scholarly journals A Cross-Sectional Study of Labial Bone and Covering Soft Tissue in Maxillary Anterior Segment: A Dilemma in Orthodontics

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Saeed Yousefzadeh ◽  
Maryam Johari ◽  
Sedigheh Sheikhzadeh ◽  
Sina Haghanifar ◽  
Hemmat Gholinia ◽  
...  

Purposes. The thickness of the buccal bone and its covering gingiva is pivotal in determining the prognosis of implant therapy as well as fixed orthodontic appliances, especially nonextraction treatments. The purpose of this study was to evaluate the buccal bone thickness and covering soft tissue in the maxillary anterior segment. Methods. This study measured the hard tissue thickness at 2 and 5 mm more apical from the crest and at the root apical apex, as well as the distance from the CEJ to the alveolar crest, using 80 CBCT images divided into three age groups. In addition, the distance from free gingiva to alveolar crest and from free gingiva to CEJ was measured. The acquired data then was analyzed using an ANOVA, t-test, and Pearson correlation to investigate any associations or statistically significant differences between parameters. Results. The highest mean soft tissue thickness at the 5 mm level was for central incisors and the least for canine. The highest mean thickness of soft tissue at the crest level and its 2 mm apical level was related to central incisors and the lowest mean thickness at these levels was related to canine. Analysis of hard tissue variables showed the lower thickness of hard tissue at higher ages compared to the young patients group, but the thickness of the soft tissue increases with age. Conclusion. The highest mean thickness of the buccal hard tissue in the maxillary anterior segment was in lateral and central incisors. Also, the most prominent thickness of the labial soft tissue was in the central and lateral incisors at levels close to the crest.

2017 ◽  
Vol 10 (3) ◽  
pp. 246-254 ◽  
Author(s):  
Daryoush Karami ◽  
Hamid Reza Alborzinia ◽  
Reza Amid ◽  
Mahdi Kadkhodazadeh ◽  
Navid Yousefi ◽  
...  

Application of surgical stents for implant placement via guided flapless surgery is increasing. However, high cost, need for some professional machines, and not taking into account the soft-tissue parameters have limited their application. We sought to design and introduce a technique named in-office guided implant placement (iGIP) to decrease the cost by using available devices in office and enhance the applicability of surgical stents. A customized surgical stent was fabricated based on prosthetic, soft- and hard-tissue parameters by taking into account the amount of available bone (using the computed tomographic [CT] data), soft-tissue thickness and contour (using a composite-covered radiographic stent), and position of the final crown (by diagnostic cast wax up and marking the final crown position with composite). The efficacy of iGIP, in terms of the accuracy of the three-dimensional position of the implant placed in the study cast and in patient's mouth, was confirmed by direct observation and postoperative CT. The iGIP can enhance implant placement in the prosthetically desired position in various types of edentulism. Using this technique minimizes the risk of unwanted consequences, as the soft-tissue thickness and contour are taken into account when fabricating a surgical stent.


2021 ◽  
Vol 15 (5) ◽  
pp. 1629-1634
Author(s):  
Saba Safarzadeh ◽  
Mohammad Monirifard ◽  
Farinaz Shirban

Background: The soft tissue thickness is affected by anterior posterior skeletal relationship. This study has been designed to evaluate the soft tissue thickness among different anterior posterior skeletal classifications. Material and Methods: In this cross-sectional study, 206 digital lateral cephalometric radiographs from patients undergoing treatment at several orthodontic clinics were evaluated. The skeletal group was determined by the ANB angle. The planned points were determined on digital radiographs using the Digimizer.V4.1.1.0 and then the measurements were done. Data were analyzed by Kruskal-Wallis, Mann-Whitney, Pearson Correlation and Spearman tests. Results: Significant difference showed between soft tissue thickness at Subnasale between class I and II, at Subnasale, Labrale Superius, Stomion Superius, Stomion Inferius between class I and III and at Subnasale, Labrale Superius, Stomion Superius, Stomion Inferius, between class II and III. Among the women, soft tissue thickness at subnasale were higher in class I group compared to class II, Subnasale, Labrale Superius, Stomion Superius, Stomion Inferius were higher in class III compared to class I and at Labrale Inferius was higher in class II compared to class III. Among the men, soft tissue thickness at Stomion Superius, Stomion Inferius and Labrale Superius were higher in class III group compared to class I and II. Conclusion: We established that soft tissue thickness in some landmarks were significantly different between skeletal groups and gender. There is a correlation in soft tissue thickness and skeletal relationship at Stomion Inferius, Subnasale, Labrale Superius, Stomion Superius. Keywords: Soft Tissue, Skeletal Classification, Cephalometry


2019 ◽  
Vol 23 (3) ◽  
pp. 297-302 ◽  
Author(s):  
Julia D. Sharma ◽  
Kiran K. Seunarine ◽  
Muhammad Zubair Tahir ◽  
Martin M. Tisdall

OBJECTIVEThe aim of this study was to compare the accuracy of optical frameless neuronavigation (ON) and robot-assisted (RA) stereoelectroencephalography (SEEG) electrode placement in children, and to identify factors that might increase the risk of misplacement.METHODSThe authors undertook a retrospective review of all children who underwent SEEG at their institution. Twenty children were identified who underwent stereotactic placement of a total of 218 electrodes. Six procedures were performed using ON and 14 were placed using a robotic assistant. Placement error was calculated at cortical entry and at the target by calculating the Euclidean distance between the electrode and the planned cortical entry and target points. The Mann-Whitney U-test was used to compare the results for ON and RA placement accuracy. For each electrode placed using robotic assistance, extracranial soft-tissue thickness, bone thickness, and intracranial length were measured. Entry angle of electrode to bone was calculated using stereotactic coordinates. A stepwise linear regression model was used to test for variables that significantly influenced placement error.RESULTSBetween 8 and 17 electrodes (median 10 electrodes) were placed per patient. Median target point localization error was 4.5 mm (interquartile range [IQR] 2.8–6.1 mm) for ON and 1.07 mm (IQR 0.71–1.59) for RA placement. Median entry point localization error was 5.5 mm (IQR 4.0–6.4) for ON and 0.71 mm (IQR 0.47–1.03) for RA placement. The difference in accuracy between Stealth-guided (ON) and RA placement was highly significant for both cortical entry point and target (p < 0.0001 for both). Increased soft-tissue thickness and intracranial length reduced accuracy at the target. Increased soft-tissue thickness, bone thickness, and younger age reduced accuracy at entry. There were no complications.CONCLUSIONSRA stereotactic electrode placement is highly accurate and is significantly more accurate than ON. Larger safety margins away from vascular structures should be used when placing deep electrodes in young children and for trajectories that pass through thicker soft tissues such as the temporal region.


2021 ◽  
pp. 200460
Author(s):  
Diana Toneva ◽  
Silviya Nikolova ◽  
Stanislav Harizanov ◽  
Dora Zlatareva ◽  
Vassil Hadjidekov

Author(s):  
Mohammed Mousa Bakri ◽  
Sung Ho Lee ◽  
Jong Ho Lee

Abstract Background A compact passive oxide layer can grow on tantalum (Ta). It has been reported that this oxide layer can facilitate bone ingrowth in vivo though the development of bone-like apatite, which promotes hard and soft tissue adhesion. Thus, Ta surface treatment on facial implant materials may improve the tissue response, which could result in less fibrotic encapsulation and make the implant more stable on the bone surface. The purposes of this study were to verify whether surface treatment of facial implant materials using Ta can improve the biohistobiological response and to determine the possibility of potential clinical applications. Methods Two different and commonly used implant materials, silicone and expanded polytetrafluoroethylene (ePTFE), were treated via Ta ion implantation using a Ta sputtering gun. Ta-treated samples were compared with untreated samples using in vitro and in vivo evaluations. Osteoblast (MG-63) and fibroblast (NIH3T3) cell viability with the Ta-treated implant material was assessed, and the tissue response was observed by placing the implants over the rat calvarium (n = 48) for two different lengths of time. Foreign body and inflammatory reactions were observed, and soft tissue thickness between the calvarium and the implant as well as the bone response was measured. Results The treatment of facial implant materials using Ta showed a tendency toward increased fibroblast and osteoblast viability, although this result was not statistically significant. During the in vivo study, both Ta-treated and untreated implants showed similar foreign body reactions. However, the Ta-treated implant materials (silicone and ePTFE) showed a tendency toward better histological features: lower soft tissue thickness between the implant and the underlying calvarium as well as an increase in new bone activity. Conclusion Ta surface treatment using ion implantation on silicone and ePTFE facial implant materials showed the possibility of reducing soft tissue intervention between the calvarium and the implant to make the implant more stable on the bone surface. Although no statistically significant improvement was observed, Ta treatment revealed a tendency toward an improved biohistological response of silicone and ePTFE facial implants. Conclusively, tantalum treatment is beneficial and has the potential for clinical applications.


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