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1.
Head Face Med ; 18(1): 30, 2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36057719

RESUMO

BACKGROUND: Guided insertion of palatal miniscrews using a lateral cephalogram instead of cone beam computed tomography (CBCT) significantly reduces the radiation level for the patient. Till now no data are available on the risk of hitting the incisors in this regard, which is one of the worst clinical complications when inserting a paramedian miniscrew. Hence, this study aims to investigate the distance between the mini-implant and the roots of the central and lateral incisors. METHODS: Lateral cephalogram, an intraoral scan, and CBCT of 20 patients were superimposed. After a miniscrew (1.7 × 8 mm) placement based on intraoral scan and lateral cephalogram, the CBCT was used as control for the distance between the miniscrews and the roots of the incisors. RESULTS: The mean value of the shortest distance between the miniscrew and roots of the incisors in the lateral cephalogram was 4.74 ± 1.67 mm. The distance between both miniscrews and the central incisors measured in the CBCT was 5.03 ± 2.22 mm and 5.26 ± 2.21 mm and between the two miniscrews and the lateral incisors was 4.93 ± 1.91 mm and 5.21 ± 2.64 mm. No significant differences between the distances in the CBCT and the lateral cephalogram could be observed. In one case, the CBCT control revealed the penetration of two palatally displaced canines after insertion based on intraoral scan and lateral cephalogram. CONCLUSIONS: The use of an intraoral scan and a lateral cephalogram for guided paramedian insertion of palatal miniscrews can prevent incisor root damage. This may reduce the radiation since no CBCT seems necessary. The current investigation focuses on the anterior paramedian area of the palate. Outside that region and in complex cases with displaced teeth in the palatal area, a CBCT might be indicated.


Assuntos
Maxila , Palato , Tomografia Computadorizada de Feixe Cônico/métodos , Incisivo/diagnóstico por imagem , Incisivo/cirurgia , Maxila/diagnóstico por imagem , Maxila/cirurgia , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/cirurgia
2.
Prog Orthod ; 23(1): 31, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36058991

RESUMO

BACKGROUND/OBJECTIVES: When the indirect bonding technique was developed in 1972 by Silverman and Cohen, many authors wondered whether this technique would improve bracket positioning accuracy compared to the direct bonding technique. Studies have found little to no difference between them regarding positioning accuracy. Recently, technological advances have improved the indirect method by allowing the user to position the brackets virtually using software applications such as OrthoAnalyzer™. To the best of our knowledge, no studies have compared direct positioning to this new digital indirect technique. Thus, the aim of this study was to compare the accuracy of placement between the two techniques in the maxillary arch using two different bracket types: conventional twin brackets and self-ligating brackets. A secondary objective was to evaluate whether bracket type affected positioning accuracy. METHODS: A maxillary arch of a patient was scanned by digital impression. Forty resin duplicates of this model were printed and then mounted on a mannequin head, on which 20 practitioners performed direct bonding using the aforementioned brackets. Later on, they performed a virtual indirect bonding of the same case virtually, with the digital impression superimposed to the patient's CBCT (cone-beam computed tomography). Afterwards, the direct bonded models were unmounted, scanned, and then superimposed to the indirect models. Differences in height, angulation and mesio-distal position of the brackets were evaluated. RESULTS: Regarding height, the differences between direct and indirect methods were not significant. Height difference was significantly greater for self-ligating brackets compared to conventional brackets. Regarding mesio-distal positioning, significant differences were noted for teeth 13 and 15 with self-ligating brackets (p-value = 0.019 and p-value = 0.043, respectively). The deviation was also greater for these brackets. Regarding angulation, the difference was significant on tooth 12 when using conventional brackets (p-value = 0.04) and on 12 and 22 when using self-ligating brackets (p-value = 0.09). CONCLUSION/IMPLICATIONS: There were no major significant differences between direct and indirect bonding. Differences were significant only on the laterals for of angulation, and on teeth 13 and 15 for mesio-distal centering. The bracket type seems to influence positioning accuracy, since self-ligating brackets had a larger deviation range than conventional brackets.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Dente Pré-Molar , Colagem Dentária/métodos , Humanos , Maxila , Modelos Dentários
3.
J Craniofac Surg ; 33(6): 1684-1689, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36054885

RESUMO

ABSTRACT: Maxillary skeletal expansion (MSE) provides a new nonsurgical method for the treatment of patients with insufficient maxillary arch expansion width. In this study the aerodynamic changes of the upper airway after MSE in adult patients were explored based on three-dimensional reconstruction technology of cone-beam computed tomographic data and the numerical simulation technology of computational fluid dynamics. An upper airway experimental model was then created based on three-dimensional printing technology and tested in vitro to verify the reliability of the numerical simulation method. The comparison between numerical simulation and experimental results shows that the 2 results are in good agreement. The results of numerical simulation showed that the cross-sectional area of the upper airway was increased after MSE, the pressure and velocity of the upper airway were reduced, and airway resistance was also reduced during exhalation and inhalation. This study shows that MSE can effectively improve the airway dynamics of patients.


Assuntos
Técnica de Expansão Palatina , Faringe , Adulto , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Maxila/diagnóstico por imagem , Nariz , Faringe/diagnóstico por imagem , Reprodutibilidade dos Testes
5.
Biomed Res Int ; 2022: 5579243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36119931

RESUMO

Background: Early diagnosis and interceptive treatment of the maxillary canine impaction is crucial as it reduces treatment complexity and decreases complications and adverse outcomes. Aim and Objectives. To determine the mean maxillary canine position among 9-10-year-old children and predict the risk of impaction of the maxillary canines. Methodology. Panoramic radiographs (PANs) of 289 healthy children aged between 9 and 10 years were observed where the average position of maxillary canines was related to the lateral incisor, sector locations, and angulations to the bicondylar line were traced. The average position was obtained by using descriptive statistics. One sample Wilcoxon signed-rank test is done to predict the risk of canine impaction by comparing the data obtained to the average position from prior studies. Results: A total of 289 PANs (126 males and 163 females) were utilized for the analysis. The findings showed that the average position of the maxillary canines in our population was statistically different from the average position of nonimpacted canines in previous studies. However, on average, more than 85% of canines in our population were still located within the safe range of satisfactory position, with females showing slight predominance outside of the acceptable range. The mean scores of the angles between the right canine and lateral incisor were significantly higher among females than males (p = 0.001). Similarly, females had a significantly higher mean angle of the left canine than males (p < 0.001). In regard to the angles between the bicondylar line and permanent maxillary canine, the mean scores were not significantly different (p > 0.05) on both the left and right side. Conclusion: There is a low risk of impaction of maxillary canines in the Malaysian population. However, more retrospective studies using more radiographic and clinical indicators need to be done to confirm the risk of impaction further.


Assuntos
Maxila , Dente Impactado , Dente Canino/diagnóstico por imagem , Feminino , Humanos , Incisivo/diagnóstico por imagem , Masculino , Maxila/diagnóstico por imagem , Estudos Retrospectivos , Dente Impactado/diagnóstico por imagem
6.
J Coll Physicians Surg Pak ; 32(9): 1219-1221, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36089726

RESUMO

Mucormycosis is an acute opportunistic infection caused by a saprophytic fungus found in the soil, decaying fruits, and vegetables. It is a rapidly progressing fungal infection mainly seen in nose and its surrounding sinuses due to inhalation of the spores of fungus from the contaminated areas. If not diagnosed and treated early, it can be life-threatening. A case of a 60-year male farmer is reported with an extensive spread of the fungal infection involving alveolar bone of maxilla, zygomatic process, and the right orbit. The radiographs demonstrated alveolar, palatal, and zygomatic bone destruction. The diagnosis of mucormycosis was made through clinical, radiographic, and histopathologic findings. An early diagnosis and treatment with antifungal drugs like amphotericin B and surgical resection can improve the prognosis. Key Words: Mucormycosis, Maxilla, Zygomatic bone, Antifungal.


Assuntos
Mucormicose , Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Humanos , Masculino , Maxila/diagnóstico por imagem , Mucormicose/diagnóstico , Mucormicose/tratamento farmacológico
7.
Med Eng Phys ; 107: 103872, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36068044

RESUMO

This study investigated the effects of miniscrew location on biomechanical performance of bone-borne rapid palatal expander (B-RPE) to midpalatal suture, using finite element (FE). Three cases of B-RPE with different miniscrew locations (3 and 6 mm from midpalatal suture and palatal interdental site) were simulated activations in partly ossified midpalatal suture maturation. This study compared the expansion amount and pattern along the suture line. Equivalent von Mises (EQV) stresses at appliance, miniscrew, midpalatal sutures, and elastic strain at the bone around miniscrew were evaluated. In all cases, they could not break the midpalatal suture of palatine bone. However, midpalatal suture at the maxilla was expanded. The expansion amount and unparallel expanding pattern were increased when miniscrews were positioned away from the suture. The interdental miniscrew position extended the suture more than the other 2 cases, but the pattern was unparallel. When the miniscrews were positioned away from the suture, the EQV stress at the appliance and elastic strain at the bone around the miniscrew were reduced. In the case of the palatal interdental miniscrew, all parameters were of lower magnitude. All cases could expand the partly ossified midpalatal suture maturation. The distance between the midpalatal suture and the miniscrew influenced appliance EQV stress, elastic strain at the bone around the miniscrew, and expansion characteristics.


Assuntos
Técnica de Expansão Palatina , Palato , Análise de Elementos Finitos , Maxila/cirurgia , Palato/cirurgia , Suturas
8.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(9): 927-931, 2022 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-36097939

RESUMO

Objective: To compare the accuracy and retention of denture bases fabricated by injection molding, milling, and three-dimensional (3D) printing fabricating, in order to provide some references for clinical practice. Methods: A maxillary edentulous jaw model made was used to duplicated 10 working casts. The casts were numbered and scanned. The wax pattern was designed by digital ways and conventional methods and then the denture bases were fabricated by injection molding, milling, and 3D printing. The tissue surface of experimental denture base was obtained using a dental laboratory scanner. The deviation between the tissue surface of the fabricated denture bases and the working model was evaluated. A digital force gauge was used to measure the traction force. Results: The milling group [(0.076±0.026) mm] was more accurate than the 3D printing group [(0.117±0.041) mm] (P<0.05) and the injection group [(0.120± 0.025) mm] (P<0.05). The accuracy of 3D printing group and that of injection group were not statistically significant (P>0.05). The milling group [(9.55±2.44) N] demonstrated greater retentive force than 3D printing group [(5.19±0.06) N] and injection molding group [(1.52±0.52) N] (P<0.05). Conclusions: The denture base fabricated by milling was more accurate and showed the greatest retentive force than the other groups. And 3D printing group showed better retentive force than the injection molding group. Both digital manufacturing methods can meet the requirements of clinical application.


Assuntos
Bases de Dentadura , Arcada Edêntula , Desenho Assistido por Computador , Humanos , Maxila , Impressão Tridimensional
10.
PLoS One ; 17(9): e0272989, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36108093

RESUMO

Intraoral scans became part of the virtual planning in Dentistry. In the new scenario of digital workflows, dental clinics and laboratories had to establish an online communication that requires the compression, decompression, and transmission of 3D files. Knowledge about the effects of these procedures on the dimensional properties of the files is fundamental to ensure a more realistic virtual planning. The aim of this study was to assess the influence of 3D file compression, decompression, and online transmission on the dimensional properties of dental models from intraoral scanning. Intraoral scan files in.stl format of 50 patients were selected from the database of a dental radiology clinic, with 25 of these patients with mixed dentition and 25 with permanent dentition. The maxilla and mandible scans of each patient were included in the study, generating a total of 100 files. A folder with the 100 files was created and replicated six times with different labels (A, B, C, D, E, F), totaling a sample number of 600 files. Folder A was compressed by WinZip and then decompressed. Folder B went through the same process, but the step of compression and decompression by WinZip was repeated 10 times. The folders C, D, E, F were sent, respectively, through the platforms WeTransfer, Dropbox, Google Drive, and OneDrive, then each of them was downloaded in their respective platforms. After the six folders went through the compression process and were sent by the platforms, each file in the folder was compared with its original file by superimposing the 3D images and identifying the dimensional deviation in the compressed file in relation to the original file. We observed that there were no differences between the six groups regarding dimensional changes from the compression, decompression and online transmission processes. The lack of dimensional changes was observed for the sets of permanent and deciduous. teeth We concluded that it is possible to compress, decompress, and transfer.stl format files online without causing dimensional distortions in the 3D model.


Assuntos
Imageamento Tridimensional , Registros , Descompressão , Humanos , Imageamento Tridimensional/métodos , Mandíbula , Maxila
11.
Shanghai Kou Qiang Yi Xue ; 31(2): 162-166, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-36110073

RESUMO

PURPOSE: This study was designed to establish a 3-dimentional finite element system to simulate the clinical scenario where labial segment was retracted with sliding mechanism in extraction cases treated by individualized lingual orthodontics. METHODS: A typical clinical case was selected. The subject was diagnosed with Class I malocclusion with alveolar protrusion and treated with extraction of 4 first premolars. The subject was under the treatment stage of frontal retraction by eBrace system, an individualized lingual appliance. The subject was also taken cone-beam CT (CBCT) based on which digital 3D reconstruction of dentition structures was formed with Mimics software. With the aid of software platform Pro/E 4.0, the important anatomical structures were defined, and relevant lingual devices, including lingual brackets, arch-wires, mini-screws and other accessories were formed. With the aids of software platform Geomagic Studio 13.0, the 3-dimentional structural mode, featuring maxillary alveolar, upper dentition, periodontal ligament, miniscrew and lingual applicance, were constructed. With the assistance of Ansys Workbench 15.0, 3D model for finite element system was finalised by conducting model meshing and defining the mechanical properties and the interface relations of the selected materials. RESULTS: Based on the digital information drawn from CBCT image, a 3-dimentional finite element system was successfully created, featuring all the elements mimicking the clinical scenario for En masse retraction. This system enabled an insight study on the effects of various retraction modes controlling the incisal torque and maintaining the dental arch integrity. CONCLUSIONS: The creation of a finite element system in this study is based on the digital data from the CBCT image of a real patient diagnosed with prognathic malocclusion and treated by lingual appliance. The clinical scenario of labial segment retraction via sliding mechanism is simulated in this finite element model.


Assuntos
Má Oclusão , Técnicas de Movimentação Dentária , Dente Pré-Molar/diagnóstico por imagem , Dente Pré-Molar/cirurgia , Análise de Elementos Finitos , Humanos , Maxila , Técnicas de Movimentação Dentária/métodos
12.
Shanghai Kou Qiang Yi Xue ; 31(2): 211-216, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-36110083

RESUMO

PURPOSE: To study the effect of orthodontic treatment with extraction on root resorption and alveolar bone morphology of the central incisor in adult patients. METHODS: Eleven adult patients receiving orthodontic treatment were enrolled, and asked to take cone-beam CT(CBCT) scanning before and after treatment. Root resorption of the upper and lower central incisors after treatment, changes in alveolar bone thickness and height of alveolar bone were measured and compared. Statistical analysis was performed using SPSS 23.0 software package. RESULTS: The length of the tooth and root was reduced to a certain degree. The change in root length of the maxillary incisor was larger than that of the mandibular incisor. The alveolar bone width of the lingual and palatal neck of the central incisor showed some reduction, and alveolar bone width of the palatal neck of the upper central incisor and the middle lingual side of the mandibular central incisor changed to a certain extent. The width of the alveolar bone in the middle labial side of the mandibular central incisor increased, but the alveolar bone on the lingual and palatal side increased after orthodontic treatment, which was more obvious than that of the maxillary central incisor. CONCLUSIONS: Orthodontic treatment with tooth extraction is accompanied by a certain degree of root resorption of the central incisor and alveolar bone on the lingual and palatal side. However it is also accompanied by an increase in the amount of alveolar bone on the labial side. More fenestration and dehiscence are observed in the mandible.


Assuntos
Incisivo , Reabsorção da Raiz , Adulto , Tomografia Computadorizada de Feixe Cônico , Humanos , Incisivo/diagnóstico por imagem , Mandíbula , Maxila/diagnóstico por imagem
13.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(9): 953-957, 2022 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-36097943

RESUMO

To explore the efficacy and value of personalized surgical schemes in the repair of maxillary sinus perforation and maxillary sinus fistula based on the size of the maxillary sinus perforation and maxillary sinus fistula. A total of 28 patients with maxillary sinus perforation and maxillary sinus fistula who were admitted to the Department of Oral and Maxillofacial Surgery, Stomatology Hospital of Kunming Medical University from July 2017 to May 2020 were included to conduct a prospective case clinical study. After the inflammation in the maxillary sinus was controlled, a proper surgical repair method was selected according to the size of the perforation and fistula based on the double-layer closure technique. The diameter of the perforation and fistula was measured with the assistance of cone-beam CT. After that, the platelet rich fibrin (PRF) repair was performed on the perforation and fistula with 3 mm≤diameter<7 mm in size in 14 patients. The PRF repair and buccal flap repair were performed on the perforation and fistula with 7 mm ≤diameter<15 mm in size in 7 patients. The adjacent buccal pad repair, palatine flap repair, and buccal flap repair were performed on the perforation and fistula with 15 mm≤ diameter<25 mm in size in 4 patients. The nasolabial axial flap repair and nasolabial free flap repair were performed on the perforation and fistula with a diameter ≥25 mm in size in 3 patients. The medical follow-up was conducted in all patients in the 1st, 2nd, and 4th week after surgery, with an overall success rate reaching 96.4% (27/28) after the initial intervention. The relapse of disease occurred in one patient (4.6%) with diabetes and a smoking history in the 2nd week after surgery. Identifying a proper surgical repair method according to the size of the oral and maxillary sinus perforation and maxillary sinus fistula based on the double-layer closure technique can improve the one-time cure rate in these patients under the premise that the inflammation in the maxillary sinus can be controlled.


Assuntos
Fístula , Seio Maxilar , Fístula/cirurgia , Humanos , Inflamação , Maxila , Seio Maxilar/cirurgia , Fístula Bucoantral/cirurgia
15.
Prog Orthod ; 23(1): 32, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36089601

RESUMO

BACKGROUND: This study aims to evaluate the impact of the loss of permanent molars on the duration of orthodontic treatment for space closure and without skeletal anchorage. METHODS: Records at the beginning (T0) and the end (T1) of orthodontic treatment were selected retrospectively. Patients were divided into two groups: loss of molar (n = 19) and control, without loss (n = 24). The impact of loss on treatment time was assessed using multiple linear regression adjusted for the number of absences, bonding failures, age, sex, PAR index at T0 and T1 at p<0.05. Treatment time was also evaluated by the number of losses and which arches were involved (upper, lower). The systematic and random errors for the PAR index were verified using the intraclass correlation coefficient (ICC) and the Dahlberg formula, respectively. RESULTS: A small random error (1.51) and excellent replicability (ICC = 99.6) were observed. Overall average treatment time was 22.5 months (± 7.95) for the group without loss and 44.7 months (± 17.3) with a loss. Treatment time was longer in cases where there was a higher number of missing molars and when both arches were involved. In addition to the loss (ß = 4.25, p < 0.001), the number of missed appointments (ß = 2.88, p < 0.001) had a significant effect and increased treatment time. Bonding failures, gender, age, and PAR index at T0 and T1 were not significantly associated with treatment time in the multivariate model (p > 0.05). CONCLUSION: Loss of the first permanent molar has a negative impact on orthodontic treatment time in cases of space closure. The treatment time is longer when there are more tooth losses and arches involved. Treatment time also increases with greater numbers of missed clinical appointments.


Assuntos
Duração da Terapia , Fechamento de Espaço Ortodôntico , Humanos , Maxila , Dente Molar , Estudos Retrospectivos
16.
Artigo em Inglês | MEDLINE | ID: mdl-36078396

RESUMO

BACKGROUND: The current study aimed to evaluate the severity and treatment difficulty of impacted maxillary canines and their relationship with gender, age group, and bucco-palatal position. METHODS: A retrospective cross-sectional study was conducted from 2017 to 2021. Patients' data and panoramic radiography were obtained from the orthodontic clinic at King Saud University's Dental University Hospital in Riyadh, Saudi Arabia. The severity factors and treatment difficulty index were used to assess the impacted maxillary canines. Statistical analyses were performed utilizing a chi-square test for categorical variables and an independent t-test for numerical variables, and a p-value of ≤0.05. RESULTS: There were 171 impacted maxillary canines in total, with a female-to-male subject ratio (11:8) and a mean age (18.7 years). Overall, 77.2% of impacted upper canines were found to be palatal. The severity of canine impaction parameters showed no significant sex or age group predilection. Buccally impacted maxillary canines were characterized by a preferable angulation to the midline, compared to the palatally impacted maxillary canines (p = 0.012). The horizontal overlap of the impacted maxillary canine cusp tip revealed a significant association with the bucco-palatal position of the impacted canine (p < 0.001). Palatal impaction was located more frequently in sectors 3 and 4. Male patients were found to have a higher total score in terms of the treatment difficulty index relative to females (p = 0.046). CONCLUSION: Despite the severity parameters having revealed no significant gender predilection, males were found to have higher treatment difficulty in maxillary canine impaction than females. The severity of the palatally impacted canine is greater than that of buccal impaction in terms of angulation to the midline and horizontal overlap.


Assuntos
Maxila , Dente Impactado , Estudos Transversais , Dente Canino/diagnóstico por imagem , Feminino , Humanos , Masculino , Maxila/diagnóstico por imagem , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Dente Impactado/diagnóstico por imagem , Dente Impactado/epidemiologia , Dente Impactado/terapia
17.
Artigo em Inglês | MEDLINE | ID: mdl-36078740

RESUMO

Limited long-term data are available when analyzing gingival recession coverage between the maxillary and mandibular sites. Therefore, the aim of this study was to evaluate the influence of location (maxilla versus mandible) of multiple gingival recessions on 24 months clinical and aesthetic outcomes of modified coronally advanced tunnel with subepithelial connective tissue graft. Forty patients with multiple gingival recessions (GR) located at maxillary or mandibular teeth were treated between January 2018 and December 2019. Reduction in GR, average root coverage (ARC), complete root coverage (CRC), increase in keratinized tissue width (KTW), increase in gingival thickness (GT), and aesthetic evaluation with the root coverage esthetic score (RES) were evaluated after 24 months. Thirty patients with 270 recessions in the upper teeth and ten patients with 90 recessions in the lower teeth completed the 2-year recall. The differences between preoperative and postoperative clinical parameters showed statistical significance only within but not between groups. ARC at 2 years was 93.31% for maxillary teeth and 93.06% for mandibular teeth (p = 0.7906). Mean RES values were comparable for upper and lower teeth (9.25 versus 8.92, respectively, p = 0.6733). However, upper teeth achieved significantly higher scores for marginal tissue contour (MTC), muco-gingival junction alignment (MGJ), and gingival color (GC). Lower teeth had decreased chances of receiving better RES (OR = 0.49, CI 0.24-0.99, p = 0.0457) in regression analysis, when compared with upper teeth. MCAT + SCTG achieved comparably favorable 2-year outcomes for the treatment of multiple GR in upper and in lower teeth. However, the individual RES components were higher in maxillary teeth, and upper teeth had higher odds of receiving better RES.


Assuntos
Retração Gengival , Tecido Conjuntivo/transplante , Estética , Gengiva/transplante , Retração Gengival/cirurgia , Humanos , Mandíbula/cirurgia , Maxila/cirurgia , Estudos Retrospectivos , Retalhos Cirúrgicos/cirurgia , Raiz Dentária/cirurgia , Resultado do Tratamento
18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 869-872, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36086290

RESUMO

Surgical drilling to place dental implants in the mandible and maxilla is associated high risk of iatrogenic injuries to inferior alveolar nerve and maxillary sinus. Real-time tissue margin sensing at the drill-tip using electrical impedance spectroscopy (EIS) could reduce this risk by providing feedback to surgeons. Studies with saline analogues, ex-vivo tissues, in-situ tissues and computer models have been previously conducted to evaluate these impedance sensors. Understanding in-vivo electrical properties of tissues in the mandible and maxilla is critical to further develop the sensor and tissue margin sensing algorithms. In this paper, we propose an in-vivo animal model using pigs and discuss methods to test the sensor. Intra-operative imaging and optical tracking systems to assist in surgical navigation are described. The process of registering imaging and tracking information to localize impedance measurement sites within the anatomy are detailed. Results from one in-vivo case of drilling through the mandible are presented and discussed. Clinical Relevance- This model is crucial for characterizing in-vivo electrical properties of mandibular and maxillary tissues encountered during dental implant surgical drilling and for translating bioimpedance sensing drill technology to clinical space.


Assuntos
Maxila , Modelos Anatômicos , Animais , Espectroscopia Dielétrica , Impedância Elétrica , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Maxila/cirurgia , Suínos
19.
Chin J Dent Res ; 25(3): 169-177, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36102885

RESUMO

OBJECTIVE: To investigate the synergistic changes of the astrocytes and neurons in the sensorimotor cortex during the process of implant osseointegration after insertion. METHODS: A total of 75 rats were allocated into three groups (n = 25): non-operated, extraction and implant. The rats in the latter two groups underwent extraction surgery of three maxillary right molars. One month later, the implant group received one titanium implant in the healed extraction socket. The rats were sacrificed on days 1, 3, 7, 14 and 28 after implantation. The brain sections, including sensory centre S1 and motor centre M1, were selected for further immunofluorescence for measurement of the synergistic morphological and quantitative changes of astrocytes and neurons. RESULTS: In layer IV of S1, the number of astrocytes in the implant group showed a descending trend with time; on days 1, 3, 7 and 14, the number of astrocytes in both the extraction group and the implant group was significantly higher than that in the non-operated group, and there was no difference between the extraction group and the implant group; however, on day 28, the number of astrocytes in the implant group was significantly lower than that in the extraction group. In layer V of M1, on days 7, 14 and 28, the number of astrocytes in the implant group was significantly lower than that in the extraction group; on days 14 and 28, the number of astrocytes in the extraction group was significantly higher than that in the non-operated group. In layer IV of S1 or layer V of M1, the number of neurons showed no significant changes between the three groups. CONCLUSION: The astrocytes in the face sensorimotor cortex were activated as a reaction to oral environment changes. This kind of neuroplasticity can be reversed by oral rehabilitation with dental implants. The motor cortex may be intimately related to osseointegration and osseoperception.


Assuntos
Implantes Dentários , Córtex Motor , Perda de Dente , Animais , Implantação Dentária Endóssea , Maxila/cirurgia , Córtex Motor/fisiologia , Córtex Motor/cirurgia , Ratos
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