title: Three-dimensional finite element analysis of the stress distribution pattern in the design modifications of U-shaped palatal major connector.
abstract: BACKGROUND
  The U-shaped maxillary major connector is considered to be the least-desirable design by many prosthodontists as it lacks rigidity, which is a primary requisite for a major connector.
  
  
  OBJECTIVE
  Design modifications in the U-shaped palatal major connector are desired because it lacks rigidity. The study also aimed to determine the best design when a U-shaped palatal major connector is indicated for clinical use.
  
  
  METHODS
  The normal design and the design-modified models (modification 1, 2, 3, 4) were loaded at the functional cusps of the premolars and the molars with a magnitude of 200 N, 250 N and 300 N at angulations of 60 o and 90 o on both sides of the maxillary arch. Results for each loading were obtained as stress distribution colored images and numerical values were recorded. A three-dimensional finite element analysis study of the design-modified models was performed using two finite element softwares, namely PRO-E and IDEAS.
  
  
  RESULTS
  The least stress value of 7.86 Megapascals (MPa) at 200 N, 60 o was recorded for the double-thickness design, followed by design 1, which was 8.03 MPa. The least stress value for the palatal mucosa and ligament was provided by design modification 1 (0.5 mm-thick U-shaped connector, 9 mm anteroposteiorly, 14.6 mm laterally), which was 9.78 MPa and 2.98 MPa, respectively.
  
  
  CONCLUSIONS
  The double-thickness group exhibited the least internal stress for the U-shaped major connector. However, it delivered the greatest stress to the palatal mucosa and the periodontal ligaments.
authors.affiliation: Department of Prosthodontics and Implantology, Meenakshi Ammal Dental College and Hospital, Chennai, India. abcv2005@yahoo.com
authors.forename: Hariharan
authors.initials: H
authors.lastname: Ramakrishnan
authors.forename: Raj G
authors.initials: RG
authors.lastname: Singh
mesh_terms: D000539:Alveolar Process / Q000502:physiology; D001641:Bicuspid / Q000502:physiology; D001696:Biomechanical Phenomena; D002858:Chromium Alloys / Q000737:chemistry; D003724:Dental Arch / Q000502:physiology; D003779:Denture Design; D003832:Denture, Partial, Removable; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008422:Materials Testing; D008437:Maxilla / Q000502:physiology; D008963:Molar / Q000502:physiology; D009061:Mouth Mucosa / Q000502:physiology; D010159:Palate / Q000502:physiology*; D021362:Palate, Hard / Q000502:physiology; D010513:Periodontal Ligament / Q000502:physiology; D018583:Pliability; D013314:Stress, Mechanical
chemical_list: D002858:Chromium Alloys