International Journal of Environmental Research and Public Health

Case Report Early Treatment of Anterior with Eruption Guidance Appliance: A Case Report

Marianna Pellegrino 1,*, Silvia Caruso 2, Tiziana Cantile 3 , Gioacchino Pellegrino 2 and Gianmaria Fabrizio Ferrazzano 3,4

1 Unit of , Vita-Salute San Raffaele University, 20132 Milan, Italy 2 Department of Health, Life and Environmental Science, University of L’Aquila, 67100 L’Aquila, Italy; [email protected] (S.C.); [email protected] (G.P.) 3 Department of Neuroscience, Reproductive and Oral Sciences, School of Paediatric Dentistry, University of Naples, Federico II, 80138 Naples, Italy; [email protected] (T.C.); [email protected] (G.F.F.) 4 UNESCO Chair in Health Education and Sustainable Development: Oral Health in Paediatric Age, University of Naples Federico II, 80138 Naples, Italy * Correspondence: [email protected]; Tel.: +39-342-739-1187

 Received: 26 April 2020; Accepted: 19 May 2020; Published: 20 May 2020 

Abstract: The purpose of this investigation was to show how to manage an anterior crossbite in early mixed dentition with an eruption guidance appliance (EGA). The analyzed clinical case reported an anterior crossbite, a bimaxillary retrusion tendency, and a horizontal growth pattern. The anterior crossbite was an unfavorable occlusal condition that could lead to a class III growth pattern. An early treatment approach was suggested to reach a correct sagittal relationship. Hence, the selected approach acted on the dentoalveolar sector, aiming to have effects on the posterior vertical dimension and to improve the sagittal jaw’s relation. An EGA was selected to treat the patient in early mixed dentition. After 7 months of therapy with night-time use, the dental malocclusion was completely resolved. The patient continued to be treated with the same device, used as active retention. With the EGA treatment, the erupting forces, rather than the active forces, were used to resolve the dental malocclusion. This approach allowed a low compliance requirement and had a minimum psychosocial and psychological impact on the patient. The early treatment was essential to give a functional occlusion and a good balance of the soft perioral tissues and muscles.

Keywords: eruption guidance appliance; class III malocclusion; early orthodontic treatment; EGA; anterior crossbite; interceptive

1. Introduction Dental malocclusion is a condition characterized by abnormal relationships among the teeth or dentition. a malocclusion in primary dentition is a determinant factor of malocclusion in permanent dentition [1]. The anterior crossbite is a discrepancy on the sagittal plane, which causes the forward shift of the . This unphysiological position of the lower jaw can favor a class III growth pattern. Class III malocclusion generally consists of hypoplasia or retrusion of the and/or prognathic mandible, and deficient maxilla accounts for 42–63% [2]. Regardless of the growth direction of both and the functional or genetic involvements, the class III relationship should be treated early [3]. It is important to minimize the aesthetic impact that the malocclusion may have on the social life of the patient, especially during adolescence. Malocclusion may lead to low self-esteem in later years, as children with primary dentition undergo a period during which they establish self-identity and early personality [4]. Furthermore, early treatment in early development is essential to avoid or to

Int. J. Environ. Res. Public Health 2020, 17, 3587; doi:10.3390/ijerph17103587 www.mdpi.com/journal/ijerph Int. J. Environ. Res. Public Health 2020, 17, x 2 of 10

Int. J. Environ. Res. Public Health 2020, 17, 3587 2 of 10 identity and early personality [4]. Furthermore, early treatment in early development is essential to avoid or to reduce the malocclusion severity and to improve therapeutic outcomes. A sagittal reducediscrepancy the malocclusion of more than severity 7 mm, in and fact, to has improve a high therapeutic risk of relapse outcomes. [5]. Early a sagittal intervention discrepancy on the ofmaxilla more thanis recommended 7 mm, in fact, to has try ato high reach risk a correct of relapse sagittal [5]. Early relation intervention before the on maxillary the maxilla sutures is recommended close [3,6,7]. toA tryclass to III reach malocclusion, a correct sagittal if allowed relation to beforedevelop, the tends maxillary to worse suturesn with close age [3,6 ,because7]. a class the III growth malocclusion, of the ifmandible allowed exceeds to develop, the growth tends toof worsenthe maxilla with. The age anterior because cr theossbite growth favors of thesuch mandible a situation exceeds [6,8]. The the growthorthodontic of the treatment maxilla. Theaims anterior to correct crossbite the sagittal, favors the such transversal a situation and [6,8 the]. The vertical orthodontic relation treatment between aimsthe upper to correct and the the lower sagittal, jaws. the Several transversal approaches and the have vertical been relation used to between treat anterior the upper crossbite and theand lower class jaws.III Several approaches. Some approaches have been adopt used functional to treat anterior appliances, crossbite which and use classmuscle III force malocclusions. to correct Somejaw relationship approaches [9] adopt. Other functional ones use appliances,orthopedic procedures, which use muscle such as force Fränkel to correct III [10] jaw, a facemask, relationship which [9]. Otherappears ones to be use the orthopedic most effective procedures, treatment such [11] as, the Fränkel association III [10 ],of a splints facemask, with which class III appears to and be thechin most-cups e ff(SECective III) treatment [12,13], [ 11a ],Rapid the association Palatal Expander of splints with(RPE) class [14] III or elastics -ancho and chin-cupsred maxillary (SEC III)protraction [12,13], a [15,16] Rapid, Palatalwhich Expanderuses high (RPE)force to [14 stimulate] or bone-anchored the three-dimensional maxillary protraction maxillary [15 growth,16], which [17]. usesAfter high 10 years force of to follow stimulate-up, the the three-dimensional predictability of the maxillary orthopedic growth treatment [17]. After, with 10 a yearssagittal of follow-up,approach, thedecreases predictability and some of thechanges orthopedic might treatment, not be ma withintained a sagittal [2,18,19] approach,. Vertical decreases plane values andsome can influence changes mightthe diagnosis, not be maintained the prognosis [2,18 and,19]. the Vertical treatment plane planning values can of influencesagittal-plane the diagnosis,-related malocclusions the prognosis [20 and– the22]. treatment planning of sagittal-plane-related malocclusions [20–22]. EruptionEruption guidanceguidance appliances appliance (EGA)s (EGA) with with di ffdifferentialerential occlusal occlusal thickness thickness are generallyare generally used used to treat to classtreat I class and class I and II class malocclusions. II malocclusions. Only one Only study one in study the literature in the literature reports that reports the anterior that the crossbite anterior cancrossbite be treated can be with treated these with kinds th ofese oral kind devicess of oral [23]. devices The purpose [23]. The of this purpose investigation of this investigation was to show howwas toto manageshow how an to early, manage unfavorable an early, occlusal unfavorable condition, occlusal such condition, as the anterior such as crossbite,the anterior with crossbite, an eruption with guidancean eruption appliance guidance (EGA). appliance (EGA).

2.2. Materials and Methods

2.1.2.1. Case Presentation AA 5-year-and-10-month-old 5-year-and-10-month-old male male reported reported with with forwardly forwardly placed placed lower frontlower teeth, front which teeth, worried which theworried patient’s the parents. patient’s He parents. was in He good was health; in good his medical health; history his medical showed history no significant showed noabnormalities significant andabnormalit he hadies never and done he had orthodontic never done treatment orthodontic before. treatment The patient’s before. father The presentedpatient’s father a skeletal presented class III a malocclusion,skeletal class III implying malocclusion, a genetic implying predisposition. a genetic predisposition The boy remained. The atboy about remained the 75th at about percentile the 75th for heightpercentile and for weight height over and the weight entire over period the of entire observation. period of observation.

2.2.2.2. ClinicalClinical Findings OnOn clinicalclinical extraoralextraoral examination,examination, thethe patientpatient hadhad a straight profile,profile, goodgood face proportions, aa flatflat cheekbonecheekbone contour,contour, anan openopen nasolabialnasolabial angleangle andand aa regularregular labiomentallabiomental angleangle (Figure(Figure1 ).1).

(a) (b)

Figure 1. Extraoral pretreatment pictures: (a) frontal view; (b) laterallateral view.view.

HeHe diddid notnot havehave clinicalclinical symptomssymptoms and the articular examination did not reveal any problem problems.s. OnOn clinicalclinical intraoralintraoral examination,examination, thethe patientpatient waswas foundfound toto bebe inin earlyearly mixedmixed dentition.dentition. OnOn the sagittal

Int. J. Environ. Res. Public Health 2020, 17, 3587 3 of 10 Int. J. Environ. Res. Public Health 2020, 17, x 3 of 10 plane,plane, there was a mesial step on the deciduous molars,molars, a canine class I on the right side and a canine class III on the left side, with an an anterior anterior crossbite with 1 mm negative overjet. A Aroundround the transversal transversal plane, he presented a 3 3-mm-mm deviation of the mandibular midline towards the left, while the maxillary dental midlinemidline was coincident with the facial midline. During the opening of the mouth mouth,, the upper and lower jaw midlines became coincident and the chin deviation disappeared. This was the sign of a functional problem and not a skeletal one. A Aroundround the vertical plane plane,, a flat flat Spee curve and a deep bite were noticed. O Oralral hygiene had to be improved (Figure2 2).).

(a) (b)

(c)

Figure 2. IntraoralIntraoral pretreatment pretreatment pictures: ( a) frontal frontal view; ( b) lateral view of right side side;; ( c) lateral lateral view of left side.side.

2.3. Diagnostic Assessments Lateral cephalogram and orthopantomogram were taken (Figure 33)) andand thethe followingfollowing analysesanalyses were performed: • MBT analysis • • GiannGiannìì analysis • • Wits appraisalappraisal • • Jarabak and FizzelFizzel polygon.polygon. • The (Table1) highlighted a class I with a class III tendency (Wits = 6 mm) − with a biretrusion (SNA = 74◦; SNB = 73◦). An increased anterior vertical dimension (SNˆGoGn = 38◦; SnaSnpˆGoGn = 32◦) due to a postinclination of the mandibular plane was associated to a hypodivergent growth pattern (SArˆArGo = 134◦; ArGoˆGoN = 58◦). a retroinclination of upper incisors (+1ˆSnaSnp = 76 ; +1ˆOccl = 93 ) and an increased interincisal angle (+1ˆ 1 = 166 ) were recorded. ◦ ◦ − ◦

(a) (b)

Figure 3. Pretreatment radiographic records: (a) orthopantomogram; (b) lateral cephalogram.

Int. J. Environ. Res. Public Health 2020, 17, x 3 of 10

plane, there was a mesial step on the deciduous molars, a canine class I on the right side and a canine class III on the left side, with an anterior crossbite with 1 mm negative overjet. Around the transversal plane, he presented a 3-mm deviation of the mandibular midline towards the left, while the maxillary dental midline was coincident with the facial midline. During the opening of the mouth, the upper and lower jaw midlines became coincident and the chin deviation disappeared. This was the sign of a functional problem and not a skeletal one. Around the vertical plane, a flat Spee curve and a deep bite were noticed. had to be improved (Figure 2).

(a) (b)

(c)

Figure 2. Intraoral pretreatment pictures: (a) frontal view; (b) lateral view of right side; (c) lateral view of left side.

2.3. Diagnostic Assessments Lateral cephalogram and orthopantomogram were taken (Figure 3) and the following analyses were performed: • MBT analysis • Giannì analysis Int. J.• Environ.Wits Res. appraisal Public Health 2020, 17, 3587 4 of 10 • Jarabak and Fizzel polygon.

(a) (b)

FigureFigure 3. Pretreatment 3. Pretreatment radiographic radiographic records: records: (a) orthopantomogram; (a) orthopantomogram; (b) lateral(b) lateral cephalogram. cephalogram.

Table 1. Cephalometric data.

Parameters Normal Range Recorded Values SNA 82 2 74 ◦ ± ◦ ◦ SNB 80 2 73 ◦ ± ◦ ◦ ANB 2 2 1 ◦ ± ◦ ◦ Wits 1 2 mm 6 mm − ± − SNˆGoGn 32 2 38 ◦ ± ◦ ◦ SnaSnpˆGoGn 20 5 32 ◦ ± ◦ ◦ FMA 25 2 23 ◦ ± ◦ ◦ SArˆArGo 143 3 134 ◦ ± ◦ ◦ ArGoˆGoN 50 5 58 ◦ ± ◦ ◦ NGoˆGoGn 70 5 71 ◦ ± ◦ ◦ +1ˆSnaSnp 110 3 76 ◦ ± ◦ ◦ IMPA 90 2 86 ◦ ± ◦ ◦ +1ˆ 1 130 5 166 − ◦ ± ◦ ◦ +1ˆOccl 60 2 93 ◦ ± ◦ ◦ 1ˆOccl 70 2 72 − ◦ ± ◦ ◦ U1/A.Pog 5 mm 2 mm 1 mm ± − L1/A.Pog 2 mm 2 mm 5 mm ± − NasˆLab 102 8 113 ◦ ± ◦ ◦ SL/Sn-Pog c 0.5 mm 1 mm 3 mm − ± − LL/Sn-Pog c 0 mm 1 mm +1 mm ± Sna: spina nasalis anterior; Snp: spina nasalis posterior; FMA: Frankfort-mandibular plane angle; +1: upper central incisor; -1: lower central incisor; Occl: occlusal plane; U1: upper central incisor; L1: lower central incisor; Nas: nasal angle; Lab: Labial angle; SL: superior ; LL: lower lip; Sn: sub-nasal point; Pog c: cutaneous pogonion.

2.4. Prognosis The class III prognosis is hardly predictable, meaning that it is difficult to predict the severity of the problem. It depends on genetic and environmental factors. If environmental factors have a major influence, there is a greater chance to control them with orthodontic therapy and to have a better outcome [2,18,19]. Reaching a correct occlusion, with an appropriate overjet and values, is fundamental to avoid dentoalveolar compensation and to favor orthognathic growth. The hypodivergent growth pattern is a positive prognostic factor.

2.5. Therapeutic Intervention The treatment goals were to resolve the anterior crossbite, reducing the class III relationship, to center the midline, to establish a stable occlusion and to improve the profile line. The treatment selected for this patient has provided for the use of a functional appliance. An EGA was chosen, specifically an LM-Activator High Short (LM-Instruments Oy, Parainen, Finland) (Figure4). Int. J. Environ. Res. Public Health 2020, 17, x 5 of 10

Int. J. Environ. Res. Public Health 2020, 17, x 5 of 10 Int. J. Environ. Res. Public Health 2020, 17, 3587 5 of 10

Figure 4. LM-Activator High Short (LM-Instruments Oy, Parainen, Finland).

The adopted device had a higher bilateral thickness on the molar sector, compared to the anterior Figure 4. LM-Activator High Short (LM-Instruments Oy, Parainen, Finland). one. Even though the intraoral device was preformed, the customization aspect was in choosing the appropriate Themodel adoptedFigure and 4. device size. LM-Activator hadFinally, a higher aHigh LM bilateral -ShortActivator thickness (LM-Instruments High on the Short molar Oy, 30 sector, Parainen,was compared selected. Finland). to The the anteriorappliance was for nightone.-time Even use though only; thein intraoralparticular device, it had was preformed,to be fitted the soon customization after dinner aspect until was inthe choosing next morning. the appropriate model and size. Finally, a LM-Activator High Short 30 was selected. The appliance DuringThe the adopted first weeks device, hadafternoon a higher use bilateral also was thickness strongly on suggested,the molar sector, to adapt compared sooner to to the us anterioring the one. Evenwas though for night-time the intraoral use only; device in particular, was preformed, it had to be fitted the soon customization after dinner until aspect the nextwas morning.in choosing the device. TheDuring afternoon the first weeks, usage afternoon was discontinued use also was stronglywhen the suggested, patient to did adapt no soonert lose to the using appliance the device. anymore duringappropriate theThe night. afternoon model The and usage orthodontic size. was Finally, discontinued check a LM- whenup-Activator was the patientfixed High every did Short not 3 lose months 30 the was appliance onlyselected. after anymore The verifying duringappliance that wasthe dailyfor night usethe -wastime night. reached use The only orthodontic and; in correctly particu check-uplar done., wasit had fixed to every be fitted 3 months soon only after after dinner verifying until that the the daily next use morning. During was the reached first weeks and correctly, afternoon done. use also was strongly suggested, to adapt sooner to using the device. The afternoon usage was discontinued when the patient did not lose the appliance anymore 3. Results3. Results during the night. The orthodontic check-up was fixed every 3 months only after verifying that the After 4 months, the patient presented a double occlusion, one in the anterior crossbite and the daily use wasAfter reached 4 months, and the correctly patient presented done. a double occlusion, one in the anterior crossbite and the other oneother closing one closing edge- edge-to-edgeto-edge on onthe the frontal frontal incisors incisors (Figure (Figure5). 5). 3. Results After 4 months, the patient presented a double occlusion, one in the anterior crossbite and the other one closing edge-to-edge on the frontal incisors (Figure 5).

Figure 5.Figure Intraoral 5. Intraoral frontal frontal picture: picture: edge edge-to-edge-to-edge occlusion obtained obtained after after 4 months 4 months of treatment. of treatment.

This was a sign that the appliance was operating. After 7 months from the beginning of the Thistherapy, was a the sign anterior that crossbitethe appliance was resolved. was operating The initial negative. After overjet7 months and deepfrom bite the were beginning treated. of the therapy,The the mandible’s anterior functionalcrossbite deviation was resolved. disappeared The and initial so the negative lower midline overjet deviated and 2deep mm onbite the were right, treated. The mandibleFigurethe opposite 5.’s Intraoralfunctional side of frontal the deviation original picture: deviation disappeared edge-to (Figure-edge6 ).occlusionand so the obtained lower after midline 4 months deviated of treatment. 2 mm on the right, the opposite side of the original deviation (Figure 6). This was a sign that the appliance was operating. After 7 months from the beginning of the therapy, the anterior crossbite was resolved. The initial negative overjet and deep bite were treated. The mandible’s functional deviation disappeared and so the lower midline deviated 2 mm on the right, the opposite side of the original deviation (Figure 6).

(a) (b)

(a) (b)

Int. J. Environ. Res. Public Health 2020, 17, x 5 of 10

Figure 4. LM-Activator High Short (LM-Instruments Oy, Parainen, Finland).

The adopted device had a higher bilateral thickness on the molar sector, compared to the anterior one. Even though the intraoral device was preformed, the customization aspect was in choosing the appropriate model and size. Finally, a LM-Activator High Short 30 was selected. The appliance was for night-time use only; in particular, it had to be fitted soon after dinner until the next morning. During the first weeks, afternoon use also was strongly suggested, to adapt sooner to using the device. The afternoon usage was discontinued when the patient did not lose the appliance anymore during the night. The orthodontic check-up was fixed every 3 months only after verifying that the daily use was reached and correctly done.

3. Results After 4 months, the patient presented a double occlusion, one in the anterior crossbite and the other one closing edge-to-edge on the frontal incisors (Figure 5).

Figure 5. Intraoral frontal picture: edge-to-edge occlusion obtained after 4 months of treatment.

This was a sign that the appliance was operating. After 7 months from the beginning of the therapy, the anterior crossbite was resolved. The initial negative overjet and deep bite were treated. The mandible’s functional deviation disappeared and so the lower midline deviated 2 mm on the Int. J. Environ. Res. Public Health 2020, 17, 3587 6 of 10 right, the opposite side of the original deviation (Figure 6).

Int. J. Environ. Res. Public HealthInt. 20 J.20 Environ., 17, x Res. Public Health 2020, 17, x 6 of 10 6 of 10 (a) (b)

(c) (c)

Figure 6. Intraoral post post-treatment-treatmentFigure 6.pictures: pictures: Intraoral ( (aa )post) frontal frontal-treatment view; view; ( (pictures:bb)) lateral (view viewa) frontal of right view; side; (b )( lateralc) lateral view of right side; (c) lateral view of left side. view of left side.

The profileprofile became harmonicThe profile (Figure became7 7).). harmonic (Figure 7).

(a) (a) (b) (b)

Figure 7. ExtraoralExtraoral p post-treatmentost-treatmentFigure 7.pictures: Extraoral ( (aa) )p frontal frontalost-treatment view; view; ( ( bpictures:) lateral lateral view. (a) frontal view; (b) lateral view. Follow-Up Follow-Up Follow-Up The patient is continuing to use the EGA during the night as a method for retention. A bigger The patient is continuingThe to usepatient the isEGA continuing during theto usenight the as EGA a method during for the retention night as. Aa methodbigger for retention. A bigger size was selected because of the molars’ eruption (LM-Activator High Long). This approach aims to size was selected becausesize of thewas molars selected’ eruption because (LMof the-Activator molars’ eruptionHigh Long). (LM This-Activator approach High aims Long). to This approach aims to keep an intermaxillary correct relation and to favor a three-dimensional growth of the dentoalveolar keep an intermaxillary correctkeep an relation intermaxillary and to favor correct a three relation-dimens andional to favor growth a three of the-dimens dentoalveolarional growth of the dentoalveolar processes. The correction of the occlusal plane has to be preserved over time. processes. The correctionprocesses. of the occlusal The correction plane has of to the be preservedocclusal plane over has time to. be preserved over time.

4. Discussion 4. Discussion The functional anterior crossbiteThe functional has an anterior unfavorable crossbite effect has on anthe unfavorable growth pattern effect because on the itgrowth can pattern because it can lead to the development leadof a skto eletalthe development problem. In ofthis a skcondition,eletal problem. the mandible In this condition,slows down the the mandible upper slows down the upper maxilla growth and its advancedmaxilla growth position and favors its advanced the mandible position’s forward favors thegrowth. mandible This ’ssituation forward has growth. This situation has to be interrupted as soonto as be possible, interrupted reaching as soon a correct as possible, occlusal reaching relation, a correctto be mainta occlusalined relation, over time to be maintained over time [24–26]. Furthermore, the[24 familiarity–26]. Furthermore, with a cla thess IIIfamiliarity malocclusion with coulda class genetically III malocclusion predispose could the genetically predispose the patient to this kind of malocclusionpatient to this [27 kind–30]. of malocclusion [27–30]. The selected early treatmentThe aimedselected to earlyreproduce treatment an ideal aimed sagittal to reproduce condition, an acting ideal sagittal on the vertical condition, acting on the vertical dimension and using thedimension eruption forces. and using The theanterior eruption crossbite forces. correction The anterior could crossbite be realized correction because could be realized because of the dental disclusion whileof the wearing dental disclu the intraoralsion while appliance. wearing In the this intraoral way, the appliance. incisor teeth In this can way, return the incisor teeth can return to their physiological position.to their Moreover, physiological this position.EGA has Moreover,some slots thisin the EGA frontal has somearea, whichslots in correct the frontal area, which correct the incisal erupting trajectory.the incisal The eruptingincisal inclination trajectory. change The incisal of the inclination teeth exploits change the of principle the teeth of exploits the principle of

Int. J. Environ. Res. Public Health 2020, 17, 3587 7 of 10

4. Discussion The functional anterior crossbite has an unfavorable effect on the growth pattern because it can lead to the development of a skeletal problem. In this condition, the mandible slows down the upper maxilla growth and its advanced position favors the mandible’s forward growth. This situation has to be interrupted as soon as possible, reaching a correct occlusal relation, to be maintained over time [24–26]. Furthermore, the familiarity with a class III malocclusion could genetically predispose the patient to this kind of malocclusion [27–30]. The selected early treatment aimed to reproduce an ideal sagittal condition, acting on the vertical dimension and using the eruption forces. The anterior crossbite correction could be realized because of the dental disclusion while wearing the intraoral appliance. In this way, the incisor teeth can return to their physiological position. Moreover, this EGA has some slots in the frontal area, which correct the incisal erupting trajectory. The incisal inclination change of the teeth exploits the principle of inclined planes described by Graber et al. [31]. The correct incisor position can avoid the expression of the mandibular growth pattern only on the mandibular body, distributing it also on the branch. The occlusal plane is the most important component affecting the lower face vertical dimension [21]. The bilaterally increased thickness on the molar section, typical of the used appliance, allows the extrusion of the anterior sector and reduces the eruption of the posterior one. This controlled eruption of molars and modification of the occlusal plane is associated with a counterclockwise rotation of the mandible and a slight vertical distraction of the condyle in the glenoid cavity [32,33]. A similar therapy concept is adopted by the treatment with splints, class III elastics, and chin-cups (SEC III). The SEC III approach provides a vertical dimension control, using a thinner ramp on the anterior sector, which causes an anterior rotation of the mandible [12,13]. The Delaire facemask, instead, uses a different approach to cure skeletal class III malocclusions. It applies active orthopedic forces on the maxilla which are inclined to the occlusal plane, resulting in forces directed forwards and downward [34]. This movement trajectory does not control the molars’ eruption with a consequent clockwise rotation of the mandible. This rotation is accepted in normodivergent and in hypodivergent patients, but it is not appropriate in hyperdivergent subjects. For this reason, in hyperdivergent patients, a bite-block appliance in the mandibular arch should be associated with a facial mask to prevent mandibular rotation with progressive closure of the gonial angle [35]. The therapy with EGA allows for perfect management of early, unfavorable occlusal conditions while waiting to understand if orthopedic therapy should proceed. Furthermore, the analyzed intraoral device stimulates the perioral muscles. To keep the device in the mouth, in fact, the patient has to make an effort to keep his closed, activating the surrounding muscles [36,37]. This muscular activation seems to stimulate a counterclockwise rotation of the mandible [5,11]. The muscular activity is also stimulated by the proprioceptive capacity of the mouth, induced by the material properties of the soft transparent biocompatible silicone. The use of EGA can be very useful during an early approach because it makes both traditional and digital teeth impressions unnecessary. This is an important advantage since both alginate and intraoral scans can be not tolerated in early age patients. This removable and easily washable oral device can also encourage better oral hygiene and better oral health status [38]. One of the main advantages of the proposed approach is the low psychosocial and psychological impact on the patient [39]. Early orthodontic treatment with EGA can control some aspects of the growth pattern, like an anterior crossbite, which could end in a class III malocclusion.

Limits of the Study The main limit of this study is the absence of a radiographic control and the impossibility of making a superimposition of traces to record the skeletal changes on the skeleton. This flaw, however, is justified by the As Low As Reasonably Achievable (ALARA) principle of radioprotection [40]. It was not possible to make a control lateral cephalogram after only 7 months of treatment in a 5-year-and-10-month-old child. The second limit is the lack of a long-term follow-up. Int. J. Environ. Res. Public Health 2020, 17, 3587 8 of 10

Following the promising results of the case report, it would be desirable to carry out a clinical study in this regard, in order to clearly assess the effectiveness of dentoskeletal effects of this kind of therapy.

5. Conclusions The treatment of the anterior crossbite with an Eruption Guidance Appliance aimed to have a sagittal control acting on the vertical plane, with an occlusal approach. The chosen EGA was able to correct the occlusal plane inclination, to cause a downward stretching of the condyle, and to harmonize the profile, improving self-esteem. The short-term effect of EGA is dentoalveolar. This therapeutic choice is extremely respectful of the patient’s everyday life because of the minimum psychosocial and psychological impact. All these features make EGA another solution to treat patients with anterior crossbite in early age, during the eruption of incisors.

Author Contributions: Conceptualization, G.P. and M.P.; methodology and formal analysis, S.C. and T.C.; validation, M.P., G.P. and G.F.F.; writing, investigation and data curation, M.P.; writing-review and editing, S.C.; visualization and supervision G.F.F.; project administration, G.P. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Conflicts of Interest: The authors declare no conflict of interest.

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