title: Evaluation of surgically retrieved temporomandibular joint alloplastic implants: pilot study.
abstract: OBJECTIVE
  The purpose of this study was to perform a retrieval analysis of temporomandibular joint (TMJ) alloplastic interpositional implants and test possible correlation between implant failure features and patient clinical outcomes. In addition, we investigated the implants' surface and examined the foreign body reaction associated with different types of alloplastic materials.
  
  
  METHODS
  Twelve implants (Proplast/Teflon [Vitek, Houston, TX] and Silastic [Dow Corning, Midland, MI]) were surgically removed from the patients' TMJs. Implant surface failure features (fracture length, perforation of the implants) were observed using stereomicroscopy and recorded for description of the failure mechanisms and to statistically compare with clinical outcomes. Patients' clinical data (pain symptoms and mandibular function) were collected and examined. Clinical outcomes were obtained relative to symptom severity (Symptom Severity Index [SSI]) and jaw function (modified Mandibular Function Impairment Questionnaire [mMFIQ]). Peri-implant soft tissues and implants were analyzed with light microscopy and stereo zoom microscopy. Electron microprobe analysis of implant fragments and peri-implant tissues was performed.
  
  
  RESULTS
  The statistical results showed that only the presence of implant perforation was statistically associated with the SSI, specifically with the pain tolerability dimension. No statistical association was seen between any of the other implant failure predictors and the SSI and between the predictors and the mMFIQ. Stereo zoom microscopy suggested that Proplast/Teflon implants (n = 7) were susceptible to perforation, layer tearing, fracture and fiber extrusion. The Silastic implants (n = 3) revealed a possible center perforation with fracture lines towards the periphery and fiber extrusion. Teflon implant wear debris particles appear to trigger a multinucleated giant cell foreign body reaction.
  
  
  CONCLUSIONS
  Facial pain was a significant correlate to perforation and breakdown of the alloplastic TMJ interpositional implants, and most likely was the reason for implant removal.
authors.affiliation: University of Minnesota School of Dentistry, Minneapolis, MN, USA. ferreirj@dentistry.unc.edu
authors.forename: Joao N A R
authors.initials: JN
authors.lastname: Ferreira
authors.forename: Ching-Chang
authors.initials: CC
authors.lastname: Ko
authors.forename: Sandra
authors.initials: S
authors.lastname: Myers
authors.forename: James
authors.initials: J
authors.lastname: Swift
authors.forename: James R
authors.initials: JR
authors.lastname: Fricton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000009:adverse effects*; D020878:Device Removal; D004129:Dimethylpolysiloxanes; D004577:Electron Probe Microanalysis; D005157:Facial Pain / Q000209:etiology; D005260:Female; D005549:Foreign-Body Reaction / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011428:Proplast; D011475:Prosthesis Failure; D012828:Silicones; D011795:Surveys and Questionnaires; D013704:Temporomandibular Joint / Q000473:pathology; D019224:Temporomandibular Joint Disc; D013705:Temporomandibular Joint Disorders / Q000601:surgery*
chemical_list: D004129:Dimethylpolysiloxanes; D011428:Proplast; D012828:Silicones; C013830:baysilon