Finite element analysis of dental implants with validation: to what extent can we expect the model to predict biological phenomena? A literature review and proposal for classification of a validation process.

A literature review of finite element analysis (FEA) studies of dental implants with their model validation process was performed to establish the criteria for evaluating validation methods with respect to their similarity to biological behavior. An electronic literature search of PubMed was conducted up to January 2017 using the Medical Subject Headings "dental implants" and "finite element analysis." After accessing the full texts, the context of each article was searched using the words "valid" and "validation" and articles in which these words appeared were read to determine whether they met the inclusion criteria for the review. Of 601 articles published from 1997 to 2016, 48 that met the eligibility criteria were selected. The articles were categorized according to their validation method as follows: in vivo experiments in humans (n = 1) and other animals (n = 3), model experiments (n = 32), others' clinical data and past literature (n = 9), and other software (n = 2). Validation techniques with a high level of sufficiency and efficiency are still rare in FEA studies of dental implants. High-level validation, especially using in vivo experiments tied to an accurate finite element method, needs to become an established part of FEA studies. The recognition of a validation process should be considered when judging the practicality of an FEA study.

Comparison of obturator prosthesis fabricated using different techniques and its effect on the management of a hemipalatomaxillectomy patient.

Odontogenic tumours involving the maxilla or mandible are usually treated with surgical resection. To prevent recurrence, extensive surgical intervention might be carried out leaving the patient with anatomical defects. However, rehabilitation of such patients with an obturator can improve function, facial form and social acceptance. In this case, we have evaluated the different designs and techniques of fabrication of an obturator prosthesis used for the rehabilitation of a hemipalatomaxillectomy patient. A 40-year-old man presented with a loose fitting obturator prosthesis. He had undergone hemipalatomaxillectomy for the treatment of an ameloblastoma 2 years earlier and had been using an obturator prosthesis since then. Hollow-bulb obturator prostheses were fabricated using two different methods, the lost salt and open lid techniques. The obturator prosthesis fabricated with the lost salt technique weighed less than the patient's old obturator. But the obturator fabricated using the open lid technique did not only considerably reduce the weight of the prosthesis but also improved health, function, aesthetics, phonetics and quality of life in this hemipalatomaxillectomy patient.

Cross-arch arrangement in complete denture prosthesis to manage an edentulous patient with oral submucous fibrosis and abnormal jaw relation.

A patient with oral submucous fibrosis and resorbed ridges poses a challenge for prosthodontic rehabilitation because of the limited mouth opening and fibrotic mucosa. The fabrication of prosthesis is very difficult due to abnormal jaw relations, influencing the long-term prognosis of the patient. To present a case of oral submucous fibrosis with severely resorbed edentulous ridges which was successfully managed by adopting a modified technique in fabricating a complete denture prosthesis. A 55-year-old female patient with completely edentulous maxillary and mandibular arches diagnosed with oral submucous fibrosis was rehabilitated with complete dentures by recording neutral zone for resorbed mandibular ridge and by arranging the posterior teeth in cross arch relation for compensation of the abnormal jaw relations. The cross-arch arrangement of posterior teeth provides a more stable and retentive complete denture prosthesis for patients with severely resorbed ridges and a wider mandibular arch.

Andrew's bridge system: an aesthetic and functional option for rehabilitation of compromised maxillary anterior dentition.

Summary A patient with several missing teeth in the anterior aesthetic region along with severe ridge defect poses a greater challenge for prosthodontic rehabilitation. In such cases treatment using fixed partial denture (FPD) may not be feasible because of the extent of edentulous span and the periodontal conditions of the abutment teeth. To present a case of multiple missing maxillary anterior teeth with class III ridge defect rehabilitated using FPD-removable partial denture. A 38-year-old female patient was successfully rehabilitated using Andrew's bridge system in the maxillary anterior region. The fixed-removable Andrew's bridge system provides a good prognosis if diagnosed and planned meticulously.