RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE, KARNATAKA.

ANNEXURE – II

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

1. NAME OF THE CANDIDATE

AND ADDRESS (in block letters)

Dr. NAIR ROHIT UNNI

POST - GRADUATE STUDENT,

DEPARTMENT OF PROSTHODONTICS,

BAPUJI DENTAL COLLEGE AND

HOSPITAL, DAVANGERE – 577 004,

KARNATAKA.

2. NAME OF THE INSTITUTION BAPUJI DENTAL COLLEGE AND

HOSPITAL,

DAVANGERE.

3. COURSE OF STUDY AND

SUBJECT

MASTER OF DENTAL SURGERY

IN PROSTHODONTICS INCLUDING

CROWN AND BRIDGE AND

IMPLANTOLOGY

4. DATE OF ADMISSION TO

COURSE03-05-2010

5. TITLE OF THE TOPIC “EVALUATION OF THE INFLUENCE OF

THE NATURAL HEAD POSITION ON THE

INCLINATION OF VARIOUS

CRANIOFACIAL PLANES OF

PROSTHODONTIC IMPORTANCE TO

THE TRUE HORIZONTAL PLANE”

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6. BRIEF RESUME OF THE INTENDED WORK:

6.1: Need for the study:

It is the goal of prosthodontic therapy to rehabilitate patients with lost or

compromised dentitions and restore them to a functionally and esthetically acceptable

level. Correct occlusal plane orientation is very important in prosthodontic reconstructive

treatment and it should closely resemble the occlusal plane of the lost natural teeth.1

The natural head position is the position of the head most comfortable for a patient

gazing at the horizon. The true horizontal plane is that plane which is perpendicular to the

force of gravity.2 Historically, the Frankfort plane (porion - orbitale) has been assumed to

be parallel to the true horizontal plane when the subject is in the natural head position.

This concept has also found application in the design of dental articulators. In addition to

the use of the Frankfort horizontal plane, Camper’s plane has also been used as a

reference for maxillary cast mounting.3

So far, information used to define the spatial relationship of the Frankfort plane to the

true horizontal plane has largely been recounted from experience.4 Knowledge about

orientation of other relevant planes such as Camper’s plane and the natural occlusal plane

to the true horizontal plane is limited. The natural head position has been shown to be

reproducible and it’s use with the true horizontal plane as the reference can avoid

individual and racial variations.5 Widespread research has been done for a craniofacial

reference plane, which in the natural head position would exhibit a constant relationship

to the true horizontal plane.6

The purpose of this study is to evaluate the relationship of the Frankfort plane,

Camper’s plane and the natural occlusal plane to the true horizontal plane when subjects

are in the natural head position.

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6.2 : Review of Literature:

The author, in a study on the validity of the axis – orbital plane and the use of orbitale

in a facebow transfer record, termed the “Frankfort horizontal plane” a misnomer and

stated that it would normally not be parallel to the true horizontal plane when the subject

is in the esthetic reference position.7

The authors evaluated frontal and lateral oriented profile photographs of 108 subjects

and quantitatively described the craniofacial soft tissue structure and head posture relative

to the ground. They found that the natural occlusal plane and Camper’s plane were

directed upward and backward in relation to the true horizontal plane in the natural head

position. The Frankfort plane was generally directed upward and forward but was closer

to the true horizontal plane in sitting photographs.8

The authors, in an integrated photographic – radiographic analysis of craniofacial

reference planes, found that the hard tissue (porion-orbitale) and soft tissue (tragus-

orbitale) Frankfort planes were not coincident in all subjects and that the tragus was

usually lower and more anterior than the porion. Their results indicated a significant

deviation of the Frankfort plane from the true horizontal.9

The authors evaluated the 3-dimensional orientation of the occlusal plane and found

that Camper’s plane and the occlusal plane appeared nearly horizontal in the frontal

projection. Laterally, however, Camper’s plane deviated from the true horizontal plane by

about 18° and the occlusal plane deviated from the same by approximately 14°. All

measurements were made with subjects in the natural head position.10

The authors assessed angles between craniofacial planes and the gravity horizontal

plane in 56 dentate subjects. They concluded that the occlusal plane was almost parallel to

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7.

the true horizontal plane in the natural head position and that Camper’s plane was not a

reliable landmark for occlusal plane reconstruction. They also stated that the Frankfort

horizontal plane did not represent the gravity horizontal plane (true horizontal plane).1

6.3 : Objectives of the study :

1. To evaluate the relationship between the Frankfort horizontal plane and the true

horizontal plane in the natural head position.

2. To evaluate the relationship between Camper’s plane and the true horizontal plane

in the natural head position.

3. To evaluate the relationship between the natural occlusal plane and the true

horizontal plane in the natural head position.

MATERIALS AND METHODS:

7.1 Source of data :

Male and female healthy subjects with normal occlusion.

7.2 Method of collection of data (including sampling procedure, if any) :

80 healthy subjects will be selected from amongst dental students studying at Bapuji

Dental College & Hospital, Davangere aged 19 – 29 years after obtaining informed

consent for participation in this cross-sectional, descriptive type of study. A pre-defined

proforma will be used to record relevant information (Patient data, criteria for selection,

photographic measurements) from each subject.

Criteria for selecting subjects will be as follows :

A. Inclusion criteria

1. Full complement of permanent dentition including 2nd molar (at least 28 fully

erupted teeth in occlusion),

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2. Angle’s class I molar relationship bilaterally.

B. Exclusion criteria

1. Overjet more than 2 mm,

2. Overbite more than 4 mm,

3. Previous orthodontic treatment ,

4. Previous craniofacial surgery / trauma,

5. TMJ disorders,

6. Facial asymmetries,

7. Occlusal or incisal wear, and

8. Congenital facial defects.

Ink dots will be marked on the inferior-most point on the lateral border of ala of nose,

the inferior-most point of the tragus of the ear, supratragal notch of the ear and on the soft-

tissue orbitale by the same operator. A Fox plane indicator will be clenched between the

teeth which will represent the extra-oral view of the natural occlusal plane. A plumb line

will be hung from the ceiling to establish a true vertical line of reference and will be

included in the ensuing image. The subject will be seated on a chair placed 150 cm from

the camera in a relaxed state in the natural head position such that the left lateral aspect of

the head faces the camera. To obtain the natural head position, the subject will be asked to

look at the reflection of his / her pupils in a mirror positioned 150 cm away at eye level.

A digital camera (7.2 mega pixel / 3x optical zoom) mounted on a tripod stand will be

adjusted to the level of the Fox plane indicator. One left – side image will be taken for

each subject in this position. The image obtained will be transferred to a computer. On the

image, the true horizontal plane will be represented by a line drawn perpendicular to the

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vertical plumb line. The Frankfort horizontal plane will be seen as a line joining the

supratragal notch with the soft tissue orbitale and Camper’s plane as a line joining the

inferior point on the tragus with the lower-most point on the lateral border of the ala of the

nose. Angular measurements (in degrees) between the true horizontal plane and the three

craniofacial reference planes will be made using the computer program, ‘Screen

Protractor, version 4.0’. Data collected from the subjects will be analyzed using

descriptive statistics, 1-sample Student t test, and independent t test.

7.3: Does the study require any investigations or interventions to be conducted on

patients or other humans or animals? If so, please describe briefly

Yes

Direct measurement of angle between Frankfort horizontal plane, Camper’s plane,

occlusal plane and the true horizontal plane is to be obtained from normal dentulous

subjects.

7.4: Has ethical clearance been obtained from your institution in case of 7.3?

Yes. Attached.

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8. LIST OF REFERENCES:

1. Petricevic N, Celebic A, Celic R, Baucic-Bozic M. Natural head position and

inclination of craniofacial planes. Int J Prosthodont 2006;19:279-80

2. Krueger GE, Schneider RL. A plane of orientation with an extracranial anterior point

of reference. J Prosthet Dent 1986;56:56-60

3. Wilkie ND. The anterior point of reference. J Prosthet Dent 1979;41:488-96

4. Ercoli C, Graser GN, Tallents RH, Galindo D. Face-bow record without a third

point of reference: Theoretical considerations and an alternative technique. J Prosthet

Dent 1999;82:231-41

5. Chiu CSW, Clark RKF. Reproducibility of natural head position. J. Dent.

1991;19:130-1

6. Solow B, Tallgren A. Natural head position in standing subjects. Acta Odont Scand

1971;29:591-607

7. Pitchford JH. A reevaluation of the axis-orbital plane and the use of orbitale in a

facebow transfer record. J Prosthet Dent 1991;66:349-55

8. Ferrario VF, Sforza C, Miani A, Tartaglia G. Craniofacial morphometry by

photographic evaluations. Am J Orthod Dentofac Orthop 1993;103:327-37

9. Ferrario VF, Sforza C, Germanò D, Dalloca LL, Miani, Jr. A. Head posture and

cephalometric analyses: An integrated photographic / radiographic technique. Am J

Orthod Dentofac Orthop 1994;106:257-66

10. Ferrario VF, Sforza C, Serrao G, Ciusa V. A direct in vivo measurement of 3-

dimensional orientation of the occlusal plane and the sagittal discrepancy of the jaws.

Clin Orthod Res 2000;3:15-22

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9.SIGNATURE OF CANDIDATE

10. REMARKS OF THE GUIDE

11. NAME & DESIGNATION OF (in block letters)11.1 GUIDE

Dr. DHANYA KUMAR B.H., M.D.S. PROFESSOR, DEPARTMENT OF PROSTHODONTICS,BAPUJI DENTAL COLLEGE AND HOSPITAL, DAVANGERE-577 004.

11.2 SIGNATURE

11.3 CO-GUIDE (IF ANY)

11.4 SIGNATURE

11.5 HEAD OF DEPARTMENT Dr. NANDEESHWAR D.B., M.D.S.

PROFESSOR AND HEAD,DEPARTMENT OF PROSTHODONTICS,BAPUJI DENTAL COLLEGE AND HOSPITAL,DAVANGERE-577 004.

11.6 SIGNATURE

12. 12.1 REMARKS OF THE

CHAIRMAN & PRINCIPAL

12. 2 SIGNATURE

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