title: Distance between periapical lesion and mandibular canal as a factor in periapical surgery in mandibular molars.
abstract: OBJECTIVE
  Mandibular molars with a periapical pathology that remains unresolved by endodontic treatment may be considered for periapical surgery (PS); even for those situated in close proximity to the mandibular canal. Our objective was to compare PS in mandibular molars situated close to the mandibular canal, and those at a greater distance, and to study the postoperative morbidity and prognosis of both groups.
  
  
  METHODS
  A follow-up study was made on PS carried out using the ultrasound technique. The cases were classified into 2 different groups in function of the proximity of the periapical lesion to the mandibular canal; group A when the distance was less than 2 mm and group B when it was equal to 2 mm. Only patients undergoing PS in mandibular molars were included in this study; minimum follow-up was set at 12 months. The postoperative morbidity was evaluated, as well as the mid- and long-term overall success. SPSS 12 (SPSS Inc, Chicago, IL) was used for statistical analysis. All estimated association measures were then tested for statistical significance, and declared significant for P values less than .05.
  
  
  RESULTS
  PS was carried out on 79 patients, with 98 lesions, involving 88 mandibular molars. Group A was made up of 22 patients with 27 periapical lesions in close proximity to the mandibular canal, involving 23 mandibular molars; and group B comprised 57 patients with 71 lesions not in close proximity to the mandibular canal, involving 65 molars. Sixty percent of the patients presented between no pain and mild pain on the second postoperative day and two thirds of the patients between mild and moderate swelling. Group A had higher average pain than group B (P < .05), peaking at 2 days, whereas in group B maximum pain was reached at 2 hours of the intervention. The success at 12 months in the mandibular molars was 66.6% with no statistically significant differences between the 2 groups (P > .05).
  
  
  CONCLUSIONS
  The success obtained in mandibular molars shows that periapical surgery is a valid treatment option, even in molars situated in close proximity to the mandibular canal.
authors.affiliation: University of Valencia, Facultad de Medicina y Odontología, Gascó, Valencia, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Martí
authors.forename: Miguel
authors.initials: M
authors.lastname: Peñarrocha
authors.forename: Berta
authors.initials: B
authors.lastname: García
authors.forename: José María
authors.initials: JM
authors.lastname: Martínez
authors.forename: Cosme
authors.initials: C
authors.lastname: Gay-Escoda
mesh_terms: D000328:Adult; D000541:Alveolectomy / Q000379:methods; D001047:Apicoectomy / Q000379:methods; D004487:Edema; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008334:Mandible / Q000294:innervation; D008340:Mandibular Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008963:Molar / Q000601:surgery; D010149:Postoperative Pain; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D011446:Prospective Studies; D011862:Radiography, Panoramic; D012184:Retrograde Obturation; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D016896:Treatment Outcome; D014464:Ultrasonic Therapy