title: Evaluation of the relationship between the maxillary posterior teeth and the sinus floor using cone-beam computed tomography.
abstract: OBJECTIVE
  The aim of this study was to evaluate the relationship between each root of maxillary premolars and molars and the maxillary sinus floor according to sex, sinus position, and age by decade in a Turkish population by using cone-beam computed tomography (CBCT) scanning.
  
  
  METHODS
  We evaluated a database of 5,166 (2,680 maxillary premolars and 2,486 maxillary molars) CBCT scans obtained from 849 patients. The vertical relationship between each root of the molar and premolar teeth to the sinus floor was classified into three types: type 1, the roots penetrated into the sinus floor; type 2, the roots contacted the sinus floor; and type 3, the roots extended below the sinus floor.
  
  
  RESULTS
  The results of the classification of each root in relationship to the sinus floor were as follows: type 3 occurred most frequently in the first (92.4 %) and second (71.6 %) premolar teeth, type 1 (34.2 %) occurred most frequently in the palatinal roots of the first molar teeth, type 3 occurred most frequently in the mesiobuccal (39.9 %) and distobuccal (39.7 %) roots of the first molar teeth, and type 2 (36.7 %) occurred most frequently in the mesiobuccal roots of the second molar teeth. No significant differences were found between the left and right sides, but several differences were found between males and females. The relationship between the posterior teeth and the sinus floor differed according to the age decade interval (p < 0.05).
  
  
  CONCLUSIONS
  The maxillary first premolars have no relationship with the maxillary sinus floor, but the maxillary second molars are closer to the sinus floor. Also the second decade and males were most susceptible to undesirable results.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Sifa University, Izmir, Turkey, dh.evrenok@hotmail.com.
authors.forename: Evren
authors.initials: E
authors.lastname: Ok
authors.forename: Enes
authors.initials: E
authors.lastname: Güngör
authors.forename: Mehmet
authors.initials: M
authors.lastname: Colak
authors.forename: Mustafa
authors.initials: M
authors.lastname: Altunsoy
authors.forename: Bilge Gülsüm
authors.initials: BG
authors.lastname: Nur
authors.forename: Osman Sami
authors.initials: OS
authors.lastname: Ağlarci
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D054893:Cone-Beam Computed Tomography; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008443:Maxillary Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D012737:Sex Factors; D014092:Tooth Root / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014421:Turkey; D055815:Young Adult