THE FIRST STAGE OF COMPREHENSIVE TREATMENT: ALIGNMENT AND LEVELING 綜合治療的第一階段:對齊和調平
OUTLINE 大綱
GOALS OF THE FIRST STAGE OF TREATMENT ALIGNMENT 治療調整第一階段的目標Principles in the Choice of Alignment Arches 選擇對齊拱門的原則Properties of Alignment Archwires Alignment Archwires 的屬性Alignment of Symmetric Crowding 對稱擁擠的對齊Alignment in Premolar Extraction Situations 前磨牙拔除情況下的對準Alignment in Nonextraction Situations 非提取情況下的對齊CROSSBITE CORRECTION 反咬合校正Individual Teeth Displaced Into Anterior Crossbite 單顆牙齒移位到前反咬合Transverse Maxillary Expansion by Opening the Midpalatal Suture 通過打開齶中縫合線進行上頜橫擴張Correction of Dental Posterior Crossbites 矯正牙科后牙反咬合IMPACTED OR UNERUPTED TEETH 阻生牙或未萌出的牙齒Surgical Exposure 手術暴露Method of Attachment 附件方法Mechanical Approaches for Aligning Unerupted Teeth 對齊未萌出牙齒的機械方法Unerupted/Impacted Lower Second Molars 未萌出/嵌塞的下第二磨牙DIASTEMA CLOSURE DIASTEMA 閉合LEVELING 水準Leveling by Extrusion (Relative Intrusion) 透過拉伸調平 (相對侵入)Leveling by Intrusion 通過入侵調平
TThe idea of dividing comprehensive orthodontic treatment into stages, which makes it easier to discuss technique, was emphasized by Raymond Begg. ^(1){ }^{1} The three major stages he proposed are used to organize this section because they still apply reasonably well to treatment with the modern edgewise appliance that now is used almost universally. These stages are: (1) alignment and leveling, Raymond Begg 強調了將綜合正畸治療分為幾個階段的想法,這樣更容易討論技術。 ^(1){ }^{1} 他提出的三個主要階段用於組織本節,因為它們仍然相當適用於現在幾乎普遍使用的現代 edgewise 設備的治療。這些階段是:(1) 對齊和調平,
(2) correction of molar relationship and space closure, and (2) 糾正磨牙關係和間隙閉合,以及
(3) finishing. The latter two stages are covered in Chapters (3) 精加工。后兩個階段在章節中介紹
15 and 16, respectively. Not every patient will require the steps of each treatment stage, but whatever the technique, it is likely that both the archwires and the way they are utilized will be changed at the various stages. Even with the most cleverly preadjusted edgewise appliance, a change of archwires will be needed before the finishing stage is reached, and some archwire adjustments are quite likely to be necessary in finishing. 分別為 15 和 16。並非每個患者都需要每個治療階段的步驟,但無論採用何種技術,弓絲及其使用方式都可能在各個階段發生變化。即使使用最巧妙的預調整邊緣設備,在達到精加工階段之前也需要更換弓絲,並且在精加工時很可能需要進行一些弓絲調整。
GOALS OF THE FIRST STAGE OF TREATMENT 第一階段治療的目標
Treatment for any patient should be undertaken only after a thorough analysis of the patient’s problems, the preparation of a treatment plan to maximize benefit for that patient, and the development of a sequence of orthodontic treatment steps (archwires and their activation [i.e., mechanotherapy]) to produce the desired result. The diagnostic and treatment planning procedure outlined in Chapters 6 and 7, which culminates in an outline of the steps in treatment, is recommended. 只有在徹底分析患者的問題、制定治療計劃以使患者受益最大化以及制定一系列正畸治療步驟(弓絲及其啟動 [即機械療法])以產生預期結果后,才應對任何患者進行治療。推薦第 6 章和第 7 章中概述的診斷和治療計劃程式,最終概述了治療步驟。
In almost all patients with malocclusion, at least some teeth are initially malaligned. The great majority also have either excessive overbite, resulting from some combination of an excessive curve of Spee in the lower arch and an absent or reverse curve of Spee in the upper arch, or (less frequently) anterior open bite with excessive curve of Spee in the upper arch and little or none in the lower arch. The goals of the first phase of treatment are to bring the teeth into alignment and correct vertical discrepancies by leveling out the arches. In this form, however, neither goal is stated clearly enough. For proper alignment, it is necessary not only to 在幾乎所有咬合不正患者中,至少有一些牙齒最初排列不齊。絕大多數也有過度的覆合,這是由於下弓 Spee 曲線過大和上弓 Spee 曲線缺失或反向彎曲的某種組合,或者(不太常見)前開牙合,上弓 Spee 曲線過多,下弓很少或沒有。第一階段治療的目標是使牙齒對齊並通過平整牙弓來糾正垂直差異。然而,在這種形式中,兩個目標都沒有足夠明確地陳述。為了正確對齊,不僅需要
bring malposed teeth into the arch but also to specify and control the anteroposterior position of incisors, the width of the arches posteriorly, and the form of the dental arches. Similarly, in leveling the arch, it is necessary to determine and control whether the leveling occurs by elongation of posterior teeth, intrusion of incisors, or some specific combination of the two. The form of the dental arches obviously varies between individuals. Although the orthodontist has some latitude in changing arch form and indeed must do so in at least one arch if the upper and lower arch are not compatible initially, more stable results are achieved when the patient’s original arch form is preserved during orthodontic treatment (see Chapter 9 for a discussion of arch form and archwire shape). The light resilient archwires used in the first stage of treatment need not be shaped to the patient’s arch form as carefully as the heavier archwires used later in treatment, but from the beginning, the archwires should reflect each individual’s arch form. If preformed archwires are used for alignment (as is usually the case because superelastic nickel-titanium [A-NiTi] wires must be preformed), the appropriate large, medium, or small arch form should be selected. 將錯位的牙齒帶入牙弓,但也要指定和控制門牙的前後位置、牙弓的后寬和牙弓的形狀。同樣,在找平牙弓時,有必要確定和控制找平是通過後牙伸長、門牙侵入還是兩者的某種特定組合而發生的。牙弓的形狀顯然因人而異。儘管正畸醫生在改變牙弓形式方面有一定的自由度,如果上下牙弓最初不相容,確實必須在至少一個牙弓中這樣做,但如果在正畸治療期間保留患者的原始牙弓形狀,則可以獲得更穩定的結果(有關牙弓形式和弓絲形狀的討論,請參見第 9 章)。第一階段治療中使用的輕質彈性弓絲不需要像治療後期使用的較重的弓絲那樣仔細地根據患者的弓形塑造,但從一開始,弓絲就應該反映每個人的弓形。如果使用預製弓絲進行對齊(通常是這種情況,因為必須預製超彈性鎳鈦 [A-NiTi] 線),則應選擇合適的大、中或小弓形。
Because the orthodontic mechanotherapy will be different, depending on exactly how alignment and leveling are to be accomplished, it is extremely important to clearly visualize the desired position of the teeth at the end of each stage of treatment before beginning that stage. Computer programs now exist to make this easier (Figure 14-1), but it is the thought process that counts. For instance, the best alignment procedures will result in incisors that are far too protrusive if the extractions necessary to prevent protrusion were not part of the plan. Similarly, unless leveling by 由於正畸機械療法會有所不同,具體取決於如何完成對齊和調平,因此在開始該階段之前,在每個治療階段結束時清楚地可視化牙齒的理想位置非常重要。現在存在計算機程式來簡化這一過程(圖 14-1),但重要的是思考過程。例如,如果防止突出所必需的拔牙不是計劃的一部分,那麼最好的對齊程式將導致門牙過於突出。同樣,除非
intrusion is planned when it is needed, the appropriate mechanics are not likely to be selected. 需要時計劃入侵,不太可能選擇合適的機制。
In this and the subsequent chapters, it is expected that the appropriate goals for an individual patient have been clearly stated, and the discussion here concerns only the treatment techniques necessary to achieve those goals. Orthodontic treatment without specific goals can be an excellent illustration of the old adage, “If you don’t know where you’re going, it doesn’t matter which road you take.” 在本章和後續章節中,預計已經明確規定了個體患者的適當目標,此處的討論僅涉及實現這些目標所需的治療技術。沒有特定目標的正畸治療可以很好地說明那句古老的格言,“如果你不知道你要去哪裡,你走哪條路都沒關係。
ALIGNMENT 對準
Principles in the Choice of Alignment Arches 選擇對齊拱門的原則
In nearly every patient with malaligned teeth, the root apices are closer to the normal position than the crowns, because malalignment almost always develops as the eruption paths of teeth are deflected. Putting it another way, a tooth bud occasionally develops in the wrong place, but the root apices are likely to be reasonably close to their correct positions even though the crowns have been displaced as the teeth erupted. The major exceptions to this guideline are the displacement of all tissues in an area, most often seen as a result of cleft palate surgery, and the severe tipping from lip pressure that displaces maxillary central incisors in Class II, division 2 malocclusion. To bring teeth into alignment, a combination of labiolingual and mesiodistal tipping guided by an archwire is needed, but root movement usually is not. Several important consequences for orthodontic mechanotherapy follow from this: 在幾乎每個牙齒排列不良的患者中,根尖比牙冠更接近正常位置,因為排列不良幾乎總是隨著牙齒的萌出路徑偏轉而發展。換句話說,牙芽偶爾會在錯誤的位置發育,但根尖很可能合理地接近它們的正確位置,即使牙冠在牙齒萌出時已經移位。該指南的主要例外是某個區域內所有組織移位,最常見的是齶裂手術的結果,以及 II 類 2 分區咬合不正中,唇壓導致上頜中切牙移位。為了使牙齒對齊,需要在弓絲引導下結合唇舌和近遠遠端傾斜,但通常不需要。由此得出的正畸機械療法的幾個重要後果:
FIGURE 14-1 Digitized dental casts (here in the Ortho-CAD system) can be used quite effectively to calculate the amount of space needed to align the teeth, show the probable outcome of alignment, and calculate the arch length needed. A, Pretreatment occlusal view of the lower arch, with a line showing the amount of space required for alignment. B, Virtual appliance in place. 圖 14-1 數位化的牙科模型(在 Ortho-CAD 系統中)可以非常有效地用於計算對齊牙齒所需的空間量,顯示對齊的可能結果,並計算所需的牙弓長度。A,下牙弓的治療前咬合視圖,其中一條線顯示對齊所需的空間量。B、虛擬設備就位。
Initial archwires for alignment should provide light, continuous force of approximately 50 gm to produce the most efficient tipping tooth movement. Heavy force, in contrast, is to be avoided. 用於對齊的初始弓絲應提供大約 50 克的輕盈、連續的力,以產生最有效的傾斜齒運動。相反,應避免使用重力。
The archwires should be able to move freely within the brackets. For mesiodistal sliding along an archwire, at least 2 mil clearance between the archwire and the bracket is needed, 4 mil clearance is desirable, and more than that provides no advantage. This means that the largest initial archwire that should be used with an 18 -slot edgewise bracket is 16 mil , and 14 mil would be more satisfactory. With the 22 -slot bracket, a 16 or 18 mil archwire would be satisfactory if they delivered the correct force. Whatever the archwire, it should be held loosely in the bracket; however, as we have pointed out in Chapter 9, friction is not the major component of resistance to sliding, and the claim that more rapid alignment is a major advantage of selfligating brackets has been shown to be incorrect. 弓絲應該能夠在支架內自由移動。對於沿弓絲的近遠中滑動,弓絲和支架之間至少需要 2 mil 的間隙,最好有 4 mil 的間隙,超過這個間隙就沒有優勢。這意味著應該與 18 槽邊緣支架一起使用的最大初始弓絲是 16 mil ,而 14 mil 會更令人滿意。使用 22 槽支架,如果 16 或 18 mil 弓絲提供正確的力,它們將是令人滿意的。無論弓絲是什麼,它都應該鬆散地固定在支架中;然而,正如我們在第 9 章中指出的那樣,摩擦力並不是抗滑動性的主要組成部分,並且聲稱更快速的對齊是自結式托槽的主要優勢的說法已被證明是不正確的。
Rectangular archwires, particularly those with a tight fit within the bracket slot so that the position of the root apex could be affected, normally should be avoided. The principle is that it is better to tip crowns to position during initial alignment rather than displacing the root apices; the corollary is that although a highly resilient rectangular archwire, such as 17 xx2517 \times 25 superelastic NiTi (A-NiTi), could be used in the alignment stage, this is not advantageous because the rectangular archwire can create unnecessary and undesirable root movement during alignment (Figure 14-2). Superelastic NiTi wires have such low torsional strength that for all practical purposes they cannot torque roots, ^(2){ }^{2} so this complication is uncommon, but 通常應避免使用矩形弓絲,尤其是那些與托槽緊密配合的弓絲,以便影響根尖的位置。原則是,最好在初始對齊期間將牙冠傾斜到位置,而不是移位根尖;推論是,儘管可以在對齊階段使用高彈性矩形弓絲,例如 17 xx2517 \times 25 超彈性 NiTi (A-NiTi),但這並不有利,因為矩形弓絲會在對齊過程中產生不必要和不需要的根部運動(圖 14-2)。超彈性 NiTi 線材的抗扭強度非常低,以至於在所有實際用途中,它們都無法擰緊根部, ^(2){ }^{2} 因此這種複雜性並不常見,但是
FIGURE 14-2 A tightly fitting resilient rectangular archwire for initial alignment is almost always undesirable because not only is resistance to sliding likely to be problematic, but also the wire produces back-and-forth movement of the root apices as the teeth move into alignment. This occurs because the moments generated by the archwire change as the geometry of the system changes with alterations in tooth position. A, Diagrammatic representation of the alignment of a malposed lateral incisor with a round wire and clearance in the bracket slot. With minimal moments created within the bracket slot, there is little displacement of the root apex. B, With a rectangular archwire that has enough torsional stiffness to create root movement, back-and-forth movement of the apex occurs before the tooth ends up in essentially the same place as with a round wire. This has two disadvantages: it increases the possibility of root resorption, and it slows the alignment process. 圖 14-2 用於初始對齊的緊密貼合的彈性矩形弓絲幾乎總是不可取的,因為不僅對滑動的阻力可能存在問題,而且當牙齒對齊時,金屬絲會產生根尖來回移動。發生這種情況是因為弓絲產生的力矩會隨著系統幾何形狀的變化而改變。A,錯位的側切牙與圓絲和托槽間隙的對齊圖示。由於在托槽內產生的彎矩最小,根尖的位移很小。B,使用具有足夠扭轉剛度以產生牙根運動的矩形弓絲,根尖的來回移動發生在牙齒最終位於與圓絲基本相同的位置之前。這有兩個缺點:它增加了根系吸收的可能性,並且會減慢對齊過程。
mesiodistal movement of the root apices can and does occur, and this tends to slow the tipping movements needed for alignment. Round wires for alignment are preferred (Figure 14-3). There is no reason to pay extra for a high-performance rectangular wire for initial alignment, when alignment with it predictably will be slower and possibly more damaging to the roots than with a smaller round wire. 根尖的近遠端運動可以而且確實發生,這往往會減慢對齊所需的傾斜運動。用於對齊的圓線是首選(圖 14-3)。沒有理由為高性能矩形線支付額外的費用進行初始對齊,因為可以預見的是,與它對齊會比使用較小的圓線更慢,並且可能對根部的損害更大。
4. The springier the alignment archwire, the more important it is for the crowding to be at least reasonably symmetric. Otherwise, there is a danger that arch form will be lost as asymmetrically irregular teeth are brought into alignment. If only one tooth is crowded out of line or if an impacted tooth has to be brought into alignment-a more severe version of the same thing-a rigid wire is needed so that arch form is maintained except where springiness is required, and an auxiliary wire should be used to reach the malaligned tooth. This important point is discussed in some detail below. 4. 對齊弓絲越有彈性,擁擠至少要合理對稱就越重要。否則,隨著不對稱不規則的牙齒對齊,存在牙弓形狀丟失的危險。如果只有一顆牙齒擠在一條線上,或者如果必須使阻生牙對齊——同樣的更嚴重版本——需要一根剛性鋼絲,以便保持牙弓形狀,除非需要彈性,並且應該使用輔助鋼絲來到達錯位的牙齒。下面將詳細討論這一重要觀點。
Properties of Alignment Archwires Alignment Archwires 的屬性
The wires for initial alignment require a combination of excellent strength, excellent springiness, and a long range of action. Ideally, there would be an almost flat load-deflection curve, with the wire delivering about 50 gm (the optimum force for tipping) at almost any degree of deflection. The variables in selecting appropriate archwires for alignment are the archwire material, its size (diameter or cross-section), and the distance between attachments (interbracket span; see Chapter 9). 用於初始對中的線材需要出色的強度、出色的彈性和長作用範圍的組合。理想情況下,將有一個幾乎平坦的負載-偏轉曲線,鋼絲在幾乎任何程度的偏轉下都能提供大約 50 克(傾翻的最佳力)。選擇合適的弓絲進行對齊的變數是弓絲材料、其尺寸(直徑或橫截面)和附件之間的距離(支架間跨度;參見第 9 章)。
At this point, superelastic A-NiTi wires are so much more effective and efficient than any alternative that there is no reason to discuss any other archwire material for alignment. The key to their success is their ability to deliver light force over a long range. The use of multiple strands of steel wire was a way to improve the performance of steel wires in initial alignment; now multiple strands of A-NiTi are being used to deliver lighter force with an archwire that is stronger and has better resistance to fracture (see Figure 14-3). Since the manufacturer’s preparation of the material determines the clinical performance, wire size is a concern primarily with respect to clearance in the bracket slot and fracture resistance. Although a 16 mil A -NiTi wire can be stiffer and deliver more force than a differently prepared 18 mil wire, that would not be possible across the total range of wire sizes, so wire size is a consideration, just less important in selecting an A -NiTi wire. 在這一點上,超彈性 A-NiTi 線比任何替代品都更有效和高效,因此沒有理由討論任何其他弓絲材料進行對齊。他們成功的關鍵是他們能夠在長距離內提供輕力量。使用多股鋼絲是提高鋼絲在初始對齊時性能的一種方式;現在,多股 A-NiTi 被用於通過更堅固且具有更好抗斷裂性的弓絲傳遞更輕的力(見圖 14-3)。由於製造商對材料的製備決定了臨床性能,因此電線尺寸主要與托槽中的間隙和抗斷裂性有關。儘管 16 mil A -NiTi 線比不同製備的 18 mil 線材更硬,傳遞的力更大,但這不可能在整個線徑範圍內實現,因此線徑是一個考慮因素,只是在選擇 A -NiTi 線材時不那麼重要。
It is possible now to obtain superelastic wires that are almost totally passive when cold but deliver the desired force when at mouth temperature. Placing a chilled wire is much easier than placing a springy one, so chilling a segment of the wire to make it temporarily passive can be a significant advantage under some circumstances. On the other hand, once mouth temperature has been reached, there is no 現在可以獲得超彈性線,這些線在冷時幾乎完全是被動的,但在口溫下提供所需的力。放置冷絲比放置有彈性的冷絲要容易得多,因此在某些情況下,冷卻一段導線以使其暫時無源可能是一個顯著的優勢。另一方面,一旦達到口腔溫度,就沒有