RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES,
KARNATAKA,
BANGALORE
ANNEXURE-II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. / NAME OF THE CANDIDATE AND ADDRESS / DR.HIMANSHU LAKHANI6/2, 1ST CROSS SHANKARPURAM, BANGALORE-04
2. / NAME OF THE INSTITUTION / VOKKALIGARA SANGHA DENTAL COLLEGE AND HOSPITAL
3. / COURSE OF STUDY AND SUBJECT / MASTER OF DENTAL SURGERY IN ORAL MEDICINE AND RADIOLOGY
4. / DATE OF ADMISSION / 29th JUNE 2013
5. / TITLE OF THE TOPIC / VISUALIZATION OF THE SUPERIOR AND INFERIOR BORDERS OF THE MANDIBULAR CANAL USING DIGITAL PANORAMIC RADIOGRAPHS AND CONE BEAM CT: A COMPARATIVE STUDY
6 BRIEF RESUME OF THE INTENDED WORK:
6.1 NEED FOR THE STUDY:
The mandibular canal is an important anatomical landmark for dental implant treatments in the posterior mandibular region1.
There may be damage to the inferior alveolar nerve if the implants are placed close to the mandibular canal resulting in the parasthesia of the lower lip and mentalis muscle area1.
Several imaging modalities have been used to assess the course of mandibular canal such as panoramic radiography(PR) , conventional tomography , computed tomography and cone beam CT(CBCT) 3.
Panoramic radiography is widely used due to its low cost and wide availability but it has a disadvantage of unequal magnification and invisibility in the facio-lingual dimension1.
Cone beam CT presents main advantage of elimination of superimposition of neighboring structures , absence of image magnification , short scanning time and radiation dose upto 15 times lower than multislice CT 3.
Hence the purpose of this study is to evaluate the radiological visibility of the superior and inferior borders of the Mandibular canal on digital panoramic images and Cone beam CT 1
6.2 REVIEW OF LITERATURE:
1. A study was conducted to evaluate the visibility of the superior and inferior borders of Mandibular canal using Panoramic Radiography and cross sectional CT images. It was shown that for both modalities , the superior border showed significantly lower score than the inferior border in all area. It was concluded that visibility of superior border was very poor on Panoramic Radiograph. The use of cross sectional CT images remarkably improved this poor visualization 1
2. A study was conducted to compare the visibility of the mandible canal at the different radiographic methods such as Panoramic Radiography , vimplant multiplanar reformatting (MPR) CT panoramic images , vimplant(MPR)-CT paraxial images and film based denta-scan MPR-CT images . It was concluded that vimplant and denta-scan MPR-CT imaging systems offer significantly better images of the Mandibular Canal than conventional Panoramic Radiographs 2
3. A study was conducted to assess the visibility of the Mandibular Canal in different regions on Cone Beam CT cross sectional images. It was concluded that Mandibular Canal was clearly visible in 53% of the hemi mandibles. Difficult and very difficult visualizations were registered in 25% and 22% of the mandibles respectively.The visibility of mandibular canal on distal regions were superior when compared to regions closer to the mental foramen. The mandibular canal presents an overall satisfactory visibility on Cone Beam CT cross sectional images in most cases 3
4. A study was conducted to investigate the efficiency of Panoramic Radiographs, conventional (cross section) tomography and computerized tomography for location of the Mandibular Canal before implant placement in the posterior region of the mandible. It was concluded that measurement obtained from computerized tomographic images were more consistent with direct measurements than the measurement obtained from Panoramic Radiographic images or conventional tomographic images 4
5. A study was conducted to evaluate the diagnostic accuracy of Cone Beam CT compared with panoramic images in predicting neurovascular bundle exposure during extraction of impacted mandibular 3rd molars. These images were compared and concluded that sensitivity and specificity were 93% and 77% for Cone Beam CT and 70% and 63% for panoramic images respectively. It was concluded that Cone Beam CT was significantly more accurate than panoramic images 5
6.3 OBJECTIVE:
· To assess the accuracy of Panoramic Radiographs in visualizing the superior and inferior borders of Mandibular Canal.
· To assess the accuracy of Cone Beam CT in visualizing the superior and inferior borders of Mandibular Canal.
· To compare the accuracy of Panoramic Radiography and Cone Beam CT in visualizing the superior and inferior borders of Mandibular Canal.
7 MATE RIALS AND METHODS
7.2 METHODS OF COLLECTION OF DATA:
7.1 SOURCES OF DATA :
60 patients requiring implants in the posterior mandibular region will be selected from the Department of Oral Medicine and Radiology , V.S.D.C.H. , Bangalore , Karnataka .these patients will be radiographed for the posterior mandibular region using panoramic imaging and CBCT.
7.2.1 INCLUSION CRITERIA:
Patients requiring implants due to missing mandibular posterior teeth.
Age :20 – 50 years
7.2.2 EXCLUSION CRITERIA:
Patients with clinically suspected or known history of diseases of the bone like:
¨ Hyperparathyroidism
¨ Hypophosphatasia
¨ Osteopetrosis
¨ Fibrous dysplasia
¨ Multiple myeloma
¨ Pagets disease
7.2.3 PLACE OF STUDY:
Ø Dept. of OMDR , V.S.D.C.H. , Bangalore , Karnataka for OPG(Sirona orthophos XG
Ø Magnus diagnostic centre , kormangala , Bangalore for CBCT (Carestream 9300 3D imaging system)
7.2.4 STUDY DESIGN:
Ø Non randomized comparative study.
7.2.5 STUDY DURATION:
Ø One and a half years.
7.2.6 SAMPLE DESIGN:
Ø Purposive
7.2.7 SAMPLE SIZE:
Ø 60 patients.
7.2.8 PROPOSED STATISTICAL ANALYSIS:
Ø Mann-whitney U test
Ø Kappa statistics
7.2.9 MATERIALS AND METHODS:
Patients with missing mandibular posterior teeth will be taken for the study. For these patients panoramic radiographs are taken under standardized conditions with imaging machine (orthophos XG).
For the same patients CBCT of the region of interest will be carried out with carestream 9300 3D imaging system.
Each panoramic image and the CBCT image will then be evaluated by three observers( two oral radiologists with a minimum 3 years experience and myself) for the visualization of the superior and inferior borders of the mandibular canal.
For panoramic images this score will be determined based on the fraction of the border of the mandibular canal that is visible. The mandible between the mental foramen and the mandibular foramen will be divided into 4 equal areas, designated as areas 1,2 ,3,4 , from anterior to posterior by drawing parallel lines.
For evaluating CBCT images , the same range of mandible , from the mental foramen to the mandibular foramen will be similarly divided into 4 equal areas. Each area will contain an equal number of cross sectional images.
Three observers (two oral radiologists and myself ) independently will evaluate the images in a darkened and quiet room to visualize the superior and inferior borders of the mandibular canal in each area using a 5 point visibility score.
After 15 days the same images will be given to the same observers for re-evaluation for any intra-observer variation
VISIBILITY SCORE FOR THE SUPERIOR AND INFERIOR BORDERS OF THE MANDIBULAR CANAL:
¨ 0: the border is wholly invisible
¨ 1: less than 1/3rd of the border is visible
¨ 2: 1/3rd - 2/3rd of the border is visible
¨ 3: more than 2/3rd of the border is visible
¨ 4: the border is wholly visible
For panor amic images , this score will be determined based on the fraction of the border of the mandibular canal that was visible .
For CBCT images , scores were determined based on the number of cross sectional images with visible borders as follows:
Visibility ratio in each area CBCT :
Number of cross Sectional images with visible borders / number of all cross sectional images.
Then the data will be compared and statical analysis will be done.
7.3 DOES THE STUDY REQUIRE ANY INVESTIGATIONS OR INTERVENTION TO BE CONDUCTED ON PATIENTS OR HUMANS OR ANIMALS? IF SO PLEASE DESCRIBE BRIEFLY
YES , For the study patient needs to undergo X-ray imaging i.e an O.P.G and CONE BEAM CT.
7.4 HAS THE ETHICAL CLEARENCE BEEN OBTAINED FROM YOUR INSTITUTION?
Yes.
8 REFERENCES:
1. , Nahar Kamrun et al. Visualization of the superior and inferior borders of the mandibular canal: a comparative study using digital panoramic radiographs and cone beam CT, Oral and maxillofacial radiology 2013;115:550-557.
2. Eun-Kyung Kim. Comparison of different radiographic methods for the detection of the mandibular canal, Korean journal of oral and maxillofacial radiology 2003; 33 :199-205.
3 Christiano Oliveira-Santos et al. Visibility of the mandibular canal on CBCT cross sectional images, J Appl Oral sci. 2011;19(3):240-243.
4. Llkay Peker et al. The use of 3 different imaging methods for the localization of the mandibular canal in dental implant planning, J of oral and maxillofacial implants 2008;23:463-470.
5. Weeraya Tantanapornkul et al. A comparative study of cone beam CT and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars , J oral surgery oral med oral path oral rad and endodontology 2007;103:253-259.
9.0 Signature of Candidate10.0 Remarks of the Guide
11.0 Name and Designation of :
11.1 Guide : / Dr. Annaji.A.G
Reader
Department Of Oral Medicine And Radiology
V.S Dental College & Hospital, Bangalore
11.2 Signature :
12.0 Head of the Department
/ Dr. Manjunath.M
Professor & Head of the Department
Department of Oral Medicine And Radiology
V.S Dental College & Hospital, Bangalore
12.1 Signature :
Consent Form
I ______son/daughter of ______, aged ______
resident of ______being under the treatment of
Dr Himanshu Lakhani do hereby give consent to perform proposed drugs/medical/surgical/anesthesia/diagnostic procedure of upon myself. The procedure has been explained to me in my own language and also likely adverse effects of the drugs being used has been explained and I agree that no responsibility will be attached to the surgeon or the hospital staff.
Signature of witness:
Place: Signature of the patient/relative
Date: