Relationship between age at menarche and skeletal maturation stages in Taiwanese female orthodontic patients.
OBJECTIVE
The age at menarche reflects a pubertal girl's physiologic maturity. The aims of this study were to evaluate the relationship between the age at menarche and skeletal maturation in female orthodontic patients.


METHODS
Hand-wrist radiographs and lateral cephalometric radiographs from 304 adolescent female subjects (age, 8-18.9 years) were selected from the files of the Department of Orthodontics, National Taiwan University Hospital (NTUH). Hand-wrist bone maturation stages were assessed using the NTUH Skeletal Maturation Index (NTUH-SMI). Cervical vertebral maturation stages (CVMS) were determined using the latest CVMS Index. Menarcheal ages were self-reported by the patients and verified by the patients' mothers. The relationships between the NTUH-SMI or CVM stages and menarcheal status were investigated.


RESULTS
More than 90% of the 148 subjects who had already attained menstruation had skeletal maturation beyond the NTUH-SMI stage four or CVMS III. However, the subjects who had never experienced menarche mostly had skeletal maturation before NTUH-SMI stage five or CVMS IV. During the period of orthodontic treatment, 19 females experienced their menarche. The mean age at menarche for the 167 female patients in total was 11.97 years. In average, menarche occurred between NTUH-SMI stages four and five or between CVM stages III and IV. The percentage of girls with menses increased from 1.2% at age 9 to 6.6% at age 10, 39.5% at age 11, 81.4% at age 12, 97% at age 13, and 100% at age 14. Compared with the results obtained 20 years previously, we found a downward shift of 0.47 years per decade for the mean age at menarche in female orthodontic patients.


CONCLUSIONS
The majority of female orthodontic patients have passed the pubertal growth spurt when they experience their menarche. Menarche usually follows the pubertal growth spurt by about 1 year and occurs after NTUH-SMI stage four or CVMS III.
Lai
Eddie Hsiang-Hua
EH
Department of Orthodontics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
Chang
Jenny Zwei-Chieng
JZ
Jane Yao
Chung-Chen
CC
Tsai
Shih-Jaw
SJ
Liu
Jen-Pei
JP
Chen
Yi-Jane
YJ
Lin
Chun-Pin
CP
D000293:Adolescent; D000365:Age Determination by Skeleton; D001846:Bone Development / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D008572:Menarche / Q000502:physiology*; D009970:Orthodontics; D013624:Taiwan