ro o 1Ppr4( SVsT' r&cr( -too c
The Development of the Permanent Teeth(
CARMEN M. NOLLA, B.S., D.D.S., M.S.*
T. is important to every dentist treat- in the mouth of different children, the I ing children to have a good under - majority of the children exhibit some standing of the development of the den- pattern in the sequence of eruption tition. In order to widen one's think- (Klein and Cody) 9 (Lo and Moyers). 1-3 ing about the impingement of develop- However, a consideration of eruption ment on dental problems and perhaps alone makes one cognizant of only one improve one's clinical judgment, a com- phase of the development of the denti- prehensive study of the development of tion. A measure of calcification (matura- the teeth should be most helpful. tion) at different age-levels will provide In the study of child growth and de- a more precise index for determining velopment, it has been pointed out by dental age and will contribute to the various investigators that the develop- concept of the organism as a whole. ment of the dentition has a close cor- In 1939, Pinney2' completed a study relation to some other measures of of the development of the mandibular growth. In the Laboratory School of the teeth, in which he utilized a technic for University of Michigan, the nature of a serial study of radiographs of the same growth and development has been in- individual. It became apparent that a vestigated by serial examination of the similar study should be conducted in same children at yearly intervals, utiliz- order to obtain information about all of ing a set of objective measurements the teeth. Therefore, an investigation of various physical and mental attri- was star ted,isirigPinney's technic, with butes. It has been found by Olson and some modifications. It seemed logkal to Hughes'6' 17, 18, 19 that there is an in- conduct such a radiographic study of the timate relationship in the functioning of development of the dentition, since ra- all the aspects of normal growth, as has diographs are used extensively in dental been shown by the plotting of a number diagnosis and clinical practice. Further- of measurements in the same graph. more, by means of serial radiographs When this relationship is appreciated, one can obtain continuous data on the one thinks of the development of the changes exhibited by the individual be- teeth, not as an isolated process, but as ing studied. one which relates to other developmen- Many investigators have studied the tal processes. development of the dentition by employ- So far, the only available measure of ing different methods of observation. dental age has been secured by noting These investigators should be recognized the eruption of teeth (Cattell). 5 Al- for their contributions because they have though the eruption of the teeth may facilitated further research. However, differ greatly in the time of appearance one still finds principles in the litera- ture that have not been explained sat- Formerly Assistant Professor of Dentistry, isfactorily and some misinterpretation of School of Dentistry, University of Michigan, Ann Arbor. Present address: 1408 Magdalena Ave., information. A review of the literature on Candado, Santurce, Puerto Rico. the development of the dentition shows 254
/ 76 FOURTH QUARTER, 1960 255
that the technics and methods used 3. . To prepare tables of development by Legros and Magitot,'l' 12 Black," 2 of permanent teeth which will permit Pierce, 20 Colyer, 7 B roomell and Fichclis,4 the interpretation of individual differ- Brady,3 Schour and Massler,22' 23, 24, 25 ences in dental growth, by the age-unit Logan and Kronfc-ld,'°' 14 and Mc- method; Call'4' 23 are inconclusive from, the point. 4. To gain information relative to the of view, of serial growth and develop- amount and kind of variation displayed ment of the individual as a whole. The by the growth 'of the permanent teeth; method most frequently used by these 5. To contribute to the understanding investigators has been the anatomic, his- of differences in dental development of tologic or radiographic study of autop boys and girls; sled material.. These methods of study 6. To reconstruct previous evidence, have a number of limitations. For in- with its errors in sampling and the omis- stance, with anatomic or microscopic sec- sions, into a theoretical set of develop- tions it is impossible to study the con- mental norms for permanent teeth from tinuity of growth in the same individual. beginning to completion; • According to Todd '26 "A dead. child is a 7. To make recommendations for fur- defective ` -.child in whom there has oc- ther study in terms of 'progress made by curred an interruption or prohibition of the current study. developmental growth sometime before It would appear that the information death, unless death is due to an acute derived would aid the dentist to assess disease or an accident, such as injury or and pace the development of a young burns. The interpretive study of actual person's dentition. Hence, .a meaningful skulls must be tempered by recognition concept, of normality, involving an in- of this fact. If we are to investigate dividual' growing child, might be se- healthy skulls, we must. do it on the liv- cured. ing." The,lmitation of the radiographic MATERIALS study is that the, developmental changes which occur prior to calcification are not The materials used for this :study con- sisted of "serial oral radiographs of twen- observed radiographically. On the other fv ty-five bo'ys' and twenty-five girls obtained c hand, a study of serial radiographs of from the files of the Child Development 5 the same individual provides, a good Laboratories of the University of Mich- method for the longitudinal study of ,igan School.. Each set of radiograph in- growth. . cluded: This investigation, now to be report- 1. Extra-oral right and left lateral ed, was formulated in accord with, the jaws, following objectives: '2. Intra-oral maxillary and mandib- 1. To organize a technic for the de- ular occiusals, tailed appraisal of the development, of 3. 'Intra-oral right and left maxillary the permanent dentition as revealed by periapicals of posterior teeth. radiographs; These radiographs were' exposed and 2. To construct norms (tables and processed by the technicians in' the De- graphs) which will display the average partment of Radiography of the School development of individual teeth, both of Dentistry, University of Michigan. for boys and girls; Usually, a set of radiographs was secured 256 JOURNAL OF DENTISTRY FOR CHILDREN for each year of the record at a time Not all of the long series were used. were approximating the individual's birthday. The radiographs were placed on a spe- that t] The total number of radiographs for the cial view table which permitted accurate ly the girls was 1746 and for the boys 1656. reading of details. The observation took is in a The range in age of the group studied cognizance only of the degree of develop- in his is shown in Table I. ment, as outlined in Figure I, which is can b a set of drawings illustrating the ten are re TABLE I stages of development of the teeth as ob- the te RANGE IN AGE served radiographically. The first column dil)Ie. (right) appraises the growth-stage of the the ol Beginning Terminal Age in Age in central and lateral incisor, the second peatin Sex Months Average Months Average the cuspid, the third the bicuspids, and In Girls 25- 80 55.3 141-279 198.2 the fourth the molars. The drawings il- the d4 Boys 41-121 68.3 163-277 201.8 lustrate for each of the ten stages (1 to the r2 10 inclusive) the appearance of the stage as pos METHOD of dental development observed radio- For e The radiographic records were select- graphically. were ed from the files on the basis of length. Although both right and left sides given root ' grade
10. APICAL ENVOY ROOT COMPLETED iiig la' was in ample . S 9. ROOT ALMOST COMPLETED OPEN APEX ilj were of the . TWO-THIRDS OF ROOT COMPLETED... VLIUC showe
7. ONE-THIRD OF ROOT COMPLETED er tha much the fl( . CROWN COMPLETED e am1 of the 5. CROWN ALMOST COMPLETED l,ecorr, one-th 4. TWO-THIRDS OF CROWN COMPLETED grade 1.1 tent 3. ONE-THIRD OF CROWN COMPLETED i.iitlica examl appro. 2. INITIAL CALCIFICATION () 0 0 0 Q Q Q Q would root i 0 0 00 0000 1. PRESENCE OF CRYPT would Tlim 0. ABSENCE OF CRYPT difhcu FIGURE 1. Stages of development of mandibular and maxillary teeth. LIC, as FOURTH QUARTER, 1960 257
re used. were observed and studied, it was found the growth-level, half-way between the )fl a spe- that the rate of growth was approximate- growth-stage, and close to the next level. accurate ly the same in both sides. This finding Attempts to appraise radiographs more ;ion took is in agreement with Pinney's experience accurately than this grading do not develop- in his earlier investigation. As a rule, it seem feasible. which is can be said that the values for one side A detailed description of the changes the ten are representative of the development of in developing teeth as observed radio- th as ob- the teeth of the maxilla and the man- graphically now will be described. In de- •t column dible. In all of the radiographs studied termining the amount of maturation of ge of the the observations were controlled by re- developing teeth, the marginal appear - e second peating the observation a second time. ance becomes the important considera- pids, and In order to obtain an appraisal of tion. The first radiographic sign of de- twings ii- the development of a particular tooth, velopment is the appearance of an al- ges (1 to the radiograph was matched as closely most circular radiolucent structure in the stage as possible with the comparative figure. the bone which has been designated as d radio- For example, if one-third of the crown the crypt. The radiolucent tooth-germ is were completed the observation was enclosed within this crypt. Important left sides given the value 3.0, if one-third of the cellular changes may have taken place root were completed the observation was prior to this stage, such as initiation, graded 7.0. When the radiographic read- proliferation, histodifferentiation, mor- ing lay between two grades this appraisal phodifferentiation and apposition. was indicated as the value of 0.5. For ex- The next change to be observed is the ample, if the reading of the radiograph appearance of small radiopaque trian- were between one-third and two-thirds gular points close to the inner coronal of the root completed it was given the border of the crypt. In the succeeding value of 7.5. When the radiograph annual radiographs, the quantiative in- showed a reading that was slightly great- crease in calcification easily is de_te__r_- er than the illustrated grade, but not as mined. The outline of the radiolucent much as half way between that stage and pulp can be followed readily through the next, the value 0.2 was added. For the different stages of development. The example, if slightly more than two-thirds completion of the apical end of the root of the crown were completed if would become 4.2, or if somewhat more than one-third of the root were completed the grade would become 7.2. If the develop- r)ent were slightly less than the grade indicated the value 0.7 was added. For example, if two-thirds of the crown were approximately completed the grade would become 3.7, or if two-thirds of the loot were almost completed the grade would become 7.7. Thus, it is possible, without much FxGui.r 2. Radiograph showing the man- difficulty, to assign the observational val- dibular first permanent molar at stage 6 or the ue as seen on the growth level above crown completed. 258 JOURNAL OF DENTISTRY FOR CHILDREN
the stage of growth is represented by the drawings and on the horizontal axis the chronological age in months is represent- ed. The readings, as plotted, and the wi.....0 ME curves obtained show the development for each individual tooth. Figure 7 shows the graphs of the mandibular and maxil- NEWS lary teeth of one of the girls studied. NNIFZM NMWAM MENEM .1! MOEN • -- FIGURE 3. Radiograph showing the mandibular first permanent molar at stage 7 (one-third of the root completed), the second permanent FIGURE 7. Graph molar and second bicuspid at stage 3.5 (more G67. than one-third of crown completed), and the DE: first bicuspid at stage 4.5 (more than two-thirds of the crown completed). The observatic graphically in ter: is the final stage to be observed radio- ment in the ordi graphically in the process of matura- age in the absci:
tion. FIGURE 5. Radiograph showing the mandibular Figures 2 to 6 are radiographs which first permanent molar at stage 10 (root com- serve as examples of the different stages pleted), the second permanent molar and sec- of growth. ond bicuspid at stage 8 (two-thirds---oLroot In recording the degree of develop- completed) and the third molar at stage 4 (two- thirds of the crown completed). ment of the individual teeth, special Mal graphs were designed for the mandibular and maxillary teeth. On the vertical axis Boys QQQe QQO 0000 )0o0 0000 a
GIRLS Ooea Oboe GQ6 FIGURE 4. Radiograph showing the mandib- FIGURE 6. Radiographs showing the maxillary ular first permanent molar at stage 7 (one-third permanent cuspid at stage 7 (one-third of the o 000 0000 of the root completed), the second bicuspid at root completed), the permanent lateral incisor stage 2 (beginning maturation), and the second at stage 8 (two-thirds of root completed) and permanent molar at stage 2.5 (less than one- the central incisor at stage 9 (apical end still third of crown completed). wide).
FOURTH QUARTER, 1960 259
MAXILLARY MANDI BULAR
DEVEL OPMENTAL LEVELS CEVELOPMENTAL LEVELS
°3 --;------f-H --4 —-_ ------±H 0000______------
00(0 0000 000c
4 33 4* *0 72 44 14 01 00 .32 144 04 44 00 (91 204 20 07 24 34 41 20 72 44 14 011700114444 04 *01, C3200QAAI A.
FIGURE 7. Graph showing developmental curves for the maxillary and mandibular teeth of case G67. DENTAL AGE connected by lines providing a dental The observation-points were recorded developmental curve. In order to tab- graphically in terms of degree of develop- ulate the data for the developmental ment in the ordinate and chronological norms of dental age, the developmental age in the abscissa. These points were curves were read back at the year-points
MAXILLARY MANDIBULAR
0000 BOYS 00011
0 0902 0000 0000
0000 0000 0000 0000 0000 0000
(4
DEVELOPMENTAL LEVELS
Y^ q If QV go
GIRLS (.9ooO 0002
720110
0900 011 0000 0.0011 0000 0000 0000 0000 aL
FIGURE 8. Norm-developmental curves for boys and girls.
260 JOURNAL OF DENTISTRY FOR CHILDREN
in chronological age so that the develop- the boys and of the girls. The interpreta- mental value, given for tabulation, is the tion of these curves reveals that the gen- intercept of the curve with successive eral type of growth displayed by each abscissa at the year-points. It is obvious tooth was the same and that the equa- that the tabulated values permit the tion which expresses the general type of assumption that the progress in the de- change in rate is an algebraic quadratic velopment of the tooth is a linear func- (y = ax2 + bx + c). Few developmental tion from the two actual points of ob- differences were shown between right servation and technically may be termed and left teeth of the same kind. No sig- interpolation, with occasional short nificant differences in sex were observed periods of extrapolation. These values in the time required for development, were averaged at the year points of boys however, the girls started dental develop- and girls, both for maxillary and man- ment at an earlier age and finished de- dibular teeth. These averages, as de- velopment earlier. With few exceptions, scribed, provide a general average of all differences for the sexes in the general teeth, a dental age as a whole. sequence of the completion of develop- RESULTS AND DISCUSSION ment of each tooth were not apparent. Norm-developmental curves for each The roots of the mandibular teeth were tooth and dental-age values, both for completed in the following order: boys and girls, were obtained. Figure 8 1. Central incisor shows the norm-developmental curves 2. Lateral incisor and first permanent for maxillary and mandibular teeth of molar
TABLE II NORMS FOR THE MATURATION OF PERMANENT TEETH FOR BOYS
Age Mandibular Teeth (Growth S :age) Maxillary Teeth (Growth S ge) (Yrs.) lii 212 515 6 1 6 8j8 lii 212 313 414 515 616 3 5.2 4.5 3.2 2.6 1.1 5.0 4.3 3.4 3.0 2.0 1.0 4.2 1.0 4 6.5 5.7 4.2 3.5 2.2 6.2 2.0 5.4 4.5 3.9 3.0 2.0 5.3 2.0 5 7.5 6.8 5.1 4.4 3.3 7.0 3.0 6.4 5.5 4.8 4.0 3.0 6.4 3.0 6 8.2 7.7 5.9 5.2 4.3 7.7 4.0 7.3 6.4 5.6 4.9 4.0 7.4 4.0 7 8.8 8.5 6.7 6.0 5.3 8.4 5.0 .8 8.2 7.2 6.3 5.7 4.9 8.2 5.0 8 9.3 9.1 7.4 6.8 6.2 9.0 5.9 1.4 8.8 8.0 7.0 6.5 5.8 8.9 5.8 1.0 9 9.7 9.5 8.0 7.5 7.0 9.5 6.? 1.8 9.4 8.7 7.7 7.2 6.6 9.4 6.5 1.8 10 10.0 9.8 8.6 8.2 7.7 9.8 7.4 2.0 91 9.3 8.4 7.9 7.3 9.7 7.2 11 9.1 8.8 8.3 9.9 7.9 2.7 9.95 9.7 8.8 8.6 8.0 9.8 7.8 3.0 I 12 9.6 9.4 8.9 8.4 33 9.95 9.2 9.2 8.7 8.3 4. 13 9.8 9.7 9.4 8.9 4.5 9.6 9.6 9.3 8.8 4.9 14 10.0 9.7 9.3 5.3 9.8 9.8 9.6 9.3 15.9 15 10.0 9.7 6.2 9.9 9.9 9.9 9.6 16.6 l6.. 10.0 7.3 10.0 17.7 (tt 17 7.6 8.0
FOURTH QUARTER, 1960 261
TABLE HI NORMS FOR THE MATURATION OF PERMANENT TEETH FOR GIRLS
Age Mandibular Teeth (Growth Stage) Maxillary Teeth (Growth Stage) (Yrs.)12l233 4 5 6 77 8 1R 2 3 4 5 6k3 717 88 3.4 2.9 1.7 5.0 1.6 4.3 3.7 3.3 2.6 2.0 4.5 1.8 4 6.6 6.0 4.4 3.9 2.8 6.2 2.8 5.4 4.8 4.3 3.6 3.0 5.7 2.8 5 7.6 7.2 5.4 4.9 3.8 7.3 3.9 6.5 5.8 5.3 4.6 4.0 6.9 3.8 6 8.5 8.1 6.3 5.8 4.8 8.1 5.0 7.4 6.7 6.2 5.6 4.9 7.9 4.7 7 9.3 8.9 7.2 6.7 5:7 8.7 5.9 1.8 8.3 7.6 7.0 6.5 5.8 8.7 5.6 8 9.8 9.5 8.0 7.5 6.6 9.3 6.7 2.1 9.0 8.4 7.8 7.3 6.6 9.3 6.5 2.1 9 10.0 9.9 8.7 8.3 7.4 9.7 7.4 2.3 9.6 9.1 8.5 8.1 7.4 9.7 7.2 2.4 10 10.0 9.2 8.9 8.1 10.0 8.1 3.2 10.0 9.6 9.1 8.7 8.1 10.0 7.9 3.2 11 9.7 9.4 8.6 8.6 3.7 10.0 9.5 9.3 8.7 8.5 4.3 12 10.0 9.7 9.1 9.1 4.7 9.8 9.7 9.3 9.0 5.4 13 10.0 9.4 9.5 5.8 10.0 10.0 9.7 9.5 r 14 9.7 9.7 6.5 10.0 9.7 68 15 10.0 9.8 6.9 9.87.3 16 10.0 7.5 10.0 8.0 17 8.0 8.7
3. Cuspid The norm-developmental values at the (S 4. First bicuspid year-points, both for boys and girls are 5. Second bicuspid reported in Tables II and III, respective- age) 6. Second permanent molar ly. In order to obtain a dental age for 7. Third molar all of the teeth as a group, the values The roots of the maxillary teeth were for the maxillary and mandibular teeth completed in the following order: were added at the year points and 1. Central and first permanent molar Tables IV and V 1 resulted. Tables IV 2. Lateral incisor and V' show the age-norm for maxillary 3. First bicuspid and cuspid and mandibular teeth combined. The 4. Second bicuspid statistical summary has permitted the 5.8 1.0 1 5. Second permanent molar preparation of dental-age scales which 6.5 1.8 6. Third molar facilitate the clinical application of the 7.2i The importance of obtaining norm- results.
7.8 ! -0 developmental curves is that one can In order to obtain a dental age in :iI show actual and average development, terms of tooth development it is neces- 8.8 4.9 This procedure enables the dentist to sary to know how much each tooth has. see the extent to which the variability developed at a series of levels. This in- 9.3 5.9 of the individual adheres or departs formation is secured by examining the 9.6 6.6 from the average. Thus, individual dif- radiographs, utilizing the technic which 10.0 7.7 ferences of clinical significance are re- has been described previously. (See Fig. 8.0 vealed. .. 1.) The developmental value obtained.
262 JOURNAL OF DENTISTRY FOR CHILDREN
TABLE IV AGE NORMS FOR MAXILLARY AND MANDIBULAR TEETH OF GIRLS AGE NORMS FOR (EXCLUDING THIRD MOLARS)
Sum of Stages for Suir Sum of Stages for Sum of Stages for 14 Maxillary and Age in Years 7 Mandibular Teeth 7 Maxillary Teeth Mandibular Teeth Age in Years 7 Ma
.3 24.6 22.2 46.8 3 4 32.7 29.6 62.3 4 5 40.1 37.9 78.0 5 6 46.6 43.4 90.0 6 .7 52.4 49.5 101.9 7 8 57.4 54.9 112.3 8 9 58.4 59.6 118.0 9 10 64.3 63.4 127.7 10 11 66.3 64.0 130.3 11 12 67.9 67.8 135:7 12 13 68.9 69.2 138.1 13 14 69.4 69.7 139.1 14 15 69.8 69.8 139.6 15 16 70.0 70.0 140.0 16 17 70.0 70.0 140.0 17
for each tooth (maxillary and mandib- lents for the growth of maxillary and The difference between ular) is added. This sum is matched with mandibular teeth, this table indicates a the average shows the the table for the translation of the de- dental age of 96 months (8 years). Sup- ability which is display velopmental value into the dental age. pose she were 7 1/2 years old chronolog- which is called the i (See Table IV-V1). For example, a girl ically, then she will be plus six months growth in tooth develo has a value of 112.0 for the sum of the in tooth development. Hence, the extent reason one should avoid maxi14ry and the mandibular teeth, ex- to which the individual displays greater dental age-equivalent as c1udirg the third molars. Referring to than average, average and lower than standard. However, thi Table IV, which shows the age-equiva- average development can be determined. one in understanding
TABLE IV' AGE NORMS FOR MAXILLARY AND MANDIBULAR TEETH OF GIRLS AGE NORMS FOF (INCLUDING THIRD MOLARS)
S. Sum of Stages for Sum of Stages for Sum of 16 Maxillary Age in Years 8 Mandibular Teeth 8 Maxillary Teeth and Mandibular Teeth Age in Years 811
7 54.2 49.5 103.7 7 8 59.5 57.0 116.5 8 9 66.7 62.0 122.7 9 10 67.5 66.6 134.1 10 11 70.0 68.3 138.3 11 12 . 72.6 73.2 145.7 12 13 74.7 75.4 . 150.1 13 14 75.9 76.5 152.4 14 15 76:7 77.1 153.8 15 16 77.5 78.0 155.5 16 17 78.0 78.7 156.7 17
FOURTH QUARTER, 1960 263
TABLE V AGE NORMS FOR MAXILLARY AND MANDIBULAR TEETH OF BOYS (EXCLUDING THIRD MOLARS)
Sum of Stages for Sum of Stages for Sum of Stages for 14 Maxillary and Age in Years 7 Mandibular Teeth 7 Maxillary Teeth Mandibular Teeth
3 22.3 18.9 41.2 4 30.3 26.1 56.4 5 37.1 33.1 70.2 6 43.0 39.6 82.6 7 48.7 45.5 94.2 8 53.7 50.8 104.5 9 57.9 55.5 113.3 10 61.5 59.5 121.0 11 64.0 62.6 126.6 12 66.8 65.3 131.6 13 67.8 67.3 135.1 14 69.0 68.5 137.5 15 69:7 69.3 139.0 16 70.0 70.0 140.0 17 70.0 70.0 140.0
The difference between the actual and child is making a greater than average, the average shows the amount of van- average, and less than average in tooth ability which is displayed, a variability development. In a graphical form, Fig- which is called the individuality of ure 9 shows the dental-age curves for growth in tooth development. For this both maxillary and mandibular teeth reason one should avoid thinking of the combined, excluding the third molar:--- dental age-equivalent as a rigid norm or The broken line shows the dental-age standard. However, this method assists curve of the girls and the solid line rep- one in understanding why any given resents the dental-age curve for the boys.
TABLE V1 AGE NORMS FOR MAXILLARY AND MANDIBULAR TEETH OF BOYS (INCLUDING THIRD MOLARS)
Sum of Stages for Sum of Stages for Sum of 16 Maxillary Age in Years S Mandibular Teeth 8 Maxillary Teeth and Mandibular Teeth
7 49.5 45.5 95.0 8 55.1 51.8 106.9 9 59.7 57.3 117.0 10 63.5 61.8 125.3 11 66.7 65.6 132.3 12 69.8 69.3 139.1 13 72.3 72.2 144.5 14 74.3 74.4 148.7 15 75.9 75.9 151.8 16 77.3 77.7 155.0 17 77.6 78.0 155.6 264 JOURNAL OF DENTISTRY FOR CHILDREN
The lower extension of the curves has ment of teeth is important, not only for been predicted only. Again, one can see reasons of diagnosis and treatment, but AGES from this curve that no significant dif- also for more detailed purposes of re- ferences for sex in the time required for search. Calcification of teeth may, in this development are apparent, since the way, be used as a criterion of dental age Teeth curves are of the same nature. and of the physiologic age of a patient. Mand. The technic which has been described It provides an index of physiologic provides a new understanding of the in- maturity of the permanent dentition. 11 3 dividuality of change with time and of Knowledge about general acceleration 4 22 individual differences among children at or retardation of calcification of the 6 33 a given time. The graph designed for the teeth of an individual is important to 44 7 compilation of the developmental curves 55 7 the orthodontist who wishes to deter- 66 4 for each tooth shows, at a glance, the mine time of treatment on the basis of stage of development of the dentition as the physiologic age of the patient. 77 8 a unit, as well as the growth of individ- Finally, it has been possible to pre- Max. ual teeth. pare a table of the average ages for the 11 41/ The information about the develop- completion of each tooth for boys and 51/ 22 33 61/ GROWTH NORMS FOR MAXILLARY AND MANDIBULAR TEETH 44 7 55 8 (EXCLUDING THIRD MOLARS) 66 41/ 60 77 8 150
BOYS 140 girls. Table 130 at which ea has become 20 that the pro Ito investigated, U) stages of cal 100 z which erupti 90
Serial anni - (total radiog girls (total ra from the files - 50 igan Child Er cD 40 -- - - were studied curate proce 30 praisal of th 20 manent denti 10 graphs. The -Predicted Norm- was appraise' I 1_1 I I FFFFET 0 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 graphs whicl DENTAL AGE from 0 to 10, FIGURE 9. Growth Norms for maxillary and mandibular teeth. appraisals wa
----- FOURTH QIJARTER, 1960 265
TABLE VI
AGES FOR COMPLETION OF CALCIFICATION OF PERMANENT TEETH
- Crown Completed Root Completed Logan and Kronfeld1 Teeth (Modified by Schour (No11a10) (Nolla16 ) Mdnd. and Massler22) Root Completed Boys Girls Boys Girls 1 1 3 yrs. 8 ma. 3 yrs. 6 mo. 10 yrs. 8 yrs. 6 mo. 9 yrs. .2 2 4 yrs. 4 mo. 4 yrs. 10 yrs. 6 mo. 9 yrs. 8 mo. 10 yrs. 3 3 6 yrs. 5 yrs. 8 mo. 13 yrs. 6 mo. 12 yrs. 12-14 yrs. 4 4 7 yrs. 6 yrs. 6 mo. 14 yrs. 12 yrs. 6 mo. 12-13 yrs. 5 5 7 yrs. 8 ma. 7 yrs. 2 mo. 15 yrs. 14 yrs. 6 mo. 13-14 yrs. 6 6 4 yrs. 3 yrs. 10 mo. 11 yrs. 6 ma. 10 yrs. 9-10 yrs. 7 7 8 yrs. 2 mo. 7 yrs. 16 yrs. 6 mo. 15 yrs. 6 mo. 14-15 yrs.
Max. 1 1 4 ¼ yrs. 4V2 yrs. 11 yrs. 10 yrs. 10 yrs. 2 2 5/j yrs. 5 yrs. 2 ma. 12 yrs. 11 yrs. 11 yrs. 3 3 6i/ yrs. 5 yrs. 10 ma. 15 yrs. 12½ to 13 yrs. 13-15 yrs. 4 4 7 yrs. 4 mo. 6 yrs. 4 ma. 14 4 yrs. 12 yrs. 9 mo. 12-13 yrs. 5 5 8 yrs. 5 mo. 7 yrs. 3 ma. 15, 4 yrs. 14 yrs. 13-14 yrs. 6 6 4V2 yrs. 4 yrs. 2 ma. 11, 4 yrs. 91,4 yrs. 9-10 yrs. 7 7 8 yrs. 2 mo. 7 yrs. 6 mo. 16 4 yrs. 15 yrs. 6 mo. 14-16 yrs. girls. Table VI shows the average age both graphically and numerically, and at which each tooth is completed. It provided material to show the dental de- has become apparent from this study velopment of each person and numerical that the process of eruption should be values for the tabulation of déiittage-- investigated, in order to determine the scales. stages of calcification in the teeth at Few developmental differences were which eruption begins. found between right and left teeth of the same kind. No significant differences SUMMARY in the rate of development were ob- Serial annual radiographs of 25 boys served in males and females, however, (total radiographs = 1656) and of 25 the girls started dental development girls (total radiographs = 1746) obtained earlier and finished earlier. The general from the files of the University of Mich- type of growth displayed by each tooth igan Child Development Laboratories was the same. The statistical summary of were studied in order to develop an ac- individual tooth development has per- curate procedure for the detailed ap- mitted the preparation of detailed praisal of the development of the per- growth-age scales which facilitate clin- manent dentition, as revealed by radio- ical application of the results. graphs. The development of each tooth CONCLUSIONS was appraised by studying the radio- graphs which were graded on a scale 1. The type of growth displayed by from 0 to 10. Each set of observational each tooth is the same. appraisals was summarized individually, 2. No significant differences in the 266 JOURNAL OF DENTISTRY FOR CHILDREN
rates of development were observed in 12. ------: The origin and formation of the dental follicle. (Trans. by M. S. Dean). Chicago, Jan- males and females. sen, McClurg and Co., 1880. 216 p. 3. On the average, differences in the 13. Lo, R. T., and MOYERS, R. E.: The sequence of eruption of the permanent teeth. Am. J. general sequence of development were Orthodont., 39:460-7, June 1953. not apparent between the sexes. 14. LOGAN, W. H. G., and KEONFELD, RUDOLF: De- velopment of the human jaws and surrounding 4. Few development differences were structures from birth to age fifteen. Am. Den:. shown between right and left teeth of A. J., 20:379-424, Mar. 1935. 15. MCCALL, J. 0., and WALD, S. S.: Clinical dental the same kind. roentgenology. 2nd ed. Philadelphia, Saunders, 1947. XVI + 349 p. (p. 100). BIBLIOGRAPHY 16. NOLLA, CARMEN M.: The development of perma- 1. BLACK, C. V.: Chart showing lines of contempo- nent teeth. Ann Arbor, University of Michigan, raneous calcification of teeth. Ill. S. Dent. Soc. 1952. 60 p. thesis. Tr., 1893. 238 p. (Frontispiece.) 17. OLSON, W. C.: Child development. Boston, D. C. 2. -: Operative dentistry. Chicago Medico- Heath and Co., 1949. XIII + 417 p. (p. 163-91) Dental Publishing Co., 1908. XI + 319 p. Vol. 18. OLsON, W. C., and HUGHES, B. 0.: Growth of the 1 facing p. 258. child as a whole. p. 199-208. (In Barker, R. C., 3. BRADY, W. J.: A chart of the average time of Kounin, J. S., and Wright, H. F. Child be- development, eruption and absorption of teeth. havior and development. New York, McGraw Kansas City, W. J. Brady, 1924. 15 p. Hill, 1943. 652 p.)
4. Ba00MELL, I. N., and FI5CHELI5, PHILIP?: Anat- 19. -: Manual for the description of growth in omy and histology of the mouth and teeth. 6th age units. Ann Arbor, University of Michigan, ed., Philadelphia, Blakiston, 1923. XIII + 461 1950. 27 p. p. (p. 102-83). 20. PIERCE, C. N.: Calcification and development of 5. CATTELL, PSYCHE: The eruption and growth of mandibular teeth. Dent. Cosmos, 26:449-55, Aug. the permanent teeth. J. Dent. Res., 8:279-97, 1884. Apr. 1928. 21. PINNEY, L. C.: Calcification and development of 6. -: Dentition as a measure of maturity. mandibular teeth. Ann Arbor, University of Cambridge, Harvard University Press, 1928. Michigan, 1939. 59 p. Thesis. 91 p. 22. SEHOUR, ISAAC, and MASSLER, MAURY: The de- 7. Coxsa, J. F.: Dental surgery and pathology. 4th velopment of the human dentition. Am. Dent. ed. London, Longmans, Green and Co., 1919. A. J., 28:1153-60, July 1941. (p. 1154). XIV + 899 P. (p. 11) 23. -: Development and growth of teeth. 33-52 8. DIAMOND, Mosss: The patterns of growth and p. (In Orban, Balint, ed. Oral histology and em- development of human teeth and jaws. J. Dent. bryology. St. Louis, Mo15y-l94-342 p.) Res., 23:273-303, Aug. 1944. 9. KLEIN, HENRY, and CODY, J. F.: Graphic charts 24. ScHOUR, ISAAC, and MCCALL, J. 0.: Chronology which depict the variations in number of erupt- of the human dentition. p. 240. (In Orban, ed permanent teeth in grade school children. Balint, ed. Oral histology and embryology. St. Am. Dent. A. .1., 26:609-11, Apr. 1939. Louis, Mosby, 1944. 342 p.) 10. KEONFELD, RUDOLF: Development and calcification 25. MASSLEE, MAURY, SCHOUR, ISAAC, and PONCHER, of the human deciduous and permanent denti- H. G.: Developmental pattern of the child as tion. Bur, 35:18-25, Mar. 1935. reflected in the calcification pattern of the 11. LEGROS, CHARLES, and MA0X70T, EanLE: Chronol- teeth. Am. J. Dis. Child., 62:33-67, July 1941, ogy of the dental follicle in man. p. 394. (In p. 46. Noyes, F. B. Dental histology and embryology. 26. TODD, T. W.: The orthodontic value of research 4th ed. Philadelphia, Lea and Febiger, 1929. and observations in development of the face. X + 527 p.) Angle Orthodont., 1:67-9, Apr. 1931.