DENTO MAXILLO FACIAL RADIOLOGY
PRESENTING:
The Department of Oral Roentgenology in the Dental School of the University of Utrecht, Netherlands. Introduction The teaching in dentistry officially started in the Netherlands, nearly 100 years ago, in 1877 with the nomination of a lecturer in dentistry at the medical faculty of the University of Utrecht. In the following historical development different departments were successively founded. The study in dentistry, however, was not an official study at the University and was consequently completed with an examination authorised by the government. In 1947 the study in dentistry was granted an official University status and was organised in a subfaculty of the faculty of medicine. At this same moment a second University, in Groningen, started also a dental school. Since than, three other dental schools were founded. One at the Roman Catholic University in Nijmegen, one at the University of Amsterdam and a fifth at the Protestant University also situated in Amsterdam.
new complex and resumed all its activities there in September 1974. The building is composed of three sections: a. the low part on the right. The preclinic b. the cube in the middle. The clinic and c. on the left the low L shaped wing containing the basic science departments. In September 1975 the school accepts 108 new students. In former years the annual acceptance was approximately 90 students. The curriculum counts 6 years each devided in 6 periods of 6 weeks. New developments may change this in 5 years with 4 periods of 13 weeks each year. From the total netto surface area of 22.100 m 2 for the complete building 1228 m 2 was reserved for the department of oral roentgenology.
The department of dental roentgenology at the University of Utrecht dental school was founded in 1964 when the teacher in oral roentgenology became a lecturer. The department at that time existed of an X-ray room adjacent to the department of oral surgery and an X-ray room for operative dentistry. A program of space requirements for an X-ray department was included in the general program for a new dental school in 1959. This program has resulted in the construction of a new dental school on the University campus in the years 1970-1974 (Fig. 1). In August 1974 the school moved from the old building to the Denlomaxillofac. Radio!' 4:49-52 (1975)
Fig. 1: The recently opened dental school of the
University of Utrecht in the Netherlands. 49
The X-ray department The department has besides the head of the department 3 full time and 3 part time staff members. They are assisted by 1 secretariat and 6 technical assistants, one of which is a certified roentgen laboratory nurse. Although all staff members take part in all the different activities there is a distribution of responsibilities for the educational program, the general X-ray diagnostic section and the research. Each year 20 .000 patients are referred to the department which requires 60.000 films to be taken. The equipment was selected and when needed modified to permit a standardisation of procedures. This principle was considered important in order to obtain routinely results of high quality. Consequently all dental X-ray machines are equiped with "long cones" for the long tube 90 " technique with aligning Fig . 2 : Examination codes introduced on the X-ray
con tro l desk.
devices. Only for Parma T . M. joint views a reduced focal spot-skin distance is possible on some machines. In extra-oral roentgenography cephalostats are used for the fixation of the patient and are also used to orient the axis of the X-ray beam in relation to the patients head. All exposure factors are prescribed in exposure tables. Because of differences between the dental X-ray machines these tables are sepa ra tely composed and accurately checked for each X-ray box. The same hold s for extra oral roentgenography but here the techniques are completed with automatic density control and preprogrammed exposure factors which permit the use of only one push button on the control desk to select all factor s. All procedures and the administration are designed to fit in a computorised automatic administration system for the whole clinic . As a first step the coding system was introduced, which was also transfered to the X-ray control desk (fig. 2). The clinical departments will suc cessively switch to the computorised system . Data recorders are already in use in policlinic, operative and prosthetic dentistry. The department for oral roentgenology can be regarded as containing four main sections. a. General X-ray diagnosis b. Annex rooms for intra-oral roentgenography during the treatment in the departments of prosthetic dentistry, operative dentistry, orthodontics and oral surgery. They are located in these different departments . c. Education in oral roentgenology d. Research in oral roentgenology
, 4
, I
50
,I
"I
Fig . 3 : Stand which permits to take a series of 6 standardised Schuller T.M. joint exposures on one film.
a. General X-ray diagnosis.
This section is situated on the second floor which is shared with oral surgery. For intra oral radiography four boxes are available. They are used for the examination of patients coming from the policlinic, which takes care of the selection of the new patients. All intra oral examinations in other departments which permit an appointment are also referred to this main intra-oral X-ray room. As a consequence all full mouth examinations for all departments are centralised here. For extra-oral X-ray examinations three rooms are available. From former experiences it was concluded that not too many types of examinations should be carried out in one single room to prevent long waiting times for the patients. This especially counts for examinations which require relative long times as tomography and skull films. For this same reason experimental work was also planned to be performed in a special X-ray room in the research section. One room in the X-ray diagnostic section is equipped for biplane cephalometric roentgenography with a focus object distance of 5.25 m for both directions. The cassette which should not be exposed is automatically covered with a lead screen when the tube selector is switched on the control desk. As a result of interplay with the department of gnathology a standardised technique for the T.M. joint was developed which permits to make retakes with reproducible results. Fig. 4: Skull stand for intra cranial centration with a special motor driven chair for the orientation and fixation of the patient.
The stand includes a cephalostat and is designed to give 6 standard Schuller T.M. joint projections on one film (Fig. 3). For general information and the screening of patients two orthopantomographes are available. Both are equipped with a rotating anode tube with a small focal spot (0.3 mm). Panoramix views obtained with the X-ray source intra orally is also possible with the Status-X machine (Siemens). Skull films are taken with the General Electric Neurotome unit. This unit was at request modified to meet the special needs for oral roentgenography following the principle of intra-cranial centration. The patient sits, separate from the X-ray stand, in a special motor driven chair (Siemens) which is movable in three directions to permit exact orientation and fixation of the patient (Fig. 4). The neurotome was selected from the existing skull stands because the pattern of movement of the two axi and the resulting direction of the X-ray beam of this machine permits the use of the most logical system for defining angles and finding the required angulation in skull roentgenography. The angulation is found with the use of two light crosses with light of different color which are mounted around the main axis, indicating: a. the direction of the X-ray beam and b. a plane making a selected angle with the X-ray beam. Before exposure the stand has only to be rotated until the plane b coincides with an orientation plane of the patient (Fig. 5). This proFig. 5: Two light crosses with a preselected angle
are used to reduce orientation procedures.
51
cedure permits the operator to give the axis of the beam the desired position without moving the beam to the orientation plane and from this plane to the desired direction and also eliminates the reading of the respective angles. Tomography is carried out with the Polytome U3 (Philips). Patient orientation is obtained using a cephalostat mounted on the table top . An automatic remote controlled light beam indicates the selected plane in focus . The general X-ray diagnostic section also contains a dark room with an X-omat 90 sec machine (Kodak) and a separate room for the preparation and storage of fluids for the dark rooms. A room for interpretating films, an archive, a sterilisation room and a dressing room for the patients complete the general X-ray diagnostic section.
.:
b. The annex rooms. The annex rooms for intra-oral roentgenography for the different clinical departments have one or two boxes equipped as in the main diagnostic section. Dark room facilities are included in the layout if required by the specific circumstances. For instance; a roller type developing machine was installed for operative dentistry because of the need for dry films during endodontic treatment.
c. Education in oral roentgenology. For the educational task the department has three special designed rooms. The X-ray room has four boxes for intra-oral roentgenography. Four small dark rooms were planned because it is well known that in general practice the dark room is one of the weak links in the X-ray diagnostic procedure. Each group of two students has its own dark room. In this way more attention can be given to the practical use of the equipment and the maintenance of the dark room. The practical course includes some experiments concerning the properties of the X-ray beam, the quality of the image and protection measures. These experiments require two radiation laboratory boxes which in fact are boxes a little larger than those for intra-oral roentgenography (Fig . 6). The four dark rooms and the two laboratory boxes are situated in one room. The third room is a small lecture room (30 seats) especially designed for the interpretation course. It is equipped with light boxes in the 52
Fig . 6 : Radiation laboratory box in the educational section.
tables, ultra-violett illumination of the blackboard, and a T.V. Transiskop circuit (Siemens), to present compensated images of the X-ray films on the monitors. This room is also used during the practical course to mount and evaluate the X-ray films and to write the reports of the course. Courses are given for dental students and oral hygienists as well as one week refresher courses for general practitioners.
d. Research in oral roentgenology . On the eighth floor are the rooms for the staff and secretariat of the department. The section for research in oral roentgenology is also situated on this floor. It contains laboratory spaces, dark rooms and a larger X-ray room. A second G .E. neurotome unit is installed in this room. This unit is equipped with an image intensifier with T .V. camera and monitor. A 35 mm Ariflex Hi-speed cine camera which permits X-ray pulsed cinemathography. The image intensifier is also equipped with a 105 mm fotospot camera permitting exposures from a single frame up to 12 frames per second. Prof. J. van Aken, Afdeling tandheelkundige rcntgeno logie Tandheelkundig lns rituu t Sorbonnelaan 16 Utrecht 2506 The Netherlands .
PRESENTING:
The Department of Oral Roentgenology in the Dental School of the University of Utrecht, Netherlands. Introduction The teaching in dentistry officially started in the Netherlands, nearly 100 years ago, in 1877 with the nomination of a lecturer in dentistry at the medical faculty of the University of Utrecht. In the following historical development different departments were successively founded. The study in dentistry, however, was not an official study at the University and was consequently completed with an examination authorised by the government. In 1947 the study in dentistry was granted an official University status and was organised in a subfaculty of the faculty of medicine. At this same moment a second University, in Groningen, started also a dental school. Since than, three other dental schools were founded. One at the Roman Catholic University in Nijmegen, one at the University of Amsterdam and a fifth at the Protestant University also situated in Amsterdam.
new complex and resumed all its activities there in September 1974. The building is composed of three sections: a. the low part on the right. The preclinic b. the cube in the middle. The clinic and c. on the left the low L shaped wing containing the basic science departments. In September 1975 the school accepts 108 new students. In former years the annual acceptance was approximately 90 students. The curriculum counts 6 years each devided in 6 periods of 6 weeks. New developments may change this in 5 years with 4 periods of 13 weeks each year. From the total netto surface area of 22.100 m 2 for the complete building 1228 m 2 was reserved for the department of oral roentgenology.
The department of dental roentgenology at the University of Utrecht dental school was founded in 1964 when the teacher in oral roentgenology became a lecturer. The department at that time existed of an X-ray room adjacent to the department of oral surgery and an X-ray room for operative dentistry. A program of space requirements for an X-ray department was included in the general program for a new dental school in 1959. This program has resulted in the construction of a new dental school on the University campus in the years 1970-1974 (Fig. 1). In August 1974 the school moved from the old building to the Denlomaxillofac. Radio!' 4:49-52 (1975)
Fig. 1: The recently opened dental school of the
University of Utrecht in the Netherlands. 49
The X-ray department The department has besides the head of the department 3 full time and 3 part time staff members. They are assisted by 1 secretariat and 6 technical assistants, one of which is a certified roentgen laboratory nurse. Although all staff members take part in all the different activities there is a distribution of responsibilities for the educational program, the general X-ray diagnostic section and the research. Each year 20 .000 patients are referred to the department which requires 60.000 films to be taken. The equipment was selected and when needed modified to permit a standardisation of procedures. This principle was considered important in order to obtain routinely results of high quality. Consequently all dental X-ray machines are equiped with "long cones" for the long tube 90 " technique with aligning Fig . 2 : Examination codes introduced on the X-ray
con tro l desk.
devices. Only for Parma T . M. joint views a reduced focal spot-skin distance is possible on some machines. In extra-oral roentgenography cephalostats are used for the fixation of the patient and are also used to orient the axis of the X-ray beam in relation to the patients head. All exposure factors are prescribed in exposure tables. Because of differences between the dental X-ray machines these tables are sepa ra tely composed and accurately checked for each X-ray box. The same hold s for extra oral roentgenography but here the techniques are completed with automatic density control and preprogrammed exposure factors which permit the use of only one push button on the control desk to select all factor s. All procedures and the administration are designed to fit in a computorised automatic administration system for the whole clinic . As a first step the coding system was introduced, which was also transfered to the X-ray control desk (fig. 2). The clinical departments will suc cessively switch to the computorised system . Data recorders are already in use in policlinic, operative and prosthetic dentistry. The department for oral roentgenology can be regarded as containing four main sections. a. General X-ray diagnosis b. Annex rooms for intra-oral roentgenography during the treatment in the departments of prosthetic dentistry, operative dentistry, orthodontics and oral surgery. They are located in these different departments . c. Education in oral roentgenology d. Research in oral roentgenology
, 4
, I
50
,I
"I
Fig . 3 : Stand which permits to take a series of 6 standardised Schuller T.M. joint exposures on one film.
a. General X-ray diagnosis.
This section is situated on the second floor which is shared with oral surgery. For intra oral radiography four boxes are available. They are used for the examination of patients coming from the policlinic, which takes care of the selection of the new patients. All intra oral examinations in other departments which permit an appointment are also referred to this main intra-oral X-ray room. As a consequence all full mouth examinations for all departments are centralised here. For extra-oral X-ray examinations three rooms are available. From former experiences it was concluded that not too many types of examinations should be carried out in one single room to prevent long waiting times for the patients. This especially counts for examinations which require relative long times as tomography and skull films. For this same reason experimental work was also planned to be performed in a special X-ray room in the research section. One room in the X-ray diagnostic section is equipped for biplane cephalometric roentgenography with a focus object distance of 5.25 m for both directions. The cassette which should not be exposed is automatically covered with a lead screen when the tube selector is switched on the control desk. As a result of interplay with the department of gnathology a standardised technique for the T.M. joint was developed which permits to make retakes with reproducible results. Fig. 4: Skull stand for intra cranial centration with a special motor driven chair for the orientation and fixation of the patient.
The stand includes a cephalostat and is designed to give 6 standard Schuller T.M. joint projections on one film (Fig. 3). For general information and the screening of patients two orthopantomographes are available. Both are equipped with a rotating anode tube with a small focal spot (0.3 mm). Panoramix views obtained with the X-ray source intra orally is also possible with the Status-X machine (Siemens). Skull films are taken with the General Electric Neurotome unit. This unit was at request modified to meet the special needs for oral roentgenography following the principle of intra-cranial centration. The patient sits, separate from the X-ray stand, in a special motor driven chair (Siemens) which is movable in three directions to permit exact orientation and fixation of the patient (Fig. 4). The neurotome was selected from the existing skull stands because the pattern of movement of the two axi and the resulting direction of the X-ray beam of this machine permits the use of the most logical system for defining angles and finding the required angulation in skull roentgenography. The angulation is found with the use of two light crosses with light of different color which are mounted around the main axis, indicating: a. the direction of the X-ray beam and b. a plane making a selected angle with the X-ray beam. Before exposure the stand has only to be rotated until the plane b coincides with an orientation plane of the patient (Fig. 5). This proFig. 5: Two light crosses with a preselected angle
are used to reduce orientation procedures.
51
cedure permits the operator to give the axis of the beam the desired position without moving the beam to the orientation plane and from this plane to the desired direction and also eliminates the reading of the respective angles. Tomography is carried out with the Polytome U3 (Philips). Patient orientation is obtained using a cephalostat mounted on the table top . An automatic remote controlled light beam indicates the selected plane in focus . The general X-ray diagnostic section also contains a dark room with an X-omat 90 sec machine (Kodak) and a separate room for the preparation and storage of fluids for the dark rooms. A room for interpretating films, an archive, a sterilisation room and a dressing room for the patients complete the general X-ray diagnostic section.
.:
b. The annex rooms. The annex rooms for intra-oral roentgenography for the different clinical departments have one or two boxes equipped as in the main diagnostic section. Dark room facilities are included in the layout if required by the specific circumstances. For instance; a roller type developing machine was installed for operative dentistry because of the need for dry films during endodontic treatment.
c. Education in oral roentgenology. For the educational task the department has three special designed rooms. The X-ray room has four boxes for intra-oral roentgenography. Four small dark rooms were planned because it is well known that in general practice the dark room is one of the weak links in the X-ray diagnostic procedure. Each group of two students has its own dark room. In this way more attention can be given to the practical use of the equipment and the maintenance of the dark room. The practical course includes some experiments concerning the properties of the X-ray beam, the quality of the image and protection measures. These experiments require two radiation laboratory boxes which in fact are boxes a little larger than those for intra-oral roentgenography (Fig . 6). The four dark rooms and the two laboratory boxes are situated in one room. The third room is a small lecture room (30 seats) especially designed for the interpretation course. It is equipped with light boxes in the 52
Fig . 6 : Radiation laboratory box in the educational section.
tables, ultra-violett illumination of the blackboard, and a T.V. Transiskop circuit (Siemens), to present compensated images of the X-ray films on the monitors. This room is also used during the practical course to mount and evaluate the X-ray films and to write the reports of the course. Courses are given for dental students and oral hygienists as well as one week refresher courses for general practitioners.
d. Research in oral roentgenology . On the eighth floor are the rooms for the staff and secretariat of the department. The section for research in oral roentgenology is also situated on this floor. It contains laboratory spaces, dark rooms and a larger X-ray room. A second G .E. neurotome unit is installed in this room. This unit is equipped with an image intensifier with T .V. camera and monitor. A 35 mm Ariflex Hi-speed cine camera which permits X-ray pulsed cinemathography. The image intensifier is also equipped with a 105 mm fotospot camera permitting exposures from a single frame up to 12 frames per second. Prof. J. van Aken, Afdeling tandheelkundige rcntgeno logie Tandheelkundig lns rituu t Sorbonnelaan 16 Utrecht 2506 The Netherlands .
