Seminar on vertical jaw relation in complete denture PDF

Preview

Summary

Seminar on vertical jaw relation in complete denture is an important topic in Prosthodontics as it is the important step in construction of complete denture.Its steps recording method a described....

Description

CENTURY INTERNATIONAL INSTITUTE OF DENTAL SCIENCES AND RESEARCH CENTRE

Department of Prosthodontics

SEMINAR ON

VERTICAL JAW RELATION GUIDED BY

SUBMITTED BY

Dr. SHILPA SHIRLAL

ASWATHY S

Dr. ABDUL RASHID

REG NO. 160020319

Dr. RAHUL RAMESH

FINAL YEAR PART II 1

Dr. LOVEBIN SIMON

2

CENTURY INTERNATIONAL INSTITUTE OF DENTAL SCIENCES AND RESEARCH CENTRE

CERTIFICATE This is to certify that the seminar titled ………………………………..is

a

bonafied

work

……………………………………………………………………………………….... done

by

……………………………………………………………………Reg.no

……………………………………………… in the subject of Prosthodontics prescribed by the university for the final year part 1 BDS course during the year 20……..to 20……….. and the seminar is found to be ………………

Date:

Department of Prosthodontics

Staff signature:

External examiner

Internal examiner

3

CONTENTS • • •

INTRODUCTION DEFINITION CLASSIFICATION VERTICAL JAW RELATION AT REST Methods to measure VDR VERTICAL JAW RELATION AT OCCLUSION Methods to measure VDO • EFFECTS OF ALTERED VERTICAL DIMENSION • CONCLUSION • REFERENCE

INTRODUCTION Recording jaw relations in the treatment of edentulous patients aims at facilitating the adaptation of the complete denture to the masticatory system to give them an optional and comfortable function. 4

To achieve this goal, the recording must include an approximate vertical dimension of occlusion , stable occlusal contacts in harmony with the existing TMJ and masticatory muscle functions. Classification of jaw relation • Orientation jaw relation • Vertical jaw relation • Horizontal jaw relation Definition The vertical jaw relation or vertical dimension is defined as the length of the face as determined by the amount of separation of the jaws under specified conditions. The distance between two selected anatomic or marked points (usually one on the tip of the nose and the other upon the chin) , one on a fixed and one on a movable member : (vertical dimension , GTP VIII)

CLASSIFICATION • Vertical dimension at rest • Vertical dimension of occlusion or occlusal vertical dimension • Vertical dimension in other positions of mandible

Vertical dimension at rest Definition The length of the face when the mandible is in rest position. (GPT) It is essential to record the vertical dimension at rest as it acts as a reference point during recording the vertical dimension at occlusion. The VD at rest should be recorded at the physiological rest position of the mandible. Physiological rest position • The postural position of the mandible when an individual is resting comfortably in an upright position and the associated muscles are in a state of minimal contractual activity. • Significance of physiological rest position • Bone to bone relation • Fairly constant throughout the life in absence of any pathosis • Can be recorded and measured within acceptable limits.. • Used to determine the VDO • The Vertical distance between the teeth at the rest position is termed as freeway space or interocclusal rest space. • In the dentulous individual this space varies from 1 to 10mm. Average = 2 – 4 mm • VD at occlusion = VD at rest – 2 to 4mm METHODS OF DETERMINING VERTICAL DIMENTION AT REST 5

Factors influence the rest position 1. 2. 3. 4. 5.

The posture of the patient A relaxed patient Neuromuscular disturbance Duration Use of several methods METHODS

Facial measurements Two marks are placed : on the tip of the nose & on the chin directly below the nose marking Measured using : divider, scale , willis gauge or dakometer. The following methods are used to make the patient assume the postural rest position. 1. Swallowing : the patient is instructed to drop the shoulder , wipe his/her lips with tongue, swallow and close the mouth. 2. Tactile sense : the patient is instructed to open the mouth wide until strain is felt in the muscle they are then asked to close the mouth slowly until they feel comfortable and relaxed. Measurement is made in this position. 3. Phonetics: the patient is instructed to repeatedly say words that contain the latter M. the lips meet when this is pronounced and the patient is instructed to stop all jaw movements when this happens. Measurement is made between the two points of reference.

4. Facial expression : a) lips are even anteroposteriorly with slight contact b) Skin around the eyes and chins is relaxed c) Relaxation around the nostrils with unobstructed breathing.

2 . Measurement of anatomic landmarks

6

Willis guide: the distance from the pupil of the eye to the rima oris should be equal to the distance from the anterior nasal spine to the lower border of the mandible , when the mandible is in its physiologic rest position. METHODS OF RECORDING VERTICAL DIMENSION OF OCCLUSION Physiologic methods 1.Niswonger’s methods( physiologic rest position) The camper’s plane or the ala-tragus line and the inter-pupilliary line are the hallmarks of this procedure. commonly used method. • An upright position leads the planes to be parallel to the floor. • The marks are made on the tip of the nose and the most stable area on the chin..

The distance between the marks is recorded after the patient is asked to swallow and relax. • Subsequently occlusal rims are fabricated so that when they occlude, have a measurement 1/8” less than the original measurement. • This 1/8” average gives a freeway space of 2 to 4 mm. VD at occlusion = VD at rest – freeway space (2-4mm) The lower rim is adjusted till the facial measurement in occlusion is 2-4 mmm less than that in rest position. 2. Swallowing threshold The maxillary and mandibular teeth come into light contact at the beginning of the swallowing cycle is used as a guide to determine occlusal vertical dimension • Building a cone of soft wax on the lower denture base in such a way that it contacts the upper occlusion rim when the jaws are open. • Flow of saliva is stimulated by a piece of chocolate • The lower wax cone is softened and the patient is asked to repeat the action of swallowing . This will gradually reduce the height of the wax cone until it just touches the upper rim while swallowing.

7

3.Phonetics: 1, Silverman‟s closest speaking space 2.The „F‟ or ;V‟ and „S‟ speaking anterior tooth relation. SILVERMANS CLOSEST SPEAKING SPACE According to him,it measures the VD when mandible is in function. When sounds like Ch,S,J are pronounced,the upper and lower teeth reach their closest relation without contact.This minimal amount of space between the upper and lower teeth in this position is called Silverman closest speaking space.

Increases freeway space indicates an inadequate vertical dimension at occlusion.Adecrease in the closest speaking space will indicate an excessive vertical dimension at occlusion.Contact of the incisal edges during speech also indicates an excessive vertical dimension at occlusion. Difference between freeway space and closest speaking spaces are; a) b) c)

closest speaking space measured during phonation While Freeway space measured during rest Patient cooperation not required in closest speaking space and it required in freeway space Average value for Closest speaking space is 3-4 mm and for freeway space is 0 -10 mm

F OR V AND S METHOD(POUND AND MURREL) In this method,incisal guidance is established by arranging the anterior teeth on the occlusal rim before recording the VDO.The anterior teeth are arranged on the occlusal rim and modified in the patients mouth based on the pronounciation of certain alphabets. The position of the anterior teeth is determined by the position of the mandible when the patient pronounces word begin withh „S‟. 8

4. Neuromuscular perception Central bearing device ( tactile sense) The central bearing screw\central bearing plate apparatus is used.The central bearing screw fits into the depression of the central bearing plate.The central bearing plate is attached to the maxillary occlusal rim and the central bearing screw is fixed to the mandibular occlusal rim Power point (maximum biting force) Boos demonstrated that the maximum biting force in ana individual is registered at VDR. The method involved attaching a pressure indicating gauge which displayed the biting pressure,to a central bearing plate and screw on the occlusal rims.The device is called bimeter and the maximum biting point is termed as power point. Boos stated that the VDO is the rest position or maximum force minus 2mm. 5. Aesthetics • Skin: If the vertical dimension is too highthe skin of the cheeks will appear very streched and the nasolabial fold will be obliterated,the nasolabial angle will be increased. The age of the patient also influence the appearance of the skin. • Lips: The contour and the fullness of the lips affected the thickness of the labial flange.The occlusal rim should be contoured to aid the lip support.A flattened appearance of lips indicate lack of lip support.

b) Mechanical methods These methods are called so because they do not require any functional movement.They are measured using simple mechanical devices. 1.Ridge relation:

“The positional relationship of the mandibular ridge to the maxillary ridge”—GPT

1.Distance from the incisive papilla to mandibular incisors. 2.Parallelism of ridges.

9

Distance from the incisive papilla to mandibular incisors The distance of the papilla to the maxillay incisor edge is 6mm. Usually the vertical overlap between the upper incisor and lower incisors is 2mm(overbite). Hence the distance between the incisive papilla and the lower incisors will be appro 4mm.Based on This value,vdo can be calculated.

Ridge parallelism The mandible of the patient is adjusted to be parallel to the maxilla. This position associated with a 5 degree opening of the jaw in the TMJ gives a correct amount of jaw separation. In patients where the upper and lower teeth are extracted togather,the upper and lower ridges will be parallel because the length of the clinical crown of the opposing anterior and posterior teeth will be equal. 2)Pre extraction records • Profile photographs: Photographs are made before extraction. They should taken in maximum occlusion as the patient can easily maintain this position during photographic procedures. The photographs should enlarged to the actual size of the patient and the distance between the anatomical landmarks should be measured and compared with that of the patient to avoid errors.

•

Profile silhouettes: An accurate silhouettes is made with cardboard or contoured with wire using patients photograph.The silhouette is taken from a pre-extraction photograph it shoes VD at rest,.

10

•

Radiography: Cephalometric profile radiographs and radiographs of the condylar fossa are used .

•

Articulated casts: Casts are mounted before extraction and following the recording of the edentulous jaw relation in centric relation. The interarch distance is compared between the two casts to verify accuracy of vertical dimension.

Effects of increased vertical dimension • Discomfort to the patient. • Trauma and pain under the basal seat areas of dentures: The jarring effect of the teeth coming into contact sooner than expected may not only cause discomfort but in most cases it will also cause pain owing to the bruising of the mucosa • Clicking sound : When occlusal vertical dimensions is increased, opposing cusp will frequently meet each other producing an embarrassing clicking sound. • Appearance: Elongated appearance and at rest the lips are parted; Patient tries to close them together producing an expression of strain. • Bone resorption : Due to continuous pressure on the residual alveolar ridge it undergoes rapid resorption. • Loss of retention and stability :Leverages are caused due to premature contacts, further loss of ridge leads to loss of retention and stability. • Generalized Hyperemia :Space between the teeth is essential when mandible is at rest. If no space is present between the teeth in denture, it may result in generalized hyperemia.

Effects of decreased vertical relation • Inefficiency : Pressure which is possible to exert with teeth in contact decreases considerably with over closure because the muscles of mastication acting from attachments have been brought closer together. • Cheek, Tongue and lip biting : Loss of muscular tone, as well as reduced vertical height, the flabby cheek tend to become trapped between the teeth during mastication. • Appearance (Denture look) : The general effect of over closure on facial appearance is of increased age because of closure approximation of nose to chin, soft tissue sag and fall in and the lines on the face are deepened. 11

• Angular cheilitis (perleche): due to folding of the corner of the mouth • Pain in temporomandibular joint : Over closure may cause pain in temporomandibular joint probably due to strain of the joint and associated ligaments.

Costen’s syndrome (Mild catarrhal deafness): There will be a tendency to push the tongue towards the throat, adjacent tissues will be displaced, which may in turn result in occlusion of Eustachian tubes which would interfere with function of ear which may cause ear discomfort and impaired hearing. • Tinnitus or snapping noises in joint. • Tenderness to palpation overT.M.J. • Dryness of the mouth. • Various neurologic symptoms such as burning or picking sensation of the tongue.

CONCLUSION • Many methods of assessing and recording vertical jaw relations in edentulous patients have been presented and evaluated. • Since there is no precise scientific method of determining the correct vertical relations, the registration of vertical relations depends upon the clinical experience and judgment of the dental surgeon himself.

12

REFERENCE • •

Textbook Of Prosthodontics-Nallaswamy 2nd Edition Textbook Of Prosthodontics-V.Rangarajan

13...