Tanner scale

The Tanner scale (also known as the Tanner stages or Sexual Maturity Rating (SMR)) is a scale of physical development in children, adolescents and adults. The scale defines physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts, genitals, testicular volume and development of pubic hair. This scale was first identified in 1969 by James Tanner, a British pediatrician, after a two-decade-long study following the physical changes in girls undergoing puberty.^[1][2][3][4]

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.^[5] 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).^[6] The Tanner scale has also been used in forensics to determine aging, but its usage has decreased due to lack of reliability.^[7]

Stages

Adapted from Adolescent Health Care: a practical guide by Lawrence Neinstein, M.D.^[8]

Genitals (male)

Illustration of the Tanner scale for males.

Tanner I

testicular volume less than 1.5 ml; small penis (prepubertal; typically age 9 and younger)

Tanner II

testicular volume between 1.6 and 6 ml; skin on scrotum thins, reddens and enlarges; penis length unchanged (9–11)

Tanner III

testicular volume between 6 and 12 ml; scrotum enlarges further; penis begins to lengthen (11–12.5)

Tanner IV

testicular volume between 12 and 20 ml; scrotum enlarges further and darkens; penis increases in length (12.5–14)

Tanner V

testicular volume greater than 20 ml; adult scrotum and penis (14+)

Photos of the Tanner scale for males.

Breasts (female)

Photos of the Tanner scale for females.

Illustration of the Tanner scale for females.

Tanner I

no glandular tissue: areola follows the skin contours of the chest (prepubertal) (typically age 10 and younger)

Tanner II

breast bud forms, with small area of surrounding glandular tissue; areola begins to widen (10–11.5)

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 (11.5–13)

Tanner IV

increased breast sizing and elevation; areola and papilla form a secondary mound projecting from the contour of the surrounding breast (13–15)

Tanner V

breast reaches final adult size; areola returns to contour of the surrounding breast, with a projecting central papilla. (15+)

Height

Sometime during Tanner 5, females stop growing and reach their adult height. Usually, this happens in their mid teens at 15 or 16 years for females. Males also stop growing and reach their adult height sometime during Tanner 5, usually this happens in their late teens at 18–19 years for males.^[9]

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 when United States federal authorities used it to assert that pornographic actress Lupe Fuentes was underage. Fuentes personally appeared at the trial and provided documentation that showed that the DVDs in question were legally produced.^[10][11]

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.^[12]

See also

• Delayed puberty
• Gonadarche
• Pubarche
• Vellus
• Precocious puberty

References

External links

Wikimedia Commons has media related to Tanner scale.

• The Male Tanner stages
• The Female Tanner stages
• "Line drawing of female Tanner stages (genitals)".
• "Line drawing of male Tanner stages".