Frequency Of The Incidence Of Malocclusion In American Negro Children Aged Twelve To Sixteen

Frequency Of The Incidence Of MalocclusionIn American Negro Children AgedTwelve To SixteenLEONARD A. ALTEMIJS, D.D.S.,Washington, D.C.Anatomists and physical anthro-pologists divide all men into threeracial groups, Negro, Caucasian andMongolian, in part on the basis oftheir cephalofacial features. Thesecephalofacial features which differen-tiate the races of mankind have beenstudied at great length by many sci-entists in every part of the world. Inthe scientific literature of our country,there is a vast wealth of informationon the heads and faces of North Amer-ican Caucasian children. On the otherhand therc is a dearth of material onthe heads and faces of North AmericanNegro children. The frequency of theincidence of malocclusion in the NorthAmerican Caucasian population hasbeen studied and recorded many times.The frequency of the incidence of mal-occlusion in the North AmericanNegro population has not been record-ed in the literature. As this racial groupcomposes approximately twelve percent of the United States' population,it seemed important and necessary togather data on this group. This studywill also seek to determine to whatextent the frequency of the incidenceof malocclusion in Negro children issimilar to Caucasian children. Thisn.sc.study will assess malocclusion by twodifferent methods, one a method thatis useful for epidemiologic purposes,the other, the usual method usingAngle's classification which is useful fororthodontic purposes.'*3MAXRIALS AND METHODSA mass survey was conducted infour junior and senior high schoolsof the District of Columbia. Theschools were selected to give a crosssection of :dl income groups. This sur-vey was made in conjunction with theannual dental inspection of the chil-dren in the public schools of the Dis-trict of Columbia by the health depart-ment. Approximately 3500 Negro chil-dren were examined. It is felt that thesize, complexity and completely homog-eneous nature of this group is truly rep-resentativeof this section of the NorthAmerican population. From this groupa selection was made of 3289 childrenbetween twelve and sixteen years of:tge who had only permanent teethin their dentitions and who had re-ceived no orthodontic treatment. Thiswas done to remove some of the var-iables in determining the frequencyof the incidence of malocclusion. This group will henceforth in this paper beDepartment of Orthodontics, Howard Uni- called the Howard group.versity The method of examination wasThis study is part of a thesis submitted to the method outlined by ~~~~l~~ andthe faculty of the Graduate School of Medi-cine of the University of Pennsylvania i,, Frankel' in a similar study of 2758partial fulfillment of requirements for the North American Caucasian childrenDoctor of Science degree in Dentistq. This between fourteen and eighteen yearsstudy wyag financed in part by U. S. PublicHealth Service Grant Number 331-331C2. of age. These children were students189 190 Altemus October. I959at the Morton High School of Cicero,Illinois and will henceforth in thispaper be called the Illinois group. Thisstudy was chosen as representative forCaucasian children. The findings re-ported by Massler and Frankel on thefrequency of the incidence of mal-occlusion according to Angle was inagreement with findings of Brucker,'Korkhaus, McCall: M~nblatt,~ Sil-Massler and Frankel's. method ofexamining the Illinois group consistedof examining the teeth twice; oncewith the mouth open and once witht!ie teeth in occlusion. Care was takento get the child's correct bite. Duringthe open mouth examination each in-dividual tooth was checked to deter-mine its relation to the contact line.The contact line may be defined asthat line connecting, the contact areasof each tdoth. Any tooth which'wasrlot in exact alignment was considered~~..z!pnsitinr?ed. This open mouth in-spection revealed those teeth that weredisplaced buccally, lingually. or thatwere rotated. The teeth were next ex-amined in occlusion. The labial andbuccal views were checked in this man-ner and also the relationship of eachtooth to the plane of-oddusion. Infraand supraeruptionswere checked by thisexamination. Duiing the closed mouthexaminatior! the relationships of theteeth and jays according to Angle'sclassification were also checked andrecorded. Each malpositioned toothwas counted only once regardless of thedirection 9r amount of displacement.Missing teeth were not counted asmalpositioned, only absent. The fewthird molars observed were not count-ed.The team of examiners, were mem-bers of the Orthodontic Departmentof the College of Dentistry, HowardUniversity. A special period of train-ing was undertaken prior to this sur-and Stallard."vey to review the classification ofAngle and the methods of Massler andFraxkel. A group of 40 children wereexamined separately by the three mem-bers of the team, using Angle's classifi-cation. The examiners agreed on 37of the children, an accuracy of ap-proximately 93 per cent. A secondgroup of 38 children were examinedby all members of the team. Theyagreed on the classifications of 35 chil-dren, again with an accuracy of 92per cent. Because of the subjectivenature of Angle's classification it wasfelt that this was a high degree of ac-curacy. Similar tests were made of thesimilarity of results using the methodsof counting the total number of mal-occluded teeth as suggested by Masslerand Frank~l.~ The total nunbe? ofteeth out ok the line of occlusion eitherbuccally, lingually, mesially, distally,rotated, infraoccluded or supraocclud-ed were counted. In the first group of40 children the three examiners foundthe foiiowing totai numbers of mai-occluded teeth: 239, 241 and 244. Inthe second group of 38 children thetotals were 227, 230 and 232. It wasfelt that this high degree of agrementwas due to the nature of these exam--inations. They are much simplet andless subjective than Angle's classifica-tion.PRESENTATION oI, DATAThe data gathered by this surveywill be presented separately for eachsex and then the combined data. Thesedata will then be compared with thedata of Massler and Frankel.6 Thesimilarity of the studies of the Howardand Illinois groups and the ages ofthe children are sufficiently close tomake these studies comparable. Theages of the children in the Howardgroup were from twelve to sixteenyears; the ages of the children in theIIlinois. group were from fourteen toeighteen years. Only children with Vol. 29, No. 4 Incidence 191permanent dentitions and who had re-ceived no orthodontic treatment wereconsidered by both groups. The Illinoisgroup were of children whose familieswere of the upper middle class andthey were of :? fairly uniform ethnicstock of North American Caucasians.The Howard group consisted of a crosssection of all income groups and thechildren represented the great racialmixture oi thc North American Negro.From the tabulation of the datagathered on the Howard group duringthe mass survey it was found that ap-proximately 83 per cent of the chil-dren examined had some form of mal-occlusion, approximately four per centhad ideal occlusion and approximately13 per cent had normal occlusion. Thedefinitions of ideal and normal oc-clusion that were used in this studyare as follows: Ideal occlusion was re-served for those cases in which nota single maloccluded tooth could bediscovered; normal occlusion was usedto designate those cases in which thedegree of displacement was so smallas to require no orthodontic treat-ment. Some degree of subjectivity wassometimes necessary to determinewhether they belonged in the categoryof normal or Class I. The classifica-tion of malocclusion according toAngle was used because of its wide useby orthodontists. The definitions ofthe various classes were taken fromthe seventh edition of Malocclusion ofthe Teeth by Edward H. Ang1e.l ClassI malocclusion had a mesiodistal rela-tionship of the jaws that was character-ized by a normal mesiodistal relation-ship of the permanent first molars. Thenormal mesiodistal relationship of thepermanent first molars has the mesio-buccal cusp of the upper first molar fallin the mesiobuccalgroove of the lowerfirst molar. One or more teeth anteriorto the molars were out of their normalpositidns. Class I1 malocclusion had thelower arch pclsterior to normal asshown by thz positions of the per-manent first molars which were distalto normal to the extent of more thanone-half the width of one cusp. Thiscondition may have been unilateral orbilateral and had two divisions. A ClassI1 molar relationship with protrusionof the upper incisors was called Divi-sion one and a similar case with re-trusion of the upper incisors was calledDivision two. If the distal molar rela-tionship existed on one side only, thesedivisions were called subdivisions. ClassI11 malocclusion had the lower archanterior to normal as shown by thepositions of the permanent first molarswhich were mesial to normal to theextent of more than one-half the widthof one cusp. Just as in Class I1 thisclassification may be unilateral or bi-lateral; if unilateral, they were calledsubdivisions. The positions of the in-cisors were not taken into considera-tion in this class.The total number of children exam-ined after the elimination of all whohad some units of the deciduous denti-tion remaining or who had received or-thodontic treatment was 3289; 1470were males and 1819 were females. Thetotals in each classification accordingto Angle were as follows: ideal oc-clusion - 68 or 3.69 per cent of thefemales, 53 or 3.61 per cent of themales, 121 or 3.69 per cent when com-bined; normal occlusion - 230 or12.64 per cent of the females, 191 or12.99 per cent of the males, 421 or12.79 per cent when combined; ClassI - 1,188 or 65.31 per cent of thefemales, 996 or 67.75 per cent of themales, 2,184 or 66.40 per cent whencombined; Class 11, Division 1 - 196or 10.77 per cent of the females, 151 or10.27 per cent of the males, 347 or10.55 per cent when combined; Class11, Division 2 - 35 or 1.92 per cent ofthe females, 17 or 1.16 per cent of themales, 52 or 1.58 per cent when com-bined; Class I11 - 100 or 5.50 per HOWARD UNIVERSITY MASS SURVEY DATATABLE I. DISTRIBUTION OF OCCLUSION ACCORDING TO ANGLE'S CLASSIFICATIONAGE INYEARS12131415162 to 16"GOOD" OCCLUSIONNUMBER OFCHILDRENEXAMINED3313784 363752991,819CLASS TIDI :. 1No. (7)41 (12.39)50 (13.23)46 (10.55) "NORMAL"OCCLUSION , OCCLUSIONI"IDEAL"CLASS I1 DIV. 2No. (%)3 (0.906)4 (1.058)6 (1.376)No. (%)13 (3.92)13 (3.41)18 (4.13)12 (3.20)12 (4.01)68 (3.69)(FEMA'LES)_-_ --MALOCCLUSIONNo. (%)46 (13.89)48 (12.70)38 ( 8.71)59 (15.73)39 (13.05)230 (12.64)CLASS I:No. (%)209 (63.41)249 (65.87)292 (66.97)241 (64.27)197 (65.89)1,188 (65.31)CLASS 111No. (%)19 (5.74)20 (5.29)25 (5.73)lS (4.80)18 (6.02)100 (5.50) HOWARD UNIVERSITY MASS SURVEY DATA13 336 12 (3.57)14 357 11 (3.08)z?53 (15.77) 213 (63.39)44 (12.60) 261 (73.10)TABLE 11. DISTRIBUTION OF OCCLUSION ACCORDING TO ANGLE'S CLASSIFICATION(MALES)43 (12.83)"GOOD" OCCLUSIONAGE IN "IDEAL" "NORMAL" OCCLUSION232 (69.25)157 (66.53)996 (67.75)32 (15.53)33 ( 9.82)31 ( 8.68)30 ( 8.96)25 (10.59)MALOCCLUSION2 (0.971)1 (0.290)4 (1.12)5 (1.49)5 (2.12)CLASS I1 CLASS I1DIV. 1 DIV. 2151 (10.27)17 (1.16)CLASS 111No. (%)6 (2.91)18 (5.36)17 (4.76)11 (3.28)12 (5.08)64 (4.35) HOWARD UNIVERSITY MASS SURVEY DATA"GOOD" OCCLUSION"NORMAL"OCCLUSION**No. (X)69 (12.85)101 (14.15)82 (10.34)102 (14.38)67 (12.52)421 (12.79)TABLE 111: DISTRIBUTION OF OCCLUSION ACCORDING TO ANGLE IS CLASSIFICATION(MALES AND FEMALES COMBINED)MALOCCLUSIONCLASS I11CLASS I1 CLASS I1DIV. 1 DIV. 2CLASS INo. ( %) No. (1.) No. (%) No. (%342 (63.69) 73 (13.59) 5 (0.931) 25 (4.66)462 (64.71) 83 (11.62) 5 (0.70) 38 (5.32)553 (69.74) 77 ( 9.71) 10 (1.26) 42 (5.30)473 (66.62) 69 ( 9.72) 13 (1.83) 29 (4.08)354 (66.17) 45 ( 8.41) 19 (3.55) 30 (5.61)2,184 (66.40) 347 (10.55) 52 (1.58) 164 (4.99)AGE INYEARS CHILDREN EXAMINED-1213141516537 23 (4.28)7 14 25 (3.50)793 29 (3.65)7 10 24 (3.38)535 20 (3.73)12 to 16 I 3,289! 121 (3.69)* "Ideal" occlusion was reserved** "Normal" occlusion was used to designate those cases in which the degree of displacement was so small as torequire no orthodontic treatment.whether they belonged in the category of "nonnal" or"c1ass I."Some degree of subjectivity was necessary in s3ine cases in order to determine MAURY MASSLER AND JOHN M. FRANKELNUMBER OFCHILDRENEXAMINED5537286986 54125TABLE IV. DISTRIBUTION OF OCCLUSION ACCORDING TO ANGLE'S CLASSIFICATION(MALES AND FEMALES COMBINED)"ICEAL"OCCLUSION*No. (%I21 (3.80)19 (2.61)21 (2.89)19 (2.91)1 (0.80)~-61 (8.38)69 (9.90)"GOOD" OCCLUSION,r2.8a0141516171814 to 18 1 2,758 I 81 (2.93)"NORMAL"OCCLUSION**No. (%)98 (17.72)125 (17.17)135 (19.34)118 (18.05)25 (20.00) CMS INo. (%)283 (51.17)367 (50.41)341 (48.85)327 (50.00)63 (50.40)501 (18.23) I 1,381 (50.07)CLASS I1DIV. 1No. (%)85 (15.37)129 (17.73)113 (16.21)112 (17.15)21 (16.60)460 (16.68)CLASS 11DIV. 2No. (%)14 (2.53)27 (3.70)19 (2-17)14 (2.14)1 (0.60)CLASS 111I52 (9.40) I64 (9.79)14 (11.20)* "Ideal" occlusion was reserved for those cases in which not a single inaloccluded tooth could be discovered.** "Normal" occlusion was used to designate those cases in which the number of inaloccluded teeth was less thanthe average number (10) and the degree of displacement was so small as to catalog it clinically as "normal" and re-quiring no treatment.belonged in the category of "normal" or "mild class I."orthodontic treatment was or was not indicated.Some degree of subjectivity was necessary in such cases in order to determine whether they For the most part the decisive factor was whether or notData for males and fernalcs wcre als9 computed separately. The findings were not significantly different. AGE INYEARSCombined2,8684,3254,7054,4693,3051213141516.2 to 16Male6.166.176.296.356.23AVERAGE NUMBER OFMALOCCLUDED TEETHNUMBER OF CHLLDREN TOTAL NUMBER OFIEXAMINED MALOCCLUDED TEETH7 14793710535PER CHILD2 , 0742,2462,1271,470Male--2063363573352 361,470Female~~3313784363752991 , 819--Combined +z-537 1 1,268~I3,289 I 9,185Femalc1,6002,2512,4592 , 3421 , 83510,48719,672 1 6.25-Female4.835.965.646.256.145.76--Comb in e d5.346.065.936.296.18-5.98 MAURY MASSLER AND JOHN M. FXANEL3444 1436735144h,95537286980 54125Z0AGE INYEARS141516171814 to 18---TABLE VI. NUMBER OF MALOCCLUDED TEETH IN CHILDREN FROM 14 TO 18 YEARS OF AGENUMBER OF CHILDRENEXAMINEDMale2093 1433130381---1,238Female Combined+_1,520 2,758-- - IAVERAGE NLTMBER OFMALOCCLUDED TEETHTOTAL NLTMBER OFMAMCCLUDED TEETHMale-2,3783,3183,5783,353 94 513,572Fema 1 e3,4674,4653,4703,685444.---1.5,531Combined5,845 11.387,783 I 10.577,048 I 10.817,038 11.071,389 11.6729,103 10.96-PER CHILD--Fernale10.0810.789.4510.5010.9910,22-Comb ine d--10.5610.6910.0910.7611.1110.55I-6loc.a(D(Dd9U 198 Alternus October, 1959cent of the females, 64 or 4.35 per centof the males, 164 or 4.99 per cent whencombined. Inspection of these totalsshows that there was no significant dif-ference in the frequency of the inci-dence of malocclusion for males and fe-males. The data for females are pre-sented in Table I; for males in Table11; and the data for the combinedsexes in Table 111.Similar data using Angle's classifica-tion were taken from the study of theIllinois group and the following totalswere found: 2758 children were exam-ined and of this number 1238 weremales and 1520 were females. Masslerand Franke15 found that the differencesin the data for males and females werenot significant and only the combineddata are presented here. These dataare presented in Table IV. Ideal oc-clusion - 81 or 2.93 per cent; normalocclusion - 501 or 18.23 per cent;Class I - 1381 or 50.07 per cent; ClassClass 11, Division 2 - 75 or 2.71 percent; Class I11 - 260 or 9.43 percent.The data compiled according to thenumber of maloccluded teeth perchild were analyzed for the Howardgroup. These teeth were out of normalalignment either occlusally, gingivally,mesially, distally, buccally, lingually orrotated. These data are presented inTable V and the totals are as follows:3289 Negro children had 19,672 mal-occluded teeth ; of these the 1470 maleshad 9185 maloccluded teeth or 6.25maloccluded teeth per male child; and11, Divirinr? 1 - 460 nr 16.68 per cent;the 1819 females had 10,487 maloc-cluded teeth or 5.76 maloccluded teethper female child. Here again we have nosignificant difference between the sexesin the frequency of the incidence of thenumber of maloccluded teeth. We hadapproximately six maloccluded teethfor each child. Similar data gatheredon the Illinois group had the followingtotals: 2758 Caucasian children had29,103 maloccluded teeth; of these the1238 males had 13,572 maloccludedteeth or 10.96 maloccluded teeth permale child; the 1520 females had 15,-531 maloccluded teeth or 10.22 mal-occluded teeth per female child. Thesedata are presented in Table VI. Therewas no significant difference in the fre-quency of the incidence of maloccludedteeth between the sexes. The combinedor average number of maloccludedteeth for the Illinois group was approx-imately 10 maloccluded teeth for eachchild.DISCUSSIONThe totals for good occlusion forboth studies according to Angle are inTable VII.It can be seen from the above tablethat the frequency of the incidence ofideal occlusion, a classification of nearperfection with not a single tooth inmalocclusion, is small in both studies -3.69 per cent in the Howard group and2.93 per cent in the Illinois group. Thepercentage of children with normal oc-clusion is seen to vary in this table12.79 per cent in the Howard groupand 18.23 per cent in the IllinoisTABLE VI1"GOOD" OCCLUSION NUMBER OF `I IDEAL ' I` NORMAL "AGE IN CHILDREN OCCLUSION OCCLUSIONYEARS EXAMINED (%Io) (%IHowardIllinois12 to 16 3,289 3.69 12.7914 to 18 2,758 2.93 18.23 Vol. 29. No. 4Incidence199TABLE VI11MALOCCLUSIONCLASS I CLASS I1 GLASS I1 CLASS I11DIV. 1 DIV.2% % % %66.40 10.55 1.58 4.99HowardIllinois 50.07 16.68 2.71 9.43group. A possible explanation of thisdifference may be found in the methodsused in classifying normal occlusion byboth studies. The Illinois group used anumerical system of determining nor-mal occlusion, namely, a dentition withan average number of less than tenslightly maloccluded teeth was callednormal. In the Howard study nothought was given to an average num-ber of maloccluded teeth, but only theconsideration as to whether orthodontictreatment was needed. But it must beadmitted that some degree of .sub-jectivity is necessary to determinewhether some of the cases beIongedin the category of "normal" or "ClassI." This degree of subjectivity willvary between any two groups of in-vestigators.The frequency of the incidence ofmalocclusion according to Angle's clas-sification in both studies is given in theTable VIII.It can be seen upon comparing thefrequencies of the incidence of thevarious classes of malocclusion that thefollowing differences exist. Class Imalocclusion had 66.40 per cent in theHoward group and 50.07 per cent inthe Illinois group. We feel this differ-ence of 16 per cent to be significant.Class 11, Division 1 malocclusion had10.55 per cent in the Howard groupand 16.68 per cent in the Illinoisgroup. There seem to be significantlyfewer children with this form of mal-occlusion in the Howard group. Class11, Division 2 malocclusion had 1.58per cent in the Howard group and 2.71per cent in the Illinois group. Thefrequency of the incidence in bothgroups was small and similar. Class I11had 4.99 per cent in the Howard groupand 9.43 per cent in the Illinois group.There are significantly fewer childrenwith this form of malocclusion in theHoward group. We feel that this in-formation relative to the differences inthe frequencies of the incidence of Class11, Division 1 and Class I11 maloc-clusion in the Howard group is relatedto larger tooth and arch size as well asthe differences in the configuration ofthe head and face of these two groups.A comparison of the average numberof maloccluded teeth showed approx-imately six in the Howard group andapproximately ten in the Illinois group.SUMMARY AND CONCLUSIONSA study has been made of the fre-quency of the incidence of malocclu-sion in the North American Negrochild population. 3289 Negro childrenwere examined in the public schoolsof the District of Columbia. These chil-dren were. between twelve and sixteenyears of age; they had only permanentdentitions and had received no ortho-dontic treatment. It is felt that thesize, complexity and completely homo-geneous nature of. this sample is repre-sentative for the great racial mixtureof the North American Negro.The frequency of the incidence ofmalocclusion was assessed by twomethods: one was a method that is 200 AltemusOctober, 1959useful for epidemiologic purposes, i.e.,simply counting the teeth that wereout of the normal alignment or occlu-sion, the other was the usual methodusing the classification of Angle. Com-parisons were made between the fre-quencies of the incidence of maloc-clusion in Caucasian children and Ne-gro children. The study made by Mas-sler and Frankel was chosen as a repre-sentative study of North AmericanCaucasian children.The Howard study has shown that:1. The frequency of the total in- cidence of malocclusion is high in the Negro child population. Approximately eighty-three per cent of the children had maloc- clusion of their teeth. About four per cent had ideal or near- ly perfect occlusion and thirteen per cent had normal occlusion, i.e., they had some teeth slightly malpositioned but not suffi- cientiy so a io i-eqiiiie ortho-dontic treatment.2. The frequency of the total in-cidence of malocclusion in theNegro child population is com-parable to the frequency of thetotal incidence of malocclusionin the Caucasian child popula-tion. This total incidence as re-ported by Massler and Frankeland many other authors is thatapproximately eighty per centof American Caucasian childrenhave malocclusion of theirteeth. Only three per cent haveideal occlusion and approx-imately eighteen per cent havenormal occlusion, Le., they havesome teeth slightly malposition-ed but not sufficiently so as to re-quire orthodontic treatment.3. There seem to be fewer maloc-cluded teeth per child in theNegro child population than inthe Caucasian child population.I.e.3.4.5.6.7.8.9.There were approximately sixmaloccluded teeth per child inthe Howard group and tenmaloccluded teeth per child inthe Illinois group.4. There are differences in thefrequency of the incidence ofthe various classes of maloc-clusion according to Angleamong North American Ne-groes and Caucasians. Therewere fewer Negro children withnormal, Class 11, Division 1and Class I11 malocclusion.Further studies to determinepossible reasons for these dif-ferences will be reported at alater date.600 "Wy Street, N.W.Angle, E. H. : Malocclusion of the Teeth(7th Ed.), S. S. White Dental Mfg.Co., Philadelphia, Pa., 1907.Brucker, M.: Studies on the Incidenceand Cause of Dental Defects in Chil-dren. Malocclusion, J. D. Bes. 22:315,1943.Herskovita, M. J.: The American Ne-gro, Alfred A. Knopt, New Pork, 1930.Korkhaus, G.: The Frequency of Ortho-dontic Anomalies at Various Ages, Int.J. Ortho. 14:120, 1928.Massler. M. and Frankel. J. M.: Prev-alence of Malocclusion in' children aged14 to 18 years, Am. J. Ortho. 37:751-768, 1951.McCall, J. 0. : A Study of Malocclusionin Preschool and School Children.Dental Items Znterest 66 : 131, 1944.Munblatt, M. A.: A Statistical Studyof Dental Occlusion in Children, DentalZtem Znterest 65:43, 1943.Silver, E. I.: Forsyth OrthodonticSurvey of Untreated Cases, Am. J.Ortho. and Oral Surg. 30:635, 1944.Stallard, H. : The General Prevalence ofGross Symptoms of Malocclusion, Den-tal Cosmos 74:29, 1932.