220 Australian Dental Journal, June, I967

The biology of the children of Hopewood House, Bowral, N.S.W.

VI. The pattern of dental caries experience*

Robert H a r r i s t

The pattern of dental caries experience has been examined by various authors and recently Backer-Dirks") published observations on schoolchildren in Holland. I t was thought that a n examination of such a pattern among the 81 children of Hopewood House, Bowral, might be of interest. Since detailed report^'?'(^"')(^)(^) have already been published on the dental caries experience of these children over a period of fifteen years (1947-1961), i t is not intended to make any reference to the parti- cular conditions existing in this Home except t o reiterate that for the greater portion of their childhood these children followed a regime which included a strict adherence to a lactovegetarian diet, and that they were relatively free from dental caries during the first decade of their lives. At about eleven to

With the aid of a grant from the National Health and Medical Research Council of Australia.

t Director, Institute of Dental Research, Sydney. Received for publication, June, 1966.

(1) Backer-Dirks. 0.-Longitudinal dental caries study in children 9-15 years of age. Arch. Oral Biol. Sp. Supp., 6 : 94-108, 1961.

(t) Lilienthal, B., Goldsworthy, N. E., Sullivan, H. I<.. and Cameron, D. A,-The biology Of the children of Hopewood House, Bowral, N.S.W. 1. Observations on dental caries extending over five years (1947-1952). D. J. Australia, 25 : 7-8, 163-168 (July-Aug.) 1953.

mGoldsworthy, N. E., et aZ.-The biology of the children of HoDewood House, Bowral. N.S.W. TI . Observations extending over five years (1952-1956 inclusive). Pts. 1-7. Austral. D. J.. 3: 5 . 309-330 (Oct.); 6, 378-398 (Dec.) 1958.

U) HarriR, R., and Sullivan, H. R.-The biology Of the rhildren of HoDewood House, Bowral, N.S.W. 111. The eruption pattern of certain permanent teeth. Austral. D. J.. 5 : 2, 78-83 (Apr.) 1960.

-.Harris, R.-The biology of the children of Hope- wood House, Bowral, Australia. 4. Observa- tions on dental-caries experience extending over five years (1967-1961). J. D. Res., 42: 6, 1387-1399 (Nov.-Dec.) 1963.

u) Harris, R.-The biology of the children of Hope- wood House, Bowral. V. Observations on dental carles experience : proximal lesions. Austral. D. J.. 8: 6, 521-528 (Dec.) 1963.

twelve years of age (when perhaps the school environment may have influenced the dietary pattern) a greater number of carious lesions was observed concurrently with increases in the prevalence of oral lactobacilli. Thus the number of caries-free children was reduced, so that in 1957 while 65 per cent of eleven-year- olds were caries-free, only 28 per cent of fifteen-year-olds were, and two years later all of the latter had some degree of caries.

A limitation imposed on this study was the loss of some subjects as the children reached adolescence. However, a sufficient number remained to warrant a study of the data to disclose whether any pattern of order of appear- ance of carious lesions could be discerned. The results of this study are presented.

Results 1. Ages when carious lesions were first

detected

Tables 1 and 2 show the ages for boys and girls a t which a carious lesion was first detected on each of the various tooth surfaces; right and left sides of the mouth a re taken as one unit.

Lesions on fissure surfaces (a) Boys: Fissure caries appeared early in

the upper and lower first molars at seven and nine years respectively, followed by the upper second premolars at eleven years and by the second molars a t thirteen years of age.

(b) Uirls : Lesions appeared in the upper and lower first molars a t eight years followed by the second molars at eleven years of age. The lower second premolar showed a lesion a t twelve, the upper at thirteen, and both upper and lower first premolars a t fourteen years.

Australian Dental Journal, June, 1967 22 I

TABLE 1 First appearance of leaiona in various tooth S U ~ ?d 7-16 YWX8 :ces in boys L

11 12 ____

~~

: I Molar,

L U1. Molar,

Fissure surfaces Premolar, U

L I

Premolar, U L

Molar, U L I

Molar, I_ *M *D

__ *M *D

*M Premolar, U

L I

Proximal surfaces

Premolar, U L *D

I- Canine U

L I

Incisor, L 1 TI- __

Incisor, U L I

Li Molar,

I- __ *U Molar, B

Li 1 Premolar, B

Li Buccal and

lingual surfaces

Premolar, B Li I Li

Canine

Li Incisor,

-I-

Fi i Incisor, I

U=upper ; L=lower ; M=mesial ; D=distal; B=buocal ; Li=lingual.

222 Australian Dental Journal, June, I967

Fissure surfaces

Proximal surfaces

Buccal and

lingual surfaces

I

-1-

-- *M *M I

-!-

U=upper ; L = lower ; M = mesial ; D = distal ; B = buccal ; Li =lingual.

Australian Dental Journal, June, I967 223

Lesions on proximal surfaces. ( a ) Boys. Posterior teeth: Such lesions

appeared in the posterior teeth on the mesial surface of the lower and upper first molar at nine and eleven years respectively, to be fol- lowed on the distal surface at twelve and thirteen years. At twelve years of age the second molar and the first and second pre- molars were first attacked.

n

' I

and lingual surfaces respectively. The pre- molars of boys' teeth were not attacked on these surfaces, but in girls the buccal surface in lower first and second premolars was attacked a t thirteen years of age.

Lesions on all surfaces ( a ) Boys: Among these children i t is

apparent that the disease was not observed in the lower incisors and canine teeth during the ages under review. Of the 64 regions recog nized as possible sites of carious attack, 11 had become involved up to the age of eleven years, 16 in the period twelve to fourteen years, and 4 in the period fifteen to sixteen years. Of the 16 surfaces attacked in the twelve to fourteen year period, 11 were on proximal surfaces of bicuspids and molars. Some observations were recorded for a smaller number of children (approximately half) in the seventeenth year and these showed further regions attacked by caries.

( b ) Girls: Among these children the disease was not observed in the lower incisors until thirteen years, and the distal of the lower canine had not been attacked before fifteen - . years. As in the case of the boys, 64 regions

Fig. 1, 2.-Mean number of carious lesions per child for UDDer and lower teeth in boys aged were recognized as possible sites of carious 7-16 years - (M: molar, P : premolar, C canine. attack and 14 were noted up to eleven years I : incisor).

( b ) Girls. Posterior teeth: The lesions

surface of the upper and lower first molar at appeared in the posterior teeth on the mesial

seven and eight years respectively, to be fol- lowed by the distal surface of the lower first I

molar and the mesial of the lower second molar at eleven years of age. At twelve years the 3 premolar teeth commenced to show signs of attack.

(6) Boys and girls. Anterior teeth: Although the anterior teeth suffered less attack than other teeth, some lesions were first noted in the upper central and lateral incisors at nine and ten years of age in the boys and eleven years of age in the girls.

Lesions on buccal and lingual surfaces Such lesions were found on very few

a lower first molar. The first appearance in C ' I 'I

occasions. The first appearance in boys waa noted a t ten years on the buccal surface of

:

Fig. 3, 4.-Mean number of carious lesions per this category in the girls was in an upper lateral incisor at ten years, followed by lesions child for upper and lower teeth in girls aged in and lower molars on both buccal 7-16 years ( M : molar, P : premolar, C : canine.

I : incisor).

224 Australian Dental Journal. June, I967

of age, 9 of which occurred in the eleventh year of age, 4 of these being proximal surfaces. In the period twelve to fourteen years, 24 sur- faces were involved and 6 in the period Afteen to sixteen years.

Among the girls a wider spread of the regions involved in the carious attack com- menced at eleven years, whereas in the boys this was delayed to the twelfth year.

2. Mean number of carious surfaces per child

All surfaces of each tooth type of the upper

( a ) Boys: Figures 1 and 2 show the mean number of carious surfaces per tooth per child at different ages in boys. It will be noted that the upper Arst molar shows the earliest evi- dence of attack with something less than 0.25 mean surface involved per child, and at six- teen years shows the most evidence of caries of the upper arch with more than 1.75 mean surfaces attacked per child. Caries in the upper second molar and second premolar begins

and lower arches

next attacked at eleven years of age, and at sixteen years has slightly less than 3.5 mean surfaces involved per child. The second pre-

AGE IN Y E ~ . R S 8 10 12 14 16

Fig. 5.-Mean number of proximal carious lesions per child for teeth in the posterior (molars and premolars) and anterior segments of the arches for boys aged 7-16 years ( P O :

posterior segment, An : anterior segment). at a later age and reaches a maximum of approximately 1.0 mean surface affected at six- teen years. l o t n

The tooth suffering the greatest attack is the lower first molar at sixteen years, when more than 2.0 mean surfaces per child were attacked. For the lower second molar and pre- molar, somewhat similar flgures to that for these teeth in the upper arch are shown. The mean number of carious surfaces affected per child at any one age in the Arst premolar, canine, and incisor teeth, is of a much lower order of magnitude than in the other teeth.

( b ) Girls: Figures 3 and 4 show the mean number of carious surfaces per tooth per child at different ages in girls. Again it will be noted that the first permanent upper molar is the Arst tooth attacked. This occurs at seven years of age, and at sixteen years of age almost 3.75 mean surfaces in this tooth per child have been attacked. In the upper second molar the Arst attack is at eleven years, and at sixteen years reaches a mean figure of 2.4

A 8 10 12 I4 16

surfaces per child, whilst in the upper second premolar the attack commences at twelve years and reaches a t sixteen years a mean figure of approximately 2.75 surfaces per child.

In the lower arch the Arst permanent molar is attacked at eight years of age, and a t six- Fig. 6:--Mean number of proximal carious lesions per child for teeth in the posterior teen years more than 4.0 mean surfaces per (molars and premolars) and anterior segments child are carious. The lower second molar is of the arches for girls aged 7-16 years (PO:

posterior segment, An : anterior segment).

12

Australian Dental Journal, June, 1967

molar in the lower arch shows a slightly greater attack a t each age than its antagonist in the upper arch. Conditions between the two arches are reversed in the first premolar teeth.

In the girls the upper canine is attacked flrst at fourteen years of age, but caries pro- gresses at a slower rate than in the other upper anterior teeth.

225

Mesial and distal surfaces of posterior and

From Figures 5 and 6 it can be noted that the number of lesions per child for each age group in both posterior and anterior segments is greater among the girls than the boys, except in the upper incisors and canines of boys aged nine to ten years. The figures also show that carious lesions were not observed in the mesial and distal surfaces of the lower

anterior segments of arches

Upper teeth . . Mean age child

(Yr.) . .

Lower teeth . . Mean ago child

(Yr.) . .

sumed in the uncooked state”. Furthermore, the conditions of life of the children were very constant until the age of secondary school (12-13 years). At this age the mean DMF teeth per child showed an increase which was progressive, though less than that observed by Barnard(*) for children in State Schools in New South Wales.

It is suggested that a situation existed in which there was an unique opportunity to study the progress of a disease commencing in a n environment in which for a number of years i t was not observed, and to note that its progress was not influenced by oral hygiene practices which employed artificial aids. Of importance in the assessment of this pro- gression is the information gained on the eruption pattern“) of the teeth of these chil- dren, which was found to be:

Order of eruption

Boys

anterior teeth of the boys and were very few in number in the same region for the girls.

Discussion The observations (2)(S)(4)(D(6) made on the oral

conditions of these children indicate quite clearly that they enjoyed in their early years comparative immunity to dental caries, and that this was accompanied either by no lacto- bacilli present at all or low lactobacillus counts in a few cases. At the same time oral hygiene was “generally unsatisfactory” and “75 per cent of the children had gingivitis”.

The dietary programme(’) indicates that the “bulk of the fruit and vegetables was con-

(1) Gillham, Jennifer, and Lennon, Dymphna.-The biology of the children of Hopewood House, Bowral, N.S.W. 11. Observations extending over five years (1952-1956 inclusive). 4. Dietary survey. Austral. D. J., 3 : 6 , 378-382 (Dec.) 1958.

Girls

In addition, the data on eruption show there is a lag of up to 1.3 years between the eruption of teeth in the upper jaw of boys and tha t of girls. This time-lag is greatest in the lateral incisors and least in the second premolar and second molars. In the lower jaw the eruption pasttern shows a lag of up to 1.5 years between the times of eruption in boys and girls, the canine and first premolars having the greatest difference. This time-lag may have some bear- ing on the marked difference between girls and boys in the mean number of carious surfaces per child per age for each of the tooth types. It will be noted from Tables 1 and 2 the greatest number of regions suffering attack

(@Barnard, P. D.-Dental survey of State school- children in New South Wales, January, 1954- June, 1955. N.H.M.R.C. Sp. Rpt. Series, No. 8, 1956.

226 Australian Dental Journal, June, 1967

the anterior teeth. From observations made on this limited number of children living in an unique environment, no clear-cut pattern of development of carious lesions can be demon- strated other than the fact that the lower incisors are relatively immune t.o t.he onslaught of the disease.

Finn(*) has, dealt with the order of suscepti- bility and the variation between the sexes, and has drawn attention to evidence which shows DMF rates are higher for girls than boys. This is confirmed in the present study. The order of susceptibility varies greatly, but most of the authorities he quotes give priority to the lower first molar which differs from our observations. Again, the conclusion that occlusal cavities in the permanent teeth occur earlier than do smooth surface cavities is not wholly supported, for the flrst lesion observed in girls was found on the mesial surface of the upper molars at seven years of age.

Carlos and Gittelsohn(l') found the attack to follow this descending order of suscepti- bility:

Lower first and second molars, upper flrst

Upper second molar; Upper flrst premolar, upper and lower second

premolars; Upper incisors ; Upper canine, lower first premolar;

molar ;

from caries in any one year was observed at twelve years of age in boys ( 7 ) , and at thirteen years of age in girls (12). The girls had, how- ever, already accumulated 21 regions attacked by caries up to and including their twelfth year as against 17 for the boys.

Since the right and left side teeth a re taken as the one unit, it will be noted from Tables 1 and 2 that of the 14 tooth regions (upper and lower units) attack had occurred in 7 of these in boys and 8 of these in girls in the period covered by the 9-12 age group. However, as each posterior tooth has flve surfaces and each anterior four surfaces exposed to the attack, some tooth regions may have more than one attack recorded during each period. Prior to these age groups only the upper and lower flrst molars in girls and the upper flrst molar in boys had suffered. It is at twelve years of age when secondary school is attended, that increased demands are made on t h e children by exposure to different social patterns and by puberty and physical activity.

Figures 1 to 4 show the pattern of caries attack, but i t should be noted that in this study the pattern is related to the age of the child in whom each tooth type Arst exhibited one or more carious lesions. The lower incisors are relatively free from caries in all children up to sixteen years of age and the pattern of eruption shows a different sequence from tha t of attack:

Although some incisors have been attacked Lower incisors; as early as nine and ten years of age, Figures 6 and 6 show clearly the overwhelmingly greater effect of the disease on the posterior (#)Finn, S. B.-Prevalence of dental caries in A

survey of the literature of dental caries (Eds. teeth in both boys and girls. The accumulation Toverud, G., Cox, G. J., Finn, S. B., Bodecker, C. F., and Shaw, J. A.), Nat. Acad. Sci. of carious lesions, which reflects the incidence N.R.C., Washington, 1952 (pp. 163-173).

of the disease, in the posterior teeth occurred in (lo) Carlos J. P. and Gittelsohn A. M.-Longi- tudinhl studiks of the natural 'history of caries. girls at more than twice the rate it did in boys 11. A life table study of caries incidence in

the permanent teeth. Arch. Oral Biol., 10: 5. and this difference is about four times greater in 739-751 (Sept.-Oct.) 1965.

Lower canine.

Australian Dental Journal, June, I967 2 2 7

Fig. 7, 8.-The mouth of a twenty-two-year-old Hopewood House male showing close proximal contacts, facets of wear on the occlusal sur- faces, in which no evidence of caries could be

detected.

Also the pattern of eruption in their subjects was different.‘“)

Lammie(l*) refers to the possibility of the effect of malocclusion on enamel caries as a n orthopsedic problem. In the period 1952-1966 inclusive, 32 children remained caries-free and of the total 81 children 50 had some form of malocclusion but only 10 of these were diagnosed‘”) as “discrepancy cases” (crowding). A t the final examination in 1961, only 3 chil- dren remained caries-free.@) This suggests that the effect of “compressive forces” from overcrowding as postulated by Lammie is an

(11) Carlos, J. P., and Cittelsohn. A. M.-Longi- tudinal studies of the natural history of caries. I. Eruption patterns of the permanent teeth. J. D. Res.. 44: 3. 509-516 (Mav-June) 1965.

Lammie, 0. A,-Dental orthop&dics. Oxford,

(18) Benson. W. B.-The bioloev of the children of The Alden Press, 1966 (pp. 173-175).

Hopewood House, Bowral;-N.S.W. 11. Observa- tions extending over flve years (1962-1966 inclusive). 6. Observations on occlusal condt- tions. Austral. D. J., 3 :6, 390-394 (Dec.) 1958.

(14) Maddern, C. B.-The essential morbid histology and morbid physiology of the lesion of caries. Austral. J. Den., 5 4 : 5 , 266-286 (Oct.) 1960.

unlikely factor in the production of dental caries.

Lammie agrees that crowding is not confined to arches with irregular occlusion. But whether or not crowding produces compressive forces which alone could weaken the enamel is un- decided in the absence of evidence. Figures 7 and 8 are from the mouth of one of the former members of the Hopewood House family who a t twenty-two years of age has no clinical or radiographic evidence of caries. His arches are complete with close proximal contact in most segments and there are well defined facets of wear on the occlusal and incisal surfaces. He is one of the few who have adhered to the lactovegetarian diet programme of his early years.

Maddern‘”) has suggested a hypothesis that the carious lesion in enamel is initiated from compressive stress occlusion. Since the chil- dren’s diet was of a n unrefined nature and contained much uncooked food, it is reasonable to assume that stresses were set up in certain areas of the enamel. Whether such areas were more susceptible to the development of carious lesions associated with the change in eating habits is speculative.

Summary 1. An analysis of the patterns of eruption

and of caries attack has been made on the children of Hopewood House, Bowral.

2. Eruption pattern and caries-attack pattern are dissimilar.

3. More tooth regions are attacked for the first time at twelve years of age among boys and at thirteen years of age among girls than at any other age.

4. The incidence of carious lesions is greater in posterior teeth than in anterior teeth and more so in the teeth of girls than those of the boys.

5. The first proximal surface to be attacked is the mesial of the upper first molar i n girls a t seven years and the mesial of the lower first molar in boys at nine years of age.

6. Lower incisor and canine teeth of both the boys and girls are relatively immune to dental caries.

Institute of Dental Research, The United Dental Hospital

of Sydney,

Sydney. 2 Chalmers Street,