Minor craniofacial anomalies among a Negro population

Minor craniofacial anomalies among a Negro population I. Prevalence of cleft uvula, commissural torus palatinus, and torus mandibularis

lip

pits,

preauricular

pits,

Blanka

Peiglovlt. Xchaumann, MS.,* Frederick D. Peagler, D.D.S., M.S.,“” and Robert J. Gorlin, D.D.S., MS.,*** Minneapolis, Minn., and Washington, D. G.

I

n an effort to determine the prevalence of several oral and facial malformations in the American Negro population, 956 Negroes were examined. The population sample consisted of 446 males and 510 females, of whom 662 were adult patients at the Dental Clinic of the College of Dentistry, Howard University, Washington, D. C., and 294 were children attending an elementary school in Washington, D. C, All persons were examined by the senior author only. The purpose of the study was to obtain sufficient data for valid comparison with data from other racial groups published by various authors. METHODS

Examination for cleft uvula was performed, after rinsing of the mouth, by lifting the uvula with a wooden tongue depressor. Commissural Zip pits were classified as such only when they appeared as openings or pits at the corners or angles of the mouth on the vermilion surface. Their unilateral or bilateral occurrence was recorded. Mere dimplings of the lip commissures, Michalowski’s foveola angularis40 were not recorded as lip pits. This study was made possible in part by United States Public Health Service Program in Oral Pathology DE-1770. *Research Fellow, Oral Pathology, School of Dentistry, University of Minnesota, Minneapolis, Minn. **Professor and Chairman, Histopathology, School of Dentistry, Howard University, Washington, D. C. ***Professor and Chairman, Oral Pathology, School of Dentistry, University of Minnesota, Minneapolis, Minn. Grant

566

Volume

29

Number 4 Preauricular pits are small invaginations of approximately the same size as commissural lip pits, located in front of the tragus of the ear. Their unilateral or bilateral occurrence was noted. TOYUS pnlatinus, an exostosis along the suture line of the hard palate, was in recorded, according to the Thoma and Goldman”s morphologic classification, one of four categories: (1) flat, (2) spindle, (3) nodular, or (4) lobular. Torus nuw&buZaris, a unilateral or bilateral exostosis situated on the lingual aspect of the mandible above the mylohyoid line in the region of the premola~~ teeth, was recorded, according to the method of Kolas and associates,*” as ( 1.) single unilateral, (2) single bilateral, (3) multiple unilateral, or (4) mnlti]~le bilateral. RESULTS

AND

DISCUSSION

Only a few examples of cleft uvula were found. Five persons (two males and three females), constituting 0.52 per cent of the total sample, were a.ffect.ed with this trait (Tables I and II). This finding is in agreement with unpublished data of Richardson,So who noted only eight eases (0.2’i per cent) among 2,968 Negroes. If cleft uvula is regarded as a microform 0-Ccleft palate,‘“, 3* one would,

Table 1. Frequency of commissural lip pits, torus palatinus, torus mandibularis. cleft uvula, and preauricular pits in 56 Negroes

Characteristic

Trait

Commissural nits

lip

L

Torus iuus

palat-

c.~~%Jz~ ix

Left Right Bilateral

3T

8.29

Totals

r4----

21.07

6.95 5.83

Flat Spindle Nodular Lobular

29 20 7 0 --

6.50 4.48 1.57

Totals

56

12.55

Torus mandibularis

33.00 27.65

39.35 100

fg,-,,Ej

26 32

50

5.10 6.28

9.81

24.08 29.62 46.30

5ixiiG-

108

51.78 35.72 12.50 0.00

16.28 6.66 2.55 0.39

100

02.90 25.73 9.x3 1 .5" u

100

57 58 87 G----

3.59

2x 34

7.18

88.88

76.93

6“

a

0.89

z----------

8.07

100

2

0.45

100

Left Right Bilateral

9 10 4

2.02 2.24 0.89

Totals

23-----

5.15

2 i

8.34 2.78

0.22

11.12

39.10 43.50 17.40

101)

0.:19 1.31 1.76

-G 39

23.07 100

3

0.59

100

12 7 1

2.35

20

3.92iG-

0.20

loll

5 8

7.65

1.37

'I.13

2x.20 2Y.70 44. ! I)

18X

30.7X 46.1;5

0.67

5.96 6.07 9.10

112 54

44.44 44.44

3 1

uvula

PreauricuIar pits

0.00

3.59

Totals Cleft

E-i’:,

60.00 35.00 5.00

13 $5

-7235

lfd

5

O..iL'

lllfl

“1 17

t’.w 1.7x

5

0.52

-z-----

4.49

4x.x!? :I933 1 I .r;n

II)0

568

Schaunzaxn,

Peagler,

and Gorlin

Table

II. Cleft uvula, literature survey and present data

Oral April,

Surg. 1970

Percentage Author

Date

Powulation

1893

Salomon

1897

German

1954

et al.

examined

Caucasians U.S. population

Berens

McIntosh

Number examined

Number with

trait

of

omurrence

3,000

55

1.83

1,686

39

2.30

Infants and young children (white and nonwhite j

5,739

11

0.19

soldiers

Meskin

et al.

1964

U.S.

dental

1,864

25

1.34

Meskin

et al.

1964

U.S.

students

7,837

115

1.47

males

Baker

patients

1966

U.S.

3,283

75

2.28

Tolarova

et al.

1967a

Czech

adults

1,189

21

1.76

Tolarova

et al.

1967b

Czech

children

1,081

138

6.38

1961

Mongolians Japanese

4,726

462

9.95

Cervenka and Shapiro

Unpub. data

Chippewa dren

chil-

605

62

10.24

Meskin

Unpub. data

Navajo

children

959

180

18.77

college

2,968

8

0.27

U.S. school children and adult dental patients

956

5

0.52

Mochizuki

et al.

and Shapiro

Richardson Present

Table

Unpub. data sample

children Indian Indian

Negroes U.S. Negro students

Commissural lip pits, literature

Ill.

survey and present data Percentage

Author Everett and Wescott

Date 1961

Population U.S. children

Witkop

1963

Chileans

Michalowski

1963

Poles

Baker

1966

U.S.

Caucasian

Baker

1966

U.S.

Negro

Baker

1966

U.S.

Mongoloid

Cervenka Present

and Barros

et al. sample

Unpub. data

Chippewa U.fduL;gro

Number emmined

examined

males males males

Indian

children

children

and

Number with trait

of

oocurrence

1,000

2

0.20

1,906

9

0.47

9,640

73

0.76

3,283

392

11.94

186

38

20.40

30

2

6.66

605

53

8.76

956

202

21.13

Minor

Volume Number

29 4

Table

IV. Torus palatinus,

Author

Date

craniofaciat

literature

anomalks

among Negroes 569

survey and present data

Examined

population

Ntl’WLbCl exfimined

Number

with trait

Percentagr Ol oocw,rrel, a

Stieda

1891

Eskimos Skulls

60

36

60.0

Hooton

1918

Skulls

60

46

76.7

Schreiner

1935

Eskimos and (skulls)

308

186

60.3

woo

1950

Skulls

366

242

66.1

Hooton

1918

Indians American (skulls)

60

36

60.0

HrdliEka

1940

Peruvian bian

211

65

30.8

woo

1950

Skulls

175

95

54.3

Akabori

1939

244

107

23.i

Osima

1939

Koreans

Sakaguchi

1941

Japanese

160

114

75.X

woo

1950

Skulls

163

76

46.6

woo

1950

Negroes American (skulls)

8i3

329

3i.7

407

66

16.2

295

19.5

956

188

19.7

40

13

32.5

Kolas

et al.

Austin

et al.

Present

Lapps

Indians pre-Colum-

Other Mongolians Japanese (skulls)

90.1

Negroes

1953

U.S. nonwhite dental patients (95 per cent Negro)

1965

U.S.

sample

dental

patients

U.S. dental patients and school children

Hooton

1918

Cawzsians Italians

(skulls)

Lachmann

1927

German

patients

1940

U.S.

dental

McCarthy

1941

U.S.

patients

Krahl

1949

U.S.

medical

woo

1950

American (skulls)

1953

U.S.

1957 1963

Miller

Kolas

and

Roth

et al.

Baptista Witkop

and Barros

1,509

2,687

466

li.3

1,040

252

24.2

2,301

8

0.3

200

48

24.0

Caucasians

667

285

43.3

patients

2,064

449

21.7

Venezuelans

1,489

364

24.5

Chileans

1,906

dental

patients

students

7

‘0.4

570

Schuumann,

Table

Peagler,

ad

Present (Per

of torus

Flat Spindle Nodular Lobular

sample cent) 11.7 5.7 2.1 0.2

VI. Age distribution

1 4 E

Totals

Number examined

Number with trait 2 24 20

:; 20 10

2 3 1 -iii

Austin et al. (1965) (per cent)

10.4 7.5 1.3 1.6

11.3 Ei 0:7

Females

35 178 85 41

446

Kolas et al. (1953) (per cent)

of torus palatinus

Males

Decade of life

Surg. 1970

V. Prevalence of types of torus palatinus

Types

Table

Oral April,

Go&n

Total

Number with trtit

Per cent with trait

4.87

29 157 114 72

3 42 39 18

11.11 26.75 34.21 25.00

64 335 199 113

20

7.81 19.70 29.65 17.70

4.76 5.71 15.00 10.00

66 ii: 7

167 rl

24.24 17.07 29.16 0.00

108 76 44 17

18 1: 1

11.84 16.67 22.73 5.88

25.88

G-i

Per cent with trait

12.55

Number esamined

510

iii

Number examined

Number with trait 5

188

Per cent with trait

19.65

in fact, expect to find a much lower prevalence of cleft uvula in Negroes than in Caucasians and Mongolians, since the occurrence of clefts among Negroes13a I5923132 is very low in comparison with Caucasians11l17p24 or Mongolians.14*25*42y 47, 54, 61 Prevalence figures on commissural lip pits ascertained by the authors listed in Table III differ considerably. Even if we regard Baker’s3 high figure of 12 per cent for Caucasian males as representative for the white race, the same author found almost twice as many pits in a Negro sample. Our finding of 21.1 per cent in Negroes was in excellent agreement with Baker’s data. There was neither sex nor side predilection. Unilateral pits were found more frequently than bilateral pits (57 per cent and 43 per cent, respectively). Preauricular pits were found in 4.5 per cent of the subjects in our series. This figure is higher than those determined for Caucasians by Selkirk56 (0.9 per cent) or Baker3 (1.6 per cent). The only data for a Negro population were those presented by Baker, who found a prevalence of 3.8 per cent in 106 males. In our sample, unilateral preauricular pits far outnumbered bilateral ones (88.4 per cent versus 11.6 per cent). No significant difference in sex distribution was noted. Among 202 persons with lip pits, 9.9 per cent also had preauricular pits, whereas only 3.1 per cent of 754 persons without lip pits showed preauricular pits. The difference was highly significant (x’ = 17.41, P
Minor craniofacial

Volume 29 Number 4

Table VII. Torus mandibularis, literature

Fiirst

Author

Date

and Hansen

1915

Hooton

1918

Hrdlieka

1930

Schreiner

1935

Hrdlicka

1940

HrdIieka Moorrees Moorrees Russell and Huxley

1940 1957 1957 1899

Hooton

1918

Hooton

1930

HrdliEka

1940

HrdliEka

1940

Witkop Mipasita Maruyania Akabori Hrdlicka

1960 1935 1937 1939 1940

Perier Drennan Hrdlicka

1933 1937 1940

Kolas et al.

1953

Austin et al.

1965

Present.sample Fiirst and Hansen

1915

Fiirst and Hansen

1915

Hooton SSchreiner Perier Grimm Mellquist & Sanberg Hrdlieka KoIas et al. Witkop RsBarros

1918 1935 1933 1938 1939 1940 1953 1963

Examined

survey and present data

sample

Greenland Eskimos (skulls) Greenland Eskimos (skulls) Eskimos--Western (skulls) Eastern Greenland Eskimos (skulls) Alaskan Eskimos (skulls) Aleuts (skulls) Eastern Aleuts Western Aleuts American Indians (Tennessee) (skulls) California Indians (skulls) American Indians (Pecos-Pueblo) (skulls) North American Indians (skulls) Peruvian pre-Columbian (skulls) Haliwar Indians Chinese (skulls) Chinese (skulls) Japanese (skulls) Mongols and Buriats (skulls) African Negro (skulls) African Negro (skulls) American and African Negro (skulls) U. S. nonwhite dental patients (95 per cent Negro) U. S. denta patients U. S. dental patients and school children Scandinavians-old (skulls) Scandinavians-recent, (skulls) Italians (skulls) Norwegians (skulls) French, Swiss (skulIs) Germans-male (skulls) Scandinavians (skulls) S. Caucasians U. S. dental patients Chileans

U.

a~~omalies amo?q .iVegroes 571

Numbe3 examined

Number with trait

Percmtqr~ 0.f omm-en

182

84.4

31

27

87. I.

710

494

51

24

215

fiR.9 4i.l

432

40.0

151 27 9 33

fi3.5

46

2

4.3

253

07

14.6

2,000

271

13.6

465

16

3.4

167 320 45 244 147

24 120 9 G3 49

3l.f: 20.0 26.fj .?I3 ;I

50 i8 53

3 21 6

6.0 Yl.9 11 .3

407

30

i.4

1,509 956

125 75

8.2 i.9

161

28

17.1

110

13

11.8

30 100 100 92 9fi3

i66 2,064 1,906

61.4 5.7 11.7

14.4

1 li

17 13 26 47 1%

1

fi.1 i.9 0.1

0

572

Schaumann,

Peagler,

Table

VIII. Prevalence of types of torus mandibularis Present (Per

Type of tOTUS Single unilateral Single bilateral Multiple unilateral Multiple bilateral

Table

IX. Age distribution

Number

of life 1 4 5 6 7 8

Totals

NzLmbe-r examined 35

178 85 41 42 35 20 10 4s

Oral April,

sample cent) 2.9 3.6 0.5 0.8

Surg. 1970

Eolas et al. (1953) (per cent)

Austin et al. (1965) (per cent)

i% 0:1 1.5

3.2 2.5 1.3 1.0

of torus mandibularis - ” .._.._”

Males Decade

and Gorlin

with

trait 0 13 11 4 4 3 i s

Per cent with Wait

Nzcmb er examined

0.00 7.30 12.94 9.75 9.52 8.57 5.00 0.00

29 157 114 72 66 41 24 7

8.07

510

Nzlmb

er

with

trait 0 6 5 ; 0 39

Per cent with trait 0.00 5.73 10.52 8.33 7.57 12.19 8.33 0.00 7.65

Number examined

Number with trdt

64 335 199 113 108 76 44 17

0 22 23 10 9 8 3 0

E%

15

Per cent with trait 0.00 6.57 11.56 8.85 a.33 10.53 6.82 0.00 7.85

occurs more frequently in the Mongolian race than in Caucasians or Negroes. Our finding of 19.7 per cent in the Negro sample agrees with that of Kolas and associatesz6and Austin and colleagues2 (16.2 per cent and 19.5 per cent, respectively) . In accord with other authors,2f 4, w ?*J2Ql31p43p64we found the ratio of affected females to males to be approximately 2:l (females 25.9 per cent, males 12.6 per cent). The frequency of types of torus palatinus was similar to that noted by Kolas and Austin and their co-workers (Table V) . Flat and spindle types constituted 88 per cent of all palatine tori (Kolas and associates reported 84 per cent; Austin and co-authors, 83 per cent). Our results concerning the prevalence of torus palatinus according to age support the previous findings of Kolas and Austin in the sense that, after the third decade of life, the number of tori does not increase but plateaus (Table VI), Torus mandibularis was found in seventy-five cases (7.85 per cent). This essentially agrees with published data for American as well as African Negroes (Table VII). Of the total number affected in our sample, thirty-seven were males (8.1 per cent) and thirty-nine were females (7.65 per cent). This supports the view that there is no sex predilection. The prevalence of different types of torus mandibularis is presented in Table VIII. Single mandibular tori were more frequent than multiple ones. As with torus palatinus, the peak of their occurrence was found to be in the third decade of life (Table IX), Among 188 persons with torus palatinus, 17.6

Volume Number

29 4

Minor

craniofacinl

ajlonzalies

a.naong Negroes

573

per cent also had torus mandibularis, while only 5.5 per cent of 768 persons without torus palatinus exhibited torus mandibularis. The ratio of approximately 3:l is highly significant (x2 = 30.51, F < 0.001). SUMMARY

A sample of 956 North American Negroes was examined for cleft uvula, commissural lip pits, preauricular pits, torus palatinus, and torus mandibularis. The following prevalences were found: cleft uvula, 0.52 per cent; cornmissural lip pits, 21.13 per cent; preauricular pits, 4.49 per cent; torus palatinus, 19.65 per cent; and torus mandibularis, 7.85 per cent. There was no significant difference in distribution by sex except for torus palatinus, which occurred twice as often in females as in males. There was a significant association between commissural lip pits and prcauricular pits. A similarly significant association was found between torus palatinus anct torus mandibularis. The authors are grateful for the aid given the organization and implementation of the* dental survey by Dr. Joseph L. Henry, Dean, College of Dentistry, Howard University; Dr. Jerome X. Oltman, Director of the Bureau of Dental Health, Washington, D. C.; Dr. Miltou Isaacson, Director of Dental Services, Bureau of Dental Health, Washington, D. C.; a.ntl Dr. Joyce Reese, Dental Clinician, Bureau of Dental Health (Merritt School), Washington, D. C. The assistance of Dr. J. Cervenka, School of Dentistry, University of Minnesota, iu the writing of this article is acknowledged with sincere appreciation. REFERENCES

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Oral April,

Surg. 1970

18. Hooton, E. A.: On Certain Eskimoid Characters in Icelandic Skulls, Amer. J. Phys. Anthrop. 1: 53-76, 1918. Hooton, E. A.: The Indians of Pecos Pueblo (cited by HrdliEkaas, 21). A. : Anthropological Survey in Alaska, Forty-sixth Annual Report, Washington, ii: Hrdlizka, 1930, Bureau of American Ethnology, pp. 306-313. A.: Mandibular and Maxillary Hyperostoses, Amer. J. Phys. Anthrop. 27: 21. HrdliEka, l-68, 1940. 22. Hrivnakova, J., Tolarova, M., Havlova, Z., and RbZiCkova, J.: Mikroformy a stigmata rozXpB, Rozhl. Chir. 45: 523-532, 1966. 23. Ivy, R. H.: The Influence of Race on the Incidence of Certain Congenital Anomalies, Notably Cleft Lip-Cleft Palate, Plast. Reconstr. Surg. 30: 581-585, 1962. 24. Knox, G., and Braithwaite, F.: Cleft Lips and Palates in Northumberland and Durham, Arch. Dis. Child. 38: 66-70, 1963. 25. Kobayashi, Y.: A Genetic Study of Harelip and Cleft Palate, Jap. J. Hum. Genet. 3: 73-107, 1958. S., Halperin, V., Jefferis, K., Huddleston, S., and Robinson, H. B. G.: The 26. Kolas, Occurrence of Torus Palatinus a.nd Torus Mandibularis in 2,478 Dental Patients, ORAL SURG. 6: 1134-1141, 1953. 0.: Zur Kenntnis der Uvula bifida, Z. Ohrenheilk. 35: 75-77, 1899. 27. Korner, 28. KBrner. 0.: Der Torus Palatinus. Z. Ohrenheilk. 61: 24-27. 1910. 29. Korner; 0.: ‘Cuber den Torus Palatinus, Munchen. Med. Wschr. 71: 1776-1777, 1924. 30. Krahl, V. E.: A Familial Study of the Palatine and Mandibular Tori (Abst.), Anat. Rec. iO3: 477, 1949. 31. Lachmann, H.: Torus Palatinus bei Degenerierten, Z. Neurol. Psychiat. 111: 616-631, 1927. 32. Longenecker, C. G., Ryan, R. F., and Vincent, R. W.: Cleft Lip and Cleft Palate; Incidence at a Large Charity Hospital, Plast. Reconstr. Surg. 35: 548-551, 1965. 33. Maruyama, Y.: Anatomische und rassenanatomische Untersuchungen des Unterkiefers des Formosa Chinesen (Fokien Stamm), Taiwan Igakkai Zasshi 36: 7458, 1937 (cited by HrdliEkazl). 34. McCarthy, F.: A Clinical and Pathological Study of Oral Disease, J. A. M. A. 116: 16-21, 1941.

35. McIntosh, R., Merritt, K. K., Richards~ M. R., Samuels, M. H., and Bellows, M. T.: The Incidence of Congenital Malformations: A Study of 5,964 Pregnancies, Pediatrics 14: 505522, 1954. 36. Mellquist, C., and Sandberg, T.: Odontological Studies of About 1,400 Mediaeval Skulls From Halland and Scania in Sweden and From the Norse Colony in Greenland, and a Contribution to the Knowledge of Their Anthropology, Odont. T. 47: Supp., l-83, 1939. 37. Meskin, L. H., Gorlin, R. J., and Isaacson, R. J.: Abnormal Morphology of the Soft Palate. I. The Prevalence of Cleft Uvula. Cleft Palate J. 1: 342-346. 1964. 38. Meskin, L. H., Gorlin, R. J., and Isaac&n, R. J.: Cleft Uvula-A Microform of Cleft Palate, Acta Chir. Plast. 8: 91-96, 1966. 39. Meskin, L. H., and Shapiro, B. L.: Cleft Uvula in Navajo Indian Children, unpublished data, 1969. 40. Michalowski, R.: Czas. Stomat. 7: 77, 1954 (cited by Michalowski41). 41. Michalowski, R.: Angeborene Mundwinkelfisteln, ihre latenten entziindlichen ZustLnde und Perleche, Derm. Wschr. 148: 281-287, 1963. 42. Miller, 5. R.: The Use of Registries and Vital Statistics in the Study of Congenital Malformations, Second International Conference on Congenital Malformations, New York, 1963, International Medical Congress, pp. 334-340. 43. Miller, S. C., and Roth, H.: Torus Palatinus: A Statistical Study, J. Amer. Dent. Ass. 27: 1950-1957, 1940. 44. Mivasita. K.: Studies on the Chinese Mandibles. V. Torus Mandibularis. J. Orient. Med. 22: 617-624, 1935. S., Ohashi, Y., Kotani, A., Shindo, J., Michi, K., and Enomoto, S.: The 45. Mochizuki, Clinical Studies of Cleft Uvula and Ankyloglossia in Iwate Prefecture, Kokubyo Z. 28: 296-302. 1961 (abstracted in Tokvo Med. Dent. Univ. Bull. 8: 350. 1961). 46. Moorrees. C. F. A:: The Aleut Dentition: a Correlative Studv ,of Dental Characteristics in an Eskimoid People, Cambridge, Mass., 1957, Harvard University Press. 47. Neel, J. V.: A Study of Major Congenital Defects in Japanese Infants, Amer. J. Hum. Genet. 10: 398-445, 1958. S.: fiber den Torus oalatinus der Koreaner. Ref. in Zbl. Zahn-. Mundu. 48. Osima, Kieferheilk. 4: 276, 1939 (cited in Becker, P. E.: Humangenetik, Stuttgart, 1964, G. Thieme Verlag, vol. 2, pp. 344-488). 49. Perier! A. L.: Recherches du torus mandibularis sur quelques groups ethniques, Bull. Schwerz. Ges. Anthrop. Ethnol. 9: 11-12, 1932-33 (cited by HrdliBkazl). 50. Richardson, E. R. : Cleft Uvula in Negro (unpublished data). 51. Russell, F., and Huxley, H. M.: A Comparative Study of the Physical Structure of the

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52. 53. 54. 55. 56. Bi.

58. 59. 60. 61. 62. 63. 64.

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craniofacictl

a~lomnlies among Neyoes

57s

Labrador Eskimos and the New England Indians, Proc. Amer. Ass. Adv. Sci., forty-eighth meeting, Columbus, Ohio, pp. 365-379, 1899 (cited by HrdliEkazl). Sakaguchi, J.: Beitrag zur Anatomle des knochernen Gaumens der Japaner, Bokutl. Zasq. 13: 395, 1939 (Ref. in Zbl. Zahn-, Mundu. Kieferheilk. 6: 344, 1941). Solomon, D. : Miasbildungen und Stellungsanomalien des ZHpfchens, Dissertation, Restock: 1897 (cited by Kiirnerrr). Sanui, Y.: Clinical Statistics and Genetics on the Cleft Lip and Cleft Palate, Jnp. (1. Hum. Genet. 7: 194-233, 1962. Schreiner, K. E. : Zur Ostologie der Lappen, Oslo, 1931, I. W. Nygaard, vol. 1. Selkirk, T. K.: Fistula Auris Congenita, Amer. J. Dis. Child. 49: 431-447, 1935. Stieda, L. : Der Gaumenwulst (Torus Palatinus) ; Ein Beitrag zur Anatomie de3 kniichernen Gaumens, Festschrift. R. Virchow, Int. Beitr. Wiss. Med. 1: 145176, 1891. Thomn, K. H., and Goldman, H. M.: Oral Pathology, ed. 5, St. Louis, 1966, Tlrc C. TV. Mosby Company. Tolarova, M., Havlovi, Z., and Rniickova, J.: The Distribution of Characters Considered To Be Microforms of Cleft Lin and/or Palate in a Population of Normal 18-21 Year Olli Subiects. Acta Chir. Plast. 9: <14. 1967a. Tol&ov& M., Havlova, Z., and R&iEkovL, J. : Distribution of Signs Considered as Micro forms of Lip and/or Palate Clefts in Normal Population of 3 to 6 Year Old Individuals, -4cta Chir. Plast. 9: 184-194. 196713. Tretsven, V. E.: Incidence of Cleft Lip and Palate in Montana Indians, .J. Speech Hearing Dis. 28: 52-57, 1963. Witkop, C. J., Jr.: Original material, 1960 (cited by Witkop and Barroso3). Witkop, C. J., Jr., and Barros, L.: Oral and Genet,ic Studies of Chileans, 1966. 1, Oral Anomalies, Amer. J. Phys. Anthrop. 21: 15-24, 1963. Woo, J. K. : Torus Palatinus, Amer. J. Phys. Anthrop. 8: 81-100, 1950.