Orthodontics and Oral Surgery
Impacted maxillary incisors
The incidence of unerupted maxillary central incisor in the 5–12 year-old
age group has been reported as 0.13% McPhee
In a referred population to regional hospitals the prevalence has been
estimated as 2.6% DiBiase
In the premaxillary region, where there is a failure of eruption of the
permanent incisors, the effects of supernumerary teeth have been reported
variably at 28% and 38%.
Tuberculate supernumerary teeth are more likely to cause an obstruction
than conical supernumerary teeth (1in 5 compared to 1 in 1).
In addition, 1/3 of compound odontomes and 1/2 of complex odontomes
prevent eruption of teeth (compound odontomes are four times more
common than complex odontomes).
In 54-78% of cases in which supernumerary teeth overlie the incisor,
removal of the supernumerary will result in the permanent incisor
erupting spontaneously within an average time of 16 months provided
there is enough space
Causes of delayed eruption
Delayed eruption can be classified into two causative groups. Hitchen
A. cleft lip and palate
B. cleidocranial dysostosis,
C. gingival fibromatosis.
D. Supernumerary teeth , odontomes,
E. abnormal tooth/tissue ratio,
F. generalised retarded eruption,
B. early extraction or loss of deciduous teeth
C. retained deciduous teeth,
D. cystic formation
E. endocrine abnormalities
F. bone disease
G. primary failure of eruption,
H. Thick bone or tissue.
Or can be classified into local and general by Fleming
Management of unerupted maxillary incisors
A. History of pain or trauma
B. Family history
2. VISUAL EXAMINATION
A. there is eruption of contralateral teeth that occurred greater than six
B. both central incisors remain unerupted and the lower incisors have
erupted greater than one year previously; or
C. there is deviation from the normal sequence of eruption (eg lateral
incisors erupting prior to the central incisor).
D. Retained deciduous A
E. Change in the color, angulation of the adjacent
F. Availability of space with labial or palatal budges
A. A dental panoramic tomography and anterior occlusal radiograph can be
taken for general assessment purposes.
B. For detailed assessment of position it has been shown that the use of a
horizontal parallax technique is better than vertical.
C. More recently, cone beam computed tomography technology has become
available for imaging the maxillofacial region and this can be used for the
localization of impacted teeth, including incisors.
Treatment depends on
3. Inter and intra arch
4. Condition of the adjacent
5. Color and shape of the adjacent
6. Smile and gingival line
7. Position and angulation
8. Pt motivation
9. Clinician philosophy
2. Segmental osteotomy
4. Interceptive by removing retained deciduous tooth.
5. Create and maintain sufficient space
75% of incisors erupt spontaneously after space creation. Of these, 55%
will align spontaneously while the rest will require some form of
6. Surgical exposure and orthodontic alignment
7. Removal with space management by orthodontic appliance or without
However, prolonged space maintenance can lead to significant alveolar
bone loss in the affected region, making later implant placement more
An alternative strategy, particularly in the younger child, is to allow
spontaneous space closure in the labial segment and then to open up
space with fixed appliances prior to definitive restoration in the
Surgical exposure can be performed in 3 ways:
I. Open exposure or Excision of mucosa overlying the incisor (if the
incisor is close to the surface and attached gingival can be preserved at
the gingival margin)
II. Apically repositioned flap. The exposure may need to be maintained
using a non-eugenol based periodontal dressing. Whitehead’s varnish
pack may cause discoloration of the underlying tooth. The short-term use
of a chlorhexidine mouthwash should be prescribed to reduce gingival
III. Closed eruption procedure. A buccal flap is raised and an orthodontic
attachment bonded to the incisor. A flap is raised and a bracket attached
to a gold chain, customised bracket bonded to the incisal tip , steel
ligature, magnet or elastomeric material is bonded to the tooth followed
by replacement of the palatal flap. The least desirable way to obtain
attachment is for the surgeon to place a wire ligature around the crown of
the impacted tooth. This inevitably results in loss of periodontal
attachment because bone that is destroyed when the wire is passed around
the tooth does not regenerate when it is removed and increases the chance
of ankylosis. The bracket should be bonded as palatally as possible so
that early fenestration does not occur leading to an unfavourable gingival
contour. The flap is sutured back into place.
It is likely that the position of the incisor, angulation, labiopalatal,
amount of attached gingiva and bone will be the main factor
influencing the choice of technique.
Ideally, a fixed orthodontic appliance should already be in place
before the unerupted tooth is exposed, so that orthodontic force can
be applied immediately. If this is not practical, active orthodontic
movement should begin no later than 2 or 3 weeks postsurgically.
Evidences for the type of exposure
Corn (1977) used a split thickness apically repositioned flap on 75 cases
and found no marginal bone loss or gingival recession after orthodontic
Some authors believe the closed eruption technique to be the method of
choice (Brin et al. 2002) in terms of aesthetic and periodontal outcomes
as it is said to replicate natural tooth eruption.
Vermette, Kokich et al. (1995) examined the differences between
surgical exposure of incisors with an apically repositioned flap and
using the closed eruption technique. Photographic examination
revealed vertical relapse of the exposed teeth in the apically
repositioned group. It was concluded that those teeth exposed with an
apically repositioned flap have less aesthetic sequelae than those
treated using a closed eruption technique.
Problem with orthodontic treatment of impacted max incisor
2. Failure of compliance
3. Resorption of the root of the adjacent teeth
5. Intrusion of adjacnt
6. Pd probl
as an angulation or deviation or sharp bend or curve in the linear
relationship of the crown of a tooth to its root, root root, crown cown
Prevalence, Antonious 2012
Permanent more than primary and dentitions.
Male more than female
Maxilla more thn mand
Anterior more than posterior
Unilateral more than bilateral
Mainly max central
(7% due to cyst, 22% trauma, 70% genetic)
A. 7% were associated with certain synergistic factors like CLP, cyst, sever
infection, thick gingivae or bone, supernumerary teeth, cysts, tumours,
odontogenic hamartoma, all of these cause deviation during
B. 22% resulted from trauma
C. 71% were developmental in nature. Stewart in 1978
B. the cement-enamel junction
C. the root
D. the root apex
Clinical features of dilacerations
2. Non-eruption of the responsible tooth,
3. the longer retention of the primary predecessor tooth,
4. possible apical fenestration of the buccal or labial cortical plate,
TREATMENT, Sandler et al 1988)
1. The dilacerated incisor may be brought into the line of the arch by
exposure and closed technique.
2. Elective root filling and apicectomy may be undertaken where
there is unfavourable labial root dilaceration.
3. If the malformation is severe, the incisor may have to be removed.
Ankylosis of incisors
The process of shedding of a deciduous tooth is known to be a dynamic one
in which the root undergoes resorption and repair at differing rates.
Sometimes repair occurs at a greater rate than does resorption and the tooth
become ankylosed to the alveolar bone
1. 10.2% after traumatic injury
2. Male more
3. Maxilla more
4. Incisor more
The following treatment options are available:
1. Periodical follow-up
3. extraction followed by orthodontic space closure with lateral incisor as
4. Extraction followed by placement of an osseointegrated implant if the
patient has completed growth.
5. Autotransplantation of developing premolars to replace missing
maxillary incisors has been documented ‘to provide physiologically
sound results’. The most commonly selected tooth for transplantation is
the lower second premolar. This has been documented to produce
6. Osteotomy of the dentoalveolar segment with immediate repositioning.
de Souza 2009 in Cochrane review found no evidence from RCTs about
the comparative effectiveness of the different treatment options for
ankylosed permanent front teeth.
SUMMARY AND RECOMMENDATIONS OF RCSEng (yaqoob et
1. Children up to nine years with incomplete root development of
Do not uncover bone from unerupted incisor maintain integrity of
Create space if required.
Monitor eruption for 18 months – 80% erupt spontaneously
If exposure required then expose minimally to eliminate soft tissue
obstruction AND WAIT FOR 6 MONTHS. If tooth is still high,
expose and bond bracket.
For best aesthetics:
avoid excision of attached gingivae; and
avoid apically repositioned flaps.
2. Children above nine years with complete or nearly complete apex:
Create space if required.
If permanent incisor high then monitor eruption for 12 months.
If tooth still unerupted at 12 months, expose and bond bracket
3. Children referred late (over 10 years):
Remove obstruction, expose and bond bracket at first operation.
Tooth is ectopic if malposition due to congenital factors or displaced
by the presence of pathology
Impacted second premolars
Similar to U1 causes
Early loss of primaries
IO by extraction of 4s to minimize the surgical approach and its
related damages, care during radiographical assessment to evaluate
the clinical condition of the impacted tooth which might be
affected by hyploasia
Extraction of the 5s
Extraction of the 7s and molar distalization to allow 5s eruption, if
the arch is well aligned