title: Unique migration of a dental needle into the parapharyngeal space: successful removal by an intraoral approach and simulation for tracking visibility in X-ray fluoroscopy.
abstract: OBJECTIVE
  The first objective was to describe a novel case of migration of a broken dental needle into the parapharyngeal space. The second was to address the importance of simulation elucidating visualization of such a thin needle under X-ray fluoroscopy.
  
  
  METHODS
  Clinical case records (including computed tomography [CT] and surgical approaches) were reviewed, and a simulation experiment using a head phantom was conducted using the same settings applied intraoperatively.
  
  
  RESULTS
  A 36-year-old man was referred after failure to locate a broken 31-G dental needle. Computed tomography revealed migration of the needle into the parapharyngeal space. Intraoperative X-ray fluoroscopy failed to identify the needle, so a steel wire was applied as a reference during X-ray to locate the foreign body. The needle was successfully removed using an intraoral approach with tonsillectomy under surgical microscopy. The simulation showed that the dental needle was able to be identified only after applying an appropriate compensating filter, contrasting with the steel wire.
  
  
  CONCLUSIONS
  Meticulous preoperative simulation regarding visual identification of dental needle foreign bodies is mandatory. Intraoperative radiography and an intraoral approach with tonsillectomy under surgical microscopy offer benefits for accessing the parapharyngeal space, specifically for cases medial to the great vessels.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan ZAY00015@nifty.com.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hidaka
authors.affiliation: Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Seiji
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nomura
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Takata
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Katori
mesh_terms: D000328:Adult; D003762:Dental Instruments; D005471:Fluoroscopy / Q000379:methods*; D005548:Foreign-Body Migration / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D057605:Natural Orifice Endoscopic Surgery / Q000379:methods; D009339:Needles; D013517:Otorhinolaryngologic Surgical Procedures / Q000379:methods*; D010614:Pharynx / Q000000981:diagnostic imaging / Q000601:surgery; D011856:Radiographic Image Enhancement / Q000379:methods; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: X-ray fluoroscopy; compensating filter; needle migration; parapharyngeal space; surgical microscope