types of changes have been developed using a variety of skeletal series. For instance, in children age is typically estimated by assessing their dental development, ossification and fusion of specific skeletal elements, or long bone length. For children, the different points of time at which different teeth erupt from the gums are best known for telling a child's age down to the exact year. But once the teeth are fully developed, age is hard to determine using teeth. In adults, degenerative changes to the pubic symphysis, the auricular surface of the ilium, the sternal end of the 4th rib, and dental attrition are commonly used to estimate skeletal age. When using bones to determine age, there might be problems that you might face. Until the age of about 30, the human bones are still growing. Different bones are fusing at different points of growth. Some bones might not follow the correct stages of growth which can mess with your analysis. Also, as you get older there is wear and tear on the humans' bones and the age estimate becomes less precise as the bone gets older. The bones then become categorized as either 'young' (20–35 years), 'middle' (35–50 years), or 'old' (50+ years). Sex determination Differences in male and female skeletal anatomy are used by bioarchaeologists to determine the biological sex of human skeletons. Humans are sexually dimorphic, although overlap in body shape and sexual characteristics is possible. Not all skeletons can be assigned a sex, and some may be wrongly identified as male or female. Sexing skeletons is based on the observation that biological males and biological females differ most in the skull and pelvis; bioarchaeologists focus on these parts of the body when determining sex, although other body parts can also be used. The female pelvis is generally broader than the male pelvis, and the angle between the two inferior pubic rami (the sub-pubic angle) is wider and more U-shaped, while the sub-pubic angle of the male is more V-shaped and less than 90 degrees. Phenice details numerous visual differences between the male and female pelvis. In general, the male skeleton is more robust than the female skeleton because of the greater muscles mass of the male. Males generally have more pronounced brow ridges, nuchal crests, and mastoid processes. It should be remembered that skeletal size and robustness are influenced by nutrition and activity levels. Pelvic and cranial