A REVIEW OF THE DESCRIPTION AND MEASUREMENT OP QUALIFICATIONS FOR DENTISTRY AND DENTAL TRAINING By Richard S. Schultz The
Psychological Corporation New YorTc City
Publications directly bearing on this problem scanty. The various topics included in this paper,
give a general survey investigations in this field.
pear to
of
of the research
are
few
and
however, approblems and trend
1. Historical
training device was actually by the ancient Japanese extracting testing ability dentist. "He learned to extract teeth by first being given a board into which a number of pegs had been driven, which he learned to These pegs were extract with the thumb and index finger only. of different sizes and shapes, and were driven into the board tighter and tighter until he who could extract them deftly was able also to 'pull' teeth in the like manner" (20). About 1700, efforts were made in France to set up standard qualifications for dentists. Pierre Fauchard (father of modern dentistry), in 1728, gave an account of what may be done with the teeth, showing an attempt at job analysis, finally ending up with a statement of the qualifications for dentistry?"all of these operations (dental) demand a skillful, steady and trained hand and a complete theory" (20). The early training of dentists was by apprenticeship. Many dentists had no specific training. Any one who cared to 'pull' teeth and perform other surgical operations was at liberty to do so. We thus find goldsmiths, barbers, blacksmiths, even one of historical fame (Paul Revere), and others who possessed "good strength" practicing dentistry along with other vocations. In 1840, the first dental school was opened in Baltimore. This event has been considered as the beginning of dentistry as a proHistorical
used for
sources
reveal that in
a
teeth
172
QUALIFICATIONS ing
173
schools opened in the following years, so that dursubsequent period of years, there was an overabundance of
fessioxi. a
FOR DENTISTRY
Many
practitioners who had received diplomas certifying qualifications; but the schools from which they came were of doubtful standard (6). the latter part of the 19th century, and more so efforts were made by associations of dental teachers now, strong and dentists to raise the educational standards, to improve the curriculum, to devise some standard qualifications for dentistry,
Throughout
requirements and qualifications for contemplating study of dentistry (1, 6, 10). The earlier selection of dental students was usually based on ability to pay the tuition fees. However, the later efforts have been to inquire into the students' experiences, interests, educational background, as well as to make some personal judgment of capabilities, and in a few instances recently, to venture aptitude tests. as
well
as
to set up entrance
students
the
2.
Qualifications
of the
Dentist
The professional and educational literature in dentistry emphasizes repeatedly that a dentist should possess many qualifications of a varied nature (1, 6, 10). But the most important qualifications stressed
"
ability," "manual dexterity," "finger power," "skill," "eye-muscle coordination," and many similar traits. All of these statements reveal the most important qualification of the dentist?the ability to work with his "hands" efficiently. The dental student spends more than half of his curriculum hours working with his hands; while the dentist certainly spends In
a
are:
mechanical
greater part of his time in much the
same manner.
Association, a very excellent paper given "Finger Training in Dentistry" (17). A comprehensive analysis is made of the necessity for training in manumotor skills and coordinations, and of their relation to effective operations on the teeth. Various traits and qualifications of the 1889,
before the British Dental
was
on
dentist
are
subject
matter
A criticism is made of the too intensive and of the too little stress on the necessary training "mechanical" training. The student crams his head full of facts, rehearses, learns, and has sufficient knowledge of the theory, but overlooks the necessity of application in the same manner to the "mechanical" side of his education. Environmental influence, interests and original capacities for motor and mechanical skill are also discussed. indicated.
174
THE PSYCHOLOGICAL CLINIC
An influence which has directed the professionalization and scientific trends in dentistry, is the work of Dr. 6. V. Black. Through many pages in his texts and other publications, he dwells on the
psychology
of the patient, and A very complete
qualifications.
indirectly analysis is
reveals many necessary made of the importance
of vision to success in dentistry. In order to obtain some facts
on "finger power" as related to operative abilities of dentists, Dr. Black devised a "Dentist's Manudynamometer." This instrument is based on the usual dynamometry principles. The subject is asked to take hold of a stylus in particular finger grasp styles and to thrust at a small disk; the movement of this disk, as well as the amount of force or With this device it was pressure exerted, is recorded graphically. the to effectiveness of certain study possible instruments, to anaof thrust of dentists and the dental strength lyze students, and to make a study of skill and finger power. Facts and figures are cited to show the value of the manudynamometer. "The range of differences between men, in power
mechanical and
of thrust with the pen grasp, runs from 5 to 35 pounds, with the average about 15 pounds, as shown by numerous tests made at meetings of dentists. It seems very curious to find large muscular men
with feeble
finger
power.
A man's
general
muscular
develop-
index to his power of handling delicate instruments." "Much careful observation has shown conclusively that delicacy in the accurate control of instrument is very generally an accompaniment of a high degree of finger power." "An ment is .
.
no
.
.
experience
of
over
.
.
ten years in
taking these measurements shows power, as well as delicacy of move-
that much increase in finger ment, can be acquired by careful training, and also that it is easily lost by careless habits." Averages are cited for a class of 160 dental students who gained in "finger power," through careful training; in the first year 9 pounds, second year 13 pounds, and third year 17 pounds. But some students lost "finger power" through "careless habits," and one student doubled his power by constant
practice (4).
3. Methods
of
Industrial Psychology
as
Applied
to
Dentistry A paper published in 1926 gives a very brief analysis of the practicing dentist's job. Efficiency methods, photographic movement studies, outlay of office and work apparatus, division of
QUALIFICATIONS
FOR DENTISTRY
175
and better working conditions at the chair are suggested (9). W. Baiters has made a very detailed analysis of the dentist at work along the lines indicated in the preceding study. Many traits are analyzed in detail in accordance with the orthodox psycho-
labor,
logical categories. The list that follows represents a summary of special aptitudes and traits that appear significant, to this investigator, for success in dentistry: ability to observe mental reactions; imageability of spatial arrangement; skill of hand; aptitudes for technical knowledge; mechanical intelligence; special ability for line, area and space form; aesthetic sense; general ability for repetitive performance; practical ability; quick judgment of situations; social intelligence; organizability; business sense; technical dexterity for drawing, photographing, and statistical representations (3). 4. Experimental Investigations
"Fifty seniors and thirty freshmen in a Dental School (University of Denver) were studied as to age, average grades, and test performance in Army Alpha and in the Downey Will-temperament tests. The seniors were also rated by their instructors as to possible success in Dentistry" (18). Intelligence score correlated -f- .41 with grades and -f- .26 with estimated probable success of seniors. For freshmen the correlation between grades and Intelligence test score was -f- .40. The Will-temperament test, grouped, correlated significantly with grades of freshmen, but not with grades or estimated success of seniors." "Apparently the age of seniors is comparatively .204 unimportant, the coefficient of correlation with grades being and with rank -(- .166. However, the freshmen correlation -f- .476 of age with grades indicates a tendency for the older men to have a better chance to handle the work in the first year.'' Scores obtained for the Army Alpha Intelligence test, at the University of Denver, when compared with the Army data and Fryer data reveal slight differences in range and central tendency. The results for the University of Denver are: Freshmen: entire range?61-180, average?123.62; Seniors: entire range?33-153, average?112.85; as compared with the Army data: middle 50 per cent?84-130, median?106; and Fryer: score range?80-128, av''
.
.
.
erage?110 (16). The intelligence of dentists ranks to the
high in the Army data.
as
compared
with other occupations
Clerical and semi-professional group according Another relative position of dentists is revealed
THE PSYCHOLOGICAL CLINIC
176
in the following order (from high to low) of occupations receiving a B rating in intelligence, by Fryer,?Physician, Teacher (public
schools), Chemist, Draftsman, Y. M. C. A. Secretary, Dentist, Executive (minor). An investigation by the present writer indicates a low consistent relationship between performance in a task involving quick and effective adjustment to a relatively novel motor situation (Miles Two-Story Duplicate Maze) and ability in dental technical courses. Scores in a general intelligence test appear less significant. In both of these tests the average score for dental students is superior to unselected" groups of college students (21). Marbe reports an investigation at the Wurzburger Dental InstiFour tests, requiring about one half hour total performance tute. used to measure the essential aptitudes for dentistry. were time, 1
''
These
are as
follows:
lending test for manual dexterity, observation, visual discrimination, form sense, judgment of direction and
1. A Wire space
personal tempo; 2. A Pearl
stringing
test for manual
dexterity
and
personal tempo;
3. A Tremometer for steadiness; 4. A Pea test (dropping three peas into a tube from full) for manual dexterity, foresight and care.
one
professor and
average poor and fell
glass
half
''
ranking of 13 Praktikanten" test rank performance was -j- .60.
A final correlation between the
by
a
so far out of the range that he was for the group was thereby raised to The correlation eliminated. In another experiment, using the same 12 subjects with 8 -f .83. obtained from three instructors. The corwere others, rankings
One student
was so
relations between the
respective rankings
and test
performance
-f- .83, +.83, -j- .73 (13, 14, 19).
were
At various times American
psychologists have been interested asked to carry out investigations in the Measurement of " Abilities for Dentistry. An address by C. E. Seashore on Selection of Students for Technical Courses" is summarized thus: "A in
or
lengthy discussion followed on the desirability of intelligence (placement) tests for students wishing to matriculate in dental schools. The gist of it was that such tests are of great value in eliminating the unfit. Seashore especially emphasized from his experience the reliability of findings as to least well qualified 10 per cent of the freshmen group" (10). i
To be
reported
in a later issue of this
journal.
QUALIFICATIONS G. M.
Whipple
mentions in
FOB DENTISTRY brief note
177
attempt made by a University of Michigan to use the standard tests such as steadiness, aiming, tapping, etc., in "Diagnosing Operative Skill in Dentistry." The outcome of this investigation, which was never fully completed, was that'' of the various tests employed one completely separated the two groups (i.e., good and poor ratings in operative skill), namely, the seemingly naive test of sharpening a lead pencil" (24). A number of investigations are in progress in the Dental Schools. Various qualifications are being studied by means of rating scales, interviews, questionnaires, interest analyses, intelligence tests, motor and mechanical tests, academic records, and personal data. Unfortunately, this information is not available at present for publication. a
graduate student under his supervision
5. Vocational Information
an
at the
and
Personal Data
An investigation made by R. B. Cunliffe through the use of questionnaire and the study of personal records on the choice of vocation of
college
students shows these
important
facts.
a a
The in-
of dental students is lower than that of any other professional group except Pharmacy; in the homes where a foreign language is spoken fewer tend to choose dentistry; and the highest proportion of fathers in the unskilled trades is found among students
telligence
choosing dentistry (8). The results of a questionnaire study by E. S. Jones, involving 32 dentists near Buffalo, are especially interesting. Only 3 out of 32 had a B.A. degree before beginning to study dentistry. As to extra-curricular activities, 25 per cent stressed summer vacation work along dental lines?such as dental assistants, or as university
laboratory for
a
assistants.
This group does not
seem
to feel the need
four-year pre-dental training (12).
The average estimated income between 35 to 40 years is about a year. Dentists seem to reach their maximum a good deal earlier than lawyers or physicians, but it is possible that they do not continue to practice as long as the other two groups. There is
$9,000
preference for specialization, and closer relationship with knowledge. Of the special qualifications for Success in Dentistry, the preferences based on the judgments of the 32 dentists are as follows:
a
marked
medical
178
THE PSYCHOLOGICAL CLINIC Mechanical aptitude
25
(78%)2
Selling ability
22
Poise and self control
21
(69%) (66%)
Optimism and kindliness Energy and vigor Ability to organize
21
(66%)
16
(50%) (31%)
Other and
good
mentioned
qualifications health.
any other work, and unstable.
trait;
10 are
perseverance,
cleanliness,
''
Good health is mentioned more frequently than this is indicative of the confining nature of the
no one
should consider this
There is
a
high
rate of
profession who is nervously physical breakdown for this
occupation.'' bibliography published by the University of Michigan cites many important references to descriptive literature on dentistry and the experience of dental practitioners (15). In line with the above specific reference to the health of the dentist is the following compact and significant abstract on occupational diseases of dentists. Among occupational diseases, in addition to specific eye defects, may be mentioned wounds of the fingers by bites, dermatoses caused by frequent washing of the hands with sublimate of mercury. By overexertion of certain muscles used in dental work neuroses may be caused, while conditions such as genu valgum (knock-knee) and genu varum (bowleg) may be produced by long hours of standing. The position of the dentist at the operation chair sometimes leads to scoliosis, and flat foot may develop as a sequel to relaxation of the muscles and ligaments. Varicose veins are also very common (2, 4, 11). An annotated
6. Methods
of
Selection
in
Dental, Schools
It was necessary to communicate personally with a representative number of dental schools in order to obtain information on the methods of selection of dental students.3 The results of this inquiry are very promising. Although many of the dental schools avoided giving details. of methods selection and qualifications Programs of research and tentative. The information is, are reported as too incomplete furnished
information, they necessarily on
therefore,
restricted.
As
a
statement of the
existing
situation and
present writer. Percentages computed by 3 The writer is indebted to the Deans of the many Dental Schools, particularly to Dr. Alfred A. Owre, Columbia University, and Dr. Charles R. Turner, University of Pennsylvania; and others who have made this informa2
tion available.
the
QUALIFICATIONS
FOR DENTISTRY
179
evidence for the necessity of an extensive scientific program, the brief survey that follows is very pertinent.
as
(a)
Academic Record in
a
Method
of
Selection
Many of the Dental Schools do not reveal a critically objective plan of selecting students. The usual procedure is to have the prospective student submit his academic record (sometimes an accompanying photograph) ; perhaps a letter of recommendation from a teacher, dean, or other person; and in some cases a personal interview is requested before final decision is made on the applicant. This method of selection is based principally on the grades of the student and whether he has taken the prerequisite courses. The final action on the applicant is made by the Dean, or by the Dean with the aid of
an
Technical Course
(b)
Admissions Committee.
Prerequisite
in
a
Method
of
Selection
Some Dental Schools have set up technical pre-dental requireas a basis for selection of students. They require that each
ments
prospective student present evidence of having passed a course (usually similar to the courses given in the Engineering Schools) in Shop Practice or Manual Training, and Mechanical or Freehand
Drawing. Drawing
One school finds it advisable to include a course in and Shop Practice consuming 10 per cent of the total number of hours in the first year dental course. Other schools state that it is preferred that students have had these courses but "the faculty may accept electives" for these courses. This method is not unlike the above except for the added precaution. It has been commented upon favorably by many dental educators. An assumption, however, seems to be made in this method of
merely
selection, that training for general skills has a high relationship to the very specific aptitudes necessary for success in dental training. One significant step is taken in this method. It recognizes that there
are
other factors to be considered in addition to academic
achievement in the selection of dental students.
(c)
Basic
Training
in Dental Technology
as a
Method
of
Selection
Two outstanding attempts have been made to deal with the problem of basic courses pertinent to the skills necessary for success in dentistry. The University of Buffalo conducts a special three-week course in "Pre-dental Technology?primarily facility in using tools, and in wire bending and the like (5). The purpose
180
THE PSYCHOLOGICAL CLINIC
of this course is "to test not scholastically but practically their "No academic credit is aptitude for success in Dentistry." given for this pre-dental course, and those in whom it discloses lack of the appropriate skill will not be admitted to the pre-dental course of the arts college.'' This plan is a significant forward step in the direction of placing the selection program at the time when the student makes a vocational decision. It should possibly avoid belated disappoint.
.
.
or more for the unsuccessful candidate. extensive course, stressing the training rather than the "testing" in basic aptitudes necessary for success in Dentistry, is given at the University of Toronto. "A course is given in the principles of Dental Technology, with laboratory classes, for the
ment and save two years
A
more
instructing students in technical procedures and, comat the early period (first year in a five-year course), mencing to train them in digital skill." This course consumes about 8 per purpose of
even
cent of the total number of curriculum hours.
Another first year
course, in Drawing, takes up over 6 per cent of the curriculum hours (22, 23). An analysis has been made, at the University of Toronto, of the basic "motor and mechanical" aptitudes and skills necessary for success in practical dentistry and research. The entire course has been analyzed into 172 separate operations. This may serve as a
basis for further Job
abilities
Analysis
as
Tests in
a
well
as
for
indicating
essential
(23). (d) Aptitude
Method
of
Selection
Dental Schools known to the writer at present a definite program based on the standardized procedure and scientific methods of Vocational Psychology for the selection of dental students. There
that have
are no
promulgated
The information that is available from two schools, in which aptitude tests are used, is presented in detail. The method of selection in one school has the basic possibilities for the development of a scientific program. The procedure is three measures. An intelligence test is given to all stuThis examination is used as a guide to instructors and not basis for elimination of students. Scholastic achievement in
based
on
dents. as a
pre-dental courses is score for eliminating This "is
more
of
a
the second students.
measure
measure
Finally
and
serves as a
there is
an
critical
aptitude test. ability," in
of artistic and mechanical
QUALIFICATIONS
FOR DENTISTRY
181
a task involving freehand carving, which is obtained after the student has been admitted. Thus, it appears that students are selected, as in the other methods mentioned, primarily on the basis of academic achievement. Columbia University, School of Oral and Dental Surgery, states
descriptive catalogue that a Dental Aptitude ExThe entire prerequisite for admission. pre-dental record of each student is carefully examined by the Committee on Admissions in order that those who are judged most capable of meeting the exacting demands of the course and of the profession of dentistry may be selected. definitely
in its
amination is
''
one necessary
''
In order to make the best selection from among the candidates eligible for admission, all applicants who are eligible will be asked to report at the Dean's office for a personal interview some-
who
are
time prior to final action of the Committee on Admissions. Those who remain on the eligible list after a personal interview will be
given
an examination as to mechanical ability and manual dexterity. It will consist of exercises in mechanical and freehand drawing, metal filing, and moulding in plastic material and will be con-
ducted by the technic teachers in the school" (7). Bibliography 1. Amer. Assoc. Dental Schools. 2. Anon.
49, 3.
5.
on
524.
Proceedings, 3d Annual Meeting, 1926. Occupational Diseases of Dentistry. Dental Record, 1929,
Balters,
W. Psychotechnik. Die Fortschritte der Zahnheilkunde. 1925, ff; 1926, 2, 677 ff; 1927, 3, 689 ff. Black, G. V. Operative Dentistry, Chicago, Medico-Dental Publishing Co., 1920. Buffalo, University of. Catalogue of the School of Dentistry, Februarv,
1,
4.
Note
693
1929.
6. Dental Education in the United States and
Canada,
Bulletin No.
19,
1926.
The Carnegie Foundation for the Advancement of Teaching. 7. Columbia University. Bulletin of Information, School of Dental and Oral
Surgery, Sept. 8.
Cunliffe,
E. B.
Away and Why! Trends in Choice of Vocation J., 1927, 6, 25-28. Davies, O. V. A Method of Applying Industrial Psychology to Dentistry. ?New Zealand Dental Journal, 1925, 20, 15?16. in Detroit.
9.
1929. Whither
Person.
10. Dental Faculties Association of American Universities. 11. 12.
Minutes and Pro-
ceedings, 1908-1924, p. 113. Hannum, J. E. Eye Strain in Various Occupations. Industrial Psychology, 1926, 1, 529-534. Jones, E. S. A Summary of Replies to Questions on the Various Occupations. Buffalo University Studies, Vol. 4, No. 4, 1926.
THE PSYCHOLOGICAL CLINIC
182 13.
Marbe, K. Priifung. Marbe, K.
Die
Eignung
zur
Zahnheilkunde und ihre
psychotechnische Wochenschrift, 1928, 31, 233-240. Die Eignung fiir die Chirurgie, Orthopadie und Zahnheilkunde. 14. Deutsche Zeitschrift fiir Chirurgie, 1928, 208, 289-317. 15. Michigan, University of. Vocational Information. A Bibliography, Yoc. Series, No. 1, 1928. 16. Payne, A. F. Organization of Vocational Guidance, 1925, p. 307. 17. Quinby, H. C. Finger Training in Dentistry. Address before Midland LiverBranch of the British Dental Assoc., Liverpool, May 17, 1889. pool, Walinsley, 1889. 18. Roe, A. M., and Brown, C. F. Qualifications for Dentistry: A Preliminary Study. Person. J., 1927, 6, 176?181. Zscli. f. 19. Schorn, M. Untersuchungen iiber die Handgeschicklichkeit. Psychol., 1929, 112, 325-378. 20. Taylor, James A. History of Dentistry. Philadelphia, Lea, 1922. 21. Schultz, R. S. The Relation of Maze Adaptability, Maze Learning, and General Intelligence. Amer. J. Psychol., 1932, 44, 249-262. 22. Toronto, University of. Calendar of the Faculty of Dentistry, 1929-30. 23. Toronto, University of. Faculty of Dentistry, Course in Dental Technology. Form Tech. 1, 1926. 24. Whipple, G. M. Diagnosing Operative Skill in Dentistry. Person. J., 7, 1928, p. 150. Deutsche Zahnartzliche
Psychological Corporation New YorTc City
Publications directly bearing on this problem scanty. The various topics included in this paper,
give a general survey investigations in this field.
pear to
of
of the research
are
few
and
however, approblems and trend
1. Historical
training device was actually by the ancient Japanese extracting testing ability dentist. "He learned to extract teeth by first being given a board into which a number of pegs had been driven, which he learned to These pegs were extract with the thumb and index finger only. of different sizes and shapes, and were driven into the board tighter and tighter until he who could extract them deftly was able also to 'pull' teeth in the like manner" (20). About 1700, efforts were made in France to set up standard qualifications for dentists. Pierre Fauchard (father of modern dentistry), in 1728, gave an account of what may be done with the teeth, showing an attempt at job analysis, finally ending up with a statement of the qualifications for dentistry?"all of these operations (dental) demand a skillful, steady and trained hand and a complete theory" (20). The early training of dentists was by apprenticeship. Many dentists had no specific training. Any one who cared to 'pull' teeth and perform other surgical operations was at liberty to do so. We thus find goldsmiths, barbers, blacksmiths, even one of historical fame (Paul Revere), and others who possessed "good strength" practicing dentistry along with other vocations. In 1840, the first dental school was opened in Baltimore. This event has been considered as the beginning of dentistry as a proHistorical
used for
sources
reveal that in
a
teeth
172
QUALIFICATIONS ing
173
schools opened in the following years, so that dursubsequent period of years, there was an overabundance of
fessioxi. a
FOR DENTISTRY
Many
practitioners who had received diplomas certifying qualifications; but the schools from which they came were of doubtful standard (6). the latter part of the 19th century, and more so efforts were made by associations of dental teachers now, strong and dentists to raise the educational standards, to improve the curriculum, to devise some standard qualifications for dentistry,
Throughout
requirements and qualifications for contemplating study of dentistry (1, 6, 10). The earlier selection of dental students was usually based on ability to pay the tuition fees. However, the later efforts have been to inquire into the students' experiences, interests, educational background, as well as to make some personal judgment of capabilities, and in a few instances recently, to venture aptitude tests. as
well
as
to set up entrance
students
the
2.
Qualifications
of the
Dentist
The professional and educational literature in dentistry emphasizes repeatedly that a dentist should possess many qualifications of a varied nature (1, 6, 10). But the most important qualifications stressed
"
ability," "manual dexterity," "finger power," "skill," "eye-muscle coordination," and many similar traits. All of these statements reveal the most important qualification of the dentist?the ability to work with his "hands" efficiently. The dental student spends more than half of his curriculum hours working with his hands; while the dentist certainly spends In
a
are:
mechanical
greater part of his time in much the
same manner.
Association, a very excellent paper given "Finger Training in Dentistry" (17). A comprehensive analysis is made of the necessity for training in manumotor skills and coordinations, and of their relation to effective operations on the teeth. Various traits and qualifications of the 1889,
before the British Dental
was
on
dentist
are
subject
matter
A criticism is made of the too intensive and of the too little stress on the necessary training "mechanical" training. The student crams his head full of facts, rehearses, learns, and has sufficient knowledge of the theory, but overlooks the necessity of application in the same manner to the "mechanical" side of his education. Environmental influence, interests and original capacities for motor and mechanical skill are also discussed. indicated.
174
THE PSYCHOLOGICAL CLINIC
An influence which has directed the professionalization and scientific trends in dentistry, is the work of Dr. 6. V. Black. Through many pages in his texts and other publications, he dwells on the
psychology
of the patient, and A very complete
qualifications.
indirectly analysis is
reveals many necessary made of the importance
of vision to success in dentistry. In order to obtain some facts
on "finger power" as related to operative abilities of dentists, Dr. Black devised a "Dentist's Manudynamometer." This instrument is based on the usual dynamometry principles. The subject is asked to take hold of a stylus in particular finger grasp styles and to thrust at a small disk; the movement of this disk, as well as the amount of force or With this device it was pressure exerted, is recorded graphically. the to effectiveness of certain study possible instruments, to anaof thrust of dentists and the dental strength lyze students, and to make a study of skill and finger power. Facts and figures are cited to show the value of the manudynamometer. "The range of differences between men, in power
mechanical and
of thrust with the pen grasp, runs from 5 to 35 pounds, with the average about 15 pounds, as shown by numerous tests made at meetings of dentists. It seems very curious to find large muscular men
with feeble
finger
power.
A man's
general
muscular
develop-
index to his power of handling delicate instruments." "Much careful observation has shown conclusively that delicacy in the accurate control of instrument is very generally an accompaniment of a high degree of finger power." "An ment is .
.
no
.
.
experience
of
over
.
.
ten years in
taking these measurements shows power, as well as delicacy of move-
that much increase in finger ment, can be acquired by careful training, and also that it is easily lost by careless habits." Averages are cited for a class of 160 dental students who gained in "finger power," through careful training; in the first year 9 pounds, second year 13 pounds, and third year 17 pounds. But some students lost "finger power" through "careless habits," and one student doubled his power by constant
practice (4).
3. Methods
of
Industrial Psychology
as
Applied
to
Dentistry A paper published in 1926 gives a very brief analysis of the practicing dentist's job. Efficiency methods, photographic movement studies, outlay of office and work apparatus, division of
QUALIFICATIONS
FOR DENTISTRY
175
and better working conditions at the chair are suggested (9). W. Baiters has made a very detailed analysis of the dentist at work along the lines indicated in the preceding study. Many traits are analyzed in detail in accordance with the orthodox psycho-
labor,
logical categories. The list that follows represents a summary of special aptitudes and traits that appear significant, to this investigator, for success in dentistry: ability to observe mental reactions; imageability of spatial arrangement; skill of hand; aptitudes for technical knowledge; mechanical intelligence; special ability for line, area and space form; aesthetic sense; general ability for repetitive performance; practical ability; quick judgment of situations; social intelligence; organizability; business sense; technical dexterity for drawing, photographing, and statistical representations (3). 4. Experimental Investigations
"Fifty seniors and thirty freshmen in a Dental School (University of Denver) were studied as to age, average grades, and test performance in Army Alpha and in the Downey Will-temperament tests. The seniors were also rated by their instructors as to possible success in Dentistry" (18). Intelligence score correlated -f- .41 with grades and -f- .26 with estimated probable success of seniors. For freshmen the correlation between grades and Intelligence test score was -f- .40. The Will-temperament test, grouped, correlated significantly with grades of freshmen, but not with grades or estimated success of seniors." "Apparently the age of seniors is comparatively .204 unimportant, the coefficient of correlation with grades being and with rank -(- .166. However, the freshmen correlation -f- .476 of age with grades indicates a tendency for the older men to have a better chance to handle the work in the first year.'' Scores obtained for the Army Alpha Intelligence test, at the University of Denver, when compared with the Army data and Fryer data reveal slight differences in range and central tendency. The results for the University of Denver are: Freshmen: entire range?61-180, average?123.62; Seniors: entire range?33-153, average?112.85; as compared with the Army data: middle 50 per cent?84-130, median?106; and Fryer: score range?80-128, av''
.
.
.
erage?110 (16). The intelligence of dentists ranks to the
high in the Army data.
as
compared
with other occupations
Clerical and semi-professional group according Another relative position of dentists is revealed
THE PSYCHOLOGICAL CLINIC
176
in the following order (from high to low) of occupations receiving a B rating in intelligence, by Fryer,?Physician, Teacher (public
schools), Chemist, Draftsman, Y. M. C. A. Secretary, Dentist, Executive (minor). An investigation by the present writer indicates a low consistent relationship between performance in a task involving quick and effective adjustment to a relatively novel motor situation (Miles Two-Story Duplicate Maze) and ability in dental technical courses. Scores in a general intelligence test appear less significant. In both of these tests the average score for dental students is superior to unselected" groups of college students (21). Marbe reports an investigation at the Wurzburger Dental InstiFour tests, requiring about one half hour total performance tute. used to measure the essential aptitudes for dentistry. were time, 1
''
These
are as
follows:
lending test for manual dexterity, observation, visual discrimination, form sense, judgment of direction and
1. A Wire space
personal tempo; 2. A Pearl
stringing
test for manual
dexterity
and
personal tempo;
3. A Tremometer for steadiness; 4. A Pea test (dropping three peas into a tube from full) for manual dexterity, foresight and care.
one
professor and
average poor and fell
glass
half
''
ranking of 13 Praktikanten" test rank performance was -j- .60.
A final correlation between the
by
a
so far out of the range that he was for the group was thereby raised to The correlation eliminated. In another experiment, using the same 12 subjects with 8 -f .83. obtained from three instructors. The corwere others, rankings
One student
was so
relations between the
respective rankings
and test
performance
-f- .83, +.83, -j- .73 (13, 14, 19).
were
At various times American
psychologists have been interested asked to carry out investigations in the Measurement of " Abilities for Dentistry. An address by C. E. Seashore on Selection of Students for Technical Courses" is summarized thus: "A in
or
lengthy discussion followed on the desirability of intelligence (placement) tests for students wishing to matriculate in dental schools. The gist of it was that such tests are of great value in eliminating the unfit. Seashore especially emphasized from his experience the reliability of findings as to least well qualified 10 per cent of the freshmen group" (10). i
To be
reported
in a later issue of this
journal.
QUALIFICATIONS G. M.
Whipple
mentions in
FOB DENTISTRY brief note
177
attempt made by a University of Michigan to use the standard tests such as steadiness, aiming, tapping, etc., in "Diagnosing Operative Skill in Dentistry." The outcome of this investigation, which was never fully completed, was that'' of the various tests employed one completely separated the two groups (i.e., good and poor ratings in operative skill), namely, the seemingly naive test of sharpening a lead pencil" (24). A number of investigations are in progress in the Dental Schools. Various qualifications are being studied by means of rating scales, interviews, questionnaires, interest analyses, intelligence tests, motor and mechanical tests, academic records, and personal data. Unfortunately, this information is not available at present for publication. a
graduate student under his supervision
5. Vocational Information
an
at the
and
Personal Data
An investigation made by R. B. Cunliffe through the use of questionnaire and the study of personal records on the choice of vocation of
college
students shows these
important
facts.
a a
The in-
of dental students is lower than that of any other professional group except Pharmacy; in the homes where a foreign language is spoken fewer tend to choose dentistry; and the highest proportion of fathers in the unskilled trades is found among students
telligence
choosing dentistry (8). The results of a questionnaire study by E. S. Jones, involving 32 dentists near Buffalo, are especially interesting. Only 3 out of 32 had a B.A. degree before beginning to study dentistry. As to extra-curricular activities, 25 per cent stressed summer vacation work along dental lines?such as dental assistants, or as university
laboratory for
a
assistants.
This group does not
seem
to feel the need
four-year pre-dental training (12).
The average estimated income between 35 to 40 years is about a year. Dentists seem to reach their maximum a good deal earlier than lawyers or physicians, but it is possible that they do not continue to practice as long as the other two groups. There is
$9,000
preference for specialization, and closer relationship with knowledge. Of the special qualifications for Success in Dentistry, the preferences based on the judgments of the 32 dentists are as follows:
a
marked
medical
178
THE PSYCHOLOGICAL CLINIC Mechanical aptitude
25
(78%)2
Selling ability
22
Poise and self control
21
(69%) (66%)
Optimism and kindliness Energy and vigor Ability to organize
21
(66%)
16
(50%) (31%)
Other and
good
mentioned
qualifications health.
any other work, and unstable.
trait;
10 are
perseverance,
cleanliness,
''
Good health is mentioned more frequently than this is indicative of the confining nature of the
no one
should consider this
There is
a
high
rate of
profession who is nervously physical breakdown for this
occupation.'' bibliography published by the University of Michigan cites many important references to descriptive literature on dentistry and the experience of dental practitioners (15). In line with the above specific reference to the health of the dentist is the following compact and significant abstract on occupational diseases of dentists. Among occupational diseases, in addition to specific eye defects, may be mentioned wounds of the fingers by bites, dermatoses caused by frequent washing of the hands with sublimate of mercury. By overexertion of certain muscles used in dental work neuroses may be caused, while conditions such as genu valgum (knock-knee) and genu varum (bowleg) may be produced by long hours of standing. The position of the dentist at the operation chair sometimes leads to scoliosis, and flat foot may develop as a sequel to relaxation of the muscles and ligaments. Varicose veins are also very common (2, 4, 11). An annotated
6. Methods
of
Selection
in
Dental, Schools
It was necessary to communicate personally with a representative number of dental schools in order to obtain information on the methods of selection of dental students.3 The results of this inquiry are very promising. Although many of the dental schools avoided giving details. of methods selection and qualifications Programs of research and tentative. The information is, are reported as too incomplete furnished
information, they necessarily on
therefore,
restricted.
As
a
statement of the
existing
situation and
present writer. Percentages computed by 3 The writer is indebted to the Deans of the many Dental Schools, particularly to Dr. Alfred A. Owre, Columbia University, and Dr. Charles R. Turner, University of Pennsylvania; and others who have made this informa2
tion available.
the
QUALIFICATIONS
FOR DENTISTRY
179
evidence for the necessity of an extensive scientific program, the brief survey that follows is very pertinent.
as
(a)
Academic Record in
a
Method
of
Selection
Many of the Dental Schools do not reveal a critically objective plan of selecting students. The usual procedure is to have the prospective student submit his academic record (sometimes an accompanying photograph) ; perhaps a letter of recommendation from a teacher, dean, or other person; and in some cases a personal interview is requested before final decision is made on the applicant. This method of selection is based principally on the grades of the student and whether he has taken the prerequisite courses. The final action on the applicant is made by the Dean, or by the Dean with the aid of
an
Technical Course
(b)
Admissions Committee.
Prerequisite
in
a
Method
of
Selection
Some Dental Schools have set up technical pre-dental requireas a basis for selection of students. They require that each
ments
prospective student present evidence of having passed a course (usually similar to the courses given in the Engineering Schools) in Shop Practice or Manual Training, and Mechanical or Freehand
Drawing. Drawing
One school finds it advisable to include a course in and Shop Practice consuming 10 per cent of the total number of hours in the first year dental course. Other schools state that it is preferred that students have had these courses but "the faculty may accept electives" for these courses. This method is not unlike the above except for the added precaution. It has been commented upon favorably by many dental educators. An assumption, however, seems to be made in this method of
merely
selection, that training for general skills has a high relationship to the very specific aptitudes necessary for success in dental training. One significant step is taken in this method. It recognizes that there
are
other factors to be considered in addition to academic
achievement in the selection of dental students.
(c)
Basic
Training
in Dental Technology
as a
Method
of
Selection
Two outstanding attempts have been made to deal with the problem of basic courses pertinent to the skills necessary for success in dentistry. The University of Buffalo conducts a special three-week course in "Pre-dental Technology?primarily facility in using tools, and in wire bending and the like (5). The purpose
180
THE PSYCHOLOGICAL CLINIC
of this course is "to test not scholastically but practically their "No academic credit is aptitude for success in Dentistry." given for this pre-dental course, and those in whom it discloses lack of the appropriate skill will not be admitted to the pre-dental course of the arts college.'' This plan is a significant forward step in the direction of placing the selection program at the time when the student makes a vocational decision. It should possibly avoid belated disappoint.
.
.
or more for the unsuccessful candidate. extensive course, stressing the training rather than the "testing" in basic aptitudes necessary for success in Dentistry, is given at the University of Toronto. "A course is given in the principles of Dental Technology, with laboratory classes, for the
ment and save two years
A
more
instructing students in technical procedures and, comat the early period (first year in a five-year course), mencing to train them in digital skill." This course consumes about 8 per purpose of
even
cent of the total number of curriculum hours.
Another first year
course, in Drawing, takes up over 6 per cent of the curriculum hours (22, 23). An analysis has been made, at the University of Toronto, of the basic "motor and mechanical" aptitudes and skills necessary for success in practical dentistry and research. The entire course has been analyzed into 172 separate operations. This may serve as a
basis for further Job
abilities
Analysis
as
Tests in
a
well
as
for
indicating
essential
(23). (d) Aptitude
Method
of
Selection
Dental Schools known to the writer at present a definite program based on the standardized procedure and scientific methods of Vocational Psychology for the selection of dental students. There
that have
are no
promulgated
The information that is available from two schools, in which aptitude tests are used, is presented in detail. The method of selection in one school has the basic possibilities for the development of a scientific program. The procedure is three measures. An intelligence test is given to all stuThis examination is used as a guide to instructors and not basis for elimination of students. Scholastic achievement in
based
on
dents. as a
pre-dental courses is score for eliminating This "is
more
of
a
the second students.
measure
measure
Finally
and
serves as a
there is
an
critical
aptitude test. ability," in
of artistic and mechanical
QUALIFICATIONS
FOR DENTISTRY
181
a task involving freehand carving, which is obtained after the student has been admitted. Thus, it appears that students are selected, as in the other methods mentioned, primarily on the basis of academic achievement. Columbia University, School of Oral and Dental Surgery, states
descriptive catalogue that a Dental Aptitude ExThe entire prerequisite for admission. pre-dental record of each student is carefully examined by the Committee on Admissions in order that those who are judged most capable of meeting the exacting demands of the course and of the profession of dentistry may be selected. definitely
in its
amination is
''
one necessary
''
In order to make the best selection from among the candidates eligible for admission, all applicants who are eligible will be asked to report at the Dean's office for a personal interview some-
who
are
time prior to final action of the Committee on Admissions. Those who remain on the eligible list after a personal interview will be
given
an examination as to mechanical ability and manual dexterity. It will consist of exercises in mechanical and freehand drawing, metal filing, and moulding in plastic material and will be con-
ducted by the technic teachers in the school" (7). Bibliography 1. Amer. Assoc. Dental Schools. 2. Anon.
49, 3.
5.
on
524.
Proceedings, 3d Annual Meeting, 1926. Occupational Diseases of Dentistry. Dental Record, 1929,
Balters,
W. Psychotechnik. Die Fortschritte der Zahnheilkunde. 1925, ff; 1926, 2, 677 ff; 1927, 3, 689 ff. Black, G. V. Operative Dentistry, Chicago, Medico-Dental Publishing Co., 1920. Buffalo, University of. Catalogue of the School of Dentistry, Februarv,
1,
4.
Note
693
1929.
6. Dental Education in the United States and
Canada,
Bulletin No.
19,
1926.
The Carnegie Foundation for the Advancement of Teaching. 7. Columbia University. Bulletin of Information, School of Dental and Oral
Surgery, Sept. 8.
Cunliffe,
E. B.
Away and Why! Trends in Choice of Vocation J., 1927, 6, 25-28. Davies, O. V. A Method of Applying Industrial Psychology to Dentistry. ?New Zealand Dental Journal, 1925, 20, 15?16. in Detroit.
9.
1929. Whither
Person.
10. Dental Faculties Association of American Universities. 11. 12.
Minutes and Pro-
ceedings, 1908-1924, p. 113. Hannum, J. E. Eye Strain in Various Occupations. Industrial Psychology, 1926, 1, 529-534. Jones, E. S. A Summary of Replies to Questions on the Various Occupations. Buffalo University Studies, Vol. 4, No. 4, 1926.
THE PSYCHOLOGICAL CLINIC
182 13.
Marbe, K. Priifung. Marbe, K.
Die
Eignung
zur
Zahnheilkunde und ihre
psychotechnische Wochenschrift, 1928, 31, 233-240. Die Eignung fiir die Chirurgie, Orthopadie und Zahnheilkunde. 14. Deutsche Zeitschrift fiir Chirurgie, 1928, 208, 289-317. 15. Michigan, University of. Vocational Information. A Bibliography, Yoc. Series, No. 1, 1928. 16. Payne, A. F. Organization of Vocational Guidance, 1925, p. 307. 17. Quinby, H. C. Finger Training in Dentistry. Address before Midland LiverBranch of the British Dental Assoc., Liverpool, May 17, 1889. pool, Walinsley, 1889. 18. Roe, A. M., and Brown, C. F. Qualifications for Dentistry: A Preliminary Study. Person. J., 1927, 6, 176?181. Zscli. f. 19. Schorn, M. Untersuchungen iiber die Handgeschicklichkeit. Psychol., 1929, 112, 325-378. 20. Taylor, James A. History of Dentistry. Philadelphia, Lea, 1922. 21. Schultz, R. S. The Relation of Maze Adaptability, Maze Learning, and General Intelligence. Amer. J. Psychol., 1932, 44, 249-262. 22. Toronto, University of. Calendar of the Faculty of Dentistry, 1929-30. 23. Toronto, University of. Faculty of Dentistry, Course in Dental Technology. Form Tech. 1, 1926. 24. Whipple, G. M. Diagnosing Operative Skill in Dentistry. Person. J., 7, 1928, p. 150. Deutsche Zahnartzliche
