SYNOPSIS

DR. POOJA N PILLAI

POST GRADUATE STUDENT

DEPARTMENT OF PROSTHODONTICS

INCLUDING

CROWN AND BRIDGE IMPLANTOLOGY

K.V.G. DENTAL COLLEGE & HOSPITAL,

KURUNJIBHAG, SULLIA (DK), KARNATAKA, 574327

Rajiv Gandhi University of Health Sciences, Karnataka, Bangalore

K.V.G. DENTAL COLLEGE & HOSPITAL,

KURUNJIBHAG, SULLIA (D.K.), KARNATAKA -574327

Rajiv Gandhi University of Health Sciences, Karnataka, Bangalore

1. / Name of the Candidate and Address / DR. POOJA N PILLAI
POST GRADUATE STUDENT,
DEPARTMENT OF PROSTHODONTICS INCLUDING CROWNAND BRIDGE IMPLANTOLOGY.
K.V.G.DENTAL COLLEGE & HOSPITAL,
KURUNJIBHAG, SULLIA (D.K.),
KARNATAKA,INDIA-574 327
2. / Name of the Institution / K.V.G.DENTAL COLLEGE & HOSPITAL,
KURUNJIBHAG, SULLIA(D.K.)
KARNATAKA,INDIA-574 327
3. / Course of study and subject / MASTER OF DENTAL SURGERY
PROSTHODONTICS
INCLUDING CROWN AND BRIDGE IMPLANTOLOGY
4. / Date of admission to course / JUNE 17th 2013
5. / Title of The Thesis / A STUDY TO CORRELATE THE RELATIONSHIP OF INTER-MOLAR DISTANCE BETWEEN MAXILLARY FIRST MOLARS TO THE RELATIVE INTER-CONDYLAR DISTANCE USING AN ARTEX® FACE BOW IN DAKSHINA KANNADA POPULATION.
6.
7. / BRIEF RESUME OF THE INTENDED WORK :
6.1 NEED FOR THE STUDY:
In completely edentulous patients, residual ridge resorption occurs after tooth loss due to a combination of mechanical, anatomical and metabolic factors1. Due to resorption, maxillary alveolar process migrates upwards and inwards2 and mandibular ridgemigrates downwards and outwards3.Thus long term edentulism makes artificial teeth arrangement more confusing4. In such cases placing artificial teeth on the crest of the ridge before it was resorbed causes discomfort and denture instability5.
In dental literature many studies are available that have utilized various anatomical landmarks for teeth arrangement6, 7. Several anatomical land marks show fixed positional relationships to some natural teeth8. These land marks serve as guide in replacing natural teeth with artificial teeth8. These include the width of the mouth, inter-alar width, bizygomatic width and interpupillary distance9, 10. Most of the studies consider anterior teeth arrangement; few studies show maxillary tubrosity could be utilized for posterior teeth arrangement.However it is stated that this landmark becomes less reliable as atrophy increases11.
Few researches have correlated inter-condylar distance with maxillary inter molar distance. It is stated that inter-condylar distance is a stable landmark that remains fairly static throughout life3. Inter-condylar distance is not affected by resorptionof the residual alveolar ridge.
The purpose of this study is to determine the relationship of relative inter-condylar distance and inter-molar distance of maxillary first molar to provide reliable and reproducible guide for the arrangement of the posterior teeth in Dakshina Kannada population.
6.2 Review of Literature
1) In one of the studies radiographic method was used to measure the inter-alar and interalar-fold widths of the nose on 80 men and women. These distances were compared to the subject’s intercanine distances as measure on artificial stone casts. In 56 subjects, the width of the skeletal nasal aperture was measured and compared to the intercanine distance. The results of this study, leads to the following conclusions. 1. There was no significant relationship between the intercanine
distance and the interalar width of the nose in the subjects. 2. There was no significant relationship
between the intercanine distance and the interalar-fold width of the nose in the subjects. 3. The
presence or absence of a significant relationship between the intercanine distance and the width of
the skeletal nasal aperture was not demonstrated conclusively in this study. Thus the results of this
study show that the width of the nose would not be a reliable guide for selecting or arranging
artificial anterior teeth6.
2) Another study shows that system for arranging artificial teeth should satisfy three goals, which are accuracy, speed, and a facility for communication. The dentist with the patient present records the anterior determinant of occlusion by placing the four central incisors according to phonetics and esthetics. All remaining teeth are placed at the laboratory according to anatomic landmarks. Then the dentist returns the trial dentures to the patient for verification, personalization, and perfection. It is the responsibility of the dentist to prescribe requirements of tooth placement in detail if he uses the services of a dental laboratory technician8.
3) In another studythey state that the incisive papilla provides a reference point on the edentulous cast that may be helpful in determining the anteroposterior position of the artificial incisors. The results of the study suggest that the labial surface of the maxillary incisors should be 12 to 13 mm from the posterior border of the incisive papilla. This measurement was significantly smaller in the sample of dentures examined, which suggests a tendency for the anterior teeth to be placed too far posteriorly in artificial dentures7.
4) Another clinical study was designed to investigate the relationship between intercondylar widths and inter dental widths of the upper and lower canines and first molar to aid in denture teeth positioning. The study was divided into two parts so that the results of the first part could be verified in the second part. In the first part 27 adult subjects were selected. A kinematic hinge axis locator was used to locate the true point of condylar rotation. The distance between these points was considered to be the ICW. A strong correlation was found between ICW and inter-dental measurements. In the second part of study inter dental measurements were estimated using the indices used in the first part. The estimated inter dental widths showed no significant differences
compared with the real widths. Thus the study concludes that ICW measurements can be used for
setting up canines and first molars in complete dentures3.
5) Another studywas done in Croatian population. They measured inter condylar distance between temporomandibular joints in radiograph. Total of 101 subjects of both sexes ranging in age from 20-80 years were evaluated. Inter condylar distance was measured from the condyle centers in the postero-anterior cranial radiographs which had previously been examined and traced on acetate paper. The results of our measurements were assessed by ANOVA analysis. The intercondylar distance between the two temporomandibular joints was within the range of 110 and 145 mm, with the mean of 126 mm. In men the intercondylar distance was within the range of 116 and 145 mm, with the mean of 130.2 mm. In women the distance ranged from 110 to 138 mm, with the mean of 123.5 mm. There was a significant difference between the two sexes. The results of measurements do not support the results of similar studies assessed by a number of researchers in other countries. The intercondylar distance in the Croatian sample was 5.25% larger suggesting larger craniofacial skeletons. Thus they conclude that radiographic assessment method will improve evaluation of subjects seeking treatment12.
6) In another study they state that there is no definitive method for the arrangement of artificial teeth in complete denture construction. A new method is introduced whereby the maxillary posterior teeth have been set in approximate positions mediolaterally similar to their natural predecessors. The procedure is based on a constant relationship derived from the natural dentition. Its clinical application proved to be suitable for the arrangement of artificial teeth for complete dentures with minimal errors4.
7) In another study they took 250 dentate subjects. Maxillary impressions were made. The vernier caliper was used to measure the distance between the mesiobuccal cusp tips of maxillary first molars. With the help of an arbitrary face bow the intercondylar distance was recorded. The distance obtained between the two condylar rods was measured with the vernier caliper. The data were recorded on the proforma for the statistical analysis. Pearson correlation coefficients (r) for the
intercondylar distance and maxillary intermolar showed positive correlation and significant (r=0.53
p=0.0005). Thus they concluded that intercondylar distance provides significant measurements for
the arrangement of posterior teeth in edentulous patients13.
6.3Aims and Objectives of the study:
Aim:
To find the relationship between inter-molar distance of maxillary first molars and relative inter- condylar distance to provide reliable and reproducible guide for arrangement of the maxillary posterior teeth.
Objectives:
1)To measure the inter-molar distance of maxillary arch.
2)To measure the relative inter-condylar distance using an Artex face bow.
3)To compare the relationship between inter-molar and relative inter-condylar distance.
4)To determine whether there is any difference in the ratio between male and female population.
MATERIALS AND METHODS :
7.1 Source of the data:
The sample size taken for the study is 100; with 50 males and 50 females.
This study will be done in Department of Prosthodontics of K.V.G. Dental College and Hospital,
Sullia.
Inclusion criteria of the subject
a)All individuals should have intact teeth.
b)Both male and female patient’s age ranging between 20-40.
c)All teeth should be present excluding third molars.
Exclusion criteria for the subject
a) Subjects with history of tempro-mandibular joint pain or dysfunction.
b) Orthodontically treated subjects.
c) Subjects with congenital or acquired orofacial deformities.
d) Subjects with crowded and mal-aligned dentition.
e) Subjects with restored maxillary first molars.
f) Subjects with attrited teeth.
7.2.Methods of collecting data
  1. Instruments and materials that will be used during course of study
Instruments
  1. Dentulous rim lock perforated stock tray (S S WHITE).
2. Artex face bow (AMANNGIRRBACH Artex-Gesichtsbogen).
3. Digital vernier caliper (0.01mm accuracy).
4. Rubber bowl for mixing alginate and dental stone.
5. Curved and straight stainless steel spatula.
6. Water and powder measuring container for alginate (supplied by manufacturer).
7. Permanent marker pen.
Materials
1. Alginate impression material (Tropicalgin ISO 1563-ADA Spec.18).
2. ADA type III dental stone (GYPROCK).
2) Methodology :
After selecting the subject suitable for the study, procedure will be explained and after
obtaining subject’s consent, they will be seated on a dental chair in an upright position.
Measurement of inter condylar distance
After seating the patient, the ear piece of the Artex® face bow (AMANNGIRRBACH Artex -Gesichtsbogen) will be positioned into the external auditory meatus. The nasion adapter will be adapted on to patient’s nasion. Then the screws of face bow will be tightened to stabilize. Markings on the horizontal arm of the facebow will be noted as the relative inter-condylar distance.
Impression & cast making procedures:
After selecting an appropriate maxillary impression tray, impression of the maxillary arch will be made using alginate (Tropicalgin ISO 1563-ADA Spec.18) The cast will be poured with hard setting dental stone (TYPE III -GYPROCK). After one hour, cast will be retrieved from the impression
On the cast markings will be made on the mesiobuccal cusp tips of both the maxillary first molars. A vernier caliper (with 0.01mm accuracy) will be used to measure the distance between the two points on either molars. The procedure will be repeated two or three times and the mean value will be calculated.
3.COLLECTION OF DATA:
The values obtained for the inter molar distance(mesio buccal cusp tips) and relative inter condylar distance will be compared to get a ratio.
4. STATISTICAL ANALYSIS:
The study result will be analyzed using
PEARSON’S CORRELATION COEFFICIENT.
TUKEY’S TEST
ANOVA
7.3. Does the study require any investigations or interventions to be conducted on patients or other humans or animals?
Yes. Alginate hydrocolloid impression will be made on the maxillary archand Artex and face bow will be used to measure the relative inter-condylar distance.
7.4. Has the ethical clearance been obtained from your institution in case of 7.3?
Yes. Institutional Ethics Committee Clearance Copy enclosed.
8. / References:
  1. Bissasu M. Pre-extraction records for complete denture fabrication: a literature review. J Prosthet Dent 2004;91:55-58.
  2. Lyman S, Boucher LJ. Radiographic examination of edentulous mouths. J Prosthet Dent 1990;64:180-82.
  3. Keshvad A, Winstanley RB, Hooshmand T. Intercondylar width as a guide to setting up complete denture teeth. J Oral Rehabil 2000; 27:217-26.
  4. Gheriani EL. A new guide for positioning of maxillary posterior denture teeth. J Oral Rehabil 2007;19:535-38.
  5. Engelmeier RL. Complete-denture esthetics. Dent Clin North Am 1996;40:71-84.
  6. Smith BJ. The value of the nose width as an esthetic guide in prosthodontics. J Prosthet Dent 1975;34:562-73.
  7. Grave AM, Becker PJ. Evaluation of the incisive papilla as a guide to anterior tooth position. J Prosthet Dent 1987;57:712-14.
  8. Roraff AR. Arranging artificial teeth according to anatomic landmarks. J Prosthet Dent 1977;38:120-30.
  9. Hasanreisoglu U, Berksun S, Aras K, Arslan I. An analysis of maxillary anterior teeth: facial and dental proportions. J Prosthet Dent 2005;94:530-38.
  10. Varjao FM, Nogueira SS. Nasal width as a guide for the selection of maxillary complete denture anterior teeth in four racial groups. J Prosthodont 2006;15:353-58.
  11. Teranaka S, Shibaji T, Minakuchi S, Uematsu H. Age-related changes in oral mechanosensitivity of symptom-free subjects.J Med Dent Sci 2008;55:61-99.
  12. Lazic B, Tepavcevic B, Keros J, Komar D, Stanicic T, Azinovic Z. Intercondylar distances of the human temporomandibular joints. Coll Antropol 2006;30:37-41.
  13. Irfan Ahmed Shaik et al. The role of inter condylar distance in the posterior teeth arrangement. Pakistan Oral and Dental Journal 2011;32:180-83.

9. / Signature of the candidate
10. / Remarks of the guide
11. / Name and designation( in block letters) of
11.1 Guide / DR. BRIJESH SHETTY
READER
11.2 Signature
11.3 Co-Guide / DR. MANOJ KUMAR AD
11.4 Signature
11.5 Head of the department / PROF. DR. PRANAV MODY
PROFESSOR AND HEAD OF THE DEPARTMENT
11.6 Signature
12. / 12.1 Remarks of the chairman and principal
12.2 Name And Signature of Principal / PROF. DR. MOKSHA NAYAK