"6 to 11 months" group, with the "less than 6 months" group second. This can be explained by the usual unlikelihood of visiting a dentist more often than each 6 months if no dental problem arises to instigate a visit sooner.

The patient who had not seen his dentist in more than 3 years was generally in a rather deplorable dental condition, on the average. The typical patient in this category required 5.09 fillings and 3.28 extractions. He had 6.90 permanent teeth missing before the indicated extractions. A total of 29.1 percent of this group needed at least one complete denture, and only 2.1 percent needed no dental treatment other than prophylaxis.

By contrast, the average patient in the "6 to 11-23 months" group needed only 1.75 fillings and 0.26 extractions. He had but 1.47 permanent teeth missing before the few indicated extractions. Only 1.5 percent of this group needed one or two complete dentures, and 29.7 percent had no dental needs other than prophylaxis.

Figures 7 and 8 graphically depict this pronounced relationship between dental needs and length of time since last visit to a dentist.

Tables 15 and 16 provide analytic data relating age groups and "length of time" groups. Tables 17 and 18 perform the same function with regard to sex and "length of time" groups.

IV. Dental needs according to region of the country

In the preceding chapter, a pronounced relationship was shown between unmet dental needs and length of time since patients had last visited dentists. Regional differences in unmet dental needs are in most instances relatively smaller; they are a function not only of differences in incidence rates but also of dental care received in the past. Some of the regional differences are undoubtedly due to fluoridation, in the earlier age groups particularly.

Although regional differences are not startling, on close inspection it is possible to discern some rather definite patterns.

With respect to the number of fillings needed among all age groups combined, the East North Central, West North Central, and South Atlantic regions are below the national average, whereas the remaining six regions are above (Table 19). Figure 9 shows the regions and the states contained in each.

The East North Central, West North Central, and South Atlantic regions were also distinguished by an average or lower than average number of teeth requiring extraction because of decay and for all reasons in the first two regions.

The East South Central, Mountain, and Pacific regions were also below the national average in number of extractions needed because of decay, and the latter two for all reasons, as well. The Middle Atlantic Region was also below the national average in total extractions. When total extractions required were added to permanent teeth previously missing, the West South Central Region had the highest average (3.96) and the Mountain Region, the lowest (2.58).

Figure 10 shows needs for fillings and extractions by region.

Need for treatment of periodontal disease was more than twice as great in the West South Central Region as in the West North Central Region.

There were four regions in which patients exceeded the national averages with respect to percentage needing complete upper or lower dentures or both: East South Central, South Atlantic, West South Central, and East North Central. More than double the percentage of patients requiring complete dentures in the Mountain Region were judged to have such need in the East South Central Region.

The greatest number of permanent teeth missing was in the East North Central Region, and the lowest was in the Mountain Region. The East South Central Region not only recorded the second greatest number of permanent teeth missing,

Table 19 Dental needs of 11,538 white patients, by region and by age

Table 19 Dental needs of 11,538 white patients, by region and by age - continued

Age

New England

Middle Atlantic

East North Central

West North Central

Pacific

United States

.26.

Upper &

Upper &

Upper

&

(%) (%) (%) (%) (%) (%) (%) (%) (%) Upper Lower lower Upper Lower lower Upper Lower lower

(%)

0.0 0.0

1.1 0.0

0.0

0.8

3.1

0.9

2.4

4.2

0.4

4.5

2.3 0.3

50Total

10.7

1.2 8.3

7.9

1.2 6.4

9.2

17

12.0

7.3

2.2

(%) (%) (%) (%) (%) (%) (%) (%) (%) (%) Upper Lower lower Upper Lower lower Upper Lower lower Upper Lower lower Upper Lower lower Upper Lower lower Upper Lower lower (%) (9%) (%) (%)

(%)

(%)

(%) (%)

0.0

0.0

0.0 0.0

0.0

0.0

0.0

0.0 0.0

0.0

0.0

0.0

1.9 0.0 6.8 4.0 0.0 4.9 23.2 3.4 1.4 6.1 2.2 0.2

0.1

0.9

8.1

3.9

0.7

1.3

3.0

0.0

3.3

3.6

0.3

3.9

19.3 7.1

1.2

8.2

5.6

3.4

10.7

7.6

1.3

12.0