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A simplified head positioner
A SIMPLIFIED FOR
LATERAL
CEIARLES
HEAD HEAD
ROENTGENOGRAPHY
D.D.S., ;1I.S.*
(G. SEICHTER, Bethesda,
POSITIONER
Md.
NTHROPOLOGIC and dental investigators have made profitable use of the positioned head roentgenogram introduced in 1931.‘,’ Since the advent of this type of roentgenogram, its value in diagnostic and research work has become indisputable. Numerous head holders have been designed’-” which are satisfactory, but they ordinarily involve the use of integrated roentgen-ray tubes, elaborate headpositioning devices, or considerable manipulation of parts before the roentgenograph can be made. The instrument presently described provides a simple and inexpensive means for obtaining adequately positioned lateral head roentgenograms for diagnostic work. Construction of this positioner can be accomplished in a few hours. All parts are fabricated of commercially available soft aluminum, plastic, and standard fastenings (Table I). The positioner is designed to be used with a dental x-ray machine, an adjustable stool, and standard 8 by 10 inch metal x-ray cassettes with intensifying screens. The cassette is retained in the channel by friction.
A
TABLE I. 1. 2. 3. 2. 3. 6.
MATERIAL
LIST
FOR HEAD POSITIONER AND CASSETTE HOLDER
Plastic rod 3/8” x 8” Plastic rod 1” x 1” diameter Plastic sheet %” x 2” x 12’ Aluminum sheet %” x 1” x 12” Aluminum angle %” x $&” x 10” Aluminum angle %” x l/16” x 6” Screws and bolts as needed.
The typical arrangement of x-ray source, head positioner, and subject are illustrated in Figs. 1, 2, and 3. The head is immobilized by insertion of the ear rods to the maximum comfortable depth in the external auditory meatus. The preciseness of roentgenograms produced through use of this device is dependent upon the care taken in seating the subject comfortably and inserting the ear rods to a sufficient depth to immobilize the head. The ability to obtain roentgenograms that are undistorted and reproducible with this type of head positioner is of prime interest. For that reason, a series oi roentgenograms of children were made. The subjects were taken from the head Received for publication July 12, 1954. *Dental Surgeon, National Institute of Dental Research, National Institutes of Qealtti, Public Health Service, U. S. Department of Health, Education and Welfare, Bethesda, Md. 40s
Volume 5 Number 5
SIMPI.IFIED
HEAD
POSITIONER
409
positioner, then the entire technique was repeated and a second exposure was made. The first and second films were traced and a second tracing made of the first film. All tracings were done with a hard pencil on 0.003 inch cellulose acetate tracing sheets. The degree of variation in angular measurements taken from repeated roentgenograms was found to be comparable to the variation noted in retracings of single x-rays (Table 11). TABLE
II.
REPRODUCIBILITY
Tracing of repeated x-rays Repeat tracings of same x-ray
OF ROENTGENOGRAPHIC
No. of cases ::
RESULTS
Mean deviation of SNa 0.36 degrees 0.33 degrees
SNa is the angle at nasion formed by connecting .the points: nasion, and the most labial part of the maxillary left incisor crown
Fig. l.-Photograph
showing
head positioner
center of sella (Fig. 4).
tursica,
in use.
Skin exposure by roentgen rays is a factor to consider in serial studies of living material. The exposure produced at skin level by use of the described equipment, a temporomandibular joint laminagraph, and an intraoral dental x-ray are compared in Table III. These measurements were made with a Victoreen r meter and corrected for temperature, humidity, chamber calibration, filtration, and backscatter.
SLEICHTER
410 Mood auppcrt
for
Standard dental x-ray extension arm ana yoae but Rwltiamrfastrned to blook
/ /
Subfsct adJustbblr
Fig. 2.-Illustration . roenrgen rays.
showing
3/B” x 6” plastic l/2”
relative
position
to
of head holder
and film
x 1” a1uo:nunl
alurntnum angle
drawing
block
posltloner
between ma Will
be seatea on wet OF chcir
rod
Fig. 3.Schematic
6"
of head positioner.
to the source
of
Volume 5 Number 3
SIMPLIFIED
HEAD
POSITIONER
411
The above data demonstrate that a simplified head-positioning device will yield roentgenograms of good quality (Fig. 4), consistently reproducible, and with a comparatively negligible amount of roentgen-ray exposure to the subject. The availability of an inexpensive method of obtaining standardized lateral head roentgenographs utilizing office equipment provides a means for a more thorough clinical evaluation of many procedures carried out by general practitioners and specialists in the dental field.
Fig. 4.-Head chine.
roentgenograph
Lateral head film
i
KV
with
head positioner
SKIN EXPOSUREPRODUCED
TABLE III. PROCEDURE
produced
/
Ma
/
SEC.
1
FILTER
5:
::10 z.2 2:o
None 2 mm. Al. None
Intraoral film
60
10
2.0
2 mm. Al.
Laminagraph
66
10
2.75
1 mm. Al.
Lateral head film Intraoral film
6.5
and standard
dental x-ray ma-
BYVARIOUSTECHNIQUES
/
DISTANCE
148 cm. 148 cm. End of plastic cone 19.3 cm. End of plastic cone 19.3 cm. 128 cm.
AV.SKIN
DOSE (IN r)
0.227 0.061 4.78 1.05 0.59
412
1. Broadbent, B. H.: A New X-ray Technique and Its Application to Orthodontia. .2nriv Orthodont. 1:45, 1931. 2. Hofrath, H.: Bedeutung Der Roentgenfern Und Ahstandsaufhahme Fur I)ic 1)iagnostik Der Kiefernaomalien, Fortschr. der Orth. 1:232, 1931. 3. Higley, I,. B. : A Head Positioner For Scientific Radiographic and Photographic I’urpow.. Int. J. Orthodont. 22:699, 1936. 4. Margolis, H. T. : Standardized X-ray Cephalometrics, Am. J. Orthodont. 26:725, l!GO. 5. Weingart, hf. A. : Simplified Crphalomctric Hrad Positioner, Am. J. Orthodont. 34:363. 1948. 6. Strauss, K. : Headgear and .%ngulating I&ice for I.ateral Skull Radiographs. I!rit. D. J. 86:1.2, 1949. 7. Graber, T. M.: New Horizons in Case Analysis-Clinical Cephalometrics, :\m. ,I (irtlxdont. 38 :603, 1952. (Freeman and Rasmussen Headholder.) 8. McCall, J. 0. and Walk, S. S.: Clinical Dental Roentgenology; Technic and Intex pretation Including Roentgen Studies of Child and Adolescent, ed. 3, PhiladelplGa. 1952, W. B. Saunders Co. p. 296. (Brady Headholder.) 11~~. OF HEALTH, I~ETIIESDA
14, MI).
EIKCATIOX,
ASD WIXFARE
LATERAL
CEIARLES
HEAD HEAD
ROENTGENOGRAPHY
D.D.S., ;1I.S.*
(G. SEICHTER, Bethesda,
POSITIONER
Md.
NTHROPOLOGIC and dental investigators have made profitable use of the positioned head roentgenogram introduced in 1931.‘,’ Since the advent of this type of roentgenogram, its value in diagnostic and research work has become indisputable. Numerous head holders have been designed’-” which are satisfactory, but they ordinarily involve the use of integrated roentgen-ray tubes, elaborate headpositioning devices, or considerable manipulation of parts before the roentgenograph can be made. The instrument presently described provides a simple and inexpensive means for obtaining adequately positioned lateral head roentgenograms for diagnostic work. Construction of this positioner can be accomplished in a few hours. All parts are fabricated of commercially available soft aluminum, plastic, and standard fastenings (Table I). The positioner is designed to be used with a dental x-ray machine, an adjustable stool, and standard 8 by 10 inch metal x-ray cassettes with intensifying screens. The cassette is retained in the channel by friction.
A
TABLE I. 1. 2. 3. 2. 3. 6.
MATERIAL
LIST
FOR HEAD POSITIONER AND CASSETTE HOLDER
Plastic rod 3/8” x 8” Plastic rod 1” x 1” diameter Plastic sheet %” x 2” x 12’ Aluminum sheet %” x 1” x 12” Aluminum angle %” x $&” x 10” Aluminum angle %” x l/16” x 6” Screws and bolts as needed.
The typical arrangement of x-ray source, head positioner, and subject are illustrated in Figs. 1, 2, and 3. The head is immobilized by insertion of the ear rods to the maximum comfortable depth in the external auditory meatus. The preciseness of roentgenograms produced through use of this device is dependent upon the care taken in seating the subject comfortably and inserting the ear rods to a sufficient depth to immobilize the head. The ability to obtain roentgenograms that are undistorted and reproducible with this type of head positioner is of prime interest. For that reason, a series oi roentgenograms of children were made. The subjects were taken from the head Received for publication July 12, 1954. *Dental Surgeon, National Institute of Dental Research, National Institutes of Qealtti, Public Health Service, U. S. Department of Health, Education and Welfare, Bethesda, Md. 40s
Volume 5 Number 5
SIMPI.IFIED
HEAD
POSITIONER
409
positioner, then the entire technique was repeated and a second exposure was made. The first and second films were traced and a second tracing made of the first film. All tracings were done with a hard pencil on 0.003 inch cellulose acetate tracing sheets. The degree of variation in angular measurements taken from repeated roentgenograms was found to be comparable to the variation noted in retracings of single x-rays (Table 11). TABLE
II.
REPRODUCIBILITY
Tracing of repeated x-rays Repeat tracings of same x-ray
OF ROENTGENOGRAPHIC
No. of cases ::
RESULTS
Mean deviation of SNa 0.36 degrees 0.33 degrees
SNa is the angle at nasion formed by connecting .the points: nasion, and the most labial part of the maxillary left incisor crown
Fig. l.-Photograph
showing
head positioner
center of sella (Fig. 4).
tursica,
in use.
Skin exposure by roentgen rays is a factor to consider in serial studies of living material. The exposure produced at skin level by use of the described equipment, a temporomandibular joint laminagraph, and an intraoral dental x-ray are compared in Table III. These measurements were made with a Victoreen r meter and corrected for temperature, humidity, chamber calibration, filtration, and backscatter.
SLEICHTER
410 Mood auppcrt
for
Standard dental x-ray extension arm ana yoae but Rwltiamrfastrned to blook
/ /
Subfsct adJustbblr
Fig. 2.-Illustration . roenrgen rays.
showing
3/B” x 6” plastic l/2”
relative
position
to
of head holder
and film
x 1” a1uo:nunl
alurntnum angle
drawing
block
posltloner
between ma Will
be seatea on wet OF chcir
rod
Fig. 3.Schematic
6"
of head positioner.
to the source
of
Volume 5 Number 3
SIMPLIFIED
HEAD
POSITIONER
411
The above data demonstrate that a simplified head-positioning device will yield roentgenograms of good quality (Fig. 4), consistently reproducible, and with a comparatively negligible amount of roentgen-ray exposure to the subject. The availability of an inexpensive method of obtaining standardized lateral head roentgenographs utilizing office equipment provides a means for a more thorough clinical evaluation of many procedures carried out by general practitioners and specialists in the dental field.
Fig. 4.-Head chine.
roentgenograph
Lateral head film
i
KV
with
head positioner
SKIN EXPOSUREPRODUCED
TABLE III. PROCEDURE
produced
/
Ma
/
SEC.
1
FILTER
5:
::10 z.2 2:o
None 2 mm. Al. None
Intraoral film
60
10
2.0
2 mm. Al.
Laminagraph
66
10
2.75
1 mm. Al.
Lateral head film Intraoral film
6.5
and standard
dental x-ray ma-
BYVARIOUSTECHNIQUES
/
DISTANCE
148 cm. 148 cm. End of plastic cone 19.3 cm. End of plastic cone 19.3 cm. 128 cm.
AV.SKIN
DOSE (IN r)
0.227 0.061 4.78 1.05 0.59
412
1. Broadbent, B. H.: A New X-ray Technique and Its Application to Orthodontia. .2nriv Orthodont. 1:45, 1931. 2. Hofrath, H.: Bedeutung Der Roentgenfern Und Ahstandsaufhahme Fur I)ic 1)iagnostik Der Kiefernaomalien, Fortschr. der Orth. 1:232, 1931. 3. Higley, I,. B. : A Head Positioner For Scientific Radiographic and Photographic I’urpow.. Int. J. Orthodont. 22:699, 1936. 4. Margolis, H. T. : Standardized X-ray Cephalometrics, Am. J. Orthodont. 26:725, l!GO. 5. Weingart, hf. A. : Simplified Crphalomctric Hrad Positioner, Am. J. Orthodont. 34:363. 1948. 6. Strauss, K. : Headgear and .%ngulating I&ice for I.ateral Skull Radiographs. I!rit. D. J. 86:1.2, 1949. 7. Graber, T. M.: New Horizons in Case Analysis-Clinical Cephalometrics, :\m. ,I (irtlxdont. 38 :603, 1952. (Freeman and Rasmussen Headholder.) 8. McCall, J. 0. and Walk, S. S.: Clinical Dental Roentgenology; Technic and Intex pretation Including Roentgen Studies of Child and Adolescent, ed. 3, PhiladelplGa. 1952, W. B. Saunders Co. p. 296. (Brady Headholder.) 11~~. OF HEALTH, I~ETIIESDA
14, MI).
EIKCATIOX,
ASD WIXFARE