts towards the pulp cavity as well as disorganization of the cell system in the pulp cavity were observed. Changes in the dentine ligaments and the reconstruction of the alveolar bone were also observed in areas where dentine and cement systems were affected. Dental slides were observed and showed that the enamel is also involved in structural remodelling of the pulp cavity. The histological assessment revealed that structural changes in macrodontic teeth involve the rearrangement of typical tooth tissues.


Assuntos
Dente , Cobaias , Animais , Bochecha , Dente/anatomia & histologia , Osso e Ossos , Polpa Dentária
9.
Beijing Da Xue Xue Bao Yi Xue Ban ; 55(1): 70-77, 2023 Feb 18.
Artigo em Chinês | MEDLINE | ID: mdl-36718691

RESUMO

OBJECTIVE: To evaluate the characteristics of severe periodontitis with various number of tooth loss during 4-year natural progression, and to analyze the factors related to higher rate of tooth loss. METHODS: A total of 217 patients aged 15 to 44 years with severe periodontitis were included, who participated in a 4-year natural progression research. Data obtained from questionnaire survey, clinical examination and radiographic measurement. Tooth loss during 4-year natural progression was evaluated. The baseline periodontal disease related and caries related factors were calculated, including number of teeth with bone loss > 50%, number of missing molars, number of teeth with widened periodontal ligament space (WPDL), number of teeth with periapical lesions and etc. Characteristics of populations with various number of tooth loss and the related factors that affected higher rate of tooth loss were analyzed. RESULTS: In 4 years of natural progression, 103 teeth were lost, and annual tooth loss per person was 0.12±0.38. Nine patients lost 3 or more teeth. Thirty-four patients lost 1 or 2 teeth, and 174 patients were absent of tooth loss. Molars were mostly frequent to lose, and canines presented a minimum loss. The number of teeth with WPDL, with periapical lesions, with intrabony defects, with probing depth (PD)≥7 mm, with PD≥5 mm, with clinical attachment loss≥5 mm, with bone loss > 50% and with bone loss > 65% were positively correlated to number of tooth loss. Results from orderly multivariate Logistic regression showd that the number of teeth with bone loss > 50% OR=1.550), baseline number of molars lost (OR=1.774), number of teeth with WPDL (1 to 2: OR=1.415; ≥3: OR=13.105), number of teeth with periapical lesions (1 to 2: OR=4.393; ≥3: OR=9.526) and number of teeth with caries/residual roots (OR=3.028) were significant risk factors related to higher likelihood of tooth loss and multiple tooth loss. CONCLUSION: In 4 years of natural progression, the number of teeth with bone loss > 50%, baseline number of missing molars, number of teeth with WPDL, baseline number of teeth with periapical lesions and number of teeth with caries/residual roots were significantly related to higher risk of tooth loss and multiple tooth loss among Chinese young and middle-aged patients with severe periodontitis in rural areas.


Assuntos
Doenças Periodontais , Periodontite , Perda de Dente , Dente , Humanos , Perda de Dente/epidemiologia , Perda de Dente/etiologia , Periodontite/complicações , Dente Molar
10.
Beijing Da Xue Xue Bao Yi Xue Ban ; 55(1): 114-119, 2023 Feb 18.
Artigo em Chinês | MEDLINE | ID: mdl-36718698

RESUMO

OBJECTIVE: To investigate the clinical application of cone-beam computed tomography (CBCT) among endodontic practitioners, and to analyze the indications and reasonability of CBCT in the diagnosis and treatment of pulpal and periapical diseases. METHODS: The clinical data were collected from patients who visited the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology and underwent CBCT examination from January to December, 2021. The data with their complete clinical information (including clinical records, radiology request forms/reports, two-dimensional and three-dimensional imaging data) were included. Those who underwent CBCT examination for orthodontic or prosthodontics were excluded. The experience and training background of the endodontic specialists, the number of patients treated in the whole year, the objective and region of interest (ROI) of CBCT examination, technical parameters, such as machine type, field of view (FoV) and radiographic reports were collected and analyzed to evaluate the impact on diagnosis. Wilcoxon and Mann-Whitney tests were used to compare the distribution of CBCT ROI. Chi-squared test and pairwise comparison were used to compare the application of CBCT by endodontic specialists with different clinical experience (senior, middle and junior). RESULTS: In 2021, a total of 3 308 CBCT scans were prescribed by 61 endodontic specialists who treated 34 952 patients throughout the year. 3 218 patients (male ∶female about 1 ∶2) amounting for 10% of the patients treated in the whole year who received CBCT scans with an median age of 35 years (28, 49). Around 98% CBCT examinations were performed after clinical examination and two-dimensional periapical radiographs were taken. The FoV of CBCT scanning less than 10 cm×10 cm accounted for 96% of the total number of the images. Among the 3 308 CBCT scans, 83% of the ROI were in posterior teeth, with a higher number of anterior teeth (Z=-2.278, P < 0.05). Maxillary and mandibular first molars accounted for 35% of the examined teeth. The objectives of CBCT scanning included three aspects: clarifying clinical diagnosis, guiding surgical and non-surgical endodontic treatment (including management of endodontic complications), and outcome assessment, accounting for 1 111 (34%), 1 745 (54%), 311 (10%), respectively. and the others 2%. In the diagnosis process, CBCT was mainly used for the diagnosis of chronic periapical periodontitis, root fracture, root resorption and dental trauma. In the study, 353 CBCT were used in the diagnosis of root fracture, with a positive diagnosis rate of 35% (125/353). 846 CBCT used to reveal the anatomy of the root canal system, of which 297 cases were used to find missed/extra canals after treatment failure, and 58% (171/297) were used to confirm the missed/extra canals. In the management of complications or errors, CBCT was mainly used to assist the diagnosis of perforation and to locate the separated instruments. In the study, 311 CBCT scans were used for outcome assessment, including 240 cases related to non-surgical treatment and 71 cases related to surgical endodontic treatment for follow-up or presence of clinical symptoms, and persistent lesions on 2D films. Among the 61 endodontic specialists who used CBCT, 23 (45%) were with senior experience, 15 (30%) with middle experience, and 23 (25%) with junior experience. The proportion of senior or junior experience prescribing CBCT examination was 10%, higher than that of middle experience (8%, χ12=39.4, χ22=29.1, P < 0.001). The application rate of chief endodontists was 18%, which was higher than that of associate chief endodontists (9%, χ12=139.4, P < 0.001). 31% (1 109/3 308) cases of diagnosis or treatment plans were changed after CBCT was taken. CONCLUSION: Use of CBCT in endodontic practice could provide more clinical information, which is helpful for diagnosis, accurate treatment and prognosis evaluation.


Assuntos
Tratamento do Canal Radicular , Dente , Humanos , Masculino , Adulto , Prevalência , Tratamento do Canal Radicular/efeitos adversos , Tratamento do Canal Radicular/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Imageamento Tridimensional
11.
PeerJ ; 11: e14523, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36650833

RESUMO

Cusp patterning on living and extinct primate molar teeth plays a crucial role in species diagnoses, phylogenetic inference, and the reconstruction of the evolutionary history of the primate clade. These studies rely on a system of nomenclature that can accurately identify and distinguish between the various structures of the crown surface. However, studies at the enamel-dentine junction (EDJ) of some primate taxa have demonstrated a greater degree of cusp variation and expression at the crown surface than current systems of nomenclature allow. In this study, we review the current nomenclature and its applicability across all the major primate clades based on investigations of mandibular crown morphology at the enamel-dentine junction revealed through microtomography. From these observations, we reveal numerous new patterns of lower molar accessory cusp expression in primates. We highlight numerous discrepancies between the expected patterns of variation inferred from the current academic literature, and the new patterns of expected variation seen in this study. Based on the current issues associated with the crown nomenclature, and an incomplete understanding of the precise developmental processes associated with each individual crown feature, we introduce these structures within a conservative, non-homologous naming scheme that focuses on simple location-based categorisations. Until there is a better insight into the developmental and phylogenetic origin of these crown features, these categorisations are the most practical way of addressing these structures. Until then, we also suggest the cautious use of accessory cusps for studies of taxonomy and phylogeny.


Assuntos
Coroa do Dente , Dente , Animais , Filogenia , Primatas , Dente Molar/anatomia & histologia
12.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 58(1): 31-39, 2023 Jan 09.
Artigo em Chinês | MEDLINE | ID: mdl-36642450

RESUMO

Dental dysplasia are abnormalities in teeth structure, morphology, number and eruption caused by genetic and environmental factors during dental development. Digital medical techniques, as the current hot spot of medical research, bring great challenges and opportunities to modern stomatology. The applications of digital techniques, such as digital diagnosis method, digital virtual simulated design, three-dimensional printing, static and dynamic guidance and artificial intelligence, can provide a more accurate, efficient, automatic and intelligent modern concepts and patterns for epidemiology, diagnosis, multidisciplinary treatment and outcome assessment of dental developmental anomalies.


Assuntos
Inteligência Artificial , Dente , Impressão Tridimensional
13.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 58(1): 50-56, 2023 Jan 09.
Artigo em Chinês | MEDLINE | ID: mdl-36642452

RESUMO

Objective: To investigate the influence of light and heavy bite force on the mandibular movement trajectories, and the influence of bite force on virtual occlusal pre-adjustment of digital full crown. Methods: From October 2021 to March 2022, 10 postgraduate volunteers (3 males and 7 females, aged 22-26 years) were recruited from Peking University School and Hospital of Stomatology. Maxillary and mandibular digital models of the participants were obtained by intraoral scanning. Jaw relations were digitally transferred under heavy bite force and mandibular movement trajectories under light and heavy bite force were recorded by jaw motion analyser. Three mandibular markers were chosen, namely the mesial proximal contact point of the central incisor (incisal point) and the mesial buccal cusp tips of the bilateral first molars. The three-dimensional displacements of the markers under two kinds of bite force in the intercuspal position (ICP), the sagittal projection of the three-dimensional displacements in the protrusive edge-to-edge position, and the coronal projection of the three-dimensional displacements in the lateral edge-to-edge position of upper and lower posterior teeth were measured. Single-sample t-test was used to compare the three-dimensional displacements and the corresponding sagittal projection and coronal projection with 0, respectively. The left maxillary central incisor and left mandibular first molar were virtually prepared by the reverse engineering software. Then dental design software was used to design digital full crown using the copy method. The mandibular movement trajectories under light and heavy bite force were separately used to guide virtual occlusal pre-adjustment. The three-dimensional deviations (mean deviations and root mean square) between the lingual surface of the left maxillary central incisor or the occlusal surface of the left mandibular first molar and that of the natural tooth before preparation were calculated (light bite force group and heavy bite force group), and the differences between the two groups were compared by the paired t-test. Results: Under the two kinds of bite force, the three-dimensional displacements of the markers in the ICP were (0.217±0.135), (0.210±0.133) and (0.237±0.101) mm, respectively; the sagittal projection of the three-dimensional displacements of the markers in the protrusive edge-to-edge position were (0.204±0.133), (0.288±0.148) and (0.292±0.136) mm, respectively; the coronal projection of the three-dimensional displacements of the mesial buccal cusp tips of the bilateral first molars in the lateral edge-to-edge position were (0.254±0.140) and (0.295±0.190) mm, respectively. The differences between the above displacements and 0 were statistically significant (P<0.05). The results of occlusal pre-adjustment showed that the mean deviations of the lingual surface of the left maxillary central incisor in the light and heavy bite force groups were (0.215±0.036) and (0.195±0.041) mm (t=3.95, P=0.004), respectively. The mean deviations of the occlusal surface of the left mandibular first molar were (0.144±0.084) and (0.100±0.096) mm (t=0.84, P=0.036), respectively. Conclusions: Both the light and heavy bite force have an influence on the mandibular movement trajectories. Virtual occlusal pre-adjustment of prostheses with mandibular movement trajectories under heavy bite force can obtain morphology of lingual or occlusal surfaces closer to the natural teeth before preparation.


Assuntos
Força de Mordida , Dente , Masculino , Feminino , Humanos , Mandíbula , Dente Molar , Ajuste Oclusal
14.
Biol Lett ; 19(1): 20220438, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36651149

RESUMO

Overcoming the non-specificity of histological accentuated growth lines in hard tissues is an ongoing challenge. Identifying season at death and reproductive events has profound implications for evolutionary, ecological and conservation studies. Dental cementum is a mineralized tissue with yearly periodicity that continues deposition from tooth formation until death, maintaining a record spanning almost the entire life of an individual. Recent work has successfully employed elemental analysis of calcified incremental tissues to detect changes in extrinsic conditions such as diet and climate and to identify two important life-history milestones: weaning and sexual maturity. Here, we employ field-emission scanning electron microscopy and energy-dispersive X-ray analysis to measure the relative concentrations of calcium, phosphorous, oxygen, magnesium and sodium in the cementum of 34 teeth from seven male and female rhesus macaques with known medical and life-history information. We find that changes in relative magnesium concentrations correspond with reproductive events in females and breastfeeding in infants. Additionally, we observe seasonal calcium patterns in 77.3% of the samples.


Assuntos
Cálcio , Dente , Animais , Masculino , Feminino , Magnésio , Macaca mulatta , Microscopia Eletrônica de Varredura
15.
Arch Oral Biol ; 146: 105606, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36577312

RESUMO

OBJECTIVES: cortical bone thickness confines the position of teeth and thus can be a limiting factor for orthodontic tooth movement. The study is aimed to correlate the cortical bone thickness of the maxilla and mandible with that of different face types, viz; dolichofacial, brachyfacial, and mesofacial. METHODS: Forty CT scans were analysed for the face types and were grouped into dolichofacial (13), brachyfacial (13) and mesofacial (14) face types. The scans were measured for the right and left side buccal and lingual cortical bone thickness at the central incisor, first and second molar regions on both the maxilla and mandible. Other parameters like basal cortical bone thickness, height, and width of cortical bone were also measured. To determine the correlation and difference between the different parameters, the obtained data was subjected to the correlation coefficient, t test, and ANOVA statistical analysis. RESULTS: Maxillary buccal cortical bone thickness of central incisors was found to be highly correlated to facial index with a correlation coefficient of - 0.833 * *. Mandibular buccal bone thickness correlated with face type and cortical bone thickness at the central incisor, first, and second molars by-0.531 * *, - 0.474 * *, and - 0.589 * *, respectively. There was a significant difference between the right and left side cortical bone thickness (p < 0.05) and also for all the parameters amongst the different face types (p < 0.05). CONCLUSION: There exists a definite correlation between the face type and the certain anatomical measurements of cortical bone morphology. Dolichofacial face types show thin buccal cortical bone, which implies the limitation of orthodontic tooth movement in these types of individuals.


Assuntos
Maxila , Dente , Humanos , Maxila/diagnóstico por imagem , Maxila/anatomia & histologia , Mandíbula/diagnóstico por imagem , Mandíbula/anatomia & histologia , Tomografia Computadorizada por Raios X , Osso Cortical/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos
16.
Comput Biol Med ; 152: 106374, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36512876

RESUMO

Periodontitis is a serious oral disease that can lead to severe conditions such as bone loss and teeth falling out if left untreated. Diagnosis of radiographic bone loss (RBL) is critical for the staging and treatment of periodontitis. Unfortunately, the RBL diagnosis by examining the panoramic radiographs is time-consuming. The demand for automated image analysis is urgent. However, existing deep learning methods have limited performances in diagnosis accuracy and have certain difficulties in implementation. Hence, we propose a novel two-stage periodontitis detection convolutional neural network (PDCNN), where we optimize the detector with an anchor-free encoding that allows fast and accurate prediction. We also introduce a proposal-connection module in our detector that excludes less relevant regions of interests (ROIs), making the network focus on more relevant ROIs to improve detection accuracy. Furthermore, we introduced a large-scale, high-resolution panoramic radiograph dataset that captures various complex cases with professional periodontitis annotations. Experiments on our panoramic-image dataset show that the proposed approach achieved an RBL classification accuracy of 0.762. This result shows that our approach outperforms state-of-the-art detectors such as Faster R-CNN and YOLO-v4. We can conclude that the proposed method successfully improves the RBL detection performance. The dataset and our code have been released on GitHub. (https://github.com/PuckBlink/PDCNN).


Assuntos
Periodontite , Dente , Humanos , Radiografia Panorâmica , Redes Neurais de Computação , Periodontite/diagnóstico por imagem , Processamento de Imagem Assistida por Computador
17.
Biochem Biophys Res Commun ; 642: 75-82, 2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-36566565

RESUMO

The right and left mandibular processes derived from the first branchial arch grow toward the midline and fuse to create the rostral tip region of the mandible during mandibular development. Severe and mild cases of failure in this process results in rare median cleft of the lower lip and cleft chin, respectively. The detailed molecular mechanisms of mandibular tip formation are unknown. We hypothesize that the Msx1 gene is involved in mandibular tip development, because Msx1 has a central role in other craniofacial morphogenesis processes, such as teeth and the secondary palate development. Normal Msx1 expression was observed in the rostral end of the developing mandible; however, a reduced expression of Msx1 was observed in the soft tissue of the mandibular tip than in the lower incisor bud region. The rostral tip of the right and left mandibular processes was unfused in both control and Msx1-null (Msx1-/-) mice at embryonic day (E) 12.5; however, a complete fusion of these processes was observed at E13.5 in the control. The fused processes exhibited a conical shape in the control, whereas the same region remained bifurcated in Msx1-/-. This phenotype occurred with 100% penetrance and was not restored at subsequent stages of development. Furthermore, Meckel's cartilage in addition to the outline surface soft tissues was also unfused and bifurcated in Msx1-/- from E14.5 onward. The expression of phosho-Smad1/5, which is a mediator of bone morphogenetic protein (Bmp) signaling, was downregulated in the mandibular tip of Msx1-/- at E12.5 and E13.5, probably due to the downregulated Bmp4 expression in the neighboring lower incisor bud. Cell proliferation was significantly reduced in the midline region of the mandibular tip in Msx1-/- at the same developmental stages in which downregulation of pSmad was observed. Our results indicate that Msx1 is indispensable for proper mandibular tip development.


Assuntos
Fator de Transcrição MSX1 , Dente , Camundongos , Animais , Fator de Transcrição MSX1/genética , Fator de Transcrição MSX1/metabolismo , Mandíbula , Dente/metabolismo , Morfogênese/genética , Transdução de Sinais
18.
J Mater Chem B ; 11(3): 657-666, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36541228

RESUMO

The objective of this study was to first identify the timing and location of early mineralization of mouse first molar, and subsequently, to characterize the nucleation site for mineral formation in dentin from a materials science viewpoint and evaluate the effect of environmental cues (pH) affecting early dentin formation. Early dentin mineralization in mouse first molars began in the buccal central cusp on post-natal day 0 (P0), and was first hypothesized to involve collagen fibers. However, elemental mapping indicated the co-localization of phospholipids with collagen fibers in the early mineralization area. Co-localization of phosphatidylserine and annexin V, a functional protein that binds to plasma membrane phospholipids, indicated that phospholipids in the pre-dentin matrix were derived from the plasma membrane. A 3-dimensional in vitro biomimetic mineralization assay confirmed that phospholipids from the plasma membrane are critical factors initiating mineralization. Additionally, the direct measurement of the tooth germ pH, indicated it to be alkaline. The alkaline environment markedly enhanced the mineralization of cell membrane phospholipids. These results indicate that cell membrane phospholipids are nucleation sites for mineral formation, and could be important materials for bottom-up approaches aiming for rapid and more complex fabrication of dentin-like structures.


Assuntos
Odontoblastos , Dente , Camundongos , Animais , Odontoblastos/metabolismo , Dentina , Fosfolipídeos/metabolismo , Colágeno/metabolismo
19.
J Oral Sci ; 65(1): 29-33, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36529512

RESUMO

PURPOSE: The study aimed to examine the association of self-rated chewing function, the number of teeth and periodontal status with metabolic syndrome. METHODS: The participants were 11,119 adults aged 40-74 years who underwent specific health checkups, including an oral health examination, in 2018 in Japan. This study used the standard questions of the specific health checkups to obtain information on self-rated chewing function. A multinomial logistic regression analysis was performed with metabolic syndrome status as the dependent variable, and age, sex, lifestyle questions, self-rated chewing function, number of teeth, and periodontal status as the independent variables. RESULTS: Number of teeth and periodontal status were significantly associated with metabolic syndrome after adjusting for confounding variables. Self-rated chewing function was significantly associated with metabolic syndrome in the crude analysis, but not after adjustment for confounding variables. Both number of teeth and periodontal status were significantly associated with self-rated chewing function. CONCLUSION: There was no significant direct association between self-rated chewing function and metabolic syndrome. Self-rated chewing function may be an indicator of poor oral condition that links to metabolic syndrome.


Assuntos
Mastigação , Síndrome Metabólica , Saúde Bucal , Dente , Adulto , Humanos , Nível de Saúde , Mastigação/fisiologia , Síndrome Metabólica/complicações , Doenças da Boca/etiologia
20.
J Dent ; 129: 104406, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36566830

RESUMO

OBJECTIVES: To describe a new protocol for digital scanning of multiple abutment teeth using the trim and lock software tools. METHODS: A reverse workflow technique was used. Scanning was performed with the interim restoration in position. The abutment teeth were then trimmed from the scan. The retraction cord or interim restoration from either the first mesial or distal abutment tooth was removed and only that tooth was scanned, allowing the dentist to easily manage gingival displacement and keep the tooth dry from crevicular fluid and saliva. Consequently, the preparation margin remained visible and uncontaminated during the scan. The adjacent abutment teeth detected in the scan were deleted from it, and the scan was then locked using a tool of the scanning software. Next, the retraction cord or interim restoration of the next abutment tooth was removed, and only that tooth was scanned. The procedure was repeated until all prepared teeth were individually scanned. RESULTS: The technique presented here facilitated the scanning of multiple abutment teeth in a simple and predictable way by utilizing the trim and lock surface tools of the scanning software and helped in avoiding closure of the gingival crevice. CONCLUSIONS: Splitting the scan for a complex case with multiple abutment teeth allows reliable 3D acquisition of the finish line of each abutment tooth. Therefore, this technique simplifies the full-arch intraoral scanning process and can improve treatment efficiency. CLINICAL SIGNIFICANCE: The trim and lock tool allows scanning of each prepared abutment tooth separately, transforming a full-arch impression into multiple single scans. This technique helps to easily manage gingival displacement and maintain an uncontaminated and dry preparation margin during the scan.


Assuntos
Técnica de Moldagem Odontológica , Dente , Desenho Assistido por Computador , Gengiva , Imageamento Tridimensional , Software
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