title: Anatomy of the nasal cavity determines intranasal  trigeminal sensitivity.
abstract: BACKGROUND
  Aim of this study was to investigate whether intranasal anatomy plays a role in intranasal trigeminal sensitivity.
  
  
  METHODS
  A total of 65 healthy subjects (30 female, 35 male) participated in this study (age range 18-35 years). Nasal cavities were assessed using magnetic resonance imaging (MRI). The area of the nasal cavity was measured in 5 coronal sections distributed across the length of the nasal cavity. Trigeminal function was assessed by determining thresholds for CO2, and responses to suprathreshold stimulation with CO2 and menthol (intensity ratings; event-related potentials). In addition, rhino-manometric measures were obtained.
  
  
  RESULTS
  A positive correlation was found between the size of the nasal cavity and trigeminal event-related potentials in response to suprathreshold CO2 and menthol stimuli. By contrast, no such correlations were found between nasal cavity size and CO2 thresholds. Results from rhino-manometry correlated only with the size of the nasal cavity in the nasal valve area.
  
  
  CONCLUSIONS
  These data suggest that, at least at a suprathreshold level, nasal anatomy plays a significant role in determining interindividual differences in the sensitivity to trigeminal stimuli.
authors.affiliation: 2nd Academic Department of Otorhinolaryngology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Iordanis
authors.initials: I
authors.lastname: Konstantinidis
authors.forename: Inga
authors.initials: I
authors.lastname: Gartz
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Gerber
authors.forename: Jens
authors.initials: J
authors.lastname: Reden
authors.forename: Thomas
authors.initials: T
authors.lastname: Hummel
mesh_terms: D000293:Adolescent; D000328:Adult; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D009296:Nasal Cavity / Q000033:anatomy & histology* / Q000502:physiology*; D014276:Trigeminal Nerve / Q000502:physiology*; D055815:Young Adult