Scientific Letters

Efficiency and predictability of maxillary expansion with Invisalign® system

Ana Sofia Rocha, Maria Gonçalves, Ana Catarina Oliveira, Teresa Pinho — Wed, 10 Apr 2024 00:00:00 +0100

The Invisalign^® system aims to ensure aesthetics and achieve positive clinical results; however, its efficacy is still debatable. Along with lower incisor intrusion and upper molar distalization, arch expansion is one of the most predictable movements that may be achieved using clear aligners. This makes the system a conceivable method for the correction of crowding and posterior dentoalveolar crossbites. The aim of this study is to analyze the effectiveness and predictability of tooth expansion in permanent dentition with Invisalign^® orthodontic aligners. A bibliographic search was carried out using the PubMed and EBSCOhost databases. Articles published between 2013 and 2023 and written in English were selected. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After a thorough review, 12 articles were included. In terms of efficiency, most studies showed an increase in all interdental measurements, with premolars showing the greatest expansion. On the other hand, predictability was weaker, as significant differences were found between the post-treatment models and the ClinCheck^® software virtual model for some interdental measurements. We concluded that the Invisalign^® system is effective in producing expansion movement, with reasonable predictability.

Four-millimeter implants supporting unsplinted metal-ceramic screw-retained crowns in posterior jaw: a retrospective case series

Mon, 08 Apr 2024 00:00:00 +0100

Little is known about the clinical performance of unsplinted crowns supported by 4-mm implants. The objective of this investigation was to evaluate the clinical performance of extra-short implants supporting single restorations. A retrospective cross-sectional study design was used and included patients treated with 4-mm implants between 2014 and 2017. The influence of crown-to-implant ratio (CI ratio), age, sex, bleeding on probing, type of arch, implant diameter, occlusion antagonist and functional loading time on mesial and distal marginal bone loss around the implants were analyzed using univariate and multivariate linear regression models. A total of 27 cone morse dental implants with 4 mm was evaluated after a minimum post-loading time of 12 months. One implant was lost after loading, leading to an implant survival percentage equal to 96,3%. No other failure conditions were observed. From the variables analyzed herein, only CI ratio, functional loading time and sex were significantly associated with marginal bone loss on the mesial site of implants; and only CI ratio, functional loading time and bleeding on probing were associated with marginal bone loss on the distal site of implants. The present results suggest that 4-mm implants placed in the posterior maxilla and mandible to support unsplinted metal-ceramic screw-retained crowns may be a very promising alternative in order to enable the rehabilitation of posterior edentulous patients, who are unable or unwilling to undergo bone grafting procedures with high morbidity. However, further prospective long-term studies should confirm if this is a viable treatment option.

Targeting p31comet to Enhance Cisplatin-induced Cytotoxicity in Oral Squamous Cell Carcinoma Cells

Wed, 17 Apr 2024 00:00:00 +0100

p31^comet plays a crucial role in silencing the spindle assembly checkpoint during mitosis. This study aimed to investigate whether p31^comet knockdown could enhance cisplatin-induced cytotoxicity in oral cancer cells. We assessed p31^comet expression in oral squamous cell carcinoma (OSCC) cells and examined the impact of p31^comet knockdown, cisplatin treatment, and their combination on OSCC cell viability and colony formation ability. Our findings indicated an upregulation of p31^comet at both mRNA and protein levels in OSCC cells compared with non-cancer cells. Knockdown of p31^comet amplified the inhibitory effects of cisplatin on OSCC cell viability and colony formation, particularly in cells more resistant to cisplatin. This suggests that exploring the combination of p31^comet inhibition and cisplatin could be a potentially promising strategy to enhance sensitivity of oral cancer cells to cisplatin.

The Use of Artificial Intelligence to Create a Virtual Patient for Oral and Maxillofacial Surgical Planning

Thu, 18 Apr 2024 00:00:00 +0100

The advancement of digital image acquisition technologies in dentistry has facilitated the creation of virtual patients through the integration of two- and three-dimensional (2D and 3D) images within digital platforms. These images, sourced from technologies such as Cone Beam Computed Tomography (CBCT), intraoral scanners (IOS), and 3D facial scanners, can be aligned and merged to comprehensively assess the bone structure, gingival and soft tissues, and the dentition. Additionally, 2D clinical photographs are incorporated into the digital project, enhancing aesthetic analysis and planning. Artificial intelligence (AI) algorithms can also be used to enhance and facilitate 3D image alignment. However, detailed information on digital workflows to work with virtual patients for dental and maxillofacial treatment planning is lacking in the literature. The purpose of this article is to describe a technique to create a virtual patient to assess the relationship between the patient’s soft and hard tissues with the optional use of AI to enhance the quality of 3D-reconstructed models from CBCT. Within the limitations of this study, the technique described herein is suggested to be useful for prosthetically-driven treatment planning of surgical procedures such as crown lengthening, bone grafts and dental implant placement.

Editorial Acknowledgment to Reviewers of Scientific Letters in 2023

Hassan Bousbaa — Mon, 08 Jan 2024 00:00:00 +0000

Our commitment to prioritizing quality over quantity in the papers published in Scientific Letters remains steadfast. The overall quality of the journal is greatly indebted to the dedicated work of the Reviewers listed below. These Reviewers are chosen based on their expertise and, throughout 2023, we have been impressed by the consistently high quality of their evaluations. Reviewers selflessly invest their time to assist Authors in refining their manuscripts. It is noteworthy that a significant portion of the Reviews were submitted within the designated two-week timeframe. On behalf of the Editorial Team, I express my sincere appreciation for their exceptional contributions and eagerly anticipate continued collaboration in 2024!

Baltazar, Fátima

Bousbaa, Hassan

Caldas, Inês

Cunha, Andrea

De Marco, Paolo

Kim, Jun Ho

Pérez-Mongiovi, Daniel

Queirós, Odília

Raemdonck, Kristof

Resende, Albina Dolores

Ricardo, Sara

Schmitt, Fernando

The Brightness of Multidisciplinary Approaches in Health Sciences Research

Tue, 09 Jan 2024 00:00:00 +0000

On behalf of the Editorial Team of Scientific Letters journal, we are pleased to announce the publication of the second issue. The second issue comprises four scientific papers, encompassing two reviews and two research articles. In 2023, Scientific Letters also published two special issues in the form of Books of Abstracts. These publications compile all abstracts that were accepted for presentation at the II TOXRUN International Congress and the II UNIPRO International Congress, both held in Portugal. We intend to add “Clinical Case Studies” and “Commentaries” to the list of article types that the journal publishes. We hope you enjoy reading this second issue and find these articles useful for your research. We invite you to submit your best papers for publication.