544 Part 4 The Transitional Years: Six to Twelve Years
earlier, incisor and lip position provide important guides to whether
arch length can be created by expansion as does the presence of
adequate facial keratinized tissue. Upright or lingually inclined
incisors may be moved facially into correct alignment if the lips
are retrusive. However, the risk associated with generalized arch
expansion is instability of the new position.
Movement of teeth
facially may upset the existing equilibrium and cause relapse after
the appliances are removed. Relapse does not occur in all cases;
some patients maintain increased arch dimensions and remain
stable after treatment is complete. However, there does not seem
to be a good method for predicting stability.
judgment and long-term retention must be relied on in many
If the clinician elects to alleviate arch length inadequacy by
expansion (because the leeway space is inadequate), several
approaches can be taken. An active lower lingual arch can be
constructed with adjustment loops to tip the incisors facially if
the overbite is not prohibitively deep to prevent movement of the
incisors (Fig. 36.41); the lower lingual arch may also move the
• Figure 36.39 (A) A panoramic radiograph was obtained on a patient who had an unerupted right
central incisor. The radiograph showed that a supernumerary tooth was blocking the eruption of the
central incisor. (B) The primary incisors and the supernumerary were removed to see if the central incisor
would erupt. It was determined the central incisor would need to be exposed and a bonded bracket and
chain attached so the tooth could be brought into alignment. (C) The space was opened for the unerupted
central incisor and it was brought into position with elastic thread tied to a base archwire. (D) The tooth
in nal position. Note the more gingival attachment on the extruded tooth. These levels should approxi-
mate one another with time.
• Figure 36.40 Extrusion with overlay wires can be used successfully
following traumatic intrusion injuries. The overlay archwire, which is a light
and exible wire and now usually nickel titanium, is ligated with a stiffer
supporting archwire, usually stainless steel. The light wire is engaged in
the bracket and provides light continuous forces over a large range to
rapidly and physiologically extrude the tooth.
CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 545
by careful investigation, there is no doubt that enough expan-
sion can be created in this manner to relieve minor to moderate
Like removable appliances, xed (banded and bonded) appliances
can be used to tip teeth. Fixed orthodontic appliances are necessary
to increase arch length when bodily movement of teeth is required
to alleviate crowding and align the teeth. Banded and bonded
appliances also oer the opportunity to eciently control rotational
molars distally a small amount. e adjustment loops, located
mesial to the molars, should not be activated beyond 1 mm because
the activation of such a large wire (0.036 inches) places extremely
large forces on the teeth. When the appliance is properly activated,
the wire contacts the tooth high on the cingulum of the incisors.
e direction of force is apical, but it tips the incisors facially
because of the inclination of the lingual surface of the teeth. In 4
to 6 weeks the appliance can be activated another millimeter. is
process is repeated until arch length is adequate for the permanent
dentition. Primary canines may have to be disked or removed as
discussed previously if the crowding is in the anterior region.
A lip bumper, a wire appliance inserted in tubes on the lower
molars, may be used to decrease lower lip pressure and achieve
generalized arch expansion in the incisor, canine, and premolar
regions (Fig. 36.42). e location of the expansion depends on
the location of the lip bumper. e lip bumper removes resting
pressure of the lips and cheeks from these teeth. e teeth move
facially as a result of lack of lip pressure and the force of resting
tongue pressure. e pressure from the lower lip may tip the
Remember that ultimately both arches must be
Arch expansion may also be accomplished via a functional
appliance with buccal shields in the vestibule.
e buccal shields
disrupt the equilibrium between the tongue and the cheek and
allow the teeth to move facially (Fig. 36.43). Some investigators
claim that properly constructed buccal shields stretch the underly-
ing periosteum of the bone and cause skeletal remodeling in the
transverse dimension. Although this claim has not been substantiated
• Figure 36.41 (A) Generalized crowding of less than 5 mm is occasionally managed with an adjustable
lingual arch if the overbite is not too deep to prevent facial movement of the mandibular incisors. (B) The
appliance is activated on several occasions by opening the adjustment loops. (C) The same patient after
• Figure 36.42 A lip bumper is also used to treat generalized crowding
of less than 5 mm. The lip bumper is designed to decrease lower lip pres-
sure on the teeth and to allow generalized expansion by facial movement
of the teeth.
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544 Part 4 The Transitional Years: Six to Twelve Yearsearlier, incisor and lip position provide important guides to whether arch length can be created by expansion as does the presence of adequate facial keratinized tissue. Upright or lingually inclined incisors may be moved facially into correct alignment if the lips are retrusive. However, the risk associated with generalized arch expansion is instability of the new position.69,70 Movement of teeth facially may upset the existing equilibrium and cause relapse after the appliances are removed. Relapse does not occur in all cases; some patients maintain increased arch dimensions and remain stable after treatment is complete. However, there does not seem to be a good method for predicting stability.71 Unfortunately, clinical judgment and long-term retention must be relied on in many cases.If the clinician elects to alleviate arch length inadequacy by expansion (because the leeway space is inadequate), several approaches can be taken. An active lower lingual arch can be constructed with adjustment loops to tip the incisors facially if the overbite is not prohibitively deep to prevent movement of the incisors (Fig. 36.41); the lower lingual arch may also move the DCBA• Figure 36.39 (A) A panoramic radiograph was obtained on a patient who had an unerupted right central incisor. The radiograph showed that a supernumerary tooth was blocking the eruption of the central incisor. (B) The primary incisors and the supernumerary were removed to see if the central incisor would erupt. It was determined the central incisor would need to be exposed and a bonded bracket and chain attached so the tooth could be brought into alignment. (C) The space was opened for the unerupted central incisor and it was brought into position with elastic thread tied to a base archwire. (D) The tooth in nal position. Note the more gingival attachment on the extruded tooth. These levels should approxi-mate one another with time. • Figure 36.40 Extrusion with overlay wires can be used successfully following traumatic intrusion injuries. The overlay archwire, which is a light and exible wire and now usually nickel titanium, is ligated with a stiffer supporting archwire, usually stainless steel. The light wire is engaged in the bracket and provides light continuous forces over a large range to rapidly and physiologically extrude the tooth. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 545 by careful investigation, there is no doubt that enough expan-sion can be created in this manner to relieve minor to moderate crowding.Like removable appliances, xed (banded and bonded) appliances can be used to tip teeth. Fixed orthodontic appliances are necessary to increase arch length when bodily movement of teeth is required to alleviate crowding and align the teeth. Banded and bonded appliances also oer the opportunity to eciently control rotational molars distally a small amount. e adjustment loops, located mesial to the molars, should not be activated beyond 1 mm because the activation of such a large wire (0.036 inches) places extremely large forces on the teeth. When the appliance is properly activated, the wire contacts the tooth high on the cingulum of the incisors. e direction of force is apical, but it tips the incisors facially because of the inclination of the lingual surface of the teeth. In 4 to 6 weeks the appliance can be activated another millimeter. is process is repeated until arch length is adequate for the permanent dentition. Primary canines may have to be disked or removed as discussed previously if the crowding is in the anterior region.A lip bumper, a wire appliance inserted in tubes on the lower molars, may be used to decrease lower lip pressure and achieve generalized arch expansion in the incisor, canine, and premolar regions (Fig. 36.42). e location of the expansion depends on the location of the lip bumper. e lip bumper removes resting pressure of the lips and cheeks from these teeth. e teeth move facially as a result of lack of lip pressure and the force of resting tongue pressure. e pressure from the lower lip may tip the molar distally.72 Remember that ultimately both arches must be coordinated.Arch expansion may also be accomplished via a functional appliance with buccal shields in the vestibule.73 e buccal shields disrupt the equilibrium between the tongue and the cheek and allow the teeth to move facially (Fig. 36.43). Some investigators claim that properly constructed buccal shields stretch the underly-ing periosteum of the bone and cause skeletal remodeling in the transverse dimension. Although this claim has not been substantiated ABC• Figure 36.41 (A) Generalized crowding of less than 5 mm is occasionally managed with an adjustable lingual arch if the overbite is not too deep to prevent facial movement of the mandibular incisors. (B) The appliance is activated on several occasions by opening the adjustment loops. (C) The same patient after treatment. • Figure 36.42 A lip bumper is also used to treat generalized crowding of less than 5 mm. The lip bumper is designed to decrease lower lip pres-sure on the teeth and to allow generalized expansion by facial movement of the teeth. 546 Part 4 The Transitional Years: Six to Twelve YearsAchieving considerable expansion often is dicult. Incisor position, prole, and periodontal status all inuence whether the patient should be treated without extraction. Patients with this degree of crowding are most appropriately referred to a specialist.e decision to extract teeth is based on the factors listed previ-ously and is further inuenced by the location of the crowding, the position of the dental midline, and the dental and skeletal relationships of the patient. After careful case analysis, appropriate AB• Figure 36.44 Expansion of the dental arches to reduce crowding can be accomplished with xed appliances and is usually indicated when there are rotations or bodily tooth movement is required. (A) Expansion during the mixed dentition using xed appliances. (B) The mechanics often are a combination of coil springs and elastomeric chains to move teeth and increase arch dimensions. A lingual arch can be used for maintenance of the intermolar dimension. (From Proft WR, Fields HW, Jr, Sarver DM. Contemporary Orthodontics. 5th ed. St Louis: Elsevier; 2013.)AB• Figure 36.45 (A) Arch expansion can be accomplished during the permanent dentition years too. (B) The anterior irregularities, mostly rotations, were managed with a xed appliance. (From Proft WR, Fields HW, Jr, Sarver DM. Contemporary Orthodontics. 5th ed. St Louis: Elsevier; 2013.)• Figure 36.43 Generalized arch expansion can also be accomplished via a functional appliance with buccal shields. The buccal shields disrupt the equilibrium between the facial musculature and the tongue and allow the teeth to move facially. problems of teeth. A variety of archwire designs can be used to expand the arch, depending on the number of teeth with attach-ments (Fig. 36.44). Clearly, any dimension of the arch can be altered with this method. After the expansion has been completed, a lower lingual arch is placed to retain the expansion.In most cases, further treatment is necessary to align the remain-ing permanent teeth when they erupt (Fig. 36.45). In addition, distal movement of the maxillary molars may be required if some of the leeway space was used to align the mandibular teeth and cannot be used for the mesial molar shift. When a class I molar relationship is present initially, this is not an issue. erefore multibonded appliances should be used sparingly in the lower arch, generally only in cases in which the molars are already class I and there is some increased overjet, unless one is prepared to complete the case appropriately by adjusting the interarch relation-ships. Regardless of which appliance is selected, expansion inuences incisor position and prole.Severe CrowdingCrowding of more than 5 mm is considered severe. is amount of crowding is managed either with generalized arch expansion or with removal of selected permanent teeth. is degree of generalized arch expansion can be accomplished with dierent appliances but usually requires bodily tooth movement with xed appliances. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 547 incisors have erupted. In addition, the patient should have a class I dental and skeletal pattern with good lip and incisor position (unless one is prepared to address these problems) because guidance of eruption does not correct skeletal problems. Guidance of eruption begins in the early mixed dentition with the eruption of the lateral incisors (Fig. 36.46A). If a signicant arch length discrepancy is predicted, the primary canines should be removed. is allows the incisors ample room to erupt and align (see Fig. 36.46B). Typically, the incisors also tip lingually and upright, causing the bite to deepen. Faciolingual incisor displacement usually improves, but rotations are more resistant to spontaneous correction.e child is observed for 2 years or until it appears that the canines and premolars are ready to erupt. At that time, another space analysis should be completed to ensure that the arch length deciency is still great enough to warrant permanent tooth extrac-tion, and a radiograph should be obtained to determine the position of the unerupted teeth. e goal of treatment is to encourage the eruption of the permanent rst premolar so that it can be extracted before the permanent canine erupts (see Fig. 36.46C). Unfortunately, the mandibular canine erupts rst nearly half the time in the mandibular arch. If it appears that the canine is ahead of the premolar and will erupt facially, the primary rst molar should be removed when half to two-thirds of the rst premolar root is formed. At this stage of root development, premolar eruption will be accelerated, and the premolar will erupt before the canine enters the arch. is makes removal of the rst premolar much easier. In the maxillary arch the rst premolar normally erupts before the canine, and this is not a problem. In some cases the primary rst molar is removed, but the permanent canine still erupts before the rst premolar. is can lead to impaction of the rst premolar, teeth may be removed to make subsequent tooth movement easier to accomplish and to minimize the eects of extraction on the prole. e permanent rst premolar is most often selected for extraction because it is located at a midpoint in the arch and because the space it occupies can be used to correct midline problems, incisor protrusion, molar relationship problems, or crowding. Other teeth can be removed depending on the specics of the case and the type of therapy used. Management of extraction cases is best performed by a specialist.In some children, crowding is so severe in the mixed dentition that expansion is not feasible, and extractions are necessary to obtain a suitable occlusion that is in harmony with the supporting structures and the facial prole. In these cases a planned sequence of extractions of primary and permanent teeth can benet the patient by reducing incisor crowding and irregularity in the early mixed dentition, which will make subsequent orthodontic treatment easier and quicker. e extractions also make room for teeth to erupt within the alveolus and through keratinized tissue rather than being forced buccally or lingually into positions that may aect the periodontal health of the teeth. Guidance of eruption and serial extraction are terms used to describe this sequence of extractions.74,75 Guidance of eruption was originally developed to manage severe crowding without orthodontic appliances but now is viewed as the rst step in treatment culminating in xed orthodontic appliance therapy. For this reason the clinician should consult with a specialist before embarking on a planned extraction sequence.Guidance of eruption should be considered an option when crowding is greater than 10 mm per arch, a measurement that should be conrmed by space analysis after the permanent lateral ABC• Figure 36.46 The initial stages of serial extraction are described here. (A) Due to severe crowding and substantial overall arch length deciencies, the primary canines require extraction. (B) This allows incisor alignment. (C) Extraction of the primary rst molars speeds up the eruption of the rst premolars that can then be extracted prior to permanent canine eruption. 548 Part 4 The Transitional Years: Six to Twelve Years• Figure 36.47 If an anterior crossbite can be corrected by tipping the teeth facially, a removable appliance will accomplish this goal. In this case a single nger spring is tipping both maxillary central incisors out of crossbite. AB• Figure 36.48 (A) Fixed appliances also can be used to tip teeth out of anterior crossbite. In this patient, both maxillary lateral incisors were in anterior crossbite. (B) After the brackets were placed, progressively larger round wires were used to tip the teeth out of crossbite. A rectangular archwire will be used to achieve proper crown and root position. requiring surgical removal. Similarly, it may become apparent that the permanent canine will erupt before the rst premolar regardless of the extraction sequence. In this situation the primary rst molar and rst premolar are removed at the same time. is procedure is called enucleation because the premolar is removed from within the alveolar bone.Surgical removal of teeth from within the alveolar bone should be avoided if possible because it carries the potential for creating bone and soft tissue defects. ese occur if the alveolar bone is fractured or removed. New alveolar bone will not be stimulated to form because no tooth will erupt through this area. Surgical soft tissue defects resolve infrequently.An alternative extraction sequence has been advocated to prevent lingual tipping of the lower incisors and the subsequent increase in overbite, but this sequence is recommended only when incisor crowding is limited. e primary canine is not removed when the lateral incisor erupts. Instead, the primary canine is retained, and the primary rst molar is extracted to accelerate the eruption of the permanent rst premolar. is allows some anterior crowding to resolve. e premolar is extracted when it erupts into the arch. e primary canine is often extracted at the same time as the premolar or is left to exfoliate when the permanent canine erupts. e drawback of this alternative is that substantial incisor crowding is not readily resolved, which somewhat defeats the goal of selective tooth removal to encourage good dental alignment.Anteroposterior Dental ProblemsAnterior CrossbiteAnterior crossbite in the mixed dentition is not an uncommon nding. e clinician should determine whether the crossbite is skeletal or dental in origin from the prole analysis and intraoral ndings. Skeletal problems should be referred to a specialist, whereas dental problems can be addressed immediately. e most common cause of nonskeletal crossbite is a lack of space for the permanent maxillary incisors to erupt. A space analysis veries the space shortage. Anterior crossbite develops because the permanent tooth buds form lingual to the primary teeth. When space is inadequate, the incisors are forced to erupt on the lingual side of the arch. If it is apparent that the permanent incisors are beginning to erupt lingually, the adjacent primary teeth should be disked or removed to provide space for the permanent incisors. If space is provided as the incisors are just beginning to erupt, they will migrate facially out of crossbite, and appliance therapy may not be necessary.If the incisor fails to erupt facially or if the anterior crossbite is not diagnosed early in the mixed dentition, appliance therapy is needed to correct the crossbite. Space for the incisors is gained by disking, extracting the adjacent primary teeth, or increasing the arch perimeter. At this point a decision must be made as to whether the teeth should be tipped into position or moved bodily into place. If tipping will accomplish treatment goals the dentist can use either a removable appliance or a xed appliance to correct the crossbite. As described earlier a removable appliance can be used to tip one or more teeth into proper alignment. e appliance is constructed of palatal acrylic with at least two Adams clasps for retention and a nger spring to move the teeth (Fig. 36.47). e spring is a double helix design that provides a physiologic amount of force over an extended range of action. e spring is activated 2 mm to provide 1 mm of tooth movement per month. As with most removable appliances, full-time wear (except for eating and brushing) is necessary to accomplish the desired tooth movement.An anterior crossbite with an accompanying deep overbite does not necessarily require a bite plane or bite-opening device during treatment. Most persons habitually keep the mandible open and occlude only during swallowing and parafunctional movements. If the crossbite has not improved after 3 months of active treatment, it may be necessary to open the bite by adding acrylic to the appliance to cover the occlusal surfaces of the posterior teeth. is limits closure and keeps the anterior teeth apart, which allows uninhibited incisor movement. In most cases the crossbite will correct quickly and the bite plane can be removed. Extended use of a bite plane is discouraged because the teeth not in contact with the appliance will continue to erupt, creating a vertical occlusal discrepancy.Fixed appliances also can tip teeth out of crossbite and do not require as much cooperation from the child. A xed appliance also provides precise control of tooth movement in all three planes of space by using rectangular wires (Fig. 36.48). e disadvantage CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 549 that are in the correct position. Alternatively, a exible titanium alloy wire can be used for alignment. is requires no wire bending or loop forming but moves both the teeth in crossbite and those not in crossbite.After alignment is completed by either method, a rectangular archwire is inserted into the brackets that can deliver a root-positioning force to the tooth previously in crossbite. e purpose of such a force is to move the root into proper position so the entire tooth essentially moves forward out of crossbite and the angulation of anterior teeth is similar.Retention must be planned in all cases, regardless of the appliance selected. Active tooth movement is usually continued until the crossbite is slightly overcorrected. e correction should be retained with a passive xed or removable appliance for 2 months if there is a positive overbite. If there is not adequate overbite, retention should be continued until adequate overbite develops. Circum-ferential supracrestal berotomy can be considered if rotational movement was made during treatment. In a small number of cases the anterior crossbite is caused by excessive spacing and aring of the mandibular incisors. A removable appliance can be constructed with an adjustable 0.028-inch labial bow to retract the lower incisors and close the space. e appliance is activated 2 mm/month and acrylic removed from the lingual surface. Treatment should be continued until the space is closed and there is positive overbite and overjet. e tooth movement can be retained with the same removable appliance, which is made passive.Incisor ProtrusionIncisor protrusion in the mixed dentition is a serious esthetic problem for the preadolescent patient. Spaced, protrusive incisors are not only unattractive but also more prone to dental injury than incisors with a normal angulation. For these reasons, treatment is usually undertaken to move the incisors lingually into a more suitable position if the overbite is not prohibitively deep and the overjet will allow lingual movement. is treatment is used for a dental problem, not a skeletal problem. Skeletal problems should be referred to a specialist for growth modication.Treatment of incisor protrusion has already been discussed in the earlier section on management of diastemas in the mixed dentition (see Figs. 36.29 and 36.30). To summarize, teeth that can be tipped back into ideal alignment can be treated with a removable appliance that incorporates an active labial bow. e bow is activated by means of an adjustment loop to provide a lingual tipping force to the ared incisors. One to 2 mm of palatal acrylic is removed from the appliance to allow the crown to move lingually and to accommodate the palatal tissue that tends to bunch up behind the tooth being moved. e retention schedule should be full-time wear for 3 months.If bodily movement of teeth is necessary to correct incisor protrusion, the maxillary rst molars should be banded and brackets bonded to the anterior permanent teeth. A small, round, exible archwire is placed in the brackets to align the teeth initially. Anterior tooth retraction is accomplished by either a round or rectangular archwire with a closing loop or elastomeric chain, depending on whether tipping or bodily tooth movement is required. A headgear or a transpalatal arch is usually used during retraction to supplement anchorage. e choice between cervical, combination, or high-pull headgear is based on the patient’s vertical facial dimensions, although this is not as simple as one might imagine. Cervical headgear is generally used when the patient has normal vertical facial propor-tions, whereas high-pull headgear is indicated when the patient has increased lower facial height. e clinician should follow cases of either a labial or a lingual xed appliance is the patient’s inability to clean around the teeth and appliance thoroughly, which can result in marginal gingivitis and caries. A maxillary lingual arch is a suitable appliance to correct an anterior crossbite if the teeth require tipping. e maxillary arch is constructed of 0.036-inch wire and has adjustment loops like those used in a lower lingual arch. Finger springs made of 0.022-inch wire provide the tooth-moving force. e springs are usually soldered on the opposite side of the arch from the tooth being moved to increase the length and range of the spring (Fig. 36.49). e springs are activated approximately 3 mm before the appliance is cemented in place. During cementation, the springs are tied with steel ligatures to the lingual arch so that they will not interfere with the seating of the appliance. After the excess cement has been cleaned away, the ligature is cut away to activate the springs. In some cases the spring slips over the incisal edge of an incisor that is not fully erupted. In these cases, additional retention is needed to keep the spring in place. e retention can come from bonding a stainless steel button or a composite ledge to the lingual surface of the tooth. Conversely, a stainless steel guidewire can be soldered to the lingual arch at the midline to prevent the spring from slipping incisally. ree millimeters of activation provides 1 mm of tooth movement per month. e appliance should be removed, reactivated, and recemented at 4- to 6-week intervals until the crossbite is corrected.In older patients, space may need to be created for crossbite correction by arch expansion because there are no primary teeth to disk or extract. In this situation the permanent molars should be banded and the incisors bonded with orthodontic brackets.An anterior crossbite that requires bodily movement of teeth to correct the problem is best managed with bonded brackets and a planned sequence of archwires. Initially, teeth can be tipped out of crossbite. Usually an archwire is selected that is strong enough to withstand the force of occlusion in the posterior segments yet exible enough in the anterior region to engage the brackets of the malaligned teeth. If posterior strength is a requirement, a stainless steel archwire with loops bent mesial and distal to the tooth in crossbite is placed. Loops in the anterior region are designed to provide horizontal or vertical tooth movement and exert optimal force to move the teeth out of crossbite while stabilizing those • Figure 36.49 Fixed lingual appliances can be used to tip the teeth out of anterior crossbite. This patient required facial movement of the maxillary left canine to correct the crossbite. A small nger spring was soldered to the base lingual arch and was activated to provide the force necessary to move the tooth. 550 Part 4 The Transitional Years: Six to Twelve Years• Figure 36.50 Posterior crossbites of dental origin in the mixed dentition can be treated with either a W arch or a quad helix. In this patient a quad helix is being used to correct a bilateral posterior crossbite. • Figure 36.51 If teeth are at fault in both arches, a simple crossbite elastic is used to correct the crossbite. Bands can be placed on both permanent right rst molars, and buttons can be welded to the lingual side of the maxillary band and to the facial side of the mandibular band. A medium-weight (4- to 6-ounce) elastic is attached from one button to the other to provide the force required to correct the crossbite. of incisor retraction carefully to prevent problems associated with retraction. A complication encountered during incisor retraction is movement of the root of the permanent lateral incisor into the path of the unerupted permanent canine. e lateral incisor root either impedes eruption of the canine or may be resorbed. To avoid this complication, the wire should be bent or the bracket placed so that the lateral incisor root is upright or even tipped slightly to the mesial.Transverse Dental ProblemsPosterior crossbite correction in the mixed dentition can be dicult and confusing. e clinician must rely on a well-documented database to determine whether skeletal or dental correction is necessary. e presence of a mandibular shift also is an important nding. A posterior crossbite with an associated mandibular shift should be managed as soon as possible to prevent soft tissue, dental, and skeletal compensation. Crossbites can be corrected with a W arch or a quad helix in the primary and early mixed dentitions. Both skeletal and dental movements occur with these appliances, and it is dicult to aect only one or the other. In the late mixed dentition the midpalatal suture may be more interdigitated, and the clinician can make primarily dental or skeletal changes depending on the appliance selected to treat the patient. Skeletal problems should be referred to a specialist for treatment with a rapid palatal expander (RPE; see Fig. 36.6), but dental problems usually can be managed without referral. It is infrequent that a patient requires skeletal crossbite correction and has no other orthodontic issues.Posterior dental crossbites are either generalized or localized. Generalized crossbites of dental origin are usually bilateral and are corrected with a W arch or a quad helix (Fig. 36.50). If the crossbite is due to a unilateral dental constriction, an unequal (asymmetric) W arch (made of 0.036-inch wire) or a quad helix (0.038-inch wire) can be used to expand the arch. Alternatively, a lower lingual arch can be used to stabilize the lower teeth, and cross-elastics can be worn to the maxillary arch to correct the crossbite unilaterally. ese appliances have been discussed in previous sections. Localized crossbites are usually due to displacement of single teeth in one or both arches. For example, a maxillary lingual crossbite involving the permanent rst molars is usually the result of lingual displacement of the maxillary molar or the facial displacement of the mandibular molar. If teeth in opposing arches are both at fault, it is easy to correct the problem using a simple crossbite elastic. e oending teeth are tted with orthodontic bands without attachments. After the bands are tted, they are removed, and a button is welded to the opposite surface of the band from the direction in which the tooth is to be moved. Another method is to bond the teeth with buttons attached to bondable pads. ere is a greater risk of bond failure than band loosening. Whether the buttons are bonded or banded, the technique to correct the crossbite is identical.In the example just noted, a button is welded to the lingual surface of the maxillary band and to the buccal surface of the mandibular band. After the bands have been welded and cemented, a medium weight (316-inch, 6-ounce elastic) is attached from button to button through the occlusion (Fig. 36.51). e elastic should be worn full time, except when the patient is eating, and should be changed at every meal. e elastic should be worn until the crossbite is slightly overcorrected. It may be prudent to leave the bands in place and discontinue the use of elastic for 1 month to ensure that the teeth do not relapse into crossbite. When the occlusion is stable after 4 to 6 weeks without elastic force, the bands can be removed.Vertical Dental ProblemsVertical problems in the mixed dentition are primarily open bite or deep bite malocclusions. Vertical problems are dicult to diagnose. Treatment is based on which teeth should be encouraged or discouraged to erupt and a specialist should be consulted. Dental open bite is most often the result of an active digit habit that has impeded eruption of the anterior teeth. In some cases the digit habit has been discontinued but the open bite has been maintained because the tongue rests between the teeth and prevents eruption. Treatment is essentially the same as that described for digit habits in the late primary and early mixed dentitions. If therapy without an appliance is unsuccessful, a palatal crib (see Fig. 27.7) is eective if the patient desires to stop the habit. e crib reminds the child to refrain from the habit and blocks the tongue from being placed forward. erapy is successful in most cases, unless the child is unwilling to abandon the habit.In some cases of open bite and minimal incisal display, the anterior teeth are encouraged to erupt. is is accomplished by CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 551 phase of comprehensive orthodontic treatment, and consultation with a specialist is appropriate.References1. Prot WR, Fields HW, Sarver DM. Contemporary Orthodontics. 5th ed. St Louis: Mosby–Year Book; 2012.2. Prot WR, White RP, Sarver DM. Contemporary Treatment of Dentofacial Deformity. St Louis: Mosby–Year Book; 2003.3. Hagg U, Pancherz H, Taranger J. Pubertal growth and orthodontic treatment. In: Carlson DS, Ribbens KA, eds. Craniofacial Growth During Adolescence, Monograph 20. Craniofacial Growth Series. Ann Arbor, MI: Center for Human Growth and Development, University of Michigan; 1987.4. Baccetti T, Franchi L, McNamara JA Jr. An improved version of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth. Angle Orthod. 2002;72(4):316–323.5. Chertkow S. Tooth mineralization as an indicator of the pubertal growth. Am J Orthod Dentofacial Orthop. 1980;77:79–91.6. ompson GW, Popovich F, Anderson DL. Maximum growth changes in mandibular length, stature, and weight. Hum Biol. 1976;48:285–293.7. Anderson G, Fields HW, Beck FM, et al. Development of cephalo-metric norms using a unied facial and dental approach. Angle Orthod. 2006;76:557–563.opening the bite and preventing the posterior teeth from erupting with acrylic stops between the teeth, while allowing the anterior teeth to erupt (Fig. 36.52). Skeletal open bite treatment has been described previously, and these patients should be referred to a specialist.Dental deep bite is caused by overeruption of the anterior teeth or undereruption of the posterior teeth. It should be distinguished from skeletal deep bite, which is characterized by a at mandibular plane angle and a short vertical dimension, as well as by overerupted and undererupted teeth. In a normal incisor-to-lip relationship, 2 mm of the maxillary central incisor is exposed when the lip is at rest. If more than 2 mm of incisor is exposed, maxillary anterior overeruption should be considered. In the mandibular arch, overeruption is dicult to diagnose; however, the curve of Spee may provide some clue. An excessive curve of Spee (2 mm or more) suggests mandibular incisor overeruption.Management of deep bite in a growing patient can usually be incorporated into comprehensive orthodontic treatment. Occa-sionally, treatment in the mixed dentition is aimed at preventing further anterior eruption and encouraging or allowing posterior eruption. is is usually only indicated when the mandibular anterior teeth are impinging on the maxillary lingual gingiva and causing tissue irritation or gingival recession. In these cases the incisor teeth are placed in contact with a bite plane, and the appliance is constructed so that acrylic touches the upper and lower incisors but allows the posterior teeth to erupt. is is a variation of the appliance shown in Fig. 36.52. e appliance must be worn full time to enable correction and then must be worn as a retainer to maintain the correction until the patient stops growing vertically.If the deep bite is deemed to be the result of maxillary incisor overeruption or a combination of maxillary and mandibular incisor overeruption, xed orthodontic appliances are placed on the teeth. An intrusion arch, a wire that connects the permanent rst molars to the incisors, is constructed to exert a light intrusive force on the incisors (Fig. 36.53). An alternative is a continuous archwire with a V bend near the molars and a 2 × 4 appliance. Because there is an equal and opposite reaction to every force placed on the teeth, the molars experience an extrusive force by either means. Specically, the molar erupts and tips distally and facially. Facial movement of the molars can be counteracted by a transpalatal arch or a lower lingual arch, but neither will prevent distal crown tipping. In the maxillary arch, headgear that delivers distal root tip to the molars can oset the extrusive and distal crown tipping forces of intrusion arches. Often overbite reduction is the rst AB• Figure 36.52 A removable bite plane can allow eruption of posterior teeth or anterior teeth to increase or reduce overbite. (A) This bite plane prevents eruption of posterior teeth while encouraging anterior teeth to erupt. (B) The bite plane is retained with the clasps around the molar tubes. For posterior eruption to occur, the acrylic would open the bite and be placed between the anterior teeth. • Figure 36.53 The intrusion arch can be used to lift the maxillary teeth and reduce overbite. The auxiliary arch, shown here extending from the molars to the incisors gingival to the brackets, is inserted in the auxiliary molar tube. The molar is tied to the segmental archwires so it uses the anchorage of the molars, premolars, and canines. 552 Part 4 The Transitional Years: Six to Twelve Years29. Cha KS. Skeletal changes of maxillary protraction in patients exhibiting skeletal class III malocclusion: a comparison of three skeletal matura-tion groups. Angle Orthod. 2003;73:26–35.30. Baik HS. Clinical results of the maxillary protraction in Korean children. Am J Orthod Dentofacial Orthop. 1995;108:583– 592.31. Merwin D, Ngan P, Hagg U, et al. Timing for eective application of anteriorly directed orthopedic force to the maxilla. Am J Orthod Dentofacial Orthop. 1997;112:292–299.32. Wells AP, Sarver DM, Prot WR. Long-term ecacy of reverse pull headgear therapy. Angle Orthod. 2006;76:915–922.33. Sakamoto T, Iwase I, Uka A, et al. A roentgenocephalometric study of skeletal changes during and after chin cap treatment. Am J Orthod Dentofacial Orthop. 1984;85:341–350.34. Sugawara J, Asano T, Endo N, et al. Long-term eects of chincup therapy on skeletal prole in mandibular prognathism. Am J Orthod Dentofacial Orthop. 1990;98:127–133.35. Jamilian A, Cannavale R, Piancino M, et al. Methodological quality and outcome of systematic reviews reporting on orthopaedic treatment for class III malocclusion: overview of systematic reviews. J Orthod. 2016;43:102–120.36. Kilic N, Kiki A, Oktay H. Condylar asymmetry in unilateral posterior crossbite patients. Am J Orthod Dentofacial Orthop. 2008;133: 382–387.37. Bell R, LeCompte E. e eects of maxillary expansion using a quad helix appliance during the deciduous and mixed detentions. Am J Orthod Dentofacial Orthop. 1981;79:152–161.38. Haas AJ. e treatment of maxillary deciency by opening the midpalatal suture. Angle Orthod. 1965;35:200–217.39. Hicks E. Slow maxillary expansion: a clinical study of the skeletal versus the dental response to low magnitude force. Am J Orthod Dentofacial Orthop. 1978;73:121–141.40. Brunetto M, Andriani Jda S, Ribeiro GL, et al. ree-dimensional assessment of buccal alveolar bone after rapid and slow maxillary expansion: a clinical trial study. Am J Orthod Dentofacial Orthop. 2013;143(5):633–644.41. Fields HW, Prot WR, Nixon WL, et al. Facial pattern dierences in long-faced children and adults. Am J Orthod Dentofacial Orthop. 1984;85:217–223.42. Firouz M, Zernik J, Nanda R. Dental and orthopedic eects of high-pull headgear in treatment of class II, division 1 malocclusion. Am J Orthod Dentofacial Orthop. 1992;102:197–205.43. Iscan HN, Sarisoy L. Comparison of the eects of passive posterior bite-blocks with dierent construction bites on the craniofacial and dentoalveolar structures. Am J Orthod Dentofacial Orthop. 1997;112:171–178.44. Yao CC, Lai EH, Chang JZ, et al. Comparison of treatment outcomes between skeletal anchorage and extraoral anchorage in adults with maxillary dentoalveolar protrusion. Am J Orthod Dentofacial Orthop. 2008;134(5):615–624.45. Tunison W, Flores-Mir C, ElBadrawy H, et al. Dental arch space changes following premature loss of primary rst molars: a systematic review. Pediatr Dent. 2008;30(4):297–302.46. Northway WM, Wainwright RL, Demirjian A. Eects of premature loss of deciduous molars. Angle Orthod. 1984;54(4):295–329.47. Kennedy DB, Turley PK. e clinical management of ectopically erupting rst permanent molars. Am J Orthod Dentofacial Orthop. 1987;92:336–345.48. Christensen R, Fields H, Casamissimo P, et al. Lower dental midline stability: eect of primary canine loss, AAPD 2017 Annual Meeting Poster Presentation (56), 2017.49. Kau CH, Miotti FA, Harzer W. Extractions as a form of interception in the developing dentition: a randomized controlled trial. J Orthod. 2004;31:107–114.50. Ericson S, Kurol J. Incisor resorption caused by maxillary cuspids: a radiographic study. Angle Orthod. 1987;57:332–346.51. Kurol J. Early treatment of tooth-eruption disturbances. Am J Orthod Dentofacial Orthop. 2002;121:588–591.8. Tulloch JFC, Phillips C, Prot WR. Benet of early class II treatment: progress report of a two-phase randomized clinical trial. Am J Orthod Dentofacial Orthop. 1998;113:62–72.9. De Clerk H, Prot W. Growth modication of the face: a current perspective with emphasis on class III treatment. Am J Orthod Dentofacial Orthop. 2015;148:37–46.10. O’Brien K, Wright J, Conboy F, et al. Eectiveness of early orthodontic treatment with the twin-block appliance: a multicenter, randomized, controlled trial. Part 2: psychosocial eects. Am J Orthod Dentofacial Orthop. 2003;124(5):488–494.11. Liu Z, McGrath C, Hägg U. e impact of malocclusion/orthodontic treatment need on the quality of life: a systematic review. Angle Orthod. 2009;79(3):585–591.12. Kiyak HA. Does orthodontic treatment aect patients’ quality of life? J Dent Educ. 2008;72(8):886–894.13. iruvenkatachari B, Harrison J, Worthington H, et al. Early orthodontic treatment for class II malocclusion reduces the chance of incisal trauma: results of a Cochrane systematic review. Am J Orthod Dentofacial Orthop. 2015;148:47–59.14. Koroluk LD, Tulloch JF, Phillips C. Incisor trauma and early treatment for class II division 1 malocclusion. Am J Orthod Dentofacial Orthop. 2003;123:117–126.15. Baumrind S, Korn EL, Isaacson RJ, et al. Quantitative analysis of the orthodontics and orthopedic eects of maxillary traction. Am J Orthod Dentofacial Orthop. 1983;84:384–398.16. Bookstein FL. On the cephalometrics of skeletal change. Am J Orthod Dentofacial Orthop. 1982;82:177–198.17. O’Brien K, Wright J, Conboy F, et al. Eectiveness of treatment for class II malocclusion with the Herbst or twin-block appliances: a randomized, controlled trial. Am J Orthod Dentofacial Orthop. 2003;124:128–137.18. Luzi C, Luzi V, Melsen B. Mini-implants and the eciency of Herbst treatment: a preliminary study. Prog Orthod. 2013;14(1):21.19. McNamara JA, Bookstein FL, Shaughnessy TG. Skeletal and dental changes following functional regulator therapy on class II patients. Am J Orthod Dentofacial Orthop. 1985;88:91–110.20. Remmer HR, Manandras AN, Hunter WS, et al. Cephalometric changes associated with treatment using the activator, the Frankel appliance, and the xed appliance. Am J Orthod Dentofacial Orthop. 1985;88:363–372.21. Keeling SD, Wheeler TT, King GJ, et al. Anteroposterior skeletal and dental changes after early class II treatment with bionators and headgear. Am J Orthod Dentofacial Orthop. 1998;113: 40–50.22. Baumrind S, Korn EL. Patterns of change in mandibular and facial shape associated with the use of forces to retract the maxilla. Am J Orthod Dentofacial Orthop. 1981;80:31–47.23. Southard T, Marshall S, Allareddy V, et al. An evidence-based comparison of headgear and functional appliance therapy for the correction of class II malocclusions. Semin Orthod. 2013;19: 174–195.24. Turley PK. Orthopedic correction of class III malocclusion with palatal expansion and custom protraction headgear. J Clin Orthod. 1988;22:314–325.25. Kim JH, Viana MA, Graber TM, et al. e eectiveness of protraction facemask therapy: a meta-analysis. Am J Orthod Dentofacial Orthop. 1999;115:675–685.26. Vaughn GA, Mason B, Moon HB, et al. e eects of maxillary protraction therapy with or without rapid palatal expansion: a prospec-tive, randomized clinical trial. Am J Orthod Dentofacial Orthop. 2005;128:299–309.27. Sar C, Arman-Özçırpıcı A, Uçkan S, et al. Comparative evaluation of maxillary protraction with or without skeletal anchorage. Am J Orthod Dentofacial Orthop. 2011;139:636–649.28. Nguyen T, Cevidanes L, Cornelis MA, et al. ree-dimensional assessment of maxillary changes associated with bone anchored maxillary protraction. Am J Orthod Dentofacial Orthop. 2011;139: 790–798. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 553 62. Tsurumachi T, Kuno T. Endodontic and orthodontic treatment of a cross-bite fused maxillary lateral incisor. Int Endod J. 2003;36:135–142.63. Andreasen JO, Andreasen FM, Andersson L. Traumatic Injuries to the Teeth, Munksgaard. Denmark: Blackwell; 2007.64. Moorrees CFA, Gron AM, Lebret LML, et al. Growth studies of the dentition: a review. Am J Orthod Dentofacial Orthop. 1969;55:600–616.65. Gianelly AA. Treatment of crowding in the mixed dentition. Am J Orthod Dentofacial Orthop. 2002;121:569–571.66. Bussick TJ, McNamara JA Jr. Dentoalveolar and skeletal changes associated with the pendulum appliance. Am J Orthod Dentofacial Orthop. 2000;117:333–343.67. Bylo FK, Darendeliler MA. Distal molar movement using the pendulum appliance. Part 1: clinical and radiological evaluation. Angle Orthod. 1997;67:249–260.68. Antonarakis GS, Kiliaridis S. Maxillary molar distalization with noncompliance intramaxillary appliances in class II malocclusion. A systematic review. Angle Orthod. 2008;78:1133–1140.69. Little RM, Riedel RA, Artun J. An evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention. Am J Orthod Dentofacial Orthop. 1988;93:423–428.70. Little RM, Riedel RA, Stein A. Mandibular arch length increase during the mixed dentition: postretention evaluation of stability and relapse. Am J Orthod Dentofacial Orthop. 1990;97:393–404.71. Little R. e eects of eruption guidance and serial extraction on the developing dentition. Pediatr Dent. 1987;9:65–69.72. Nevant CT, Buschang PH, Alexander RG, et al. Lip bumper therapy for gaining arch length. Am J Orthod Dentofacial Orthop. 1991;100:330–336.73. Owen AH III. Morphologic changes in the transverse dimension using the Frankel appliance. Am J Orthod Dentofacial Orthop. 1983;83:200–217.74. Hotz RP. Guidance of eruption versus serial extraction. Am J Orthod Dentofacial Orthop. 1970;58:1–20.75. Kjellgren B. Serial extraction as a corrective procedure in dental orthopedic therapy. Trans Eur Orthod Soc. 1947;8:134–160.52. Ericson S, Kurol J. Early treatment of palatally erupting maxillary canines by extraction of primary canines. Eur J Orthod. 1988;10:283–295.53. Sigler LM, Baccetti T, McNamara JA Jr. Eect of rapid maxillary expansion and transpalatal arch treatment associated with deciduous canine extraction on the eruption of palatally displaced canines: a 2-center prospective study. Am J Orthod Dentofacial Orthop. 2011;139(3):e235–e244.54. Bonettia GA, Zanarinib M, Parentic SI, et al. Preventive treatment of ectopically erupting maxillary permanent canines by extraction of deciduous canines and rst molars: a randomized clinical trial. Am J Orthod Dentofacial Orthop. 2011;139(3):316–323.55. Kokich VO, Kinzer GA, Janakievski J. Congenitally missing maxillary lateral incisors: restorative replacement. Am J Orthod Dentofacial Orthop. 2011;139:435–445.56. Olsen T, Kokich V. Postorthodontic root approximation after opening space for maxillary lateral incisor implants. Am J Orthod Dentofacial Orthop. 2010;137:158e1–158e8.57. Zachrisson B, Rosa M, Sverker T. Congenitally missing maxillary lateral incisors: canine substitution. Am J Orthod Dentofacial Orthop. 2011;139:434–445.58. Schneider U, Moser L, Fornasetti M, et al. Esthetic evaluation of implants vs canine substitution in patients with congenitally missing maxillary lateral incisors: Are there any new insights? Am J Orthod Dentofacial Orthop. 2016;150(3):416–424.59. De-Marchi LM, Pini NI, Ramos AL, et al. Smile attractiveness of patients treated for congenitally missing maxillary lateral incisors as rated by dentists, laypersons, and the patients themselves. J Prosthet Dentistry. 2014;112(3):540–546.60. Czochrowska EM, Stenvik A, Bjercke B, et al. Outcome of tooth transplantation: survival and success rates 17–41 years posttreatment. Am J Orthod Dentofacial Orthop. 2002;121:110–119.61. Ostler M, Kokich V. Alveolar ridge changes in patients congenitally missing mandibular second molars. J Prosthet Dent. 1994;71: 144–149. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 553.e1 Case Study: Treating Ectopic Eruption of First Permanent MolarsMichael A. Ignelzi, Jr.Ectopic eruption of maxillary rst permanent molars occurs in approximately 3% to 4% of patients (Table E36.1).1–5 Pulver2 speculated that ectopic eruption of maxillary rst permanent molars was the result of one or more factors, including: larger than normal maxillary primary and permanent teeth; reduced maxillary length; maxilla positioned posteriorly relative to the cranial base; abnormal eruption angle of rst permanent molar; and delayed calcication of the rst permanent molar.There are two types of maxillary rst permanent molar ectopic eruption: reversible (able to self-correct or “jump,” and do not require treatment) and irreversible (unable to self-correct, have become locked, are on “hold,” and do require treatment). Several studies have shown that the majority of rst permanent molar ectopic eruption is reversible and does not require treatment (see Table E36.1).The challenge for the clinician is to identify irreversible ectopic eruption and render timely, efcient, and effective treatment. Failure to render treatment in these instances will likely create a cascade of events. The second primary molar will exfoliate prematurely, the rst permanent molar will continue to erupt in a mesial direction, creating a mesial migration into the space previously held by second primary molar, and there will be insufcient space for the second premolar to erupt. Bjerklin and Kurol6 and Dabbagh et al.5 identied clinical and radiographic ndings that help to predict irreversible ectopic eruption. Bjerklin and Kurol found that children with irreversible eruption had signicantly larger permanent molars and a more pronounced mesial angle of eruption. Although not statistically signicant, they also reported a tendency toward a shorter maxilla. Dabbagh et al. reported that increased magnitude of impaction, increased second primary molar resorption, increased severity of “lock,” and bilateral occurrence were positively correlated with irreversible ectopic eruption.Two general approaches have been used to treat irreversible ectopic eruption of maxillary rst permanent molars: interproximal wedging or distal tipping. Both approaches share three goals. The rst is to alter the eruption of the ectopically erupting rst permanent molar so the tooth reaches an optimal position. The second is to regain space lost as a result of mesial migration of the rst permanent molar so the second premolar has adequate space to erupt into proper position. The third is to retain, if possible, the second primary molar. Premature loss of the second primary molar creates the need for a space-maintaining appliance. In cases of unilateral loss of a second primary molar a band and loop will sufce. If loss is bilateral, a xed bilateral space maintainer, such as a Nance appliance, is necessary to hold the rst permanent molar after it has been moved into an optimal position.This case report will demonstrate two different approaches to correct ectopic eruption of maxillary rst permanent molars where second primary molars had exfoliated or were mobile and at risk for early exfoliation. The panoramic (Fig. E36.1A) and bitewing radiographs (Fig. E36.1B and C) exposed in Case 1 illustrate bilateral ectopic eruption of maxillary rst permanent molars, signicant mesial migration and impaction of #3 and #14, thick enamel ledges on both #A and #J, moderate resorption of the maxillary right second primary molar (tooth #A), and severe root resorption of the maxillary left second primary molar (tooth #J). Bitewing radiographs, as opposed to periapical radiographs, are better suited to assess ectopic eruption over time because it is reasonably easy to reproduce the same perspective in subsequent projections if one opens proximal contacts and directs the radiation beam 5 degrees above the occlusal plane. Clinical examination revealed that tooth #A exhibited class I mobility and tooth #J exhibited class II mobility.Fig. 36.2A–C illustrates the appliance that was used to treat bilateral ectopic eruption of the maxillary rst permanent molars. Treatment, as opposed to continued observation, was undertaken in Case 1 primarily Reference nPrevalence of Ectopic Eruption (%)No. of Subjects With Ectopic EruptionNo. of Ectopic EruptionsSelf-Correcting Ectopic Eruption (%)Irreversible Ectopic Eruption (%)Young, 1957 1619 3.2 52 60 40Pulver, 1968 831 3.1 26Bjerklin and Kurol, 1981 2903 4.3 126 59 41Barberia-Leache et al., 2005 509 4.3 22 36 69.4 30.6Dabbagh et al., 2017 44 N/A 44 65 71 29Ectopic Eruption of the Maxillary First Permanent MolarTABLE E36.1 ABC• Figure E36.1 Bilateral ectopic eruption of the maxillary rst permanent molars in Case 1 is seen on the panoramic (A) and posterior bitewing radiographs (B and C). Continued 553.e2 Part 4 The Transitional Years: Six to Twelve Yearsbecause the rst permanent molars were unlikely to self-correct, or “jump,” into proper position. The second primary molars were mobile and at risk for premature exfoliation, the ectopically erupting rst permanent molars were positioned mesially, and a signicant amount of root resorption on #A and #J had already occurred, creating a ledge that would make it unlikely for the ectopically erupting rst permanent molars to self-correct. Although not observed on this patient, another factor that would warrant treatment would be mesial angulation of the rst permanent molars. If #A and #J were not mobile or at risk for early exfoliation, they could have provided anchorage to counteract the forces needed to distalize the ectopically erupting rst permanent molars. Given the second primary molar mobility, the rst primary molars were chosen to contribute to the anchorage. Tooth #J was so mobile that it exfoliated after the bitewing radiographs had been exposed and before the appliance had been delivered (compare Fig. E36.1C with Fig. E36.2A). Anchorage to counteract the forces needed to distalize the rst permanent molars was achieved by using a Nance button as well as bands on teeth #B and #I. Buttons were bonded on the occlusal surfaces of the ectopically erupting rst permanent molars and elastomeric chains were used to distalize the ectopically erupting rst permanent molars. Fig. E36.2B and C illustrate proper distalization of the rst permanent molars. After the rst permanent molars have been “unlocked” and moved into their proper positions, a passive elastomeric chain is left in place and the rst permanent molars are allowed to erupt. The occlusal buttons are left in place until they interfere with complete eruption of the rst permanent molars. The occlusal buttons are then removed so that the rst permanent molars can erupt into occlusion. If the patient is able to tolerate the appliance, it may be left in place until the second premolar erupts into proper position. Alternatively, a bilateral space maintainer, preferably a Nance appliance, may be placed to prevent mesial drift of the rst permanent molars.Case 2 (Fig. E36.2D) illustrates an alternative approach to correcting ectopic eruption of the maxillary right rst permanent molar following early exfoliation of the maxillary right second primary molar. An approach similar to that shown in Fig. E36.2A, B, and C was attempted in Case 2, but the patient was unable to tolerate the Nance button. An alternative approach was taken that secured anchorage by using a transpalatal arch connecting the maxillary left rst permanent molar and the maxillary right rst primary molar. A buccal tube was soldered to the facial surface of the rst primary molar band and a buccal tube was bonded to the facial surface of the rst permanent molar. One segment of 0.018-inch stainless steel wire was cut to run through the tubes and extend 10 mm beyond the buccal tubes. This amount of extra wire is necessary to guide the permanent molar as it is moved distally. Prior to placing the segment of stainless steel wire into the buccal tubes, a nickel titanium open coil spring was placed onto the segment of stainless steel wire. The coil spring was cut longer than the distance between brackets by 6 mm to provide force to move the molar as the spring returns to shape after being compressed to t the space. After placing the segment of stainless steel wire into the buccal tubes, rounded loops were bent at the ends of the segment of stainless steel wire for patient comfort. Additional activations were accomplished by adding a longer segment of 0.018-inch stainless steel wire and closed coil spring adjacent to the existing nickel titanium open coil spring. Placing closed coil spring effectively activates the open coil spring by the width of the closed coil ABCD• Figure E36.2 Correction of bilateral ectopic eruption of the maxillary rst permanent molars in Case 1 using a Nance button, banded rst primary molars, bonded occlusal buttons, and elastomeric chains (A, B, and C, respectively). An alternative approach to anchorage was used in Case 2. Correction of unilateral ectopic eruption was accomplished using a transpalatal arch connecting the rst permanent molar with the rst primary molar, a soldered tube, a bonded tube, a segment of stainless steel wire, and an open coil spring (D).