26 showed enlargementof the proximal and distal interphalangeal joints and ulnar deviation of the | hand. No rhuematoid nodules were present. The x-ray changes wereconsistent with a diagnosis of Table 18 Results of Bentonite Flocculation Test Age,yr No.in agegroup osteoarthritis of the hands, but there was no evi- BFT titer 0 4 % Ye Yo Ysa bse but rheumatoid arthritis cannot be completely ruled out. Males 0- 9 10-19 20-29 14 24 17 9 3 2103 Ib 1 40-49 13 20 >60 11 9 2 - - ~ - 99 84 9 4 O 0 2 1 1 1 - ~ ~ 2 30-39 50-59 Total 9 11 9 9 0- - 2 1 = = fe - - = - - 1 = 1 = - ~ ~ 4. UnusualSkeletal Findings = 4 Females 0- 9 10-19 20-29 30-39 40-49 12 13 18 12 6 8 10 14 11 5 2 1 - > 60 16 ll 2 1 - - 85 66 6 7 5 50-59 Total 8 7 1 2 3 1 dence for rheumatoid arthritis. The BFT was negative. This is probably a case of osteoarthritis, = - a - - - 0 0 i As noted previously, hand and wrist x-rays had shown congenital hypoplasia of the middle phalanx in some children. The same condition was noted in someof the adults (Figure 12). The middle phalanxof the fifth finger was shortened and slightly broadened. This was found both unilaterally and bilaterally and was occasionally associated with lengtheningof the ulna. Twenty subjects showed definite changes, and some additional ones had only moderate shortening of the phalanx. - DENTAL SURVEY Majuro Children 2. Rheumatoid Factor in Sera’ The prevalence of sera positive for “rheumatoid factor” by the bentonite flocculation test (BFT)is shown in Table 18. Individual data arelisted in Appendix 6 according to age and sex. Thetotal prevalence of positive sera is not greatly different from that reported for white American populations. There was no apparentdifference in arthritis incidence between the exposed and unexposed groups. Three individuals, all in the unexposed group, had definitely positive sera (Table 19), but with no evidence ofjoint disease. One (#953) had bronchial asthma andprostatic hypertrophy, but these findings, since they were commonin the population, were probably coincidental. Thereis no apparent explanation for the presence of rheumatoid factor in these individuals. 3. Clinical Evidence of Arthritis A 59-year-old male (#878) had someclinical findings compatible with rheumatoid arthritis. He had complained of pain and swelling in his hands, wrists, and knees for 5 to 10 years, but with no limitation of function. Physical examination Thirty Majuro children were examined, ranging in age from 2 to 13 years andselected at random, Widespread caries were present in 75% of the children <12 years old. Many erupting permanentteeth showedretained root fragments in the adjacent gingival crevice. Althoughthe oral hygiene could berated fair to good, the incidence of caries remained high. Bunchingof the lower incisors was a common finding in males and fe- males in the 7 to 9-year age group. Eruption time of the bicuspids appeared advanced,possibly because of premature loss of the deciduous molars. All the children in this age group showedsignsof retarded jaw development in comparison with children in the continental United States. Rongelap Children No significant difference was found in caries incidence, eruption time, and morphology of the teeth, or growth of the jaws, between the exposed and the unexposed children. In both groups about 20% showed retarded jaw development which had resulted in narrowing of the arches plus bunching of the lower anterior teeth. The Rongelap children had a much lowerincidenceofcaries than