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Vertical measurements for planning palatal mini-implants in lateral radiography and CBCT images
OOOO Volume 117, Number 5
ABSTRACTS Abstracts e405
Vertical measurements for planning palatal mini-implants in lateral radiography and CBCT images De Rezende Barbosa GL1,2, Ramirez Sotelo LR1, Távora DM1, Almeida SM1 1.UNIVERSITY OF CAMPINAS, PIRACICABA DENTAL SCHOOL, SÃO PAULO, BRAZIL 2. UNIVERSITY OF NORTH CAROLINA, SCHOOL OF DENTISTRY, CHAPEL HILL, NORTH CAROLINA
Background: Skeletal anchorage uses implants as a temporary anchor during orthodontic treatment and to avoid complications during the insertion of palatal mini-implants, such as perforation of the nasal cavity and injuries to the incisive foramen, proper pre-operative planning must be done. It is necessary to evaluate the value of the additional information obtained from cone beam computed tomography (CBCT) images compared to conventional lateral radiography (CLR) so that a better indication of imaging technique is performed in cases of insertion of minipalatal implants. Objective: Compare linear measurements related to palatal bone height in the region of the first premolars for planning palatal mini-implant insertion on CLR, CBCT and reconstructed images from CBCT scan, virtual lateral radiography (VLR). Materials & Methods: 110 images of CLR, VLR and CBCT from the same patient were used. Measurements were performed between the intersections of the long axis of the first premolar with the hard palate floor and the nasal floor, which corresponded to the relevant dimension of available bone for mini-implant insertion. To evaluate the height in the median region on the first premolar site on the CT slice, measurements were made between the cortical layer of the nasal floor and the hard palate.
Results: The values found on CLR were not statistically different (p> 0.05) from those of CBCT. The values for the VLR were statistically different (p <0.05) from those of CBCT and CLR, being underestimated when compared to the gold standard and the radiographic technique.
Table 1 – Median, minimum, maximum, mean, standard deviation and confidence interval values of the evaluated image modalities. Median
Minimum value
Maximum value
Mean
SD
CI 95%
CBCT (Gold standard)
6,88
0,64
14,49
7,06
2,65
6,56; 7,56
CLR
6,25
1,74
13,58
6,39
2,28
5,96; 6,83
5,58
1,16
12,14
5,76
2,10
5,37; 6,16
VLR *†
* Statistical difference from the gold standard (p<0.05) † Statistical difference from the CLR (p < 0.05) Conclusions: The measurements made for planning palatal mini-implants at the level of the first premolars are comparable on CLR and multi-planar reconstructions of CBCT, while they are underestimated in virtual examinations.
A
B
C
Figure 1 – Measurements of the relevant dimensions between the outer cortical layer of the nasal floor and the outer cortical layer of the oral hard palate in the region of upper first premolar. (A) CLR image (B) VLR image (C) CBCT image - midsagittal plane on sagittal window.
Sponsored by:
A Survey of Radiation Safety Practices at US Dental Schools
Vijay Parashar, BDS,DDS, MDSc.; a Robyn Call BS. a; Thomas McDaniel DMD a; James Geist DDS, MS b a Midwestern University College of Dental Medicine Arizona b University
of Detroit Mercy, Detroit, MI
BACKGROUND
USE OF RADIATION DOSIMETERS
RADIOGRAPHY MEDIUM – INTRA-ORAL
PATIENT PROTECTION
RADIOGRAPHY MEDIUM – EXTRA-ORAL
POSITION INDICATING DEVICE
HANDHELD UNITS
In the U.S., the National Council of Radiation Protection and Measurements (NCRP) is recognized as the relevant source from which to derive standards of radiation exposure. The most recent report from the NCRP (145), published in 2003, recommends that the dental occupational dose of radiation should not exceed 50 mSv in any 1 year, and patient exposure should not exceed 1 mSv (excluding doses from natural background and medical care). Dosimeters are recommended only for personnel who will exceed the recommended dose, as well as pregnant women. Although the FDA has issued guidelines regarding the criteria for prescribing dental radiographs, it is left up to individual states to set standards and regulate radiation exposure in healthcare settings.
OBJECTIVES To determine methods currently being employed in dental schools to minimize radiation exposure to patients and providers.
METHODS In order to determine the practice and inclusion of radiation safety in dental education, a simple twelve-question survey form was created. The questionnaire was formulated to be short and informative. This questionnaire was electronically sent to Oral & Maxillofacial Radiology instructors at 58 dental schools in October 2012. Most schools responded immediately with the survey information. Many of the remaining schools responded after a second e-mail request. Specific information sought in the survey includes: 1) use of dosimeters by students, staff, faculty, 2) length of Position Indicating Device (PID) on x-ray units currently being used, 3) shape of collimators used, rectangular, round, etc., 4) radiography medium used, digital versus film. 5) Use of and training in handheld unit radiography by dental students. This project was reviewed and approved by Midwestern University’s Institutional Review Board.
RESULTS - Overall, the response rate was remarkable. Forty-two U.S. dental schools responded (72 percent response rate) to the survey. -Selection criteria is the primary basis for making need based radiographs, only two schools reported that radiographs were made on all new patients routinely. - Division head of Oral & Maxillofacial Radiology is responsible for establishing and implementing radiation safety policies at 76% of school and Clinic Dean is responsible for these duties in rest of the schools.
ABSTRACTS Abstracts e405
Vertical measurements for planning palatal mini-implants in lateral radiography and CBCT images De Rezende Barbosa GL1,2, Ramirez Sotelo LR1, Távora DM1, Almeida SM1 1.UNIVERSITY OF CAMPINAS, PIRACICABA DENTAL SCHOOL, SÃO PAULO, BRAZIL 2. UNIVERSITY OF NORTH CAROLINA, SCHOOL OF DENTISTRY, CHAPEL HILL, NORTH CAROLINA
Background: Skeletal anchorage uses implants as a temporary anchor during orthodontic treatment and to avoid complications during the insertion of palatal mini-implants, such as perforation of the nasal cavity and injuries to the incisive foramen, proper pre-operative planning must be done. It is necessary to evaluate the value of the additional information obtained from cone beam computed tomography (CBCT) images compared to conventional lateral radiography (CLR) so that a better indication of imaging technique is performed in cases of insertion of minipalatal implants. Objective: Compare linear measurements related to palatal bone height in the region of the first premolars for planning palatal mini-implant insertion on CLR, CBCT and reconstructed images from CBCT scan, virtual lateral radiography (VLR). Materials & Methods: 110 images of CLR, VLR and CBCT from the same patient were used. Measurements were performed between the intersections of the long axis of the first premolar with the hard palate floor and the nasal floor, which corresponded to the relevant dimension of available bone for mini-implant insertion. To evaluate the height in the median region on the first premolar site on the CT slice, measurements were made between the cortical layer of the nasal floor and the hard palate.
Results: The values found on CLR were not statistically different (p> 0.05) from those of CBCT. The values for the VLR were statistically different (p <0.05) from those of CBCT and CLR, being underestimated when compared to the gold standard and the radiographic technique.
Table 1 – Median, minimum, maximum, mean, standard deviation and confidence interval values of the evaluated image modalities. Median
Minimum value
Maximum value
Mean
SD
CI 95%
CBCT (Gold standard)
6,88
0,64
14,49
7,06
2,65
6,56; 7,56
CLR
6,25
1,74
13,58
6,39
2,28
5,96; 6,83
5,58
1,16
12,14
5,76
2,10
5,37; 6,16
VLR *†
* Statistical difference from the gold standard (p<0.05) † Statistical difference from the CLR (p < 0.05) Conclusions: The measurements made for planning palatal mini-implants at the level of the first premolars are comparable on CLR and multi-planar reconstructions of CBCT, while they are underestimated in virtual examinations.
A
B
C
Figure 1 – Measurements of the relevant dimensions between the outer cortical layer of the nasal floor and the outer cortical layer of the oral hard palate in the region of upper first premolar. (A) CLR image (B) VLR image (C) CBCT image - midsagittal plane on sagittal window.
Sponsored by:
A Survey of Radiation Safety Practices at US Dental Schools
Vijay Parashar, BDS,DDS, MDSc.; a Robyn Call BS. a; Thomas McDaniel DMD a; James Geist DDS, MS b a Midwestern University College of Dental Medicine Arizona b University
of Detroit Mercy, Detroit, MI
BACKGROUND
USE OF RADIATION DOSIMETERS
RADIOGRAPHY MEDIUM – INTRA-ORAL
PATIENT PROTECTION
RADIOGRAPHY MEDIUM – EXTRA-ORAL
POSITION INDICATING DEVICE
HANDHELD UNITS
In the U.S., the National Council of Radiation Protection and Measurements (NCRP) is recognized as the relevant source from which to derive standards of radiation exposure. The most recent report from the NCRP (145), published in 2003, recommends that the dental occupational dose of radiation should not exceed 50 mSv in any 1 year, and patient exposure should not exceed 1 mSv (excluding doses from natural background and medical care). Dosimeters are recommended only for personnel who will exceed the recommended dose, as well as pregnant women. Although the FDA has issued guidelines regarding the criteria for prescribing dental radiographs, it is left up to individual states to set standards and regulate radiation exposure in healthcare settings.
OBJECTIVES To determine methods currently being employed in dental schools to minimize radiation exposure to patients and providers.
METHODS In order to determine the practice and inclusion of radiation safety in dental education, a simple twelve-question survey form was created. The questionnaire was formulated to be short and informative. This questionnaire was electronically sent to Oral & Maxillofacial Radiology instructors at 58 dental schools in October 2012. Most schools responded immediately with the survey information. Many of the remaining schools responded after a second e-mail request. Specific information sought in the survey includes: 1) use of dosimeters by students, staff, faculty, 2) length of Position Indicating Device (PID) on x-ray units currently being used, 3) shape of collimators used, rectangular, round, etc., 4) radiography medium used, digital versus film. 5) Use of and training in handheld unit radiography by dental students. This project was reviewed and approved by Midwestern University’s Institutional Review Board.
RESULTS - Overall, the response rate was remarkable. Forty-two U.S. dental schools responded (72 percent response rate) to the survey. -Selection criteria is the primary basis for making need based radiographs, only two schools reported that radiographs were made on all new patients routinely. - Division head of Oral & Maxillofacial Radiology is responsible for establishing and implementing radiation safety policies at 76% of school and Clinic Dean is responsible for these duties in rest of the schools.