Digitization in Skin Shade Matching for Maxillofacial Prostheses: A Systematic Review

Color matching of maxillofacial prostheses for the restoration of maxillofacial defects is an important factor for esthetic results. Various methods have been introduced for the accurate and reliable color matching of prostheses with the skin color of patients. A systematic review was conducted to search the existing literature on color-matching digital techniques for maxillofacial prostheses. An electronic literature search was conducted in PubMed/Medline, Scopus, and Web of Science from January 2000 to December 2022 using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Two independent reviewers conducted the search. Eight articles that fulfilled the inclusion criteria after a full-text evaluation were included in this review. Most of these studies were published in prosthodontics journals and conducted in various countries around the world. A computerized color formulation system was used in three studies; a non-contact spectroradiometer (PR 705; Photo Research Inc., Chatsworth, CA) with a Xenon arc lamp was used in two studies; a mobile phone colorimeter was used in one study; additive manufacturing of 3D facial skin with a spectrophotometer was used in one study; and a recently introduced computerized method known as e-skin (Spectromatch, Bath, UK) was used in two studies. Most of these methods were accurate in color matching, except for the additive manufacturing system, which showed less accuracy, but good repeatability. Owing to a lack of sufficient studies, no method can be labeled as the best method for color-matching maxillofacial prostheses. The latest computerized method, the e-skin, can be used to achieve better accuracy and good color matching. However, further studies are required to validate the use of e-skin for precise color matching.

An in vitro study of digital impressions and three-dimensional printed models of orbital defects using mobile devices and monoscopic photogrammetry

PURPOSE

The purpose of this study was to perform an in vitro evaluation of digital impressions using a mobile device and monoscopic photogrammetry in cases of orbital defects with undercuts.

METHODS

Three 10-mm-square cubes were attached to a diagnostic cast of a patient with a right orbital defect. Still images acquired with a mobile device were used to generate facial three-dimensional (3D) data. Two types of still images were used: one was a whole face image, and the other was a defect site-focused image. For comparison, an extraoral scanner was used to obtain facial 3D data. Five dental technicians fabricated 3D printed models using additive manufacturing and measured the distances between the measurement points using a digital caliper. The discrepancy between the distances measured on the diagnostic cast of the patient and the 3D printed model was calculated. Friedman test was used to analyze the discrepancy, and the Bonferroni test was used to verify the differences between the pairs.

RESULTS

Statistical significance was found with respect to the type of 3D model fabrication method.

CONCLUSION

Within the limitations of this in vitro study, the results suggested that the workflow can be applied to digital impressions of the maxillofacial region.

[Total nasal defect reconstruction with nasal prosthesis. Two case reports]

Total nasal defects after injures or surgical interventions can negatively affect patient's quality of life. Maxillofacial prosthesis is a contemporarily and reliable solution. This method gives us opportunity to restore missing tissues and helps patients to overcome social and psychological difficulties. In this article we demonstrated advantages and disadvantages of the method in two clinical cases. The application of magnetic and adhesive retention in different cases is described. Also, we outlined clinical and technological steps of maxillofacial prosthesis manufacture. Modified procedure of impression obtaining is offered.

Mechanical effects of residual bone mass, a maxillofacial prosthesis, and a reconstruction plate on the mandible after marginal resection

In this study, analytic models were used to simulate marginal resection in the area of the second premolar to the second molar region, and the mechanical effects on the mandible of residual bone mass, a maxillofacial prosthesis, and a reconstruction plate were evaluated by three-dimensional finite element analysis. As residual bone mass decreased, maximum principal stress increased near the anterior ramus of the mandible, and maximum shear stress increased at the anterior buccal region of the resected area. In the mandible with a maxillofacial prosthesis, the maximum principal stress distribution at the anterior ramus was lower, and the distribution of maximum shear stress at the anterior buccal region of the resected area was higher. When a reconstruction plate was used, maximum principal stress and maximum shear stress were lower. Thus, lower residual bone mass was associated with increased mandible deflection and torsion. In addition, presence of a maxillofacial prosthesis decreased deflection but increased torsion, and presence of a reconstruction plate decreased deflection and greatly decreased torsion. These findings suggest that decreased residual bone mass and maxillofacial prostheses increase fracture risk; however, presence of a reconstruction plate was effective in decreasing torsional stress, thereby reducing fracture risk in the mandible.

Retention systems used in maxillofacial prostheses: A review

Defects in the face area caused by trauma, accident, tumor or congenital defects are treated with special facial prostheses. Besides esthetics, the most common problem with these prostheses is the retention of prostheses. In the present article review, the methods used for the retention of prostheses from past to present were researched, and the advantages of adhesives and implants, which are the most commonly used current methods, were evaluated. Current techniques, new materials, treatment options, and implementation procedures are described. The success of maxillofacial prostheses in meeting the expectations of patients and dentist doctors is increasing day by day with the development of adhesive material science, the emergence of technical knowledge, and the development of implant technology. Increasing the retention provides both ease of use and acceptance by the patient. Therefore, the chosen method for retention has great importance in the long-term prognosis of the prosthesis.

Adjuvant therapy for intra oral surgical oncological defect with ancillary prosthesis: A literature review

The role of a maxillofacial prosthodontist in the treatment of facial defects cannot be underestimated. A multidisciplinary approach is required during the rehabilitation procedure to bring out effective results. Ancillary maxillofacial prostheses limit the patient's disability and improve function. These prostheses are inevitable in restoring the function, esthetics, general, and psychological health of the patients. This article reviews the various ancillary-maxillofacial prostheses and throws light on their historical development.

Magnet retained lip prosthesis in a geriatric patient

Surgical resection of lips is a relatively rare procedure. A defective lip may cause the patient to feel socially vulnerable as well as functionally handicapped and the defect will influence the patient's self-esteem and body image. Patients with labial defects also experience speech problems along with drying and crusting of the tissues in the area of defect. The lip and cheek provide a valve mechanism for speech. Rehabilitation of patients with this type of surgery creates numerous challenges for both the surgical and the maxillofacial prosthetic teams. The goals of prosthetic treatment include regaining favorable speech and restoration of esthetics. This case report presents a 65-year-old woman who was referred for restoration of her lost lip. This case paper describes a quick and simple method of positioning magnets with lip prosthesis attached to maxillary denture and thus esthetics and speech of the patient is restored. Use of retention magnets simplify the clinical and laboratory phase retains the denture and makes it stable and comfortable for the patient. The advent of magnets has enhanced the dental practitioner's capabilities with a remarkably improved potential for increasing prosthesis stability and preserving tissue.

Preparation of an adhesive in emulsion for maxillofacial prosthetic

Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA) based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA-MMA-EA) and (AA-MMA-2EHA) with different molar ratios. The formulation based on (AA-MMA-2EHA) with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives.