APPENDIX 4: A chronological listing of animal, clinical, and endemic studies of fluoride and bone, with quotations.

APPENDIX 4: A chronological listing of animal, clinical, and endemic studies of fluoride and bone, with quotations.

1) Clinical trials finding association between fluoride therapy and bone fracture.
2) Animal studies finding fluoride reduces the strength/quality of bone
3) Fluoride & Bone Mineral Density (BMD)

3a) Fluoride, BMD, & Trabecular Bone
3b) Fluoride, BMD, & Cortical Bone

4) Fluori de & Osteoporosis (Endemic Fluorosis Studies)

(This is appendix 4 to a report critiquing the September 2002 review of fluoridation issued by the Irish Government's Fluoridation Forum. To read the full critique, click here. Appendix 4 was produced by Michael Connett.)

1) Clinical trials finding association between fluoride therapy and bone fracture. (Back to top)

Inkovaara J, et al. (1975). Phophylactic fluoride treatment and aged bones. Br Med J. 3: 73-74.

"Fractures and exacerbation of arthrosis were more frequent in the fluoride group...The many fractures in the fluoride group, 14 during treatment and the following month as against 6 among the controls, were surprising. Three or four of the fractures in the fluoride group appeared to be spontaneous hip fractures. In the past fractures have not been regarded as being caused by fluoride but as resulting from prolonged osteoporosis before treatment. We believe that the fluoride treatment here was probably partly responsible for the fractures in our cases."

Gerster JC, et al. (1983). Bilateral fractures of femoral neck in patients with moderate renal failure receiving fluoride for spinal osteoporosis. Br Med J (Clin Res Ed). 287(6394):723-5.

"Two patients with moderate renal failure sustained spontaneous bilateral hip fractures during treatment with fluoride, calcium, and vitamin D for osteoporosis....As bilateral femoral neck fractures are very rare these data suggest a causal link between fractures and fluoride in patients with renal failure. Thus fluoride should be given at a lower dosage, if at all, to patients with even mild renal failure."

Dambacher MA, et al. (1986). Long-term fluoride therapy of postmenopausal osteoporosis. Bone. 7: 199-205.

"[T]he increased number of new crush fractures of the spine during the first year of treatment raise the possibility of fluoride-induced microfractures."

O'Duffy JD, et al. (1986). Mechanism of acute lower extremity pain syndrome in fluoride-treated osteoporotic patients. Amer J Med. 80: 561-566.

"How fluoride can produce stress microfractures is unclear. That they are complications of fluoride therapy is clear, as there were no microfractures in the 101 patients in the calcium-treated group."

Hedlund LR, Gallagher JC. (1989). Increased incidence of hip fracture in osteoporotic women treated with sodium fluoride. Journal of Bone and Mineral Research. 2:223-5.

"[T]he six hip fractures occurring in patients receiving fluoride during 72.3 patient years of treatment is 10 times higher than would be expected in normal women of the same age. The probability of observing six fractures in 2 years is extremely small (0.0003). In four of the hip fracture cases, the history suggested a spontaneous fracture. These findings suggest that fluoride treatment can increase the risk of hip fracture in osteoporotic women."

Bayley TA, et al. (1990). Fluoride-induced fractures: relation to osteogenic effect. Journal of Bone and Mineral Research. 5(Suppl 1):S217-22.

"Using all 61 fluoride-treated patients, femur fractures/patient were significantly correlated to bone fluoride (p less than 0.05) and to age (p less than 0.05)... These results suggest that fluoride therapy may be implicated in the pathogenesis of hip fractures which may occur in treated patients despite a rapid, marked increase in bone mass."

Gutteridge DH, et al. (1990). Spontaneous hip fractures in fluoride-treated patients: potential causative factors. J Bone Miner Res. 5 Suppl 1:S205-15.

"We report 11 fluoride-treated postmenopausal patients who developed spontaneous fractures of the femoral necks...In all there were 19 spontaneous fractures: 5 were asymptomatic, including 2 with deformity; 12 fractures required surgery. Five were incomplete (stress) fractures."

Riggs BL, et al. (1990). Effect of Fluoride treatment on the Fracture Rates in Postmenopausal Women with Osteoporosis. New England Journal of Medicine. 322:802-809.

Fluoride treatment was "associated with a significant three-fold increase in the incidence of nonvertebral fractures, both incomplete and complete...This increased rate of fracturing suggests that bone formed during fluoride therapy has increased fragility."

Schnitzler CM, et al. (1990). Bone fragility of the peripheral skeleton during fluoride therapy for osteoporosis. Clin Orthop (261):268-75.

"Bone fragility during fluoride therapy for osteoporosis was observed in 24 (37.5%) of 64 patients treated with sodium fluoride, calcium, and vitamin D for 2.5 years who developed episodes of lower-limb pain during treatment. Eighteen (28%) of these patients had clinical and roentgenographic features of 41 stress fractures and 12 new spinal fractures. There were 26 periarticular, six femoral neck, three pubic rami, three tibia and fibula, one greater trochanter, and two subtrochanteric fractures. Vertebral fractures appeared first, then periarticular, then femoral neck, and lastly long-bone shaft fractures. All fractures were spontaneous in onset. The peripheral fracture rate during treatment was three times that in untreated osteoporosis."

Haguenauer D, et al. (2000). Fluoride for the treatment of postmenopausal osteoporotic fractures: a meta-analysis. Osteoporosis International. 11(9):727-38.

"We conducted an effectiveness meta-analysis to determine the efficacy of fluoride therapy on bone loss, vertebral and nonvertebral fractures and side effects in postmenopausal women...[A]lthough fluoride has an ability to increase bone mineral density at the lumbar spine, it does not result in a reduction in vertebral fractures. Increasing the dose of fluoride increases the risk of nonvertebral fractures and gastrointestinal side effects without any effect on the vertebral fracture rate."

Gutteridge DH, et al. (2002). A randomized trial of sodium fluoride (60 mg) +/- estrogen in postmenopausal osteoporotic vertebral fractures: increased vertebral fractures and peripheral bone loss with sodium fluoride; concurrent estrogen prevents peripheral loss, but not vertebral fractures. Osteoporosis International. 13(2):158-70.

"Vertebral fracture rates and peripheral bone density changes were surprising - and demonstrate that NaF administration is capable of increasing vertebral fracture rates and of increasing peripheral (nonspinal) bone loss. Thus our study demonstrates the potential for an anti-osteoporosis agent, under certain circumstances, to worsen a patient's clinical state."

2) Animal studies finding fluoride reduces the strength/quality of bone (Back to top)

Gedalia I, et al. (1964). Effects of Estrogen on Bone Composition in Rats at Low and High Fluoride Intake. Endocrinology. 75: 201-205.

"When the drinking water supplied to rats contained 50 ppm F, the breaking strength, specific gravity and ash content of the dry defatted femur were somewhat lower than in control or estrogen-treated rats; the decrease in the mean breaking strength was significant statistically (p < 0.01)." The authors note that the observed decrease in breaking strength, in the fluoride-treated bone, "is in agreement with the known fact that the breaking strength of bone decreases with increased fluoride intake."

Daley R, et al. (1967). The Effects of Sodium Fluoride on Osteoporotic Rats. The Journal of Bone and Joint Surgery. (Abstract). 49A:796.

"[T]he heavily fluorinated bone tended to break under less stress than did bone from any other group. These findings suggest that the heavily fluorinated bone was not as strong as the bone from normal rats or from rats fed low-calcium diets without fluoride."

Beary DF. (1969). The Effects of Fluoride and Low Calcium on the Physical Properties of the Rat Femur. Anat Rec. 164: 305-316.

"In the low calcium group a similar significant increase in flexibility appeared at the 10.0 ppm dosage level as well as the 45.0 ppm, but a significant decrease in strength at the two dosage levels were observed. These were in direct relation to the amount of fluoride given."

Wolinsky I, et al. (1972). Effects of fluoride on metabolism and mechanical properties of rat bone. American Journal of Physiology. 223(1): 46-50.

"Femurs of fluoride-treated rats exhibited a decrease in mechanical strength as manifested by a decrease in ultimate stress to breaking as well as decrease in limit and modulus of elasticity."

Chan MM, et al. (1973). Effect of Fluoride on Bone Formation and Strength in Japanese Quail. Journal of Nutrition. 103: 1431-1440.

"Our observations corroborate the findings that, in general, elevated dietary fluoride results in an acceleration of bone mineralization. Uniquely, however, the increase in mineralization was accompanied by a decrease in bone strength." The authors conclude that "the changes in bone that occur with prolonged and excessive fluoride ingestion may result in a reduction of bone strength."

Riggins RS, et al. (1974). The Effects of Sodium Fluoride on Bone Breaking Strength. Calc Tiss Res. 14: 283-289.

"The administration of sodium fluoride increased bone diameter, indicating stimulation of periosteal bone formation, but bone strength was reduced or not affected by fluoride ingestion."

Riggins RS, et al. (1976). The effect of fluoride supplementation on the strength of osteopenic bone. Clin Orthop. (114):352-7.

"The strength of osteopenic bone from calcium deprived rats, quail and roosters was significantly reduced after fluoride supplementation...This detrimental effect on bone strength must be considered in any therapeutic attempt to use fluoride ion to stimulate bone formation in osteopenic bone disorders."

Robin JC, et al. (1980). Studies on osteoporosis III. Effect of estrogens and fluoride. J Med.11(1):1-14.

"In the present study high levels of fluoride in the drinking water did not prevent osteoporosis, but in some experiments, by certain criteria, tended to increase it."

Burnell TW, et al. (1986). Effect of dietary fluorine on growth, blood and bone characteristics of growing-finishing pigs. J Anim Sci. 63(6):2053-67.

"The data reported herein suggested that levels of dietary F greater than 7 ppm are detrimental to bone integrity. Breaking stress and modulus of elasticity were reduced significantly at each level of added dietary F in both experiments. Similar observations have been made with nearly all species that have been subjected to F ingestion."

Moskilde L, et al. (1987). Compressive strength, ash weight, and volume of vertebral trabecular bone in experimental fluorosis in pigs. Calcif Tiss Res. 40: 318-322.

"[T]he mechanical parameters for the fluorotic animals were unchanged...or decreased...It is concluded that the increased bone mass during the initial stages of fluoride treatment does not necessarily indicate an improved bone quality."

Turner CH, et al. (1992). The effects of fluoridated water on bone strength. J Orthop Res. 10(4):581-7.

This study examines the effect of fluoridated water on bone strength in rats. The authors conclude that "The results demonstrate that water fluoride levels of 1 ppm may lead to increased bone strength, while water fluoride levels of 4 ppm would be expected to cause a decrease in bone strength."

Sogaard CH, et al. (1995). Effects of fluoride on rat vertebral body biomechanical competence and bone mass. Bone. 16(1): 163-9.

"Load corrected for ash content, which is a measure of bone quality, decreased significantly after fluoride therapy. It is concluded that the increase in bone mass during fluoride treatment does not translate into an improved bone strength and that the bone quality declines. This investigation thereby supports the hypothesis of a possible negative effect of fluoride on bone quality."

Lafage MH, et al. (1995). Comparison of alendronate and sodium fluoride effects on cancellous and cortical bone in minipigs. A one-year study. J Clin Invest. 95(5):2127-33.

"NaF reduced the strength of cancellous bone from the L4 vertebrae, relative to the control animals, and the stiffness (resistance to deformation) of the femora."

Bone strength "did not increase with bone volume, suggesting that for bones with higher volume, there was less strength per unit volume, that is, a deterioration in bone 'quality.'"

Turner CH, et al. (1996). High fluoride intakes cause osteomalacia and diminished bone strength in rats with renal deficiency. Bone. 19(6):595-601.

"Our study also demonstrated evidence of osteomalacia in rats receiving 15 ppm fluoride, or the equivalent of 3 ppm fluoridated water for humans. This finding is consistent with the case studies of Juncos and Donadio showing skeletal fluorosis in two individuals with renal insufficiency who were consuming water containing 1.7-2.6 ppm fluoride."

Turner CH, et al. (1997). Fluoride treatment increased serum IGF-1, bone turnover, and bone mass, but not bone strength, in rabbits. Calcif Tissue Int. 61(1):77-83.

"[T]he increases in (fluoride-induced) bone mass and bone formation were not reflected in improved bone strength. Fluoride decreased bone strength by about 19% in the L5 vertebra (P <0.01) and 25% in the femoral neck (P < 0.05)... Therefore, fluoride's tendency to increase bone crystal size may contribute to its negative effects on bone quality."

3) Fluoride & Bone Mineral Density (BMD) (Back to top)

Note: Fluoride has been used in the treatment of osteoporosis due to its capacity to increase bone mass. However, while fluoride does in fact increase bone mass, it can also decrease bone mass.

To understand how fluoride alters bone mass it is important to understand the differences in how fluoride affects the two types of bone of the human skeleton: trabecular bone and cortical bone. While fluoride will usually increase bone mass of trabecular bone, it will rarely increase - but frequently decrease - bone mass of the cortical.

An important point to consider in this regard, is the fact that trabecular bone is the predominant form of bone in the axial skeleton (vertebrae, ribs, cranium) while cortical bone is the predominant form of bone in the appendicular skeleton (limbs). Thus, one would expect fluoride to have different effects on the axial and apendicular skeleton.

3a) Fluoride, BMD, & Trabecular Bone (Back to top)

Riggs BL, et al. (1990). Effect of Fluoride treatment on the Fracture Rates in Postmenopausal Women with Osteoporosis. New England Journal of Medicine. 322:802-809.

"[T]he large increase in the mineral density of cancellous (trabecular) bone in the vertebrae during fluoride treatment did not result in a significant reduction in the rate of vertebral fracture..."

Lindsay R. (1990). Fluoride and Bone - Quantity Versus Quality. Editorial. New England Journal of Medicine. Vol. 322. No. 12. March 22.

"[A]lthough the risk of fractures normally rises as the bone mass declines, increases in bone mass with fluoride treatment may not reduce fracture rates."

Carter DR, Beaupre GS. (1990). Effects of fluoride treatment on bone strength. J Bone Miner Res. 5 Suppl 1:S177-84.

"Due to possible adverse influences of fluoride on the mineralized tissue physical characteristics...the increase in bone mass does not necessarily result in an increase in bone strength."

Fratzl P, et al. (1994). Abnormal bone mineralization after fluoride treatment in osteoporosis: a small-angle x-ray-scattering study. J Bone Miner Res 9(10):1541-9.

"All clinical studies that have been conducted during the past 32 years indicated that NaF is effective in increasing trabecular bone mass in the spine...[T]rabecular bone after fluoride treatment consists of old bone (with normal ultrastructure) and newly formed bone with a completely different mineral ultrastructure, similar to fluorotic bone...[T]he mechanical stability of such tissue is certainly different from normal: mineral is hard but brittle...In light of the present data, very important clinical questions must be addressed. First, fluoride treatment seems to be an intriguing example, in which bone mineral density (BMD) measurements do not at all correlate with the biomechanical properties of bone. Consequently, BMD data from clinical studies without exact analysis of antifracture effectiveness are useless for assessment of the risk-benefit ratio of fluoride treatment."

Sogaard CH, et al. (1995). Effects of fluoride on rat vertebral body biomechanical competence and bone mass. Bone. 16(1): 163-9.

"It is concluded that the increase in bone mass during fluoride treatment does not translate into an improved bone strength and that the bone quality declines."

Jiang Y, et al. (1996). Effects of low-dose long-term sodium fluoride preventive treatment on rat bone mass and biomechanical properties. Calcif Tissue Int. 58(1):30-9.

Fluoride-induced new bone mass "did not increase vertebral strength nor proportionally improve femoral strength, indicating that intrinsic biomechanical properties of the bones could be changed by fluoride treatment."

Turner CH, et al. (1997). Fluoride treatment increased serum IGF-1, bone turnover, and bone mass, but not bone strength, in rabbits. Calcif Tissue Int. 61(1):77-83.

"[T]he increases in (fluoride-induced) bone mass and bone formation were not reflected in improved bone strength." Rather "Fluoride decreased bone strength by about 19% in the L5 vertebra (P <0.01) and 25% in the femoral neck (P < 0.05)."

"Vertebral fracture rates and peripheral bone density changes were surprising - and demonstrate that NaF administration is capable of increasing vertebral fracture rates..." despite an increase in vertebral BMD.

3b) Fluoride, BMD, & Cortical Bone (Back to top)

Dambacher MA, et al. (1978). Long term effects of sodium fluoride in osteoporosis. In: Fluoride and Bone; Proceedings of the Second Symposium CEMO, Nyon, Switzerland, Oct. 9-12, 1977, pp. 238-241. Editors: B Courvoisier, A Donath, and CA Baud. Hans Huber Publishers, Bern.

"On sodium fluoride cortical bone decreased while an increase of cancellous bone, especially in the lumbar spine, was observed... A decrease of the cortical bone was found with different methods, the Soerensen-Cameron method and the measurement of the cortical aerea according to Garn. This bone loss was seen in the right radius, femora, and the metacarpalia IV-VI in both NaF dose groups."

Bang S, et al. (1978). Morphometric and biophysical study of bone tissue in industrial fluorosis. In: Fluoride and Bone; Proceedings of the Second Symposium CEMO, Nyon, Switzerland, Oct. 9-12, 1977, pp. 168-175. Editors: B Courvoisier, A Donath, and CA Baud. Hans Huber Publishers, Bern.

"[S]ignificantly higher values were obtained for TBV [Trabecular Bone Volume] (p<0.05), CP [Cortical Porosity] (p<0.0005) and PLS (p<0.00005) of fluorotic bone tissue as compared with the control samples."

Riggs BL, et al. (1980). Treatment of primary osteoporosis with fluoride and calcium: Clinical tolerance and fracture occurrence. JAMA. 243(5): 446-449.

"In this series, we found increased vertebral trabeculation in one third of the patients, but this was associated with, if anything, decreased density of the distal radius, a site containing predominantly cortical bone. The possibility that trabecular (lamellar) bone is increased at the expense of cortical (osteonal) bone cannot be excluded at the present time."

Riggs BL. (1983). Treatment of osteoporosis with sodium fluoride: An appraisal. Bone and Mineral Research. 2: 366-393.

"The dramatic increase in the predominantly trabecular bone of the axial skeleton during fluoride therapy is not accompanied by a corresponding increase in the predominantly cortical bone of the appendicular skeleton...Indeed, several investigators have reported that cortical bone decreases significantly during treatment...These reports raise the possibility that fluoride therapy may protect against fractures of the vertebral bodies (which consist of predominantly trabecular bone) but may not protect the proximal femur, and could even increase the risk for fractures of this bone, which is predominantly cortical...Since hip fracture is more catastrophic than is vertebral fracture, it will be important for future studies to evaluate the effect of sodium fluoride therapy on mineral content of the proximal femur."

Burnell TW, et al. (1986). Effect of dietary fluorine on growth, blood and bone characteristics of growing-finishing pigs. J Anim Sci. 63(6):2053-67.

"When F was fed at levels up to approximately 132 ppm in the diet, cortical bone wall thickness decreased (both experiments)...Histological evaluation of cortical bone properties provided additional evidence in support of the decreased (P<0.004) bone width (thickness) observed macroscopically."

Hodsman AB, Drost DJ. (1989). The response of vertebral bone mineral density during the treatment of osteoporosis with sodium fluoride. J Clin Endocrinol Metab. 69(5):932-8.

"We have documented a clinically relevant increase in vertebral BMD, although there was a significant reduction in cortical BMD at the radial site...The responders were classified according to their increase in vertebral BMD. However, this same group had a significant decline in forearm BMD, a predominantly cortical site in the appendicular skeleton...Most reports have found either no change in BMD at cortical sites or a decrease....Although data on femoral neck BMD were not available in this study, clearly such measurements would have been of great importance."

Kragstrup J, et al. (1989). Effects of sodium fluoride, vitamin D, and calcium on cortical bone remodeling in osteoporotic patients. Calcif Tissue Int. 45(6):337-41.

"The therapy had no effect on the thickness of cortical bone in the iliac crest but increased the porosity slightly..."

Kragstrup J, et al. (1989). Effects of fluoride on cortical bone remodeling in the growing domestic pig. Bone. 10: 421-424.

"The purpose of the experiment was to assess the effects of fluoride (F-) on the remodeling process of cortical bone...The rate of remodeling was increased in cortical bone from pigs receiving F- due to an increased activation of new remodeling...The porosity of cortical bone was slightly but significantly increased."

Riggs BL, et al. (1990). Effect of Fluoride treatment on the Fracture Rates in Postmenopausal Women with Osteoporosis. New England Journal of Medicine. 322:802-809.

"Although the large increase in the mineral density of cancellous bone in the vertebrae during fluoride treatment did not result in a significant reduction in the rate of vertebral fracture, the small increases in bone mineral density at the sites composed of mixed cortical and cancellous bone and decreases in bone mineral density at the sites containing predominantly cortical bone were associated with a significant three-fold increase in the incidence of nonvertebral fractures, both incomplete and complete."

"We conclude that fluoride therapy increases cancellous but decreases cortical bone mineral density and increases skeletal fragility."

Patel S, et al. (1996). Fluoride pharmacokinetics and changes in lumbar spine and hip bone mineral density. Bone. 19(6):651-5.

"It is important to note that FN (Femoral Neck) BMD in some individuals decreased markedly (by as much as 19%) for a minimal increment in LS (Lumbar Spine). This does suggest that fluoride therapy can decrease FN BMD (and possibly increase fracture risk) without any potential benefit at the lumbar spine." In light of these findings, the authors suggest that "all patients treated with fluoride need to have BMD measurements at the LS and FN to allow discontinuation of fluoride if this disparity in BMD changes is observed."

"A surprising finding in our study was in the changes in BMD at nonspinal sites in patients in group F CaD - where significant bone loss occurred by 27 months at all nonspinal sites examined... The serial BMD changes in the present study are strongly suggestive of an anabolic action of fluoride at the spine (a chiefly trabecular site) with a catabolic action at many other sites, chiefly cortical."

4) Fluoride & Osteoporosis (Endemic Fluorosis Studies) (Back to top)

Note: Fluoride is well known to cause osteosclerosis, a bone condition marked by an increase of bone mass. Fluoride's osteosclerotic properties is what prompted the medical community to begin using fluoride as a treatment for osteoporosis. The idea was that fluoride-induced osteosclerosis (an increase in bone mass) would serve to counteract osteoporosis, a condition marked by a loss of bone mass.

What wasn't appreciated at the time, however, was that fluoride can have very contradictory effects on bone. While fluoride certainly causes osteosclerosis, it can also cause osteoporosis, the very condition which fluoride was being used to treat. That fluoride can cause osteoporosis has become evident through the research that has been conducted over the past 30 years on skeletal fluorosis.

In this section, we highlight some of this research. To help clarify the relevance of the skeletal fluorosis studies, it is instructive to note the comment made by Riggs (1984) in his comprehensive review of fluoride as a treatment for osteoporosis.

"[N]ew bone formed under the stimulus of fluoride administration may exhibit various degrees of osteosclerosis, osteoporosis, osteomalacia, and architectural disorganization. Of these manifestations, only osteosclerosis increases bone strength. When fluoride is used therapeutically, therefore, it is obvious that conditions must be carefully chosen so as to maximize the development of osteosclerosis and to minimize the undesirable manifestations of osteoporosis and osteomalacia."

Krishnamachari KA, Krishnaswamy K. (1973). Genu valgum and osteoporosis in an area of endemic fluorosis. The Lancet. 2(7834):877-879.

"Anteroposterior views of the cervicothoracic and lumbodorsal spine showed the presence of osteosclerosis in all but two patients. The most striking radiological feature, however, was severe osteoporosis of the lower end of the femur and upper ends of the tibia and fibula and rarefaction of the metacarpal bones. In some patients, rarefaction of pelvic bones, femoral neck, and lower ends of radius and ulna was also observed."

Christie DP. (1980). The spectrum of radiographic bone changes in children with fluorosis. Radiology. 136(1):85-90.

"Painful, crippling deformities in Tanzanian children from an area of endemic fluorosis reported... Combinations of osteomalacia, osteoporosis, and osteosclerosis result in a spectrum of bone changes from an early age."

Lian ZC, Wu EH. (1986). Osteoporosis--an early radiographic sign of endemic fluorosis. Skeletal Radiol. 15(5):350-3.

"Radiological investigation of skeletal fluorosis was carried out among the inhabitants from two areas where the fluoride content of water was high, using both conventional radiography and radiographic measurements of bone mineral content (BMC)... It is very interesting to observe that in the majority of our cases, osteosclerosis in the spine and pelvis was always combined with osteoporosis of the long bones. It might be an indication that the axial skeleton undergoes a quite different pathological process from the appendicular skeleton..."

Mithal A, et al. (1993). Radiological spectrum of endemic fluorosis: relationship with calcium intake. Skeletal Radiol. 22(4):257-61.

"Skeletal fluorosis continues to be endemic in many parts of India. Osteosclerosis and interosseous membrane calcification have long been regarded as hallmarks of this disease. Our study showed in addition a wide variety of radiological patterns: coarse trabecular pattern, axial osteosclerosis with distal osteopenia and diffuse osteopenia. Subjects with osteopenic changes had a significantly lower dietary intake of calcium than those groups having normal radiological findings, predominant osteosclerosis or coarse trabecular pattern."

Wang Y, et al. (1994). Endemic fluorosis of the skeleton: radiographic features in 127 patients. Am J Roentgenol. 162(1):93-8.

This study examines the radioagraphic features of 127 patients with skeletal fluorosis. It is reported that 54% of the patients have osteosclerosis, while 40% have osteopenia (osteoporosis, 22% & osteomalacia, 18%). According to the authors: "Two different osteopenic patterns were defined: an osteoporotic pattern with overall decreased bone density and an osteomalacic pattern that combines the features of osteoporosis with bone deformity." The authors note how, in the past, skeletal fluorosis was "thought to result merely in osteosclerosis" but that "later, various radiologic features were found, including osteosclerosis, osteomalacia, and osteoporosis."

Note: Click here for information on the arthritic symptoms of skeletal fluorosis.

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