Penn Dental Medicine
Established in 1878, Penn Dental Medicine is among the oldest university-affiliated dental schools in the nation. The school's mission is to transform global oral health and well-being through exceptional clinical care, innovation, education, and research.
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Publication Sagittal and Vertical Changes of the Maxilla after Surgically Assisted Rapid Palatal Expansion: A Systematic Review and Meta-Analysis(MDPI, 2023-05) Lin, Jia-Hong; Wang, Steven; Abdullah, Usama Al; Le, Anh D.; Chung, Chun-Hsi; Li, ChenshuangSurgically assisted rapid palatal expansion (SARPE) is often performed to correct the transverse deficiency in the maxilla for skeletally mature patients. However, there is little consensus on the sagittal and vertical displacement of the maxilla after SARPE. This systematic review aims to analyze the position changes of the maxilla in the sagittal and vertical dimensions after the completion of SARPE. Registered with PROSPERO (registration number: CRD42022312103), this study complied with the 2020 PRISMA guideline and was conducted on 21 January 2023. Original studies were screened from MEDLINE (PubMed), Elsevier (SCOPUS), and Cochrane, and supplemented by hand-searching. Cephalometric changes of skeletal vertical and sagittal measurements were the focus. A fixed-effects model was applied in R for meta-analysis. After applying inclusion and exclusion criteria, seven articles were included in the final review. Four studies had a high risk of bias, and the other three had a medium risk of bias. Meta-analysis revealed that the SNA angle increased by 0.50° ± 0.08° (95% confidence interval, 0.33° to 0.66°), and the SN–PP angle increased by 0.60° ± 0.09° (95% confidence interval, 0.41° to 0.79°) after SARPE. In summary, the maxilla displayed statistically significant forward and clockwise downward movement after SARPE. However, the amounts were small and might not be clinically significant. Due to the high risk of bias of included studies, our results must be taken cautiously. Future studies are needed to discern the effects of direction and angulation of the osteotomies of SARPE on the displacement of the maxilla. © 2023 by the authors.Publication Mandibular alveolar bone thickness in untreated Class I subjects with different vertical skeletal patterns: a cone-beam computed tomography study(EH Angle Education and Research Foundation Inc, 2023-11-01) Formosa, Joseph; Zou, Min; Chung, Chun-Hsi; Boucher, Normand S.; Li, ChenshuangObjective: To evaluate the mandibular alveolar bone thickness in untreated skeletal Class I subjects with different vertical skeletal patterns. Materials and Methods: A total of 50 preorthodontic treatment cone-beam computed tomography (CBCT) images of a skeletal Class I Chinese population with near-normal occlusion were selected. The buccal and lingual alveolar bone thicknesses of mandibular canines to second molars were measured at 2 mm below the cementoenamel junction (CEJ), mid-root, and root apex levels. Differences in the measurements were analyzed with Mann-Whitney U-test. The correlation between alveolar bone thickness and the sella-nasion–mandibular plane (SN-MP) angle was calculated using Pearson correlation coefficients and linear regression analysis. Results: Buccal alveolar bone was thinner on all mandibular canines to first molars but thicker on second molars in comparison with lingual alveolar bone. Buccal alveolar bone was within 1 mm at the levels of 2 mm below CEJ and mid-root for the canines and first premolars. Significant differences were detected among subjects with different vertical patterns, with a negative correlation between the SN-MP angle and alveolar thickness, especially in the canine and premolar regions. The thinnest buccal and lingual alveolar bone were detected in the high-angle group canine region (0.50 mm at the levels of 2 mm below CEJ and mid-root for the buccal side, 0.90 mm at the level of 2 mm below the CEJ for the lingual side). Conclusions: To avoid periodontal complications, buccal-lingual movement of the mandibular canines and first premolars should be limited, especially in high-angle patients. Ó 2023 by The EH Angle Education and Research Foundation, Inc.Publication The Mechanical and Clinical Properties of Customized Orthodontic Bracket Systems—A Comprehensive Review(MDPI, 2024-10) Elabed, Issa; Zheng, Zhong; Zhang, Yu; Chung, Chun-Hsi; Li, ChenshuangThe rise of computer-aided design and computer-aided manufacturing (CAD/CAM) and 3D printing technologies in orthodontics has revolutionized the development of customized labial and lingual bracket systems with a variety of materials, which offer potential advantages over traditional orthodontic brackets. To highlight the current state of knowledge regarding the mechanical and clinical properties of CAD/CAM and 3D-printed custom bracket systems, we conducted a comprehensive search across the PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases to identify relevant articles published before April 2024. Mechanical (including fracture toughness, hardness, modulus of elasticity, frictional resistance, slot accuracy, torque transmission, and shear bond strength) and clinical (including treatment efficiency and duration, cost, and comfort) properties were compared between traditional and customized orthodontic bracket systems in the current review. Our findings suggest that customized brackets have the potential to increase bracket slot precision, reduce treatment time, and offer cost-efficiency. However, it is worth noting that the advantages and disadvantages of customized bracket systems vary depending on the bracket material and the manufacturing methods, warranting comprehensively controlled investigations in the future. © 2024 by the authors.Publication Accurate gingival segmentation from 3D images with artificial intelligence: an animal pilot study(Springer, 2023-12) Yang, Min; Li, Chenshuang; Yang, Wen; Chen, Chider; Chung, Chun-Hsi; Tanna, Nipul; Zheng, ZhongBackground: Gingival phenotype plays an important role in dental diagnosis and treatment planning. Traditionally, determining the gingival phenotype is done by manual probing of the gingival soft tissues, an invasive and time-consuming procedure. This study aims to evaluate the feasibility and accuracy of an alternatively novel, non-invasive technology based on the precise 3-dimension (3D) soft tissue reconstruction from intraoral scanning and cone beam computed tomography (CBCT) to predict the gingival biotype. Methods: As a proof-of-concept, Yorkshire pig mandibles were scanned, and the CBCT data were fed into a deep-learning model to reconstruct the teeth and surrounding bone structure in 3D. By overlaying the CBCT scan with the intraoral scans, an accurate superposition was created and used for virtual measurements of the soft tissue thickness. Meanwhile, gingival thicknesses were also measured by a periodontal probe and digital caliper on the buccal and lingual sides at 3 mm apical to the gingival margin of the posterior teeth and compared with the virtual assessment at the same location. The data obtained from virtual and clinical measurements were compared by Wilcoxon matched-pairs signed-rank analysis, while their correlation was determined by Pearson’s r value. The Mann–Whitney U test was used for intergroup comparisons of the amount of difference. Results: Among 108 investigated locations, the clinical and virtual measurements are strongly positively correlated (r = 0.9656, P < 0.0001), and only clinically insignificant differences (0.066 ± 0.223 mm) were observed between the two assessments. There is no difference in the agreement between the virtual and clinical measurements on sexually matured samples (0.087 ± 0.240 mm) and pre-pubertal samples (0.033 ± 0.195 mm). Noticeably, there is a greater agreement between the virtual and clinical measurements at the buccal sites (0.019 ± 0.233 mm) than at the lingual sites (0.116 ± 0.215 mm). Conclusion: In summary, the artificial intelligence-based virtual measurement proposed in this work provides an innovative technique potentially for accurately measuring soft tissue thickness using clinical routine 3D imaging systems, which will aid clinicians in generating a more comprehensive diagnosis with less invasive procedures and, in turn, optimize the treatment plans with more predictable outcomes. © 2023, The Author(s).Publication Transverse dentoalveolar development in Chinese children and adolescents: A cross-sectional study using revised Andrews’ Element III analysis(Elsevier, 2024) Shen, Jie; Liu, Zhongyu; Shuai, Jing; Yin, Yijia; Wang, Zheng; Ding, Wanghui; Chung, Chun-Hsi; Chen, Qianming; Zhao, XuefengIntroduction: This study investigated the prevalence of maxillary transverse deficiency (MTD) in Chinese children and adolescents using revised Andrews’ Element III analysis and studied transverse developmental characteristics of the maxillomandibular complex. Methods: Plaster or digital casts of 794 participants aged 7-18 years were evaluated. MTD was diagnosed when the maxilla-mandible width difference, represented by the decompensated maxillary and mandibular first molars, exceeded 4 mm. Results: The average prevalence of MTD among patients aged 7-18 years was 31.1%. Patients with MTD exhibited narrower maxillary and/or wider mandibular arches. Strikingly, 32.3% of participants with posterior crossbite because of local crowding or mandibular deviation were not diagnosed with MTD. Dental compensation, such as a greater buccolingual inclination of the first molars, was common in patients with MTD. Transverse growth of the maxillomandibular complex was completed by 17 years old, with the maxilla undergoing greater transverse growth than the mandible. The physiological buccolingual inclination of first molars was observed in patients without MTD. The 95% reference value of the palatal arch width was 31.9-42.3 mm. Conclusions: The prevalence of MTD is 31.1% among Chinese children and adolescents. However, it is often camouflaged by dental compensation and sagittal discrepancy. The etiology of MTD is uncoordinated width in the maxillomandibular complex, which is not solely attributed to a narrow maxilla but also to an excessively wide mandible. To enhance diagnostic accuracy, individualized measurements of the maxillomandibular complex and a revised dental decompensation formula, rather than posterior crossbite alone, are recommended for transverse diagnosis. A potential presence of MTD is indicated when the palatal arch width is <31.9 mm. © 2024 American Association of OrthodontistsPublication Periodontal and orthodontic management of impacted canines(Wiley, 2024) Qali, Mohammad; Li, Chenshuang; Chung, Chun-Hsi; Tanna, NipulThe maxillary and mandibular canines are described by many clinicians as the “cornerstone” of the arch. When in their optimal position, they play a critical role in providing a well-balanced occlusal scheme that contributes toward functional as well as neuromuscular stability, harmony, esthetics, and dentofacial balance. When an aberration is noted with the normal eruptive and development process, early diagnosis with strategic intervention is critical and may often require a multidisciplinary approach. A proper diagnosis, risk assessment, and management of the soft tissues, hard tissues, and adjacent structures are vital for a successful outcome. This review highlights the diagnostic and treatment modalities that require consideration for the orthodontic as well as the periodontal management of impacted canines. The reader is guided through the etiology, diagnosis, prevention, and intervention of clinical cases that were managed with different approaches. © 2024 The Author(s). Periodontology 2000 published by John Wiley & Sons Ltd.Publication ffects of Plasma Treatment on the Strength of Bonding to Ceramic Surfaces in Orthodontics—A Comprehensive Review(MDPI, 2023-11) Gershater, Elizabeth; Griswold, Olivia; Talsania, Brooke E.; Zhang, Yu; Chung, Chun-Hsi; Zheng, Zhong; Li, ChenshuangOver the past several decades, orthodontic treatment has been increasingly sought out by adults, many of whom have undergone restorative dental procedures that cover enamel. Because the characteristics of restorative materials differ from those of enamel, typical bonding techniques do not yield excellent restoration–bracket bonding strengths. Plasma treatment is an emerging surface treatment that could potentially improve bonding properties. The purpose of this paper is to evaluate currently available studies assessing the effect of plasma treatment on the shear bond strength (SBS) and failure mode of resin cement/composite on the surface of ceramic materials. PubMed and Google Scholar databases were searched for relevant studies, which were categorized by restorative material and plasma treatment types that were evaluated. It was determined that cold atmospheric plasma (CAP) treatment using helium and H2O gas was effective at raising the SBS of feldspathic porcelain to a bonding agent, while CAP treatment using helium gas might also be a potential treatment method for zirconia and other types of ceramics. More importantly, CAP treatment using helium has the potential for being carried out chairside due to its non-toxicity, low temperature, and short treatment time. However, because all the studies were conducted in vitro and not tested in an orthodontic setting, further research must be conducted to ascertain the effectiveness of specific plasma treatments in comparison to current orthodontic bonding treatments in vivo. © 2023 by the authors.Publication Vertical Control in Molar Distalization by Clear Aligners: A Systematic Review and Meta-Analysis(MDPI, 2024-05) Park, Tiffany H.; Shen, Christie; Chung, Chun-Hsi; Li, ChenshuangBackground: Molar distalization is used to correct molar relationships or to create space for mild anterior crowding. However, whether clear aligners can provide proper vertical control with the sequential distalization strategy has been highly debated. Thus, the current study aimed to systematically review the amount of dentoskeletal changes in the vertical dimension that results from sequential molar distalization in clear aligner therapy without temporary anchorage devices (TADs). Methods: Registered with PROSPERO (CRD42023447211), relevant original studies were screened from seven databases and supplemented by a manual search by two investigators independently. Articles were screened against inclusion and exclusion criteria, and a risk of bias assessment was conducted for each included article. Relevant data were extracted from the included articles and meta-analysis was performed using RStudio. Results: Eleven articles (nine for maxillary distalization and two for mandibular distalization) were selected for the final review. All studies have a high or medium risk of bias. For maxillary molar distalization, the meta-analysis revealed 0.26 mm [0.23 mm, 0.29 mm] of maxillary first molar intrusion based on post-distalization dental model analysis, as well as 0.50 mm [−0.78 mm, 1.78 mm] of maxillary first molar intrusion and 0.60 mm [−0.42 mm, 1.62 mm] of maxillary second molar intrusion based on post-treatment lateral cephalometric analysis. Skeletally, there was a −0.33° [−0.67°, 0.02°] change in the SN-GoGn angle, −0.23° [−0.30°, 0.75°] change in the SN-MP angle, and 0.09° [−0.83°, 1.01°] change in the PP-GoGn angle based on post-treatment lateral cephalometric analysis. There was insufficient data for meta-analysis for mandibular molar distalization. Conclusions: No significant changes in vertical dimension were observed, both dentally and skeletally, after maxillary molar distalization with a sequential distalization strategy. However, further studies on this topic are needed due to the high risk of bias in the currently available studies. © 2024 by the authors.Publication Csf1 from marrow adipogenic precursors is required for osteoclast formation and hematopoiesis in bone(eLife, 2023-02-13) Zhong, Leilei; Lu, Jiawei; Fang, Jiankang; Yao, Lutian; Yu, Wei; Gui, Tao; Duffy, Michael; Holdreith, Nicholas; Bautista, Catherine A.; Huang, Xiaobin; Bandyopadhyay, Shovik; Tan, Kai; Chen, Chider; Choi, Yongwon; Jiang, Jean X.; Yang, Shuying; Tong, Wei; Dyment, Nathanial; Qin, LingColony-stimulating factor 1 (Csf1) is an essential growth factor for osteoclast progenitors and an important regulator for bone resorption. It remains elusive which mesenchymal cells synthesize Csf1 to stimulate osteoclastogenesis. We recently identified a novel mesenchymal cell population, marrow adipogenic lineage precursors (MALPs), in bone. Compared to other mesenchymal subpopulations, MALPs expressed Csf1 at a much higher level and this expression was further increased during aging. To investigate its role, we constructed MALP-deficient Csf1 CKO mice using AdipoqCre. These mice had increased femoral trabecular bone mass, but their cortical bone appeared normal. In comparison, depletion of Csf1 in the entire mesenchymal lineage using Prrx1Cre led to a more striking high bone mass phenotype, suggesting that additional mesenchymal subpopulations secrete Csf1. TRAP staining revealed diminished osteoclasts in the femoral secondary spongiosa region of Csf1 CKOAdipoq mice, but not at the chondral-osseous junction nor at the endosteal surface of cortical bone. Moreover, Csf1 CKOAdipoq mice were resistant to LPS-induced calvarial osteolysis. Bone marrow cellularity, hematopoietic progenitors, and macrophages were also reduced in these mice. Taken together, our studies demonstrate that MALPs synthesize Csf1 to control bone remodeling and hematopoiesis. © 2023, Zhong et al.Publication Advancing collagen-based biomaterials for oral and craniofacial tissue regeneration(Springer, 2023-12) Zhang, Bo; He, Yunxiang; Liu, Jialing; Shang, Jiaojiao; Chen, Chider; Wang, Tianyi; Chen, Mei; Li, Yifei; Gong, Guidong; Fang, Jie; Zhao, Zhihe; Guo, JunlingThe oral and craniofacial region consists of various types of hard and soft tissues with the intricate organization. With the high prevalence of tissue defects in this specific region, it is highly desirable to enhance tissue regeneration through the development and use of engineered biomaterials. Collagen, the major component of tissue extracellular matrix, has come into the limelight in regenerative medicine. Although collagen has been widely used as an essential component in biomaterial engineering owing to its low immunogenicity, high biocompatibility, and convenient extraction procedures, there is a limited number of reviews on this specific clinic sector. The need for mechanical enhancement and functional engineering drives intensive efforts in collagen-based biomaterials concentrating on therapeutical outcomes and clinical translation in oral and craniofacial tissue regeneration. Herein, we highlighted the status quo of the design and applications of collagen-based biomaterials in oral and craniofacial tissue reconstruction. The discussion expanded on the inspiration from the leather tanning process on modifications of collagen-based biomaterials and the prospects of multi-tissue reconstruction in this particular dynamic microenvironment. The existing findings will lay a new foundation for the optimization of current collagen-based biomaterials for rebuilding oral and craniofacial tissues in the future. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Author(s).