GB2237138A

GB2237138A - Model simulating parts of the mouth

Info

Publication number: GB2237138A
Application number: GB9018696A
Authority: GB
Inventors: Pascal Auroy
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-31
Filing date: 1990-08-24
Publication date: 1991-04-24
Anticipated expiration: 2010-08-24
Also published as: DE4027085C2; FR2651353B1; GB2237138B; GB9018696D0; DE4027085A1; FR2651353A1

Abstract

A teaching model of the mouth simulates hard parts consisting of the bony crests 34, 36 and soft parts consisting essentially of the cheeks, the lips 2', 2'', the velum, the tongue 6 and the floor of the mouth. A flexible elastomer in the form of a continuous piece forms all the soft parts and covers the internal surfaces of the hard parts, except where teeth (if any) project from the bony crests. <IMAGE>

Description

1 MODEL SIMULATING PARTS OF THE MOUTH

This invention relates to the field of means for teaching the techniques of the art of dentistry, and more particularly relates to a device, called a teaching model, which simulates the. mouth cavity. A preferred embodiment of the invention is designed in particular for teach.ing the techniques associated with prost-hLeses,, and in particular those relating to total prostheses.

It will be recalled that the taking of an impression of the sides of the mouth cavity (base of the vestibule) is of even greater importance when the mouth is totally without teeth, because it is then a question of preparing a (removable) -orosthesis which will be seated on those parts of the vestibule which adhere to the jaw bones (as opposed to the cheeks and lips) down to the "base of the vestibule", including the median and lateral "brakes" and the ligaments. The cbj ect of taking an impression in the event of a total prosthesis is to define the distribution of the various zones according to their dynamics, namely: a) a zone of attached static mucosa serving as a support surface for the prosthesis, b) a zone in which paraprosthetic organs are enveloped by movable constituent parts which may have a destabilising effect on the prosthesis.

2 ijumerous teaching models which can be used in teaching dentistry have bee,n proposed, and reference may be made to the following published patents, noting hawever that none of these models, also referred to as nannequins when they include the entire head and sometimes the body of thle patient, are not designed for the special purpose considered above.

Thus a patent FR-2 250 171 (DENTAL-EZ) discloses a mannequin simulating a patient subjected to dental care; the mouth of the mannequin may be opened as a result of the flexibility of the material constituting the cheeks and lips. Many parts (the dentures, cheeks, tongue, etc.) are detachable. Such a mannequin is very poorly suited, if at all suited, to the taking of an impression and cannot be used to teach this operation with a view to the such preparation of a prosthesis. Other patents as M-2 483 105 (PIE), FR-2 502 368 (Neumann), FR-2 286 454 (Xialtenbadh), FR-2 289 988 (Kaltenbach), FR-2- 318 470 (Kaltenbach), FR-2 318 471 (Kaltenbach), EP-0 253 457 (Tavor) disclose teaching mannequins also intended for teaching the techniques ofdental care operations: extraction, drilling, etc. These publications give rise to a similar ccnTnent to that made in relation to the first publication cited. Publications FR-2 331 103 (Mandl) and EP-0 195 718 (Cmnissariat etc.) may also be cited, and disclose mannequins whose design shows evidence of greater 3 concern for faithful anatcmical and physiological reproduction,, but which are designed for other purposes than the teaching of dental skills, and as a consequence are also unsuitable for learning the taking of impressions.

Thus it would appear that the designers of the prior art, although they have taken pains to reproduce the major features of the anatomy of the mouth, have not atteffpted to reproduce its texture. Some- others, in Darticular the last cited, have att " ted to reproduce the mechanical qualities of the tissues, but not those of the mouth cavity with its functional characteristics. None have attempted to overcot-tie the breaks in continuity between the different parts constituting their models.

In accordance with this invention a teaching model of the mouth intended for the purposes of pre-clinical teaching, of the type' of model sLnulating parts of the mouth, namely the hard parts formed by the bony crests, and the soft parts consisting essentially of the cheeks, the lips, the velum, the tongue, the floor of the mouth, is characterised in that a flexible elastcx-,ier constituting a continuous phase forms on the one hand all the parts which simulate the soft parts of the mouth and on the other band forms at least the covering of the inner surfaces of the parts of the model simulating the hard Parts of the mouth.

A Preferred embodiment of invention has the object of reproducing, 4 as closely as possible to reality, Che texture and anatwy of the mouth cavity in order that all conventional techniques (opening with a mirror,, taking of impressions, etc.) can be performed. It will be noted that the modeli although initially and principally designed to teach the taking of impressions with a view to total prostheses, may also serve to teach all the in-mouth techniques practigbd by dental surgeons. Another object of the invention is to provide a model of the mouth which can be fitted to certain conventional types of existing mannequins.

Preferably, the marts of the model simulating the hard parts of the mouth each incorporate a rigid body whose inner surf ace has tile shape of the bony crest, apart from the thickness of the said covering. Preferably also, the thickness of the walls simulating the. cheeks, and the hardness of the elastomer, are such that they permit 4 easy manual separation of the hard parts frcxn each other.

As a result of these arrangements the model mky reproduce not only the anatomy of the mouth cavity, but also the texture Of its tissues. and finally places the trainee in a situation similar to reality in which he can record by taking an impression, parts, such as the base of the vestibule, which are of importance for the total prosthesis.

Advantageously, the flexible elastomer will be a silicone polymer and the rigid body will be formed frcn, a rigid alveolar (,foam) material simulating the internal structure of bone, such as high density rigid polyurethane foam. As a result of this latter characteristic the model, having an internal texture comparable to that of bone, may be used for manipulations of a surgical type, for example resection.

In a particular embodiment, the model is generally cylindrical incorporating in its cylindrical face a first orifice forming the mouth and the lips and, in a position substantially diametrically opposite to the first orifice, a second orifice forming the pharynx, while its upper and lower faces, which are substantially circular, each include means for attachment to a mannequin.

Advantageously, the attachment means each consist of a threaded rod of which one end is embedded in a said part of the model simulating the hard marts of the mouth. As a result of this arrangement the model may easily be mounted on an e-xist4Ang conventional mannequin which incorporates means for attachment of parts simulating the jaw bones.

This invention will be better understood and further details Will appear fram the following description of an edbodiment of the invention, given by way of example, and which relates to the figures in the acclying drawing, in which:

Figure 1 is a perspective view of a teaching model of the mouth embodying the invention, seen as a whole from the front; 6 Figure 2 is an axial cross-section along the line of arrow A of the model in the preceding figure; Figure 3 is an axial cross-section along the line of arrow B of the model in Figure 1; Figure 4 is a transverse cross-section along the line of arrow C of the model in Figure 1; and Figure 5 is a transverse cross-section along the line of arrow D of the model in Figure 1.

In Figure 1 a teaching model of the mouth model 1 has a general cylindrical shape and incorporates in its cylindrical face two diametrically opposite orifices: a first orifice 2 having the conformation of the mouth, with its upper lip 2' and lower lip 2", and a second orifice 4, which can be seen through the first, which, for better understanding of the drawing, has been shown substantially open, representing the pharynx. Within the open mouth may be seen tongue 6, and the upper 8 and lower 9 toothless bony crests respectively, these parts reproducing with palate 10 the hard parts of the mouth cavity, the velum 11 being extended by the uvula 12, and, partly, the inner surfaces of cheeks 14, 16.

The cylinder making up the model is cut in Figure 1 by three planes at right angles to each other: two axial planes 21 and 22 and a transverse plane 23 passing substantially through the line 26 joining the lips, or in 7 the vicinity of the centre of the mouth cavity; arrows, A, B, C, D are shown perpendicular to these planes and serve to indicate the clirection of observation in the cross-sections in the following Figures.

In Figures 2 to 5 certain anatomical details described in the previous Figure are indicated by the same reference numbers; distinction is however made between the lower lateral 26 and anterior 28, and upper vestibules 27 and 29 respectively, - lying within the bony crests and the cheeks and lips respectively. To facilitate teaching taking of impressions, it is desirable that these features are satisfactorily accessible for application of the material used for taking the imression.

It should also be noted, particularly from Figures 2 and 3, that the model consists of two components: a first component (flexible elastomer) illustrated by single hatching, a coquonent which is clearly shown by a comparison of Figures 1 and 2 to form a single continuous phase 32, and a second component shown by double hatching, which is shown from a comparative examination of the Figures to form two separate blocks 34 and 36, which are entirely covered by the first component in the anatomical parts of the model. The first component is a flexible elastomer; suitable mechanical characteristics are a Shore hardness in the range 25 to 35, e.g. approximately 30, an elongation on fracture of approximately 600 to 650% and a tear strength of amroximately 20 KNIM; plasticised silicone resins provide a suitable elastomer; 9 Lnvention is not restricted to these embodLments.

DW/BSW/24.8.90 P00017GB.Des CLADE 1.

2.

3.

- Agent's Ref: P00017GB A teaching model of the mouth intended for the purposes of preclinical teaching, of the type of model simulating parts of the mouth, namely hard parts consisting of the bony crests, and the soft parts consisting essentially of the cheeks, the lips, the velum, the tongue and the floor of the mouth, characterised in that a flexible elastamer in the form of a continuous phase forms on the one hand all the parts of the model which simulate the soft parts of the mouth and on the other hand forms at least the covering of the internal surfaces of the parts 0 the model simulating the hard parts of the mouth.

g A model of the mouth according to claim 1, characterised in that the parts of the model simulating hard parts of the mouth each incorporate a rigid body whose =er surface has the shape of the bony crests, apart from the thickness of the said covering.

A model according to claim 2, characterised in that the said rigid body is constructed of a rigid foam material simulating the internal structure of bone.

1 1\ A model according to any one of the foregoing claims characterised in that it is generally cylindrical, bearing in its cylindrical face a first orifice simulating the mouth and the lips and in a position substantially diametrically opposite to the first orifice a second orifice, simulating the pharynx, and that its upper and lower substantially circular faces each include means for attachment to a mannequin A model according to any preceding claim, characterised in that the thickness of the walls simulating the cheeks, and the hardness of thle elastomer are such that they permit C easily manual separation of the hard parts fron, each other.

6.

7.

A model according to any preceding claim characterised in that the flexible elastamer is a silicone polymer.

A model according to claim 4. characterised in that the said rreans of attachment each consist of a threaded rod of which one end is embedded in said parIts of the model simulating the hard parts of the mouth.

Claims

8. A model according to any preceding Claim,, characterised in that the

said hard parts are initially totally without teeth.

11 9. A model according to any of claims 1 to 7, charact erised In that at least one hard part forming at least one tooth ernerges from at least one bony crest through the said flexible covering.

10. A model according to claim 3, characterised in that the material forming the rigid bodies (34, 36) of the hard parts is a high density rigid polyurethane foam.

A teaching model of the mouth substantially as hereinbefore described with, reference to the accompanying drawings.

DW/BT/24.8.90 P00017GB.Cl Published 1991 otIbe Patent Office. State House. 66/71 High Holbom. London WCIR4TP- Further copies maybe obtained from Sales Branch. Unit 6. Nine Mile Point Cwmrclinfach. Cross Keys, Newport. NPI 7HZ. Printed by Multiplex techniques ltd, St Mary Cray. Kent.