Co esponding au ho : Camila Alejand a Val e de A é alo
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Sa e a eas o mini-implan placemen in o hodon ics: Bibliog aphic e iew
E ika C is ina Cas o Espinoza 1, Ma ía Es hela Li a do Ochoa 1, Camila Alejand a Val e de A é alo 1, * and
Vale ia del Rosío Siguencia 2
1 Den is y School, Uni e si y o Cuenca, Cuenca, Ecuado .
2 Depa men o O hodon ics Den is y, Den is y School, Uni e si y o Cuenca, Cuenca, Ecuado .
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 1777-1780
Publica ion his o y: Recei ed on 15 July 2025; e ised on 20 Augus ; accep ed on 23 Augus 2025
A icle DOI: h ps://doi.o g/10.30574/wja .2025.27.2.3037
Abs ac
O hodon ic ancho age using mini-implan s has es ablished i sel as an e ec i e means o op imizing biomechanical
con ol du ing o hodon ic ea men . Howe e , i s success la gely depends on he selec ion o he inse ion si e, as an
inapp op ia e loca ion can comp omise ana omical s uc u es and dec ease p ima y s abili y. The pu pose o his
e iew was o iden i y he sa es a eas o mini-implan placemen , in eg a ing e idence published be ween 2010 and
2025. S udies using cone-beam compu ed omog aphy (CBCT), ana omical analyses, and sys ema ic e iews ha
e alua ed in e adicula spaces, co ical hickness, and a ia ions acco ding o age, sex, and skele al pa e n we e
included.
The esul s show ha , in he maxilla, he sa es in e adicula spaces a e loca ed be ween he second p emola and i s
mola , as well as be ween he i s and second mola s on he buccal su ace; in he an e io egion, he app op ia e si e
is be ween he cen al and la e al inciso s, 6 mm om he cemen oenamel junc ion. In he mandible, he p e e ed si e
is be ween he i s and second mola s, 6 mm o mo e apically, and in he an e io egion, be ween he la e al inciso
and canine. The pa amedian egion o he pala e, especially be ween he i s and second p emola s, p o ides he
hickes co ex and he g ea es s abili y. Ex a-al eola al e na i es include he in azygoma ic c es and he
mandibula buccal co ex.
In conclusion, al hough sa e si es exis , mini-implan s abili y is in luenced by indi idual ana omical ac o s, so
indi idualized CBCT planning is ecommended.
Keywo ds: Mini-implan s; Sa e zones; In e adicula ; In azygoma ic idge
1. In oduc ion
Tempo a y ancho age using mini-implan s has become an impo an ool in o hodon ics o a oid pa ien dependency
and allow o con olled oo h mo emen . Howe e , he s abili y and sa e y o hese de ices depend la gely on he
inse ion si e. Imp ope placemen can cause con ac wi h oo h oo s, pe o a ion o he maxilla y sinus, o damage o
he in e io al eola ne e. The e o e, he li e a u e has iden i ied "sa e zones" based on he a ailabili y o in e adicula
space, he quan i y and quali y o co ical bone, so issue ana omy, and he dis ance o c i ical ana omical s uc u es.
This e iew in eg a es clinical and omog aphic e idence published be ween 2010 and 2025 on he ecommended si es
o mini-implan placemen in he al eola and pala al egions, and in ex a-al eola a eas such as he in azygoma ic
idge and he mandibula buccal co ex. S udies in ol ing compu ed omog aphy (CT and CBCT), ana omical
measu emen s on cada e s, and sys ema ic e iews a e included.
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2. Re iew Me hodology
A sea ch was conduc ed in PubMed, PMC, and open-access da abases using e ms such as mini-implan s, sa e zones,
in e adicula , and in azygoma ic c es . A icles in English and Spanish published be ween 2010 and 2025 ha
e alua ed mesiodis al in e oo dis ance, buccal and pala al/lingual co ical hickness, and bone densi y a di e en
heigh s om he cemen oenamel junc ion we e selec ed. A icles compa ing a ia ions by age, sex, and skele al pa e n
we e also e iewed.
S udies using cone beam compu ed omog aphy (CBCT) we e speci ically consul ed o i s accu acy in measu ing
in e adicula dis ances and co ical hickness, as well as e iews es ablishing clinical guidelines. Da a we e syn hesized
by ana omical egion (maxilla, mandibula , pala al, ex aal eola a eas).
In he maxilla, he e a e buccal in e adicula spaces, which a e di ided in o:
• An e io egion. Fayed e al. [1] e alua ed 100 pa ien s using CBCT and de e mined ha , in he an e io egion
o he maxilla, he op imal si e o mic oimplan s is loca ed be ween he cen al inciso and he la e al inciso ,
6 mm apical o he cemen oenamel junc ion. This space o e s g ea e mesiodis al dis ance wi hou
comp omising he oo s and a ela i ely hick pala al co ex [1].
• Pos e io egion. The same s udy no ed ha , on he buccal su ace, he mos secu e inse ion si es a e be ween
he second p emola and i s mola , as well as be ween he i s and second mola s[1]. A 2025 CBCT s udy
(Gup a e al.)[2] measu ed he dimensions a 6 mm om he CEJ in 100 subjec s and ound ha he la ges
mesiodis al space (app oxima ely 3.5 mm) and he la ges bucco-pala al dis ance (app oxima ely 14 mm) a e
eco ded be ween he i s mola and second p emola . Fu he mo e, he la ges buccal co ex (app oxima ely
1.9 mm a 4 mm apical) is loca ed be ween he i s and second mola s[2]. These indings suppo ha he
pos e io a ea be ween p emola s and mola s is p e e able o mini-implan s o 1.2–1.6 mm diame e .Co ical
pala ina
• An e io pa amedian zone. The li e a u e highligh s he pa amedian pa o he pala e (3–5 mm om he
midline and 6–8 mm pos e io o he inciso s) as one o he bes a eas o mini-implan s due o i s hick co ical
bone and ke a inized mucosa. The s udy by Fayed e al. [1], indica ed ha he la ges pala al co ex
(app oxima ely 1.77 mm a 6 mm apical) was loca ed be ween he i s and second p emola s [2], so he sligh ly
mo e apical pala al inse ion be ween p emola s o e s s abili y and a oids he inciso pala al canal.
On he o he hand, in he mandible, he o al in e adicula spaces a e di ided in o:
• An e io egion. Acco ding o Fayed e al. [2], he ecommended si e in he an e io mandible is loca ed
be ween he la e al inciso and he canine, 6 mm om he cemen oenamel junc ion [1]. The in e adicula
dis ance is mode a e, and he inse ion should be sligh ly angled o a oid con e gen oo s.
• Pos e io egion. Bo h he s udy by Fayed e al. [2] and Gup a e al. ag ee ha he wides and hickes co ical
space (app oxima ely 4.7 mm mesiodis al dis ance and app oxima ely 13.6 mm bucco-lingual hickness a 6
mm om he cemen oenamel junc ion) is loca ed be ween he i s and second mandibula mola s [2].
Fu he mo e, he la ges buccal (3 mm) and lingual (2.6 mm) co ex a e loca ed a his si e [2]. The e o e,
inse ion in he mola egion, p e e ably 6 mm o mo e apical o he cemen oenamel junc ion, educes he isk
o oo con ac .
3. Fac o s In luencing Co ical Thickness
Da a om Casse a e al. [3] demons a ed ha co ical hickness and densi y inc ease om he al eola c es o he
base; hey a e g ea e in adul s han in adolescen s and in men han in women. Fu he mo e, he mandibula co ex is
hicke and dense han he maxilla, and he pos e io egion p esen s highe alues han he an e io egion [4]. These
in e indi idual di e ences jus i y selec ing longe mini-implan s o inc easing he a achmen le el (6–8 mm om he
c es ) o achie e s abili y in pa ien s wi h hin co ices [4].
4. Ex aal eola Zones
4.1. In azygoma ic C es (IZC)
The in azygoma ic idge, loca ed abo e he mesiobuccal oo o he maxilla y i s mola , p o ides hick co ical bone and an
ex aal eola a achmen ha a oids oo s and sinuses. Se e al s udies indica e ha he sa e zone is 11–14 mm abo e he al eola c es
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 1777-1780
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be ween he i s and second mola s, whe e he bone is mo e han 3 mm hick. Mini-implan s a e placed a a 30–70° inclina ion o
maximize bone ajec o y leng h and minimize pene a ion in o he maxilla y sinus. This zone is especially use ul o dis alizing he
maxilla o co ec ing Class II de o mi ies [5].
4.2. Mandibula Buccal Shel
The ou e co ex o he mandible, abo e he ex e nal oblique line and behind he second mola s, cons i u es a use ul
ex aal eola a ea o dis alizing mandibula ee h. CBCT s udies epo ha he hickes bone is loca ed be ween he
mandibula i s and second mola s, 4–5 mm abo e he mucogingi al junc ion, wi h a co ical hickness o 3–4 mm. The
inse ion is angled 20–30° o he occlusal plane o maximize bone su ace a ea and a oid he in e io al eola ne e [6].
O he conside a ions
• Angle and dep h o inse ion. A 60–70° angle is ecommended in he buccal in e adicula egion o inc ease
he co ical con ac leng h and mo e he ips away om he oo s. In he pala al egion and ex aal eola a eas,
he angle may be smalle (30–45°) due o g ea e bone hickness [3].
• Minimum dis ance be ween oo s. Fo sc ews wi h a diame e o 1.2–1.6 mm, a minimum in e adicula
space o 3 mm is equi ed o p ese e 1 mm o bone a ound he implan . The s udy by Gup a e al. [2] showed
ha he spaces be ween he i s mola and second p emola in he maxilla and be ween he i s and second
mola s in he mandible exceed his measu emen a 6 mm om he cemen oenamel junc ion [7].
• Ana omical a ia ions and age. The co ex hickens wi h age and in men[3]; in adolescen s o pa ien s wi h
hin co ex, i is ecommended o use longe sc ews o o selec he pala al egion. People wi h c anio acial
synd omes such as Down synd ome may ha e limi ed sa e zones, so speci ic omog aphic maps help wi h
planning [8].
• Pos ope a i e ca e. Rigo ous hygiene, ligh immedia e loading, and he absence o mic omo emen s a o he
su i al o mini-implan s. So issue in lamma ion is conside ed one o he main ac o s o ailu e.
5. Discussion
The e idence e iewed demons a es ha he egions wi h he g ea es co ical hickness and in e adicula dis ance
a e concen a ed in he pos e io si es o he maxilla and mandible. The space be ween he maxilla y second p emola
and i s mola o e s, 6 mm om he cemen oenamel junc ion, a mesiodis al space o app oxima ely 3.5 mm and a
buccopala al hickness o 14 mm [2]. In he mandible, he space be ween he i s and second mola s p esen s an e en
g ea e dis ance and hickness, wi h a buccal co ex o app oxima ely 3 mm [2]. These measu emen s allow he inse ion
o s anda d-diame e mini-implan s wi hou isk o oo con ac .
The pa amedian pala ine egion is also a p i ileged a ea due o he combina ion o ke a inized mucosa and hick co ical
bone; howe e , he ope a o should a oid he incisi e canal and he g ea e pala ine o amen. Da a om Fayed e al.
and Gup a e al. indica e ha he pala al co ex eaches alues g ea e han 1.7 mm be ween he i s and second
p emola s [2].
Va ia ions in co ical hickness by age, sex, and skele al pa e n sugges ha “sa e zone” guidelines a e no absolu e.
Casse a e al. demons a ed ha adul s and men ha e hicke co ices han adolescen s and women[3]; u he mo e,
he co ical bone is hicke lingually han buccally[4]. These obse a ions unde sco e he impo ance o indi idual
assessmen using 3D imaging be o e inse ion.
Ex aal eola a eas such as he in azygoma ic c es and he mandibula buccal su ace expand he ancho age
possibili ies o block mo emen s. Thei main ad an age is ha hey a oid he in e adicula space and p o ide hick
co ical bone. Howe e , ca e mus be aken wi h s uc u es such as he maxilla y sinus and in e io al eola ne e, and
he inse ion angle mus be adjus ed o maximize he leng h o he bone ac .
6. Conclusions
Selec ing he app op ia e si e o mini-implan placemen in o hodon ics is a de e mining ac o in ensu ing hei
s abili y and clinical success. In he maxilla, he sa es in e adicula spaces a e loca ed be ween he second p emola
and he i s mola , as well as be ween he i s and second mola s on he buccal su ace. In he an e io egion, he a ea
be ween he cen al and la e al inciso s, app oxima ely 6 mm om he cemen oenamel junc ion, is also conside ed
sui able o he inse ion o hese de ices.
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In he mandible, he p e e ed in e adicula si e is loca ed be ween he i s and second mola s, p o ided ha inse ion
is 6 mm o mo e apical o he cemen oenamel junc ion, and ha he e is su icien mesiodis al space and a buccal co ex
o app oxima ely 3 mm. In he an e io egion, he space be ween he la e al inciso and he canine has been iden i ied
as a ecommended a ea.
Rega ding he pala al co ex, he pa amedian egion o he pala e ep esen s he mos a o able si e, pa icula ly
be ween he i s and second p emola s, because i o e s a g ea e amoun o co ical bone and, consequen ly, a mo e
s able suppo o mini-implan s.
Addi ionally, he e a e ex a-al eola a eas ha cons i u e sa e al e na i es in speci ic cases. These include he
in azygoma ic c es , loca ed be ween 11 and 14 mm abo e he al eola c es , and he mandibula buccal su ace
pos e io o he mola s. Placemen in hese a eas equi es ca e ul planning and he use o adiog aphic s udies o a oid
comp omising adjacen ana omical s uc u es.
Finally, i is impo an o conside ha he s abili y o he mini-implan depends no only on he ana omical loca ion bu
also on indi idual ac o s such as bone quali y, age, sex, and skele al s uc u e o he pa ien . In his ega d, al hough
he e a e gene ally sa e a eas, an indi idual assessmen using cone beam compu ed omog aphy (CBCT) is always
ecommended o de e mine he mos app op ia e inse ion si e in each case [3]. This e iew highligh s he impo ance
o in eg a ing ana omical e idence wi h indi idual clinical assessmen o selec he op imal loca ion o mini-implan s
and minimize complica ions.
Compliance wi h e hical s anda ds
Disclosu e o con lic o in e es
No con lic o in e es o be disclosed.
Re e ences
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