title: Factors influencing the outcome of extracorporeal shock wave lithotripsy in the management of salivary calculi.
abstract: OBJECTIVE
  To identify the factors that affect outcome (stone clearance, partial clearance without symptoms, and residual stone with symptoms unchanged) of extracorporeal shock wave lithotripsy (ESWL). To develop and validate a predictive model for outcome of treatment.
  
  
  METHODS
  Prospective controlled trial.
  
  
  METHODS
  There were 142 salivary calculi (78 submandibular, 64 parotid) entered into a prospective clinical trial of ESWL. The results were analyzed and a predictive model generated, which was validated using a second group of patients treated by the same technique.
  
  
  RESULTS
  ESWL achieved complete success (stone and symptom free) in 67 (47.15%) of cases (submandibular 28/78, 35.9%; parotid 39/64, 60.9%). Partial success (residual stone and symptom free) was obtained in a further 49 (34.5%) (submandibular 29/78, 37.2%; parotid 20/64, 31.3%). Failure occurred in 26 (18.3%) of cases (submandibular 21/78, 26.9%; parotid 5/64, 7.8%).
  
  
  CONCLUSIONS
  ESWL can eradicate salivary calculi but its effectiveness is dependant mainly on size of the stone. Using a regression analysis model stone clearance can be reliably predicted based on stone size. A less important factor is the radiodensity of the stone, whereas a greater proportion of parotid calculi are eliminated by ESWL than submandibular calculi.
authors.affiliation: Departments of Oral Medicine, Dental Radiology, Maxillofacial Surgery, King's College London Dental Institute, London, UK. michael.escudier@kcl.ac.uk
authors.forename: Michael P
authors.initials: MP
authors.lastname: Escudier
authors.forename: Jackie E
authors.initials: JE
authors.lastname: Brown
authors.forename: Venkata
authors.initials: V
authors.lastname: Putcha
authors.forename: Pasquale
authors.initials: P
authors.lastname: Capaccio
authors.forename: Mark
authors.initials: M
authors.lastname: McGurk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D006801:Humans; D008096:Lithotripsy; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis; D015494:Salivary Gland Calculi / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult