Tanner scale explained

Tanner scale
Purpose:Defines physical measurements of development
Synonyms:Tanner stages

The Tanner scale (also known as the Tanner stages or sexual maturity rating (SMR)) is a scale of physical development as pre-pubescent children transition into adolescence, and then adulthood. The scale defines physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts, length of the penis, volume of the testes, and growth of pubic hair. This scale was first quantified in 1969 by James Tanner, a British pediatrician, after a two-decade-long study following the physical changes in girls undergoing puberty.[1] [2]

Due to natural variation, individuals pass through the Tanner stages at different rates, depending in particular on the timing of puberty. Among researchers who study puberty, the Tanner scale is commonly considered the "gold standard" for assessing pubertal status when it is conducted by a trained medical examiner.[3] In HIV treatment, the Tanner scale is used to determine which regimen to follow for pediatric or adolescent patients on antiretroviral therapy (adult, adolescent, or pediatric guidelines).[4] The Tanner scale has also been used in forensics to determine aging, but its usage has decreased due to lack of reliability.[5]

Stages

Adapted from Adolescent Health Care: A Practical Guide by Lawrence Neinstein.[6]

Genitals (male)

Tanner I
  • testicular volume less than 1.5 ml; small penis (prepubertal)
    Tanner II
  • testicular volume between 1.6 and 6 ml; skin on scrotum thins, reddens and enlarges; penis length unchanged
    Tanner III
  • testicular volume between 6 and 12 ml; scrotum enlarges further; penis begins to lengthen
    Tanner IV
  • testicular volume between 12 and 20 ml; scrotum enlarges further and darkens; penis further increases in length and starts to increase in breadth
    Tanner V
  • testicular volume greater than or equal to 20 ml; adult scrotum and penis

    Breasts (female)

    Tanner I
  • no glandular tissue: areola follows the skin contours of the chest (prepubertal)
    Tanner II
  • breast bud forms, with small area of surrounding glandular tissue; areola begins to widen
    Tanner III
  • breast begins to become more elevated, and extends beyond the borders of the areola, which continues to widen but remains in contour with surrounding breast
    Tanner IV
  • increased breast sizing and elevation; areola and papilla form a secondary mound projecting from the contour of the surrounding breast
    Tanner V
  • breast reaches final adult size; areola returns to contour of the surrounding breast, with a projecting central papilla

    Pubic hair (both male and female)

    Tanner I
  • no pubic hair at all (prepubertal)
    Tanner II
  • small amount of long, downy hair with slight pigmentation at the base of the penis and scrotum (males) or on the labia majora (females)
    Tanner III
  • hair becomes more coarse and curly, and begins to extend laterally
    Tanner IV
  • adult-like hair quality, extending across pubis but sparing medial thighs
    Tanner V
  • hair extends to medial surface of the thighs

    Height

    During Tanner V, females stop growing and reach their adult height. Usually, this happens in their mid teens at 14 or 15 years for females.

    Males also stop growing and reach their adult height during Tanner V; usually this happens in their late teens at 16 to 17 years, but can be a lot later, even into the early 20s.

    Historical data

    In 1970, boys reached the last Tanner stage, the postpubertal stage, on average at the age of 14.9 years and girls around the age of 14 depending on social class and the particular study.[7] In the nearly fifty years since those studies, the ages at which children are beginning puberty has only declined: "The age of puberty, especially female puberty, has been decreasing in western cultures for decades now [...] for example, at the turn of the 20th century, the average age for an American girl to get her period was 16 or 17. Today, that number has decreased to 12 or 13 years."[8]

    Criticism

    The scale has been criticized by the pornography industry for its potential to lead to false child pornography convictions, such as in the case of pornographic actress Lupe Fuentes where in 2009 United States federal authorities used it to assert that she was not an adult despite her age. Fuentes personally appeared at the trial and provided documentation that showed that the DVDs in question were legally produced.[9] [10]

    Tanner, the author of the classification system, has argued that age classification using the stages of the scale misrepresents the intended use. Tanner stages do not match with chronological age, but rather maturity stages and thus are not diagnostic for age estimation.[11]

    See also

    External links

    Notes and References

    1. Marshall WA, Tanner JM . Variations in the pattern of pubertal changes in boys. Arch. Dis. Child. . 45 . 239 . 13–23 . February 1970 . 5440182 . 2020414 . 10.1136/adc.45.239.13.
    2. Marshall WA, Tanner JM . Variations in pattern of pubertal changes in girls . Arch. Dis. Child. . 44 . 235 . 291–303 . June 1969 . 5785179 . 2020314 . 10.1136/adc.44.235.291.
    3. Dorn LD, Biro FM . Puberty and Its Measurement: A Decade in Review. Journal of Research on Adolescence . 21 . 1 . 180–195 . February 2011 . 10.1111/j.1532-7795.2010.00722.x.
    4. Web site: Adolescents and Young Adults with HIV Considerations for Antiretroviral Use in Special Patient Populations Adult and Adolescent ARV. AIDSinfo. en-US. 2019-08-01.
    5. Book: Encyclopedia of forensic and legal medicine. Payne-James, Jason,, Byard, Roger W.. 9780128000557. Second. Amsterdam, Netherlands. 924663619. 2015-09-29.
    6. Book: Adolescent health care : a practical guide. 2008. Lippincott Williams & Wilkins. Neinstein, Lawrence S., Neinstein, Lawrence S.. 9780781792561. 5th. Philadelphia. 148727849.
    7. Marshall . W. A. . Tanner . J. M. . Variations in the Pattern of Pubertal Changes in Boys . Archives of Disease in Childhood . 1 February 1970 . 45 . 239 . 13–23 . 10.1136/adc.45.239.13 . 5440182 . 2020414 .
    8. Web site: The decreasing age of puberty . Texas A&M Health Science Center. 10 January 2018 .
    9. News: Lupe Fuentes Saves Man From Bogus 'Child Porn' Charge. April 16, 2010. AVN. November 9, 2013. January 29, 2012. https://web.archive.org/web/20120129004325/http://business.avn.com/articles/Lupe-Fuentes-Saves-Man-From-Bogus-Child-Porn-Charge-394003.html. dead.
    10. Web site: Adult Film Star Verifies Her Age, Saves Fan From 20 Years In Prison. Radar Online. April 21, 2010.
    11. Rosenbloom. AL. Tanner, JM . Misuse of Tanner puberty stages to estimate chronologic age.. Pediatrics. December 1998. 102. 6. 1494. 10.1542/peds.102.6.1494. 9882230.

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