title: The effects of menstrual phase on orthodontic pain following initial archwire engagement.
abstract: OBJECTIVE
  To explore the effects of menstrual cycle on orthodontic pain following initial archwire engagement.
  
  
  METHODS
  Female participants with regular menstrual cycles were recruited and assigned into follicular group or luteal group. Demographical and baseline variables were collected: age, education, menstrual duration, anxiety, oral health impact profile-14 (OHIP-14), and index of complexity outcome and need (ICON). Following initial archwire engagement, orthodontic pain was determined through visual analogue scale (VAS) on 1st day, 2nd day, and 3rd day. Demographical and baseline variables were compared between the two groups. Two-way repeated-measures anova was used to examine the effects of menstrual phase, time, and their interactions on orthodontic pain. Multivariate linear regression was employed to examine the independent effect of each variable on orthodontic pain.
  
  
  RESULTS
  Finally, 37 and 39 were assigned to the follicular and luteal groups, respectively, with balanced demographical and baseline data. Orthodontic pain was significantly affected by menstrual phase and time (both P < 0.001), but there was no interaction (P > 0.05). Moreover, orthodontic pain was independently predicted by menstrual phase, OHIP, education level, and anxiety (all P < 0.05).
  
  
  CONCLUSIONS
  We suggest that practitioners arrange female patients to receive initial archwire engagement during their follicular phases to relieve orthodontic pain.
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: H
authors.initials: H
authors.lastname: Long
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: M
authors.initials: M
authors.lastname: Gao
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: L
authors.initials: L
authors.lastname: Liao
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
authors.forename: W
authors.initials: W
authors.lastname: Lai
mesh_terms: D000328:Adult; D001007:Anxiety / Q000150:complications; D004522:Educational Status; D005260:Female; D005498:Follicular Phase; D006801:Humans; D008183:Luteal Phase; D009909:Oral Health; D009971:Orthodontics, Corrective / Q000009:adverse effects*; D010147:Pain Measurement; D013997:Time Factors; D014098:Toothache / Q000209:etiology* / Q000523:psychology; D055815:Young Adult
keywords: follicular phase; initial archwire; luteal phase; menstrual cycle; menstruation; orthodontic pain