Challenges and Solutions for Cost-Effective and Practical Dental Cast Fabrication With a Desktop Fused Deposition Modeling (FDM) 3D Printer.

The objective of this study was to investigate the feasibility of using a cost-effective desktop three-dimensional (3D) fused deposition modeling (FDM) printer to fabricate dental casts to overcome the problems of conventional dental plaster casts, such as fragility and low portability. First, a 3D computer-aided design (CAD) model of the dental cast was prepared in the Standard Triangle Language (STL) format. Twelve 3D models were fabricated using a desktop FDM 3D printer under different 3D printing parameters/conditions, including shape, placement direction, and infill percentage.

[Long-Term Response to CDK4/6 Inhibitor for Multiple Metastases of Breast Cancer].

The patient was a 60-year-old woman. She was diagnosed with hypertension, symptomatic epilepsy, renal failure, and cerebral infarction. During follow-up, she was found to have a mass in her left breast and was referred to our department.

[A Case of Ectopic Mediastinal Goiter Developed during Administration of Rheumatrex].

We report a case of ectopic goiter that developed during administration of rheumatrex and in which we had difficulty in differentiating it. A 46-year-old woman had been diagnosed with rheumatoid arthritis(RA) and had been taking rheumatrex(12.5 mg/week)for the past 2 years.

The dimensions of preformed nickel-titanium archwires measured at the bracket positions corresponding to the central incisor, canine, and first molar.

Introduction: Variation in the thickness of commercially available preformed rectangular archwires at the bracket positions has not been thoroughly studied. Therefore, this study measured the edgewise (height) and flatwise (width) dimensions of preformed rectangular nickel-titanium (NiTi) archwires at bracket positions corresponding to the central incisor, canine, and first molar and compared them among bracket positions.

Methods: Sixty types of preformed rectangular NiTi mandibular archwires indicated as 0.

Dimensional changes over time in stereolithographic models fabricated with a 3D printer.

This study aimed to ascertain the effects of the shape of stereolithographic models fabricated with a three-dimensional (3D) printer and the use of different types of liquid resin on the dimensional changes of these models over time, to obtain valuable information for determining the period for which such models can be used following fabrication. Stereolithography models with the shape of a large truncated cone or a small truncated cone were fabricated using liquid resin as surgical guides (Group G) or master casts (Group M). (four groups in total, each n = 11).

Evaluation of peri-implant bone defects on cone-beam computed tomography and the diagnostic accuracy of detecting these defects on panoramic images.

Purpose: This study was conducted to identify the typical sites and patterns of peri-implant bone defects on cone-beam computed tomography (CBCT) images, as well as to evaluate the detectability of the identified bone defects on panoramic images.

Materials And Methods: The study population included 114 patients with a total of 367 implant fixtures. CBCT images were used to assess the presence or absence of bone defects around each implant fixture at the mesial, distal, buccal, and lingual sites.

Factors Related to Masticatory Rhythm in Patients with Oral Tumors.

Older adults who have undergone surgery for oral tumors are at increased risk of impaired masticatory rhythm. This study investigated the correlations between masticatory rhythm, objective masticatory performance, and subjective masticatory performance as well as factors related to masticatory rhythm. The participants were 44 adults (24 men, 20 women; age range 42~90 years old) who had undergone maxillectomy, mandibulectomy, or glossectomy and were rehabilitated with a maxillofacial prosthesis.

Frequently used extraoral maxillofacial prosthetic materials and their longevity - A comprehensive review.

The longevity of an extraoral prosthesis depends on its physical and mechanical properties and user maintenance. Faced with multiple outcome measures, researchers find it difficult to determine the most appropriate extraoral prosthetic material. This comprehensive review evaluates the most used extraoral prosthesis materials and qualitatively assesses their longevity and function.

Advancing maxillofacial prosthodontics by using pre-trained convolutional neural networks: Image-based classification of the maxilla.

Purpose: The study aimed to compare the performance of four pre-trained convolutional neural networks in recognizing seven distinct prosthodontic scenarios involving the maxilla, as a preliminary step in developing an artificial intelligence (AI)-powered prosthesis design system.

Materials And Methods: Seven distinct classes, including cleft palate, dentulous maxillectomy, edentulous maxillectomy, reconstructed maxillectomy, completely dentulous, partially edentulous, and completely edentulous, were considered for recognition. Utilizing transfer learning and fine-tuned hyperparameters, four AI models (VGG16, Inception-ResNet-V2, DenseNet-201, and Xception) were employed.

Assessment of the color stability of two silicone elastomers for maxillofacial prostheses upon exposure to cold beverages.

Purpose: This study investigated the color stability of different commercially available silicone materials for facial prostheses upon exposure to everyday beverages. It was hypothesized that the beverages would not alter the color of the silicone under conditions simulating daily exposure.

Methods: Sixty specimens were fabricated using two materials - VST-50 and Silfy - and exposed to commercially available cold mineral water, tea, or coffee.

Evaluation of the color stability of three maxillofacial silicone materials after exposure to beverages: An in vitro study.

Purpose: Oral cancer often requires treatments like surgical intervention, involving surgical resection of lips and other facial parts. For those patients, prosthetic rehabilitation following surgery promotes social reintegration. This study explores the color stability of various commercially available silicone materials for facial prostheses when exposed to everyday beverages like coffee and tea.

Time-study research on maxillofacial prosthetic treatment.

Unreasonable medical fees can cause problems such as increased medical costs, greater medical disparities, decreased medical standards, and physician shortages. To prevent such problems, it is important to set appropriate medical fees, ensure their proper use, and improve the efficiency of medical care. The treatment of patients with maxillofacial defects is generally more expensive compared with general prosthodontic treatment because it involves more materials and requires more frequently follow-ups for longer period.

Digital design of open hollow obturator framework using existing dentures: A dental technique.

Computer-aided design and computer-aided manufacturing technology has been applied to the fabrication of maxillary obturator frameworks, both directly and indirectly. However, with earlier techniques, it was not possible to accurately determine the position of the framework conforming to the palate, an issue that has been resolved in current fabrication methods. Using the patient's existing denture, prosthodontists can determine where the framework should be positioned in the defect area.

Case report of a patient with mandibulectomy followed up for 11 years.

Mandibular deviation and rotation following mandibulectomy can significantly impact oral function and quality of life. The postoperative course of a 57-year-old patient who underwent mandibulectomy for oral cancer and findings over 11 years of follow-up observation to monitor changes in the mandibular position are described here. Based on the observations, it is important to raise awareness regarding the necessity of continued monitoring of mandible position and regular adjustments of prostheses for patients who have undergone mandibulectomy.

Creating and analyzing digital scans of a mandibulectomy cast with simulated trismus.

Statement Of Problem: Trismus associated with maxillofacial defects resulting from tumor resection or radiotherapy can make dental treatment uncomfortable for patients. Using an intraoral scanner instead of making a conventional impression could help to make prosthetic rehabilitation more comfortable. However, limited information is available regarding the feasibility and accuracy of intraoral scanners for scanning mandibular defects.

Use of digital technology in prosthesis fabrication for an elderly patient with a maxillectomy and severe trismus: A clinical report.

This clinical report describes a novel approach based on digital technology to fabricate a maxillofacial prosthesis for a 90-year-old woman with severe trismus who had undergone maxillectomy on the right side. The approach was safe, rapid, and less burdensome on this elderly patient, and the storage and communication of intraoral and maxillofacial prosthesis data without temporal and spatial constraints was helpful. A combination of digital and analog technology provided a maxillofacial prosthesis that improved the quality of life of this elderly patient with head and neck cancer and severe trismus.

Combined digital-conventional workflow to fabricate a definitive obturator from an interim obturator for a patient with an anterior maxillectomy defect.

An existing interim obturator can be reproduced as the definitive one using digital technology, with benefits for a patient with a maxillectomy. By digitally scanning the oral condition and the existing interim obturator, a definitive obturator, including a computer-aided designed and computer-aided manufactured metal framework, was fabricated and delivered to a patient with an anterior maxillectomy defect by following a combined digital and conventional workflow. This technique can hasten the adaptation of the patient to the new obturator and ensure a more comfortable and safer clinical procedure.

Lingual nerve impairment/injury after retrieval of the displaced mandibular third molar into the floor of the mouth.

Retrieval of the displaced mandibular third molar in the floor of the mouth is challenging as the lingual nerve is always at risk of injury. However, there are no available data to show the incidence of the injury caused by the retrieval. The goal of this review article is to provide the incidence of the iatrogenic lingual nerve impairment/injury caused by the retrieval based on the review of the existing literature.

Buccal Nerve Trunk Block Anesthetizes the Buccal Mucosa Beyond the Papilla of the Parotid Duct.

Purpose: The limited area of anesthesia of the buccal mucosa with concomitant conventional buccal nerve block (conventional BNB) may be involved in failed inferior alveolar nerve block (IANB). The aims of this study were to examine the extent of anesthesia by buccal nerve trunk block (BNTB) and compare the success rates of IANB with BNB.

Methods: This prospective parallel-group randomized single-blinded clinical trial included patients scheduled for removal of a mandibular third molar at the Nippon Dental University Hospital between September 2021 and March 2022.

Differences in periodontal parameters between SPT patients who regularly and irregularly visited the dental clinic analyzed at tooth level: a 14-year retrospective cohort study.

The purpose of this study was to evaluate the periodontal status of patients who routinely did SPT, when compared to patients that did not SPT. This retrospective cohort study was conducted at a general dental office from 2001 to 2019. Patients aged 18 to 81 years who visited the dental office over a 10-year period were assigned into two groups: an SPT group, which included patients who continually visited the dental office for SPT one or more times every year, and an irregular group, consisting of patients who did not visit the dental office at least once a year.

Usefulness of preoperative computed tomography findings for airway management in patients with acute odontogenic infection: a retrospective study.

Odontogenic infection is more likely to affect the airway and interfere with intubation than non-odontogenic causes. Although anesthesiologists predict the difficulty of intubation and determine the method, they may encounter unexpected cases of difficult intubation. An inappropriate intubation can cause airway obstruction due to bleeding and edema by damaging the pharynx and larynx.

Application of Medical Imaging and 3D Printing Technology in Teaching the Handling of Novel Medicine in Periodontal Surgery.

Recently, fibroblast growth factor-2 (FGF-2) agents for periodontal tissue regeneration have been increasingly applied to the treatment of periodontal disease. Our current challenge for resident dentists with little clinical experience is to enhance instruction in the handling of new medicine in addition to teaching conventional procedures in periodontal tissue regeneration. This report describes using case-specific, cost-effective three-dimensional (3D) models for dentists' lectures and periodontal surgical training.