口腔外文图书atlas of removable orthodontic appliances 2nd ed_W

1、An Atlas of Removable Orthodontic AppliancesSecond editionGORDON C. DICKSONB Ch U (Leeds).F D S, D Orth, R C S (Eng)Orthodontic Consultant to the Portsmouth Hospital GroupALBERT E. WHEATLYF B I S T. M O T AChief Technician, Dental Wing, Royal Portsmouth HospitalTurkish PowerOrTHoTaMiNe Tarafndan Yen

2、iden Dzenlenmitirby OrTHoTaMiNeCONTENTSPreface 8The Materials 10The Tools 12Anodic Polishing Apparatus 14Wire Bending 16 Construction of the AdamsClasp 24Variations of the Adams Clasp 38The Adams Clasp forExtraoral Traction 40Alternative Clasps 42The Effect of a Finger-spring 44Resistance to Displac

3、ement46Resistance to Tooth Move- ment (Anchorage)50The Simple CantileverSpring 56Boxing-in 62Paired Cantilever Springs 64Double Cantilever Springs66The Kinked Cantilever Spring 68Premolar RetractionSprings 70Palatal Movement of Premolars and Molars 72Mesial and Distal Move- ment of Incisors 74Latera

4、l Movement of Canutes 76Labial Movement ofCanines 78 Distal Movement ofCanines 80 The Labial CanineRetractor 82 Sleeving the CanineRetractor 84 Adjusting the Retractor86The Cut-and-bend Spring 88Palatal Movement ofLateral Incisors 90 The Sved Bile Plate 92The Effect of a Bite Plane 94 The Labial Arc

5、h 96The Labial Arch as aRetainer 98The Roberts Retractor 100Construction of theRoberts Retractor 102Apron Springs 104Variations of, andAdditions to, Labial Arches 106More Variations of the Labial Arch 108by OrTHoTaMiNeLabial Movement of Upper Incisors (Schwarz) 124Rotation of a Single Tooth 126Rotat

6、ion by Contra-actingThe Inverted Labial Arch 110 Space-maintainers 112Expansion Screws 114 Asymmetrical RadialExpansion 120 Distal Movement ofBuccal Segment (Schwarz) 122Springs 132Extraoral Traction 134Extraoral Anchorage 138 Buccal Movement ofPremolars 144Incisor Elongation 146The Andresen Applian

7、ce 150 The Oral Screen 156THE MATERIAL Sby OrTHoTaMiNeStainless steel wireThis must be HAR D POLISHED British Standard No. 3507 (1962) Hard drawn, unpolished wire isinferior and should not be used. It is specified in metric diameter measurement and the correct sizes for each appliance will be found

8、on the text-page opposite each appliance.Stainless steel tubeTubing may be HARD POLISHED or BRIGH TANNEALED . It is usually specified by internal diameter only, the thickness of the tube wall being appropriate for orthodontic purposes.Stainless steel tapeAs used in orthodontics, tape is supplied SOF

9、T, POLISHED ONE SIDE, the other side being matt to facilitate adhesion of cement.AcrylicresinCLEAR acrylic denture base is used for the constructionof all appliances, chiefly as it allows blanching of the tissues over pressure areas to be detected visually, and alsobecause it shows more clearly when

10、 food debris has collected around the springs.10by OrTHoTaMiNeTHE TOOLSby OrTHoTaMiNeFor the vast majority of removable appliances lour instruments only are required.1. Universal pliersThese are used for all wire bending with the exception of the formation of loops or coils. The beaks are stout, tap

11、ered and rectangular in section, and meet only at the tips. Beaks which are in contact throughout their length tend to eject a large diameter wire (Inset A) . The beaks of Universal pliers are parallel when gripping the wire (Inset B). When the pliers become worn they should be resharpened, maintain

12、ing a beak size of 1 mm square at each tip and cutting back so that a 0. 6mm wire can be passed between them at the base when the pliers are closed.2. Loop-formingpliersThese have round, tapered beaks around which loops or coils of various sizes may be formed.3. Wire cuttersThe diagonal type of wire

13、 cutter is used and must have hardened blades.4. Hollow-choppliersUsed for making bends in wires which are already anchored at both ends in an appliance, these pliers have one beak round and the other hollowed so as to wrap round its opponent. They therefore exert pressure simultaneously at three po

14、ints on the wire. They may also be used for increasing the bend in the labial canine retraction spring shown on page 82.12by OrTHoTaMiNeby OrTHoTaMiNeANODI C POLISHIN G APPARATUSThe anodic polishing bath illustrated is used for reducing the diameter of stainless steel wire where a variation in thick

15、ness is required.In use the positive pole is connected to the wire to be thinned using a crocodile clip and so forming the anode. The cathode (negative pole) is formed of a stainless steel plate.A current of 8 amps at 20 volts is suitable for most purposes. A variable resistance is unnecessary as th

16、e current can be varied by moving the anode nearer to , or further f rom , the cathode.14by OrTHoTaMiNeWIRE BENDING, 1by OrTHoTaMiNeSoft curvesFor labial arches of all kinds, smooth curves are formed by holding one end of the wire firmly on one hand and forming a curve with the thumb of the other ha

17、nd. The thumb is then drawn firmly along the wire, creating a smooth curve of large radius. Repeating the process will increase the curve to any desired extent. Avoidance of the use of pliers will ensure a bend without kinks.16by OrTHoTaMiNeby OrTHoTaMiNeWIRE BENDING, 2Right angle bendsHolding ihc w

18、ire at right angles to the long axis of the pliers the wire is held against the thumb and the bend made by pressing the thumb f i rmly on the wire as closely as possible to the plier beak. (For clarity in the illustration the thumb is shown a little too fat back.)18by OrTHoTaMiNeby OrTHoTaMiNeWIRE B

19、ENDING, 3Acute bendsThese are formed by holding the wire along the beaks of the pliers and bending firmly back with the forefinger.20by OrTHoTaMiNeby OrTHoTaMiNeWIRE BENDING, 4Small radius bendsHolding the wire at right angles to the plier beak the wire is bent with the thumb placed a short distance

20、 away from the bend.22by OrTHoTaMiNeby OrTHoTaMiNeCONSTRUCTION OF THE ADAMS CLASP, 1If desired the clasp may be pre-lightened by trimming the plaster tooth as shown.24by OrTHoTaMiNeby OrTHoTaMiNeCONSTRUCTION OF THE ADAMS CLASP, 2Forming the bridgeA careful estimate is made by eye of the mesiodistal

21、width of the tooth. A piece of 0.7mm wire about 12cm (5in) long is held at right angles to the pliers at a point where the width of their beaks is equal to about two- thirds of the tooth-width.Using the thumb and forefinger the two ends, which should be of equal length, are pushed backwards as far a

22、s the plier beaks will permit. The tips of the beaks are then used to increase these bends to slightly less than a right angle so that the ends of the wire cross each other.A26by OrTHoTaMiNeby OrTHoTaMiNeCONSTRUCTION OF THE ADAMS CLASP, 3Forming the first arrowheadAs the length of the arrowhead will

23、 vary according to the height of the crown of the tooth to be clasped, this is first estimated and a bend made in a position which will place the bridge about half-way up the crown. This is made in two stages.First stage: a right angle bend as shown opposite.28by OrTHoTaMiNeby OrTHoTaMiNeCONSTRUCTIO

24、N OF THE ADAMS CLASP, 4Forming the first arrowhead (contd.)Second stage: this bend is increased by bending thc wire backwards over the beak-lips (as on page 21).30Iby OrTHoTaMiNeby OrTHoTaMiNeCONSTRUCTION OF THE ADAMS CLASP, 5Forming the second arrowheadHolding the clasp in the position shown, the s

25、econd arrowhead is formed in the same way as the first (Inset D). Each arrowhead is then squeezed lightly between the plier beaks (Inset E) to increase the sharpness of the arrowheads. This should not be carried to excess or the wire will later break at this point.32by OrTHoTaMiNeby OrTHoTaMiNeCONST

26、RUCTION OF THE ADAMS CLASP, 6Aligning the arrowheadsEach arrowhead in turn is held in the pliers as shown and bent until the plane of the arrowhead lies at about 45to the bridge.34by OrTHoTaMiNeby OrTHoTaMiNeCONSTRUCTION OF THE ADAM S CLASP, 7Forming the togsA right angle bend is formed at a level s

27、lightly below the bridge by holding the arrowhead as shown (the thumb has been withdrawn for clarity).Over the contact point of the tooth a second, shallow bend is formed and the clasp presented to the tooth . It is essential that the bridge should not lie in contact with the buccal surface of the t

28、ooth and these last bends should be increased if necessary to achieve this.Finally the tags are completed by bending over the palate and the ends turned under and forced int o the plaster (page 25). The tags should lie out of contact with the plaster so that they will later be completely surrounded

29、by acrylic material.When the clasp has become slack in wear it is lightened by increasing the bend in the tag at a pointimmediately overlying the contact point of the tooth.36by OrTHoTaMiNeby OrTHoTaMiNeVARIATIONS OF THE ADAMS CLASPThe auxiliary claspA. A second arrowhead is formed as shown and unit

30、ed to the bridge of the main clasp using hard solder and stain less steel flux. The minimum amount of heat should be used and the solder should not be heavily polished, otherwise it will be removed entirely from the surface and will have no mechanical hold. Soldering may be carried out either on the

31、 model or after processing.The incisor claspB. A single incisor can be clasped as shown in the left-hand diagram, the arrowheads resting against the mesiolabial and distolabial aspects of the tooth.C. Two central incisors can be clasped as shown.MaterialsAll clasps are made with 0.7mm wire.by OrTHoT

32、aMiNeby OrTHoTaMiNeTHE ADAMS CLASP FOR EXTRAORAL TRACTIONWhere upper first premolars have been extracted an auxiliary arrowhead may be used (page 38) but this is not easy to adjust. A variation is to place arrowheads on the mesial of the second premolar and the distal of the molar as in diagram AThi

33、s form of retention is of value in extraoraI anchorage (page 138) but for convenience of accom modating adjustment loops of friction stops, ii is con- venient to offset the tubing in which the arch fits as shown in diagrams B and C.ConstructionAdams clasps Extraoral arch: Tubing.Attachment of tubing

34、0.7mm stainless steel wire 1.25mm wire1.25 internal diameter stain- less steelStrapping with 2.0 x 0.1 mm stainless steel tape or binding with soft wire and soldering40by OrTHoTaMiNeby OrTHoTaMiNeALTERNATIV E CLASPSBoth the clasps illustrated use the same principle as the Adams clasp i.e. retention

35、from the undercut areas present on the mesiobuccal and distobuccal corners of the molar teeth.Theball-ended claspA, B.Prefabricated ball-ended wires are bent in the for m shown and sprung int o the angular undercuts. Alterna- tively, stainless steel wire may be bent int o a sharp, closed curve and c

36、ut of f short to replace the balls.The Duyzings claspC.Tw o stainless steel wires are bent over the maximumcontour of the toot h f ro m mesial and distal aspects and then curved back upon themselves so that the lower part lies below the maximu m contour and the ends are sprung into the undercuts.Mat

37、erialsBoth clasps are made from 0.7mm stainless steel wire.42by OrTHoTaMiNeby OrTHoTaMiNeTHE EFFECT OF A FINGERSPRINGA. On the toothOwing to the tact that the palatal surface of an upper incisor tooth has a downward and forward slope, it acts as an inclined plane and the horizontal forward thrust of

38、 a fingerspring is convened into an upward and forward thrust. In the case illustrated in diagram A the palatal surface is at 60c to the horizontal and the thrust may be divided, as shown by the length of the lines, into an upward component of two units and a forward com ponent of three unitsB. On t

39、he applianceReciprocally, in accordance with Newtons Third Law of Motion, the tooth exerts a backward and downward force on the spring, as represented in diagram B. It follows that the clasps on such an appliance must be placed, not only to resist the backward thrust of the tooth, but also to resist

40、 a considerable downward dis- placing force.44by OrTHoTaMiNeby OrTHoTaMiNeRESISTANCE TO DISPLACEMENT, 1Downward displacementof anupperapplianceIn diagram A a labial arch is used to retract upper incisors. There is a backward force on the incisor com - bined with a downward force due to the inclined

41、plane effect. Reciprocally a forward and upward force is exerted on the appliance. Only the forward force is resisted by the clasped molar tooth (black) while the palate acts as a fulcrum and receives the upward force.In diagram B a palatally placed spring is moving the incisors forward. The incline

42、d plane of the tooth here exerts a backward and downward force on the anterior part of the appliance, which would pivot on the clasped first molar (black). Additional clasps must be placed on the first premolars (black) to produce an upward com- ponent and prevent displacement.46by OrTHoTaMiNeby OrT

43、HoTaMiNeRESISTANCE TO DISPLACEMENT, 2A lingually placed spring exerts a forward force on the sloping surfaces of the lower incisors and consequently receives an upward and backward thrust from the teeth.A clasp placed on the first premolar (black) acts as afulcrum about which the appliance will pivo

44、t, t i l l ing the posterior end downwards.The downward thrust is countered by placing an occlusal rest on the second molar tooth (black), so giving an upward thrust and stabilizing the appliance. (If the second molar is uncrupted the occlusal rest may be placed on the distal portion of the first mo

45、lar )48by OrTHoTaMiNeby OrTHoTaMiNeRESISTANCE TO TOOTH MOVEMENT (ANCHORAGE), 1Retraction of labial segmentA. If, following extraction of first premolars, an attempt is made to retract the entire labial segment at once, the only teeth resisting this movement are the fourremaining posterior teeth. It

46、may be expected, therefore, that the forward movement of these teeth will exceed the backward movement of the incisors and canines.B. When the canines alone are retracted the incisors take part in the anchorage. Only two teeth are being moved against an anchorage of eight teeth. Although these will

47、inevitably undergo some slight forward movement, this will be small compared with the distal movement of the canines.C. The canines now being in the fully corrected positions, an appliance designed to retract only the four incisors can utilize all the six remaining teeth as anchorage, so producing a

48、 major movement of the incisors with little further forward movement of these teeth.50by OrTHoTaMiNeby OrTHoTaMiNeRESISTANCE TO TOOTH MOVEMENT (ANCHORAGE), 2D. Distal movement of a buccal segmentFollowing extraction of an upper second molar the first molar and both premolars of that side may be move

49、d distally, three teeth moving against an anchorage of nine teeth. The labially displaced canine is not included in either part of the appliance.52by OrTHoTaMiNeby OrTHoTaMiNeRESISTANCE TO TOOTH MOVEMENT (ANCHORAGE) , 3The properapplicationof extraoral tractionAAtthe commencement of extraoral tracti

50、on designed to move ail the upper teeth posteriorly following extraction of second molars, the labial arch is bent away from the labial segment. All the extraoral force is then directed against the cheek teeth, which will move distally.B. At the completion of distal movement of the cheek teeth the l

51、abial arch is bent back to rest against the labial segment, not to press against it. When the extra- oral force is applied the labial segment will move posteriorly. At the next visit the labial arch will be seen to stand awayfrom the incisors Until the extraoral force is applied. It can then once mo

52、re be adjusted to rest against the anterior teeth.C. If the labial arch is adjusted (via the U-loops) to press against the incisors, application of the extraoral force will increase pressure on the incisors, but will not release the forward force on the cheek teeth produced by the tension in the U-loops. The anchorage problemgenerated within the appliance is not removed by the application of extraoral force.54by OrTHoTaMiNeby OrTHoTaMiNeTHE S