Prevention of Dental Disease










534 Part 4 The Transitional Years: Six to Twelve Years
Fixed appliances (braces) can be used to correct irregularities and
are indicated when bodily movement of teeth or rotational control
is necessary. Orthodontic appliances have evolved to a point in
which specic brackets are designed for specic teeth. e brackets
are constructed to provide proper crown and root positioning when
they are precisely placed on the teeth. e bracketing process is
described in Fig. 36.26.
ere are several ways in which brackets can be bonded to
teeth. e traditional phosphoric acid etch, rinse, dry, and applica-
tion of a primer is still used in orthodontic practice. As companies
have developed all-in-one etch and prime technology, the traditional
technique has been replaced with a one-step etch and prime
conditioner. is reduces the number of steps required, makes
isolation easier, and decreases the time to place brackets. e method
is described in Fig. 36.27.
Another method to reduce bonding time and to theoretically
be more accurate with bracket placement is indirect bonding.
e method is considered a more accurate way to place braces
because the clinician may mark and measure each tooth, has
unlimited working time, and complete access to each tooth.
This method is described in Fig. 36.28. Intraoral scanners
are replacing the traditional impression so the clinician can
scan the teeth and feed the data directly to a computer (see
Fig. 36.28C).
e clinician should understand the physical properties of
orthodontic wires. An initial archwire must be selected that
is strong enough to withstand the force of occlusion in the
posterior segments yet exible enough in the anterior region to
be deected into the brackets and deliver a light, continuous
force. e initial wire is normally made of a nickel titanium
(NiTi) alloy of an appropriate diameter to provide ample strength
and flexibility. Other wires can be selected, such as small-
diameter stainless steel or braided stainless steel, based on the
amount of irregularity of the teeth. If posterior wire strength is
critical, loops can be bent into the archwire to produce anterior
exibility. Retention is essential after tooth movement in the
mixed dentition because the teeth have a strong propensity to
relapse.
Most retention problems are due to stretching and compres-
sion of gingival bers during tooth movement. Gingival bers
reorganize very slowly following tooth movement, and in some
cases irregularity returns even if retention is well conceived. Some
clinicians have suggested that if the periodontium is healthy, a
circumferential supracrestal berotomy may be performed to reduce
relapse.
When treatment is complete or nearly complete, the supracrestal
gingival bers are cut with a scalpel using a 12B blade, under local
anesthesia. eoretically, the stretched gingival bers will not need
to reorganize but will reattach in a new position after being cut.
Extreme care should be taken in patients with a thin gingival
biotype.
Crowding Problems
e rst sign of crowding in the mixed dentition usually coincides
with eruption of the permanent incisors. Arch length insuciency
may manifest in several ways, ranging from slight incisor rota-
tion and irregularity to gross incisor malalignment. e rst
step should be to perform a space analysis and determine the
extent of the arch length inadequacy. is nding is then placed
in the context of the facial prole analysis and posterior dental
relationships.
reparative dentin is formed. However, in the anterior region the
attrition must be accomplished mechanically with a handpiece
and bur. A small amount of tooth structure is removed at each
appointment, and after each session calcium hydroxide paste is
applied to the exposed dentin to stimulate the reparative process.
Usually the tooth can be treated at monthly appointments without
permanent injury to the pulp. When treatment is complete, the
exposed dentin is covered with a calcium hydroxide base and a
resin restoration is placed.
Alignment Problems
Anterior and posterior tooth irregularities with adequate space
should be regarded as dierent from anterior and posterior space
shortages. Tooth irregularity alone consists simply of rotated and
tipped teeth in which there is no shortage of arch length when the
leeway space is considered. Arch length discrepancies (i.e., a true
lack of space) also result in tooth irregularities but are a dierent
situation and require dierent management and timing.
Appliance Considerations
Tooth irregularities can be managed with either xed or removable
appliances. If a simple tipping force and no rotation are required
to align the tooth, a removable appliance with a nger spring is
an appropriate choice. A great variety of removable appliances
exist; however, several essential components must be included in
the design. e appliance must be retentive so the force applied
to the tooth will not dislodge the appliance. Adams clasps are
often prescribed and are very retentive, although they require careful
adjustment and may interfere with the occlusion. Other types of
clasps, such as ball clasps and “C” clasps, are also popular but
provide distinctly less retention and exibility. Multiple clasps
should be used to enhance the retention. Additional retention and
stability are gained from the palatal acrylic in maxillary appliances.
A helical nger spring made of 0.022-inch stainless steel wire
incorporated into the palatal acrylic delivers a light, continuous
force. e spring should be activated 2 mm to move the tooth
approximately 1 mm/month (Fig. 36.25).
Figure 36.25 Removable appliances can be used to manage align-
ment problems but are more effective for some problems than for others.
Notice that the maxillary right lateral incisor can easily be tipped facially,
but it is more difcult to rotate the left lateral incisor and requires use of
the lingual nger spring and the labial bow in concert to create a move-
ment. In general, this type of movement is more efcient with a xed
banded and bonded appliance.

CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 535
adjacent permanent teeth. Early removal of the mesiodens allows
the permanent teeth to erupt normally, and the space usually closes
spontaneously.
In some cases a large diastema may be due to faciolingual rather
than mesiodistal positioning of the incisors. Flared incisors are
cosmetically unappealing and are at greater risk of traumatic injury.
63
If the teeth can be tipped back into an ideal position to close the
diastema and if the overbite will not hinder tooth movement, a
removable appliance may be selected. e appliance is designed
to include at least two clasps for retention, palatal acrylic, and a
Mild to Moderate Spacing
Many children have a midline diastema in the mixed dentition,
and this is considered a normal stage of development. Occasionally,
a large midline diastema is present that is due to a mesiodens or
other midline intrabony pathologic process, protruding incisors, or a
tooth size problem. A diastema caused by a midline supernumerary
tooth or abnormality is managed by removal of the supernumer-
ary tooth or the abnormality. e supernumerary tooth should
be removed as early as possible without causing injury to the
AB
CD
E F
Figure 36.26 Orthodontic appliances are designed to provide proper crown and root positioning when
they are precisely placed on the teeth. Therefore it is imperative to follow the appropriate sequence when
placing the appliances. This is the sequence of steps when using an acid-etched and light-cured resin.
(A) Before the appliances are placed, the teeth selected for treatment must be thoroughly cleaned, prefer-
ably with pumice. (B) After the teeth have been cleaned, they are isolated to provide a eld free of salivary
contamination. (C) An etching solution or gel as shown here is painted on the facial surface of the teeth.
The tooth is rinsed with water (D) and dried (E). (F) The tooth is painted with a bonding agent.
Continued

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534 Part 4 The Transitional Years: Six to Twelve YearsFixed appliances (braces) can be used to correct irregularities and are indicated when bodily movement of teeth or rotational control is necessary. Orthodontic appliances have evolved to a point in which specic brackets are designed for specic teeth. e brackets are constructed to provide proper crown and root positioning when they are precisely placed on the teeth. e bracketing process is described in Fig. 36.26.ere are several ways in which brackets can be bonded to teeth. e traditional phosphoric acid etch, rinse, dry, and applica-tion of a primer is still used in orthodontic practice. As companies have developed all-in-one etch and prime technology, the traditional technique has been replaced with a one-step etch and prime conditioner. is reduces the number of steps required, makes isolation easier, and decreases the time to place brackets. e method is described in Fig. 36.27.Another method to reduce bonding time and to theoretically be more accurate with bracket placement is indirect bonding. e method is considered a more accurate way to place braces because the clinician may mark and measure each tooth, has unlimited working time, and complete access to each tooth. This method is described in Fig. 36.28. Intraoral scanners are replacing the traditional impression so the clinician can scan the teeth and feed the data directly to a computer (see Fig. 36.28C).e clinician should understand the physical properties of orthodontic wires. An initial archwire must be selected that is strong enough to withstand the force of occlusion in the posterior segments yet exible enough in the anterior region to be deected into the brackets and deliver a light, continuous force. e initial wire is normally made of a nickel titanium (NiTi) alloy of an appropriate diameter to provide ample strength and flexibility. Other wires can be selected, such as small-diameter stainless steel or braided stainless steel, based on the amount of irregularity of the teeth. If posterior wire strength is critical, loops can be bent into the archwire to produce anterior exibility. Retention is essential after tooth movement in the mixed dentition because the teeth have a strong propensity to relapse.Most retention problems are due to stretching and compres-sion of gingival bers during tooth movement. Gingival bers reorganize very slowly following tooth movement, and in some cases irregularity returns even if retention is well conceived. Some clinicians have suggested that if the periodontium is healthy, a circumferential supracrestal berotomy may be performed to reduce relapse.When treatment is complete or nearly complete, the supracrestal gingival bers are cut with a scalpel using a 12B blade, under local anesthesia. eoretically, the stretched gingival bers will not need to reorganize but will reattach in a new position after being cut. Extreme care should be taken in patients with a thin gingival biotype.Crowding Problemse rst sign of crowding in the mixed dentition usually coincides with eruption of the permanent incisors. Arch length insuciency may manifest in several ways, ranging from slight incisor rota-tion and irregularity to gross incisor malalignment. e rst step should be to perform a space analysis and determine the extent of the arch length inadequacy. is nding is then placed in the context of the facial prole analysis and posterior dental relationships.reparative dentin is formed. However, in the anterior region the attrition must be accomplished mechanically with a handpiece and bur. A small amount of tooth structure is removed at each appointment, and after each session calcium hydroxide paste is applied to the exposed dentin to stimulate the reparative process. Usually the tooth can be treated at monthly appointments without permanent injury to the pulp. When treatment is complete, the exposed dentin is covered with a calcium hydroxide base and a resin restoration is placed.Alignment ProblemsAnterior and posterior tooth irregularities with adequate space should be regarded as dierent from anterior and posterior space shortages. Tooth irregularity alone consists simply of rotated and tipped teeth in which there is no shortage of arch length when the leeway space is considered. Arch length discrepancies (i.e., a true lack of space) also result in tooth irregularities but are a dierent situation and require dierent management and timing.Appliance ConsiderationsTooth irregularities can be managed with either xed or removable appliances. If a simple tipping force and no rotation are required to align the tooth, a removable appliance with a nger spring is an appropriate choice. A great variety of removable appliances exist; however, several essential components must be included in the design. e appliance must be retentive so the force applied to the tooth will not dislodge the appliance. Adams clasps are often prescribed and are very retentive, although they require careful adjustment and may interfere with the occlusion. Other types of clasps, such as ball clasps and “C” clasps, are also popular but provide distinctly less retention and exibility. Multiple clasps should be used to enhance the retention. Additional retention and stability are gained from the palatal acrylic in maxillary appliances. A helical nger spring made of 0.022-inch stainless steel wire incorporated into the palatal acrylic delivers a light, continuous force. e spring should be activated 2 mm to move the tooth approximately 1 mm/month (Fig. 36.25).• Figure 36.25 Removable appliances can be used to manage align-ment problems but are more effective for some problems than for others. Notice that the maxillary right lateral incisor can easily be tipped facially, but it is more difcult to rotate the left lateral incisor and requires use of the lingual nger spring and the labial bow in concert to create a move-ment. In general, this type of movement is more efcient with a xed banded and bonded appliance. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 535 adjacent permanent teeth. Early removal of the mesiodens allows the permanent teeth to erupt normally, and the space usually closes spontaneously.In some cases a large diastema may be due to faciolingual rather than mesiodistal positioning of the incisors. Flared incisors are cosmetically unappealing and are at greater risk of traumatic injury.63 If the teeth can be tipped back into an ideal position to close the diastema and if the overbite will not hinder tooth movement, a removable appliance may be selected. e appliance is designed to include at least two clasps for retention, palatal acrylic, and a Mild to Moderate SpacingMany children have a midline diastema in the mixed dentition, and this is considered a normal stage of development. Occasionally, a large midline diastema is present that is due to a mesiodens or other midline intrabony pathologic process, protruding incisors, or a tooth size problem. A diastema caused by a midline supernumerary tooth or abnormality is managed by removal of the supernumer-ary tooth or the abnormality. e supernumerary tooth should be removed as early as possible without causing injury to the ABCDE F• Figure 36.26 Orthodontic appliances are designed to provide proper crown and root positioning when they are precisely placed on the teeth. Therefore it is imperative to follow the appropriate sequence when placing the appliances. This is the sequence of steps when using an acid-etched and light-cured resin. (A) Before the appliances are placed, the teeth selected for treatment must be thoroughly cleaned, prefer-ably with pumice. (B) After the teeth have been cleaned, they are isolated to provide a eld free of salivary contamination. (C) An etching solution or gel as shown here is painted on the facial surface of the teeth. The tooth is rinsed with water (D) and dried (E). (F) The tooth is painted with a bonding agent. Continued 536 Part 4 The Transitional Years: Six to Twelve YearsG HIJK L(G) A small amount of resin is placed on the bracket pad. (H) The bracket is placed on the tooth. (I) The bracket is adjusted to the proper orientation with the tooth based on the long axis of the crown and root and height from the incisor edge. (J) The excess resin is cleaned up. (K) The resin is light cured. (L) An archwire is placed in the bracket and ligated with steel ligature ties or elastomeric ties. • Figure 36.26, cont’d CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 537 the incisors are bonded with orthodontic brackets. e rst step is to align teeth with small, round archwires. After initial alignment, the teeth are retracted via a larger rectangular wire with closing loops or elastomeric chain (Fig. 36.30). Rectangular archwires are necessary to provide full control of tooth position during retraction. 0.028-inch labial bow with adjustment loops (Fig. 36.29). e labial bow is activated to tip the incisors lingually by closing the adjustment loops. At the same time, acrylic must be removed from the lingual side of the appliance to permit tooth movement and accommodate excess gingival tissue. e labial bow is activated approximately 2.0 mm/month until the diastema is closed and the teeth are in ideal position.Fixed orthodontic appliances are suggested if incisors are so protrusive that bodily movement is required to close the diastema or if the teeth are rotated. e molars are banded or bonded and ABC• Figure 36.27 One-step tooth preparation has been developed to save time in the bonding process. This replaces the etch, rinse, and dry steps. After the tooth is cleaned and dried, an etch/primer is used. (A) The etch/primer is combined in a special bubble “pop” dispenser. (B) The one-step liquid etch/primer is rubbed on the tooth for several seconds. (C) The preparation is lightly air-dried. The tooth is now ready for the bracket and bonding resin to be applied. ACB• Figure 36.28 (A) After the patient has had an impression, a stone model is poured. A separating medium is painted on the model and the clinician marks the teeth with a pencil to indicate the long axis of the tooth. The braces are placed on the model with some type of stable adhesive. Unlike a patient, the model can be turned whatever way the clinician needs to place the bracket in the optimal position. (B) Next, an indirect bonding tray is constructed that includes the brackets that are to be transferred to the patient’s teeth. The patient’s teeth are prepared in a similar manner to direct bonding, and a small amount of resin is placed on each bracket. After the adhesive has set, the tray is peeled away from the teeth and a wire is inserted in the brackets. (C) The advent of scanned models makes indirect bonding even easier. This model was constructed from a digital scan of the patient’s teeth. Virtual brackets are placed on the teeth, and the clinician can manipulate bracket placement until the bracket is in the optimal position. The design allows the clinician to move the bracket freely in all three dimensions. From this virtual setup, an indirect bonding tray is fabricated. ([A] Courtesy Dr. Linwood Long, Jr; [B and C] Courtesy Dr. Michael Mayhew.) 538 Part 4 The Transitional Years: Six to Twelve YearsAB• Figure 36.29 (A and B) A Hawley retainer with an active labial bow, and appropriate posterior retentive clasps can be used to tip anterior teeth lingually and reduce overjet if there is room available in the arch and the overbite and overjet are not prohibitive. This appliance is not good at controlling rotations. (From Proft WR, Fields HW Jr, Sarver DM. Contem-porary Orthodontics. 5th ed. St Louis: Elsevier; 2013.)BA• Figure 36.30 (A) When rotations are present or bodily movement is required to close space and retract incisors, the best alternative is a xed appliance. This patient required both transverse expansion and diastema closure to make room for the permanent canines. (B) The space closure was completed using xed appliances and elastomeric chain. Headgear may be necessary to reinforce the molar anchorage at the same time because the molars have a strong tendency to come forward while the incisors are retracted. It is important to determine if teeth should be tipped or bodily moved in the treatment planning phase. At the same time, a decision on headgear is based on initial molar position, the amount of space to close, and vertical dimensions of the face.If the diastema is due to a discrepancy in size between the upper and lower anterior teeth (the mandibular teeth are relatively larger than the maxillary), treatment usually requires the addition of resin to the interproximal surfaces of the maxillary incisors. Closing the space using orthodontics only will result in reduced overjet and overbite and possible anterior occlusal trauma. In addition, relapse is common because the occlusion will force the space open again.Treatment to close a midline diastema not associated with an anteroposterior position or a tooth size problem is usually initiated if the diastema is greater than 2 mm and one of the following three situations exist. e rst is if the diastema inhibits or disturbs the eruption of the lateral incisors. In general, treatment is started to coincide with the normal eruption time of the lateral incisor. If the diastema is large enough to be esthetically objectionable, a clinician can consider treatment if the patient is being teased or suering psychological problems due to appearance. If the diastema is still present after eruption of the permanent canines, treatment can be considered. e diastema is due to faulty mesiodistal positioning of the incisors, but the choice of appliance is still based on the tooth movement required to close the space. If the central incisors can be tipped together to close the diastema, a removable appliance can be used. Finger springs are either incorporated into the palatal acrylic or soldered to the labial bow to engage the distal edge of the incisor crown (Fig. 36.31). e springs are activated at a rate of 2 mm/month, and closure should not take more than 2 months.Brackets are bonded on the facial surface of the central incisors if the teeth require bodily mesiodistal movement or rotational control to close the diastema. After initial alignment, a large segmental or full rectangular archwire is placed in the brackets, and the teeth are moved together via elastomeric chain (Fig. 36.32). No matter which type of treatment is used to close a midline diastema, retention can be a problem and should be planned. In most cases a removable appliance maintains the space closure. e appliance should be adjusted periodically if the diastema is closed before the lateral incisors and canines have erupted fully. If the diastema reopens during or following retention and the clinician determines the frenal attachment is contributing to the continued opening of the diastema, a surgical procedure, frenectomy, can be performed. e frenectomy is completed after space closure because the scar tissue created by the procedure may actually impede closure if the surgery is accomplished rst. If the diastema again reopens following retention and the frenectomy, a small orthodontic wire can be bonded to the lingual surface of the incisors to keep the teeth together (Fig. 36.33). e only contraindications to a bonded wire retainer are an excessively deep bite (occlusion will dislodge the bonded wire) and poor oral hygiene. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 539 • Figure 36.31 In this case a midline diastema is due to the mesiodistal positioning of the maxillary central incisors. A removable appliance with nger springs incorporated into the palatal acrylic closes the space, tipping the teeth together. (From Proft WR, Fields HW, Jr, Sarver DM. Contemporary Orthodontics. 5th ed. St Louis: Elsevier; 2013.)BA• Figure 36.32 (A) If bodily mesiodistal movement is needed to close a diastema, xed appliances are placed on the teeth. (B) After initial align-ment, either a segmental or a full archwire is placed in the brackets, and the teeth are moved together with an elastomeric chain. AB• Figure 36.33 (A) Following diastema closure, retention is required. (B) One method that reduces the need for patient cooperation is the light, multistranded bonded wire. The wire must be placed far enough gingivally to prevent occlusal interferences. In addition, the patient must clean the area carefully and avoid direct contact with hard foods. Mild CrowdingAs mentioned earlier, children can have various amounts of irregularity without any real arch length shortage when the leeway space is included. Mild irregularity is even considered normal in patients who have no arch length discrepancy. Longitudinal studies of persons with ideal occlusions show that there is a period when up to 2 mm of transitional irregularity occurs early in the mixed dentition and eventually resolves.64 Observation is usually the best course. Some patients have little or no overall arch length shortages and demonstrate noticeable crowding during incisor eruption. is is due to the larger permanent incisors and the transitional crowding they cause during the transition from the primary to mixed dentitions. Gianelly65 has described these conditions and noted that a large percentage of patients with irregularity can be treated simply by protecting the leeway space with a lingual arch. On the other hand, if the leeway space is left unattended, the molars will move anteriorly into the leeway space and a true arch length shortage will exist.e clinical management of irregularity without a true arch length shortage can take several forms depending on the amount of irregularity. In general, if the irregularity is minor, no treatment is indicated. If the irregularity is slightly more severe, interproximal stripping or disking of the primary teeth (usually the canines) can be accomplished to provide temporary space (Fig. 36.34). Disking 540 Part 4 The Transitional Years: Six to Twelve Years• Figure 36.34 When the arch length discrepancy is determined to be 2 mm or less and the lateral incisor is erupting lingual to its proper position, the primary canine can be disked with either a high- or low-speed handpiece or a handheld strip. In this case a tapered ssure bur in a high-speed handpiece is being used to disk the mesial surface of the primary canine. WHITE SPOT LESIONSJohn R. ChristensenTooth movement with xed appliances (braces) carries some risk for teeth. One unfortunate consequence of xed appliance therapy is the development of white spot lesions (WSLs). WSLs are dened as “the rst sign of caries-like lesion on enamel that can be detected with the naked eye.”1 Practically, a WSL is a thin white line around the periphery of an orthodontic bracket that appears more white and chalky when the teeth are dried. The white appearance is due to demineralization of the surface and subsurface enamel.WSLs have been demonstrated as early as 4 weeks after the placement of orthodontic appliances.2 The development of WSLs is reported to be very rapid in the rst 6 months of orthodontic treatment and then begins to slow after 12 months.3 The prevalence for WSLs has been reported to be from 2% to 96% of orthodontic cases. The wide disparity is due to the different methods used to dene a WSL. For example, the use of quantitative light-induced uorescence yields a higher number of WSLs compared with a visual examination.4 Regardless of the denition, it is apparent that WSLs do develop during orthodontic treatment. One report showed 62% of patients develop a least one WSL on one of the maxillary anterior teeth and that an average of 3.9 teeth of the 6 had WSLs.5These statistics provide a dilemma for the clinician. First, orthodontic treatment is initiated to not only improve the function of the masticatory system but to improve the esthetics of a patient’s smile. A prudent clinician would know there is a high likelihood of white spot development during orthodontic treatment. The presence of a WSL detracts from the esthetics of a nished case. Therefore it is important for the clinician to identify those patients at greatest risk for white spot development and to create a plan to prevent the occurrence of such lesions. Heymann and Grauer developed a risk assessment analysis to differentiate patients into high- and low-risk candidates for WSL prior to orthodontic treatment.4 If a patient exhibited two of the following characteristics they were deemed to be high risk for white spot development. The characteristics were existing WSL, poor oral hygiene, high dietary sugar exposure, long treatment time, labial appliances, and a high DMFT score. Although these characteristics seem reasonable and rather easy to determine, the next step is more difcult. In other words, if a patient is classied as high risk, what preventive measures should be taken?Prevention can be divided into four approaches. The rst is diet. The second is oral hygiene. The third is chemotherapeutic agents. The last is the design and delivery of the orthodontic appliance itself. Diet counseling has been studied extensively in preventing dental caries, but there is a paucity of articles looking at dietary recommendations and WSL development during orthodontic treatment. It appears that dietary counseling has minimal inuence on the development of WSLs.6 This does not mean the clinician should not discuss diet with a prospective orthodontic patient, but it appears that other factors have more inuence on WSL development.Oral hygiene instruction prior to orthodontic treatment is critical to help a patient maintain excellent oral hygiene during treatment. The change in the local environment (brackets, adhesive, and wires) makes cleaning more time consuming and more difcult. There are no statistically signicant ndings on oral hygiene and reduction in WSLs, but there are tendencies one can point to. The rst is a prospective study on orthodontic patients that found the level of visible plaque around the appliance shortly after bonding was the best predictor for WSLs at appliance removal.7 Another divided the study group into good, medium, and poor compliance groups for oral hygiene. The good compliance group developed 1.0 WSLs during treatment, the medium compliance 1.4, and the poor compliance group 3.3 lesions. Although these numbers were not statistically signicant, it appears that good compliance with oral hygiene measures inuences white spot development.6These ndings are rather distressing for the clinician. If neither diet nor oral hygiene inuences the development of WSLs during orthodontic treatment, what should a clinician do? The most recent focus is on chemotherapeutic agents to inuence the effect of plaque and bacteria on the enamel surface or to make the enamel surface more resistant to breakdown. Fluoride exposure is probably the most popular and widely tested chemotherapeutic agent. Fluoride can be delivered via toothpaste, rinses, professional application, and release from the orthodontic appliance (adhesive and elastomeric ties). However, there are no studies that have shown uoride release from the orthodontic appliance has a signicant inuence on enamel demineralization.There are many studies promoting the use of uoride during orthodontic treatment to prevent or reduce WSLs, but these studies are not rigorous enough to avoid potential bias under close examination. A recent Cochrane review suggested a professionally applied uoride varnish delivered at every orthodontic appointment may reduce WSLs by 70%.8 Because uoride delivery from toothpaste and over-the-counter rinses is highly dependent on patient cooperation, a professionally applied uoride varnish at every orthodontic appointment may be the best way to protect a patient against demineralization.Other chemotherapeutic agents used to promote oral hygiene have been investigated to see if they decrease decalcication. The use of an essential oil mouthrinse reduced plaque and gingivitis scores in orthodontic patients.9 The study did not look at reduction of WSLs. A second study did report a decrease in WSLs with the use of MI Paste Plus (GC America, Alsip, IL) during orthodontic treatment.10Often demineralization becomes apparent during orthodontic treatment. When discovered, the clinician has several choices. The rst is to inform the patient (and parents) of the condition. The clinician can review risk factors and begin more aggressive uoride therapy or add additional therapies such as amorphous calcium phosphate (ACP). MI Paste is a product that contains casein phosphopeptide ACP, a milk-derived protein that helps to promote enamel remineralization. Studies are equivocal about whether the effect of MI Paste on remineralization of WSLs is greater than uoride products, but it has been shown to enhance remineralization similar to uoride products.11 ACP is contraindicated in patients with milk protein allergies. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 541 The other choices for the clinician in cases of severe demineralization is to accelerate the nish of treatment, nish with less than ideal results, or discontinue treatment all together. This is a difcult situation for patients, parents, and doctors. The decision should be made after all meet to discuss the advantages and disadvantages of each possible alternative. After orthodontic treatment is completed or discontinued, postorthodontic treatment of WSLs can be initiated.Treatment of WSLs or demineralization after orthodontic treatment is unpredictable. Many variables such as the size and depth of the lesion and whether the lesion is active (porous enamel) or arrested (nonporous enamel) make treatment outcomes successful in some and fail in others. Postorthodontic treatment of WSLs can be divided into three or four strategies. The rst is recognition of the problem and resumption of good oral hygiene practices at home. These practices are no different from normal hygiene recommendations, such as twice daily brushing with uoride toothpastes.A second strategy is to apply some type of remineralizing solution on the affected teeth. This can include professional application of uoride, ACP, or a combination of the two. These applications can be applied at a predetermined interval to help with the natural resolution of WSLs.Alteration of the enamel surface can also improve the appearance of WSLs. The most common alteration of the surface has been microabrasion. In microabrasion, the teeth are isolated with a rubber dam to protect the patient’s soft tissues and a slurry of acid and abrasive material is rubbed or applied on the enamel surface. Many acids have been used; hydrouoric, hydrochloric, citric, nitric, and phosphoric acids have all been tested. The abrasive material has been dental pumice, synthetic diamond dust, aluminum oxides, and silicon carbide.12 The procedure removes 25 to 200 µm of enamel and improves WSLs if they are shallow. Many clinicians use a tooth-bleaching regimen following the microabrasion to give better results.In some cases, bleaching of the teeth may provide desired results. The bleaching procedure may be done in the dental ofce, or the bleaching material may be delivered with trays at home. The bleaching material may be a hydrogen peroxide–based material or a carbamide peroxide material of varying percentage. It appears bleaching will lighten both the white spot and the unaffected healthy enamel, with the healthy enamel lightening more than the white spot.13 This difference in color change helps to disguise the difference between the WSLs and healthy enamel.Restorative procedures can be used to treat WSLs. The most conservative restorative procedure is called resin inltration. The resin inltration procedure consists of placing acid etch on the facial surface of the tooth to create porosities in the enamel. An unlled or low viscosity resin is applied to the facial surface and allowed to penetrate the porous enamel surface to ll the WSL. This technique is relatively new during the writing of this chapter, and long-term data on effectiveness are difcult to nd. It appears there is promise for improvement of WSLs with this treatment.14,15Finally, the clinician can restore WSLs with a traditional restorative approach. The affected areas of enamel are removed with an appropriate dental bur and handpiece. The preparation may be beveled and the tooth restored with a traditional acid etch, primer, and color-matched composite resin. The obvious issue with restoration is that tooth structure is removed and replaced with a composite resin. This procedure is not reversible and will require additional care and treatment for the lifetime of the tooth.The presence of a WSL at the end of orthodontic treatment is at best a frustration and at worst an esthetic failure for the patient and clinician. Based on available literature, the clinician should implement a sound oral hygiene plan and apply uoride varnish during treatment to avoid or minimize white spot development. At the end of treatment, the clinician can choose from several treatment options based on the size, number, and appearance of WSLs on the teeth. One can safely say there is no one treatment to completely eliminate or disguise this problem.References1. Fejerskov O, Nyvad B, Kidd EAM. Dental Caries: The Disease and Its Clinical Management. Copenhagen: Blackwell Munksgaard; 2003.2. Reilly MM, Featherstone JD. Decalcication and remineralization around orthodontic appliances: an in vivo study. J Dent Res. 1985;64:301.3. Tufekci E, Dixon JS, Gunsolley JC, et al. Prevalence of white spot lesions during orthodontic treatment with xed appliances. Angle Orthod. 2011;81:206–210.4. Heymann GC, Grauer D. A contemporary review of white spot lesions in orthodontics. J Esthet Restor Dent. 2013;25:85–95.5. Behrents RG. Offense or defense? Am J Orthod Dentofacial Orthop. 2016;149(3):303–304.6. Hadler-Olsen S, Sandvik K, El-Agroudi MA, et al. The incidence of caries and white spot lesions in orthodontically treated adolescents with a comprehensive caries prophylactic regimen—a prospective study. Eur J Orthod. 2011;34:633–639.7. Øgaard B, Larsson E, Henriksson T, et al. Effects of combined application of antimicrobial and uoride varnishes in orthodontic patients. Am J Orthod Dentofacial Orthop. 2001;120:28–35.8. Benson PE, Parkin N, Dyer F, et al. Fluorides for the prevention of early tooth decay (demineralised white lesions) during xed brace treatment. Cochrane Database Syst Rev. 2013;(12):CD003809.9. Tufekci E, Casagrande ZA, Lindauer SJ, et al. Effectiveness of an essential oil mouthrinse in improving oral health in orthodontic patients. Angle Orthod. 2008;78(2):294–298.10. Robertson MA, Kau CH, English JD, et al. MI Paste Plus to prevent demineralization in orthodontic patients: a prospective randomized controlled trial. Am J Orthod Dentofacial Orthop. 2011;140(5):660–668.11. Li J, Xie X, Wang Y, et al. Long-term remineralizing effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on early caries lesions in vivo: a systematic review. J Dent. 2014;42(7):769–777.12. Sundfeld RH, Croll TP, Briso AL, et al. Considerations about enamel microabrasion after 18 years. Am J Dent. 2007;20(2):67.13. Knösel M, Attin R, Becker K, et al. External bleaching effect on the color and luminosity of inactive white-spot lesions after xed orthodontic appliances. Angle Orthod. 2007;77(4):646–652.14. Senestraro SV, Crowe JJ, Wang M, et al. Minimally invasive resin inltration of arrested white-spot lesions: a randomized clinical trial. J Am Dent Assoc. 2013;144(9):997–1005.15. Knösel M, Eckstein A, Helms HJ. Durability of esthetic improvement following Icon resin inltration of multibracket-induced white spot lesions compared with no therapy over 6 months: a single-center, split-mouth, randomized clinical trial. Am J Orthod Dentofacial Orthop. 2013;144(1):86–96.WHITE SPOT LESIONS—cont’dmay be accomplished with a handheld strip, a sandpaper disk in a low-speed handpiece, or a tapered bur in a high-speed handpiece. e enamel-reducing instrument must be held vertically to reduce the true mesiodistal dimension of the tooth even subgingivally to be successful. e procedure is performed without anesthesia so that the child can indicate any discomfort. Extreme discomfort usually indicates that sucient enamel has been removed to cause the pulpal tissues to react. Careful disking can yield 2 to 4 mm of space. A professional-strength topical uoride preparation can be applied to the canines after disking and may reduce postoperative sensitivity. Note that in the mixed dentition, interproximal reduction of permanent teeth before the eruption of the permanent canines 542 Part 4 The Transitional Years: Six to Twelve YearsA true arch length discrepancy of 0 to 2 mm may not be apparent or may be manifested as a mild irregularity, most likely in the incisor region. Treatment may be indicated for these children if the lateral incisors erupt lingual to their proper position or in very irregular positions. If treatment is deemed necessary, interproximal stripping of primary teeth as described earlier may be used. With true, small arch length shortages, ultimately minor crowding will either be accepted, permanent teeth will have to be reduced in the mesiodistal dimension, or the arch will have to be expanded with xed or removable appliances, as described in the next section.Moderate CrowdingTreatment for a moderate arch length discrepancy of less than 5 mm is based on the facial prole, incisor position, crowding, and the amount of facial keratinized tissue. If the prole is straight, with good anteroposterior or slightly retrusive position of the lips and incisors, a small amount of expansion can be tolerated to accommodate all the teeth. Expansion is not a good treatment option if the incisors are already protrusive. e clinician should always keep in mind the interaction between crowding, incisor position, and prole because they are essentially all part of the same problem just expressed in a dierent way.Moderate crowding may be localized or generalized. Localized crowding may be the result of space loss after extraction or premature exfoliation of a primary tooth. If space loss is 3 mm or less, the adjacent tooth usually can be tipped into proper position with a removable appliance, an active lingual arch, or a xed banded and bonded appliance. For example, a removable appliance with a nger spring can tip a permanent maxillary or mandibular rst molar distally after removal of a primary second molar compromised by ectopic eruption. Numerous other xed appliances such as lingual holding arches or a Nance lingual arch supporting segmental arches with compressed coil springs can be used (Fig. 36.36A). Alternatively, a Nance arch with compressed helical springs can be used to move posterior teeth distally (Fig. 36.36B). Regardless of the appliance conguration, the method is basically the same, and these appliances can be used either unilaterally or bilaterally. For arch perimeter increases in the maxillary arch, the distal molar movement is accompanied by an anterior movement of the anchor or anterior segment.66,67 Without additional anchorage, the anterior teeth move facially in a ratio of approximately one-third anterior and two-thirds posterior (Fig. 36.37). With additional anchorage, such as TADs in the anterior palate, distal molar movement of approximately 1 mm/month has been demonstrated with no change in the position of the anterior teeth.68 e challenge then is to preserve the distal molar movement and retract and align the remaining teeth.Alternatively, headgear can be used if bilateral space regaining is desired. After the space has been regained, arch length should be near ideal and should be maintained. A band and loop appliance or a lingual archlike appliance can be placed to maintain the space.If localized crowding is not due to terminal molars drifting anteriorly but is in the anterior or midportions of the arch, per-manent tooth impaction is likely. Orthodontic tooth movement is necessary to increase the space and allow room for eruption (Fig. 36.38). Fixed orthodontic appliances are placed on a portion or the entire arch, and the teeth are aligned with light, exible archwires. After alignment, a heavy archwire is placed to maintain good arch form during space-regaining movements. A compressed coil spring is the simplest means to open space and provides adequate force to open the space. After the space has been opened, the clini-cian should allow the tooth up to 6 months to erupt. If the tooth and evaluation of the patient’s tooth size is contraindicated. If teeth are prematurely reduced, an iatrogenic tooth size problem may be created.If it is apparent that disking will not alleviate the anterior irregularity, it may be appropriate to extract the primary canines and place a lingual arch so that the available space can be used by the larger incisors for alignment, and the smaller premolars can erupt later in the remaining space. For the most part, this therapy is undertaken in the mandibular arch, although there are a few situations in which it is indicated in the maxilla. A lingual arch is necessary because the lower incisors tend to tip lingually without the support of the primary canines. is results in shortening of arch length and some reduction in dental alveolar bone. In this situation the lingual arch is placed in a passive state (i.e., the arch exerts no force to move the incisors and increase the space). e clinician should communicate to the parent that this treatment requires close supervision and the primary rst molars may have to be disked or extracted when the permanent canines erupt. e lingual arch remains in place until the second premolars have erupted or until it is evident there will be sucient space for all the permanent teeth to erupt. Essentially, one is using the leeway space and controlling all available arch length to achieve alignment of the teeth (Fig. 36.35). In some cases, this means the molars (those that are end to end) will not achieve a class I relationship because the mandibular mesial molar shift has been prevented. Either headgear or interarch mechanics such as elastics will need to be used to achieve the correct occlusal relationships. In other situations a class I molar relationship may have already been present and this is not a concern.AB• Figure 36.35 Space that is available in the arches (leeway) can be used to alleviate crowding by maintaining space when crowding is present and allowing alignment when the larger primary second molars exfoliate or are extracted. (A) This patient shows some crowding with the primary second molars in place. (B) A lower lingual arch was placed so the leeway space could be used for spontaneous alignment. CHAPTER 36 Treatment Planning and Management of Orthodontic Problems 543 BA• Figure 36.36 A xed appliance can be used to distalize molars in either arch. In the maxillary arch (A), a modied Nance palatal arch and nickel titanium springs on an archwire, or a Nance arch and helical springs can be used to distalize molars (B). Some anterior incisor movement also occurs. tooth is moved into the arch (Fig. 36.39). Several methods can be used to generate the force to move the tooth occlusally, but using an overlay exible wire (usually NiTi) is simple and eective. e overlay wire technique is an especially applicable technique for extruding traumatically intruded incisors so that they can be assessed and/or accessed for endodontic treatment. e method is simple, does not impinge on the adjacent tissue, permits easy cleaning, and allows reasonably efficient movement of teeth (Fig. 36.40).Patients characterized by anterior or generalized crowding of less than 5 mm present dicult treatment decisions. As stated does not erupt within that time period, it may be necessary to surgically expose the tooth. ere are two surgical methods to expose a tooth. e rst is a closed exposure. In a closed exposure a ap is elevated and the tooth is located. An orthodontic attach-ment, often a bracket pad with a soldered gold chain, is bonded to the tooth. e gold chain is tied to the existing orthodontic appliances, and the ap is replaced. e clinician applies force to the gold chain by elastomeric thread, auxiliary wires, or loops from a continuous archwire to bring the tooth into position. Closed exposure is preferred when the tooth crown is located beyond the mucogingival junction. e other type of surgical exposure is an open exposure. In this type of exposure, the soft tissue is elevated and repositioned around the crown to provide adequate keratinized tissue around the impacted tooth. Open exposure is considered when the crown is below the mucogingival junction and minimal repositioning is required. Adequate attached gingiva is essential for good periodontal support and esthetic appearance. Closed exposure simulates the actual eruption of the tooth and usually results in better hard and soft tissue esthetics. If the clinician is not well versed in surgical exposure, the patient is best referred to a specialist. In an open exposure the tooth can be allowed to erupt or an orthodontic attachment is bonded to the crown and the • Figure 36.37 Another approach to distalizing molars is to use palatal forces and springs supported by teeth and the palate. Even with this method, some anterior tooth movement is observed unless the appliance is supported with temporary anchorage devices. BA• Figure 36.38 Many situations rely on the same principles for treatment of crowding in the anterior segment. In general, the rst step is to align and open space. (A) This patient lost the maxillary right central incisor to trauma and subsequently space redistributed. (B) The teeth were aligned with a segmental arch in the rst phase of treatment, and then a coil spring was used to open the space for the prosthetic replacement.

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