CLINICALSECTION

Versatility and benefits of mini-implantsfor vertical and sagittal anchorage in agrowing open bite class II patient

Sergio Estelita, Guilherme Janson and Kelly ChiquetoBauru Dental School/University of Sao Paulo, Bauru, Sao Paulo, Brazil

This case report presents the details of a growing patient with a class II malocclusion, anterior open bite, and posterior

crossbite, where the side effects of treatment mechanics were significantly reduced by the use of mini-implants for anchorage.

Key words: Mini-implant, anchorage, open bite, class II

Received 14 February 2011; accepted 18 November 2011

Introduction

The treatment of class II open bite malocclusion during

active growth and in the early permanent dentition

frequently presents a challenge for orthodontists. It

requires patient compliance with removable orthopaedic

appliances and/or intermaxillary elastics for complete

sagittal and vertical correction.1 Furthermore, unfa-

vourable growth can increase the side effects of the

orthodontic mechanics and make it difficult to achieve

overall malocclusion correction without causing unde-

sirable dentoskeletal and aesthetic changes.

The use of anterior vertical elastics to close an anterior

open bite leads to incisor extrusion that can cause or

increase the gingival exposure during smiling.2–4 In

addition, intermaxillary class II elastics produce extru-

sion of the mandibular posterior teeth that is undesir-

able for open bite correction. Class II correction with

headgear and functional appliances is usually associated

with distalization and/or extrusion of the posterior teeth,

which are not favourable for open bite correction.5,6

Mini-implants have frequently been used for intrusion

of posterior teeth in adult patients and this is now a

useful treatment option for open bite correction without

extrusion of the anterior teeth and increase in face

height.2,4,7–9 Mini-implants have also been used to

correct class II malocclusion through distalization of

upper buccal segments. It is known that restraint and

control of excessive vertical maxillary growth, especially

in the posterior region to prevent downward and

backward rotation of the mandible, is desirable in the

treatment of growing patients with open bite associated

with class II malocclusion.10,11 The use of mini-implants

for this specific treatment objective has rarely been

reported.

This case report shows a patient with an open bite

class II malocclusion, where mini-implants were needed

to correct both sagittal and vertical discrepancies.

Case report

A 12-year-old girl sought orthodontic treatment in the

Orthodontic Department of Bauru Dental School,

University of Sao Paulo, Brazil. The chief patientcomplaints were concerning her anterior open bite

and dental crowding. The patient’s mother reported a

history of thumb-sucking in her daughter, which had

been discontinued years ago.The mother also reported

no family history of similar malocclusions and the

daughter had received regular medical and dental care.

Extra-oral examination (Figure 1a–c)

The patient presented with a symmetrical face and a

moderate degree of lip strain in an attempt to achieve lip

seal. She had a convex facial profile, slight mandibularretrusion, acute nasolabial angle and increased lower

anterior facial height. During smiling, there was

increased posterior gingival show, an increased buccal

corridor and a flat smile arc.

Intra-oral examination (Figure 2a–e)

The patient presented in the early permanent dentition

with a class II division 1 incisor relationship, a 5 mm

overjet and 3 mm anterior open bite. There was a

Journal of Orthodontics, Vol. 39, 2012, 43–53

Address for correspondence: S. Estelita, Bauru Dental School/

University of Sao Paulo, Bauru, Sao Paulo, Brazil.

Email: sergioestelita@yahoo.com.br# 2012 British Orthodontic Society DOI 10.1179/14653121226815

bilateral class II molar relationship and a bilateral

posterior crossbite involving the premolars. There was

4 mm of crowding in the upper arch and 3 mm of

crowding in the lower arch. The upper dental centreline

was coincident with the mid-facial axis, but the lowerdental centreline was slightly deviated towards the left

side. The lower second premolars, particularly the lower

right, presented with an abnormal morphology.

The patient had excellent dental health and oral

hygiene.

The dental health component of the Index of Ortho-

dontic Treatment Need was 3e, and the Aesthetic

Component was 4.

Radiographic examination (Figure 3a–c and

Table 112–15)

The cephalometric evaluation showed a small antero-

posterior skeletal discrepancy, increased lower facial

height and proclined maxillary incisors.The panoramic

radiograph showed that the maxillary and mandibular

third molars were present. There was no evidence of

restorations, caries or any other pathology.

Anterior open bite, posterior crossbite and class II

molar relationship have been significantly associated

with non-nutritive sucking habits;16 therefore, the

aetiology of the malocclusion could have been more

(a) (b)

(c) (d) (e)

Figure 2 Pre-treatment intra-oral photographs: (a) right buccal; (b) frontal; (c) left buccal; (d) maxillary occlusal; and (e) mandibular

occlusal. Note the open bite, class II and crossbite malocclusions, besides tooth crowding

(a) (b) (c)

Figure 1 Pre-treatment facial photographs: (a) frontal, (b) frontal smiling: note the unaesthetic smile, and (c) profile: note the profile

convexity and the slight mandibular retrusion

44 Estelita et al. Clinical Section JO March 2012

associated with the digit habit and consequent dentoal-

veolar changes, than with a severe skeletal discrepancy.

Problem list

Considering the extra-oral, intra-oral and radiographic

examination, the following problem list was elaborated:

N moderate lip strain;

N posterior gummy smile;

N increased buccal corridor;

N flat smile arc;

N acute nasolabial angle;

N anterior open bite;

N bilateral class II malocclusion;

N bilateral posterior crossbite of the premolars;

N upper and lower arch crowding;

N lower dental centreline slightly deviated towards left

side;

N slight mandibular retrusion and facial height increase.

Aims of treatment

Considering that the patient did not have a significant

skeletal discrepancy or facial imbalance, the primary

treatment objective was to correct the malocclusion

orthodontically, avoiding any adverse side effects due to

the treatment mechanics. It was decided to correct it mainly

by intrusion of the posterior teeth instead of extrusion of the

anterior teeth, avoiding an anterior gummy smile. This

treatment could also prevent the increase of the posterior

gummy smile, increased lower facial height and mandibular

retrusion due to backward rotation.

The treatment of the class II malocclusion also required

distalization of the maxillary teeth to reduce the overjet and

dental crowding, increasing the nasolabial angle, reducing the

profile convexity and promoting a passive lip seal. However,

distal movement of the posterior teeth is not desirable during

open bite correction;5,6 therefore extraction of premolars

would allow the achievement of the treatment aims without

causing adverse effects inherent to distalization of posterior

teeth.5 Furthermore, it has been demonstrated that open bite

malocclusions treated with extractions might achieve more

stable results when compared to non-extraction treatment.17

Finally, the slight lingual tipping of the upper posterior teeth

should be treated to correct the localized posterior crossbite

and decrease the buccal corridor.

Aims of treatment

N relief of crowding;

N reduction of the overjet;

(a) (b)

(c)

Figure 3 Pre-treatment radiographs: (a) lateral cephalometric

radiograph; (b) cephalometric tracing showing an increased lower

facial height; and (c) panoramic radiograph: note that the upper

third molars represent a negative factor for class II correction with

molar distalization

Table 1 Pre-treatment cephalometric measurements and norms.

Variables Pre-treatment Normal (SD)12–15

SNA (u) 82 82 (3)

SNB (u) 78 79 (3)

ANB (u) 4 3 (2)

SN.GoGn (u) 33 32 (5)

FMA 27 27 (3)

MMPA (u) 31 26 (6)

LPFH/LAFH* 0.57 (41/72) 0.66

FP (LAFH/TAFH6100){ 57% (72/125) 55%

U1.NA (u) 32 22 (6)

U1 to MxPl (u) 120 116 (5)

U1-NA (mm) 8 4 (2)

L1.NB (u) 28 25 (5)

L1 to MnPl (u) 94 93 (5)

L1-NB (mm) 5 4 (2)

U1.L1 (u) 116 129 (8)

L1-APo (mm) 2 3 (2)

Nasolabial angle (u) 89 105 (10)

Overjet (mm) 6 3 (2)

Overbite (mm) 23 2 (2)

*Facial height index (FHI).{Facial proportion.

JO March 2012 Clinical Section Mini-implant for vertical and sagittal anchorage 45

N correction of the anterior open bite, avoiding anterior

teeth extrusion;

N correction of the posterior dental tipping, decreasing

the buccal corridor;

N obtain a class I canine relationships without distaliza-

tion of posterior teeth;

N finish to class I canine and class II molar relation-

ships;

N obtain passive lip seal;

N improvement of the facial aesthetics.

Treatment plan

To achieve the treatment aims, the following plan was

decided upon:

N extraction of upper left first and upper right second

premolars;

N placement of bands on the upper first molars and a

transpalatal arch;

N placement of upper and lower fixed appliances to

align and level the arches;

N maintain the transverse molar relationships during

premolar crossbite correction;

N placement of mini-implants between the upper first

molars and premolars to aid anterior retraction of the

maxillary teeth and intrusion of posterior maxillary

teeth;

N final detailing of the occlusion;

N retention using a maxillary Hawley retainer and a

canine-to-canine mandibular bonded retainer.

Treatment progress

The right second premolar was considered to be

displaced palatally, which is why this tooth was

extracted, along with the upper left first premolar.

Two weeks after extractions, a 0.036-inch stainless steel

transpalatal arch was manufactured and soldered to thefirst molar bands to maintain the transverse molar

relationships during correction of the palatally placed

premolars (Figure 2b). Fixed 0.02260.028-inch pre-

adjusted edgewise appliances (Morelli Metal Brackets,

Roth prescription, Sorocaba, SP, Brazil) were placed to

level and align the maxillary and mandibular arches

with a typical wire sequence characterized initially by

0.016-inch Ni–Ti alloy, followed by 0.016-, 0.018-,0.020- and 0.01960.025-inch stainless steel archwires

(3M Unitek, Monrovia, CA, USA). The extraction

space allowed anterior and posterior alignment without

upper incisor protrusion.

After alignment, the mini-implants were inserted

under local infiltrative anaesthesia in the maxillary

buccal alveolar bone between the first and second upper

molars for anterior retraction. The insertion protocoldid not include prior cortical bone drilling with a

surgical drill, and the mini-implants were screwed into

place manually using a screwdriver. On the left side, a

self-drilling 1.567 mm mini-implant (SH 1514-07,

Absoanchor; Dentos, Daegu, Korea) was inserted,

whereas on the right side, a self-drilling 1.668 mm

bracket head mini-implant (16-G2-008, JEIL Dual-Top

Anchor System; JEIL Medical Corporation, Seoul,Korea) was placed to anchor the anterior retraction

forces. The anterior segmental retraction was accom-

plished with rectangular stainless steel archwires

(0.01960.025-inch) and 200 g of force was applied on

each side with intramaxillary elastic chains extending

from the mini-implant to the crimpable hook to retract

the upper anterior teeth en masse. The time taken for the

retraction phase was 11 months, which can be consid-ered normal when skeletal anchorage is used because the

molars are not displaced towards the extraction space.

After retraction of the anterior teeth using the mini-

implant as anchorage, the 0.01960.025-inch stainless

steel archwire was sectioned distal to the canines. Theupper first molar bands and transpalatal arch were

removed. Sequentially, the second molars were banded,

and the first molar bands were replaced into position

without the transpalatal arch and an alginate impression

taken in order to fabricate a new 0.036-inch stainless

steel transpalatal arch that extended to the second molar

(Figure 4). This procedure allowed posterior arch

intrusion without affecting the anterior teeth.

The use of the transpalatal arch was maintained until

the end of the intrusion phase to counteract the molar

buccal tipping tendency during vertical intrusion and

making it unnecessary to place a palatal mini-implant.An intrusion force of 300–350 g, exerted by elastic

chains, was used for molar intrusion and checked with

an orthodontic tension gauge (Correx series 040-712-00;

Dentaurum Orthodontics). A vertical force was applied

during the eight months up to complete closure of the

open bite (Figure 4). The mini-implants were stable

during the retraction and intrusion mechanics and were

removed before the treatment finishing phase.

After closure of the open bite, the transpalatal arch

was removed to allow individual tooth positioning

during finishing. Continuous rectangular stainless steel

archwires (0.01860.025-inch) were used with finishingbends to improve individual teeth positions and occlusal

relationships (Figure 5a–c). Final settling was achieved

with vertical intermaxillary elastics (0.75 in; 2 oz) used

for only 6 weeks to obtain excellent dental interdigita-

tion. Before fixed appliance removal, the rectangular

archwire was segmented distal to the upper and lower

46 Estelita et al. Clinical Section JO March 2012

lateral incisors to evaluate occlusal changes and open

bite correction stability with minimal tooth retention for

two months (Figure 5d–f). The total treatment time was

30 months, including tooth alignment (7 months), ante-

rior retraction (11 months), molar intrusion (8 months)

and treatment finishing (4 months).

Following fixed appliance removal, a maxillary

Hawley retainer and a mandibular fixed retainer were

placed. The Hawley retainer was worn full-time for

18 months, followed by 6 months of night-time wear,

whereas the patient was warned that the lingual fixed

retainer would need to be maintained permanently.

(a) (b) (c)

(d) (e) (f)

Figure 5 (a–c) Treatment finishing with some compensatory bends to improve individual teeth positions and interdigitation. (d–f)

Segmented rectangular archwires to evaluate the initial open bite correction stability before appliance removal

(a) (b)

(c) (d) (e)

Figure 4 Progressive intrusion of maxillary posterior teeth to correct anterior open bite with buccal mini-implant and transpalatal arch;

(a,b) the mini-implants are being used to intrude the first and second upper molars; (c,d) advanced intrusion phase: note the degree of

molar intrusion and open bite closing; (e) transpalatal arch to avoid excessive buccal tipping of the posterior teeth during intrusion

mechanic without palatal mini-implants

JO March 2012 Clinical Section Mini-implant for vertical and sagittal anchorage 47

Treatment results

The patient’s facial aesthetics were significantly

improved by establishing a passive lip seal, a better

nasolabial angle, and a more orthognathic soft tissue

profile, even as the lower anterior facial height remained

unchanged (Figure 6). The posterior gummy smile was

satisfactorily corrected by posterior intrusion of the

maxillary arch. The anterior gingival exposure was

slightly increased during alignment, but only to the

extent necessary to correct the initial flat smile arc. The

buccal corridor was reduced after correction of the

palatal placed upper premolars. Thus, the patient’s smile

aesthetic was greatly improved.

An excellent occlusal result was obtained (Figure 7).

The anteroposterior discrepancy was resolved, and a

normal overjet, and class I canine and class II molar

relationships were established. The vertical problem was

corrected, and a 2.5 mm overbite was achieved after

open bite closing at the expense of the posterior

intrusion of the maxillary arch. An adequate transverse

relationship of the arches was achieved.

Cephalometrically, the ANB angle was improved from

4u to 2u (Figures 8 and 9, and Table 2). The lower

anterior face height/lower posterior face height (LAFH/

LPFH) showed that this facial height index was changed

from 0.57 to 0.62 because of a LPFH increase and

LAFH control during treatment (Figures 8 and 9, and

(a) (b) (c)

Figure 6 Post-treatment facial photographs; (a) frontal; (b) frontal smiling: note the smile aesthetic improvement; and (c) profile: the

nasolabial angle, profile convexity and lip seal also showed favorable changes

(a) (b)

(c) (d) (e)

Figure 7 Post-treatment intra-oral photographs: (a) right buccal; (b) frontal; (c) left buccal; (d) maxillary occlusal and (e) mandibular occlusal.

Final occlusion obtained with molar intrusion and upper premolars extractions for anterior open bite and class II correction during growth

48 Estelita et al. Clinical Section JO March 2012

Table 2). The facial proportion (LAFH/total anterior

face height — TAFH) was slightly improved towards

the normal value (55%) due to an increase in the upper

anterior face height, because the LAFH was not signi-

ficantly changed. These changes suggest that there was a

counterclockwise mandibular rotation with both the

Frankfort-mandibular plane angle (FMA) and max-

illary-mandibular planes angle (MMPA) reducing from

27u to 24u and from 31u to 29u, respectively.

The maxillary incisors were retracted without

significant lingual tipping because of adequate torque

control. The different rates of vertical alveolar

growth established between the anterior and poster-

ior segments of the maxillary arch by molar intrusion

contributed to achieving a normal overbite. The man-

dibular incisors were slightly proclined, because inter-

proximal enamel reduction was not undertaken during

alignment of the slight mandibular crowding. The

interincisal angle was not significantly changed because

the maxillary and mandibular incisors were tipped

slightly in opposite directions. The premolar extraction,

growth and the absence of distalization mechanics may

have allowed uprighting of the third molar eruption

axis. A supernumerary maxillary molar was only dia-

gnosed at the end of the treatment and its extraction

was requested.

Discussion

Considering that the skeletal imbalance was not

excessive, orthodontic-surgical correction was not con-

sidered as a treatment option. The open bite ortho-

dontic correction with anterior teeth extrusion was not

considered because, in this case, posterior intrusion

could present significant advantages, such as lower

facial height maintenance or reduction, unchanged

anterior gingival level, posterior gummy smile correc-

tion, counterclockwise mandibular rotation, antero-

posterior discrepancy improvement and lip strain

reduction. For these reasons, posterior intrusion was

considered the best choice. Several appliances have

been proposed for posterior molar intrusion, mainly

for situations when significant growth potential is still

present. High-pull headgear and bite blocks can obtain

relative intrusion, but their efficiency depends on

patient compliance.1,18

The lower facial height was unchanged in spite of

the patient being treated during active facial growth

for 3 years. Considering that the posterior alveolar

growth and the vertical growth of the maxillary basal

bone are important factors for increasing the lower

anterior facial height, the real and relative intrusion of

posterior maxillary teeth (i.e. intrusive tooth move-

ment associated with the reduction rate of vertical

alveolar growth) contributed to the lower anterior

facial height maintenance, counteracting the effects of

vertical growth of the maxillary basal bone and the

posterior alveolar growth of the mandible.19 On the

other hand, the increased rate of the posterior facial

height was not directly influenced by the treatment

mechanics because it depends on the lowering of the

middle cranial fossa and the increase in the ramus

height.20,21 As a consequence, the posterior facial height

demonstrated a greater increase than the anterior fa-

cial height (Table 2), and the mandibular plane rotated

in a counterclockwise direction, which can be more

easily achieved in growing compared with non-growth

patients.4,22 This desirable skeletal change allowed

a greater anterior mandibular growth expression

(Table 2).2,19,22

A greater treatment effect on dentoskeletal vertical

discrepancies can be obtained if, as suggested, the

(a) (b)

(c)

Figure 8 Post-treatment radiographs: (a) lateral cephalometric

radiograph; (b) cephalometric tracing: note that the mandibular

counterclockwise rotation contributed to reduce the mandibular

retrusion and control the anterior facial height increase; (c)

panoramic radiograph: note the uprighting of the third molar

eruption axis, which can be associated to distalization mechanics

absence. A supernumerary maxillary molar was diagnosed and its

extraction was requested

JO March 2012 Clinical Section Mini-implant for vertical and sagittal anchorage 49

intrusion mechanics are applied to maxillary and man-

dibular molars to treat more severe open bite cases.

Considering that molar intrusion with skeletal ancho-

rage in adult patients has been described as simpler

and more advantageous than double-jaw orthognathic

surgery,9 it can be speculated that the use of mini-

implants for molar vertical control during active facial

growth may be a suitable option for treatment of

severe vertical discrepancies. In fact, this protocol

applied to growing patients allows real molar in-

trusion, different rates of vertical alveolar growth

between anterior and posterior maxillary arch seg-

ments, and facial height index reduction, which en-

hance mandibular counterclockwise rotation and chin

advancement.11,19 However, this is only one case

report, and a RCT study design would be required

to determine effectiveness with an acceptable level of

scientific evidence.

Considering the maxillary arch crowding and pro-

trusion, acute nasolabial angle and lip strain, the class

II malocclusion could be better corrected by distaliza-

tion of maxillary teeth instead of mesial movement of

Table 2 Post-treatment measurements and cephalometric changes.

Variables Pre-treatment Post-treatment Change

SNA (u) 82 82 0

SNB (u) 78 80 z2

ANB (u) 4 2 22

SN.GoGn (u) 33 29 24

FMA 27 24 23

MMPA (u) 31 29 22

LPFH/LAFH 0.57 (41/72) 0.62 (45/72) z0.05

FP (LAFH/TAFH6100) 57% (72/125) 56% (72/128) 21%

U1.NA (u) 32 31 21

U1 to MxPl (u) 120 118 22

U1-NA (mm) 8 6 22

L1.NB (u) 28 30 z2

L1 to MnPl (u) 94 98 z4

L1-NB (mm) 5 6 z1

U1.L1 (u) 116 114 22

L1-APo (mm) 2 4 z2

Nasolabial angle (u) 89 94 z5

Overjet (mm) 6 2 24

Overbite (mm) 23 2 z5

Figure 9 Superimposition of cephalometric tracings. (a) Cephalometric tracings superimposed on the sella–nasion plane at sella. (b)

Maxilla tracings superimposed on the palatal plane at ANS, and mandible tracings superimposed on the mandibular plane at menton

50 Estelita et al. Clinical Section JO March 2012

the mandibular arch. Therefore, class II intermaxillary

elastics and removable or fixed functional applianceswere not selected in this case. The appliances usually

used for maxillary arch distalization were also

not used because the distal movement of the poste-

rior teeth is not the best approach to open bite

correction.5,6 Thus, maxillary premolar extraction

and incisor retraction would allow overjet and canine

relationship correction, tooth alignment and improve-

ment of the nasolabial angle, profile convexity, andlip seal without the undesirable effects of posterior

teeth distalization and patient compliance with re-

movable appliances for anchorage reinforcement. Fur-

thermore, the presence of the maxillary third molar

represents a negative factor when molar distalization is

intended.23 Finally, the extraction protocol can

improve open bite correction stability.17 The mini-

implants were used for both posterior intrusion andanterior retraction.

In this case report, tooth extractions were accom-

plished prior to molar intrusion. However, if tooth

crowding and class II correction can be expected after

arch expansion and molar intrusion, then initialextractions should be avoided or at least delayed and

their need re-evaluated. Although molar intrusion for

open bite correction has been associated with improve-

ment in the class II malocclusion owing to the

counterclockwise mandibular rotation,8 intermaxillary

elastics are sometimes required to achieve a class I

molar relationship.19 Thus, molar intrusion does not

always ensure class II relationship correction. Perhaps,the degree of class II molar relationship severity can be

used as a helpful clinical parameter to define when the

maxillary premolar extraction should be associated

with molar intrusion to adequately correct the ante-

roposterior discrepancy.

Although tooth extraction can benefit the open bite

correction stability, molar intrusion relapse is an

undesirable event that can occur at a rate of 18–

30%.2,7,24 In Baek’s study,7 most intrusion relapse

occurred during the first year of retention. Because of

this, the author suggested the application of an appro-

priate retention method during this critical period toenhance the long-term stability of the treatment. In

fact, a small degree of molar intrusion relapse can cause

a significant incisor overlap reduction.

The upper arch width showed only slight deficiencyand was restricted to the premolar region because the

transverse discrepancy seemed to originate from lin-

gual tipping of the maxillary posterior teeth and not

from the basal bone. The mini-implants inserted into

the maxillary posterior buccal bone can help to correct

the lingual tipping of the posterior teeth, mainly the

one associated with posterior crossbite, open bite and

class II malocclusions, making their clinical benefits

significantly greater than their inherent biological and

financial costs. In this case, mini-implants were not

used to correct the lingual tipping of the posterior

teeth because of an alternative treatment plan, but

their use for this intent could make the transpalatal

arch dispensable.

Molar root resorption during intrusion can be consid-

ered an undesirable side effect of this clinical procedure.

Although the panoramic radiograph is not adequate for

accurate measurement of root resorption, a qualitative

comparison shows that the maxillary molar roots were

without any significant external apical root resorption

(Figures 3 and 8). This finding is not different from other

reports, which did not observe a significant amount of root

resorption.2,25–28 According to Ari-Demirkaya et al.,25 the

intruded molars had a root resorption rate only 0.5 mm

greater than that of non-intruded molars. More recently,

Heravi et al.27 found a mean root resorption of 0.4 mm.

These studies considered the root resorption degree sta-

tistically significant, but not clinically significant. Thus,

this minimal root shortening has not been considered

a limiting factor for molar intrusion with skeletal

anchorage.

The improvement in facial aesthetics obtained from

orthodontic treatment is consequent to the favourable

dentoskeletal changes, which depend on the efficient

control of undesirable mechanics. In this report, the

lower facial height control associated with overjet and

class II correction, without posterior teeth distalization

and patient compliance, contributed to achieving a

passive lip seal, nasolabial angle opening and a less

convex soft tissue profile.8 At the end of the treatment,

the patient was very satisfied with these changes,

corroborating the many studies in which laypersons

and orthodontists from various races and ethnic groups

agree that an orthognathic profile with a balanced or

slightly reduced lower facial height is preferred to a

convex or concave silhouette with increased facial

height.29,30

Smile aesthetics represents a very important psycho-

social factor that influences self-perception of smile

attractiveness. In this case, anterior vertical elastics

were not used to avoid an anterior gummy smile,

whereas the posterior gummy smile was satisfactorily

reduced by intrusion mechanics. The flat smile arc was

corrected, and the size of the buccal corridor was

reduced with maxillary arch expansion. Thus, the smile

attractiveness was greatly improved, and the self-

perception of the patient about the smile changes was

significantly positive.

JO March 2012 Clinical Section Mini-implant for vertical and sagittal anchorage 51

Conclusions

Mini-implants inserted into the maxillary posterior

buccal alveolar bone can be useful for posterior

intrusion, anterior retraction and arch expansion in

patients with a class II malocclusion, an anterior open

bite and posterior crossbite. Additionally, the use of

mini-implants for intrusion during active growth can

lead to a favourable mandibular counterclockwise ro-

tation with significant benefits for vertical and ante-

roposterior discrepancy correction without patient

compliance.

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