|About Discussion Pages|
Cite this page: Hill, M.A. (2019, October 19) Embryology Puberty Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Puberty_Development
Evaluation of characteristics of the craniofacial complex and dental maturity in girls with central precocious puberty
Angle Orthod. 2018 Sep;88(5):582-589. doi: 10.2319/112317-809.1. Epub 2018 Apr 30.
Lee HK, Choi SH, Fan D, Jang KM, Kim MS, Hwang CJ. Abstract OBJECTIVES: To identify unique characteristics of the craniofacial complex and dental maturity in girls with central precocious puberty (CPP). MATERIALS AND METHODS: This study included 34 Korean girls with idiopathic CPP (mean age, 8.6 ± .5 years) and 28 normal healthy girls of the same chronological age. An initial evaluation of the growth pattern of the craniofacial complex and dental maturity was conducted by analyzing lateral cephalometric and panoramic radiographs. RESULTS: The mandibular ramus height (44.4 ± 4.1 mm) and total mandibular length (10.8 ± 4.3 mm) ( P = .004 and .021, respectively) were greater and the lower anterior facial height was lesser (63.2 ± 2.4 mm) ( P = .040) in the CPP group than in the reference group. In addition, the gonial angle (12.9 ± 6.1°; P = .045) and the mandibular plane angle (34.9 ± 4.8°; P = .012) were smaller in girls with CPP than in normal healthy girls. All the mandibular teeth were more mature in girls with CPP ( P < .001). A strong positive correlation was observed between the mandibular tooth formation stages and the presence of CPP in girls ( r = .756 to .957; P < .001). CONCLUSIONS: CPP had an effect on the anteroposterior growth of the mandible in the craniofacial complex and the rotation of the mandibular plane angle. Early maturation of the mandibular teeth was observed in girls with CPP. KEYWORDS: Bone age; Central precocious puberty; Craniofacial complex; Dental maturity PMID: 29708396 DOI: 10.2319/112317-809.1
Puberty timing associated with diabetes, cardiovascular disease and also diverse health outcomes in men and women: the UK Biobank study
Scientific Reports 5, Article number: 11208 doi:10.1038/srep11208
Received 09 December 2014 Accepted 20 April 2015 Published 18 June 2015
Early puberty timing is associated with higher risks for type 2 diabetes (T2D) and cardiovascular disease in women and therefore represents a potential target for early preventive interventions. We characterised the range of diseases and other adverse health outcomes associated with early or late puberty timing in men and women in the very large UK Biobank study. Recalled puberty timing and past/current diseases were self-reported by questionnaire. We limited analyses to individuals of White ethnicity (250,037 women; 197,714 men) and to disease outcomes with at least 500 cases (~0·2% prevalence) and we applied stringent correction for multiple testing (corrected threshold P < 7.48 × 10–5). In models adjusted for socioeconomic position and adiposity/body composition variables, both in women and men separately, earlier puberty timing was associated with higher risks for angina, hypertension and T2D. Furthermore, compared to the median/average group, earlier or later puberty timing in women or men was associated with higher risks for 48 adverse outcomes, across a range of cancers, cardio-metabolic, gynaecological/obstetric, gastrointestinal, musculoskeletal, and neuro-cognitive categories. Notably, both early and late menarche were associated with higher risks for early natural menopause in women. Puberty timing in both men and women appears to have a profound impact on later health.
Testicular volumes revisited: A proposal for a simple clinical method that can closely match the volumes obtained by ultrasound and its clinical application
Int J Pediatr Endocrinol. 2012 Jun 8;2012(1):17. doi: 10.1186/1687-9856-2012-17.
Sotos JF1, Tokar NJ.
BACKGROUND: The testicular volumes obtained with the clinical methods, calculated using the ellipsoid equation W2 x L x π/6, correlate with those obtained by ultrasound (US) and are useful clinically, but overestimate ultrasound values, mainly because of the inclusion of the scrotal skin and epididymis, have much variability, and may not be accurate or reproducible.The US measurement is somewhat inconvenient, because it requires another procedure and, mainly, is costly.It would be helpful to have a simple, low cost clinical method that approximates or closely matches the results obtained by ultrasound.Formulas, equivalent to the ellipsoid equations, were developed to calculate testicular volumes with corrections of the width (W), length (L), and height (H) of the testis obtained in the scrotum to avoid the inclusion of the scrotal skin and epididymis. SUBJECTS & METHODS: The US observations in our hospital of the width, height, length, height/width, and length/width ratios and volumes of 110 testes from 55 children from 1 month to 17 ½ years of age were reviewed. Based on these observations and those reported by others, formulas to apply to the clinical measurements were developed to approximate the volumes obtained by ultrasound. The validity and accuracy of the formulas were determined. For the clinical application of the formulas, measurements of the width of the testis in the scrotum, with a centimeter ruler, were obtained in 187 study subjects in different stages of puberty and adults, for a total of 374 testicular determinations. RESULTS: The widths obtained in the scrotum were corrected by subtracting the values of the double scrotal skin. The formulas were then applied and the testicular volumes determined. The testicular volumes were then compared to the ultrasound values reported in hundreds of subjects by four different groups and statistically analyzed. The volumes obtained by the formulas (means ± SD) closely matched the volumes obtained by ultrasound. CONCLUSION: A simple clinical method, based on the width of the testis obtained in the scrotum with a centimeter ruler, which can determine testicular volumes closely matching those reported by ultrasound, is proposed.
Quantification of cranial base growth during pubertal growth
Malta LA, Ortolani CF, Faltin K. J Orthod. 2009 Dec;36(4):229-35. PMID: 19934240
BJU Int. 2004 May;93(7):1015-7. Correlation of ultrasonographic and orchidometer measurements of testis volume in adults. Schiff JD1, Li PS, Goldstein M. Author information Abstract OBJECTIVE: To determine the correlation between testicular volume measured with an orchidometer or high-resolution scrotal ultrasonography (US) with colour-flow Doppler analysis. PATIENTS AND METHODS: In all, 159 men (mean age 36.6 years) presenting for infertility evaluation underwent both a physical examination by a one experienced examiner and high-resolution US with colour-flow Doppler analysis. An orchidometer was also used to measure testicular volume after stretching the scrotal skin tightly over the testis and after warming with a heating pad. The US was interpreted by a radiologist who had no knowledge of the orchidometer estimates. The volume was calculated as 0.71 x length x width x height. RESULTS: For the right testes the mean orchidometer and US estimates were 18.4 and 18.3 mL, yielding a correlation coefficient of 0.72 (r (2) = 0.52, P < 0.01). On the left the respective values were 17.1 and 16.9 mL, with a correlation coefficient of 0.69 (r (2) = 0.48, P < 0.01). CONCLUSION: Orchidometer estimates of testicular volume correlate closely and very significantly with US estimates in adults. In the hands of an experienced examiner orchidometer measurements provide an accurate, rapid and inexpensive assessment of testicular volume. PMID 15142154
Can occur over a broad range of time and differently for each sex: girls (age 7 to 13) boys (age 9 to 15).
The physical characteristics that can be generally measured are: genital stage, pubic hair, axillary hair, menarche, breast, voice change and facial hair.
The physiological process is initiated by the hypothalmus releasing gonadotropin releasing hormone (GnRH) which signals the pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH) which in turn signals throughout the body sexual development.
Links: Endocrinology - Puberty | Endocrinology - Endocrine changes in puberty | Endocrinology - Gonad | Clinical Methods - The Adolescent Patient | Clinical Methods - Staging Criteria for Secondary Sexual Development | NICHD - Puberty | UCSF - Male Development |
Premature development of the signs of puberty which can occur in both girls (before age 7 or 8) and in boys (before age 9).
Links: Endocrinology - Precocious sexual development | NICHD - Precocious Puberty | Nemours Foundation - Precocious Puberty | MedlinePlus - Obesity May Trigger Earlier Puberty for Girls | Time Magazine - Teens Before Their Time |
Determined in boys by a lack of increase in testicular volume by the age of 14 years. In girls, no breast development by the age of 13.5 years and a lack of menstruation by the age of 16 years. There can also be a "pubertal arrest" where there is no progress in puberty over 2 year period.
While the hypothalamic expression of gonadotropin releasing hormone (GnRH) is a known puberty trigger, it was not known what initiated the GnRH secretion. Recent research suggests that an earlier signal could come from increased neuronal and hypothalamic expression of a peptide family (kisspeptins) and their receptor (G protein-coupled receptor GPR54) in the hypothalamus. A single gene (Kiss1) encodes these 145 amino acid kisspeptins and it was originally identified as a human metastasis suppressor gene (suppresses melanomas and breast carcinomas without affecting tumorigenicity).
Two hypothalamic nuclei, the arcuate nucleus and anteroventral periventricular nucleus (AVPV), are thought to contain the kisspeptin secreting neurons.
The anteroventral periventricular nucleus differs in males and females (sexually dimorphic). The arcuate nucleus (and medial preoptic area, MPOA) is linked into the olfactory system, through the vomeronasal organ, perhaps in relation to the influence of pheromones on sexual behavior and neuroendocrine function (in mice).
The original discovery of the peptide was made by scientists located in Hershey, PA, USA and named the gene "Kiss1" after the "Hershey chocolate kiss".
References: Seminara SB. Mechanisms of Disease: the first kiss-a crucial role for kisspeptin-1 and its receptor, G-protein-coupled receptor 54, in puberty and reproduction. Nat Clin Pract Endocrinol Metab. 2006 Jun;2(6):328-34. | Dungan HM, Clifton DK, Steiner RA. Minireview: kisspeptin neurons as central processors in the regulation of gonadotropin-releasing hormone secretion. Endocrinology. 2006 Mar;147(3):1154-8.
Gonadotropin Releasing Hormone (GnRH)
Neurons in the hypothalamic arcuate nucleus (and other nuclei) synthesise this hormone along with gonadotrophin associated peptide (GAP), which are both released and transported by hypophyseal portal capillaries to the anterior pituitary and bound by a membrane receptor.
GnRH increases during early puberty, followed by an increased pituitary responsiveness, then increasing sex steroid levels and then increased nocternal Luteinizing hormone (LH) secretion.
American Academy of Family Physicians Puberty: What to Expect When Your Child Goes through Puberty
Most embryology textbooks (by definition) do not cover postnatal developmenty in any detail. The links below are to useful scientific external online resources.
- PHYSICAL DEVELOPMENT, GROWTH, MATURATION, AND AGEING
- Patterns of Human Growth (PDF document)
- Causes and Mechanisms of Linear Growth Retardation
The links below are to general public external text resources (this listing is for information purposes only and is not intended as an endorsement of a commercial product).
- Ready, Set, Grow!: A What's Happening to My Body? Book for Younger Girls, by Lynda Madaras and Linda Davick
- What's Happening to My Body? Book for Boys: The New Growing-Up Guide for Parents and Sons, Third Edition by Lynda Madaras, Area Madaras, Dane Saavedra, and Simon Sullivan
- Sex, Puberty, and All That Stuff: A Guide to Growing Up, by Jacqui Bailey and Jan McCafferty