Skeletal fluorosis is a bone disease caused by excessive accumulation of fluoride leading to weakened bones. In advanced cases, skeletal fluorosis causes painful damage to bones and joints. Symptoms
Symptoms are mainly promoted in the bone structure. Due to a high fluoride concentration in the body, the bone is hardened and thus less elastic, resulting in an increased frequency of fractures. Other symptoms include thickening of the bone structure and accumulation of bone tissue, which both contribute to impaired joint mobility. Ligaments and cartilage can become ossified. Most patients with skeletal fluorosis show side effects from the high fluoride dose such as ruptures of the stomach lining and nausea. Fluoride can also damage the parathyroid glands, leading to hyperparathyroidism, the uncontrolled secretion of parathyroid hormones. These hormones regulate calcium concentration in the body. An elevated parathyroid hormone concentration results in a depletion of calcium in bone structures and thus a higher calcium concentration in the blood. As a result, bone flexibility decreases making the bone more susceptible to fractures. Causes
Common causes of fluorosis include inhalation of fluoride dusts or fumes by workers in industry and consumption of fluoride from drinking water (levels of fluoride in excess of levels that are considered safe.) In India, especially the Nalgonda region (Telangana), a common cause of fluorosis is fluoride-rich drinking water that is sourced from deep-bore wells. Over half of groundwater sources in India have fluoride above recommended levels.Fluorosis can also occur as a result of volcanic activity.
Without the use of a technological aid, nasal emission is sometimes judged by listening for any turbulence that may be produced by the nasal airflow, as when there is a small velopharyngeal opening and there is some degree of mucous in the opening. More directly, methods recommended include looking for the fogging of a mirror held near the nares or listening through a tube, the other end of which is held in or near a nares opening.There have been many attempts to use technological augmentation more than a mirror or tube to aid the speech pathologist or provide meaningful feedback to the person attempting to correct their hypernasality. Among the more successful of these attempts, the incompleteness of velopharyngeal closure during vowels and sonorants that causes nasal resonance can be estimated and displayed for evaluation or biofeedback in speech training through the nasalance of the voice, with nasalance defined as a ratio of acoustic energy at the nostrils to that at the mouth, with some form of acoustic separation present between the mouth and nose. In the nasalance measurement system sold by WEVOSYS, the acoustic separation is provided by a mask-tube system, nasalance measurement system sold by Kay-Pentax, the acoustic separation is provided by a solid flat partition held against the upper lip, while in the system sold by Glottal Enterprises the acoustic separation can be by either a solid flat partition or a two-chamber mask.However, devices for measuring nasalance do not measure nasal emission during pressure consonants.