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Management and effects of mesiodens teeth on the
upper central incisor
Ibrahim Awni Nashashibi, BDS, D Orth, RCS
Department of Preventive Dental Sciences, King Saud University College of Dentistry, P.O. Box 60169, Riyadh 11545, Saudi Arabia
This study illustrates the orthodontic management of
erupted or unerupted mesiodens teeth in the maxilla. The effect of mesiodens
varies from impaction, displacement or rotation of the central incisors, space
loss, and median diastema.
While rare in the primary dentition, supernumerary teeth are quite
frequent in the permanent dentition and occur more frequently in the
premaxilla.
Supernumerary teeth are divided into three main types: (a)
supplemental teeth where its main effect on occlusion is to increase the
crowding potential; (b) conical teeth or mesiodens near the midline which
causes median diastema; and (c) tuberculate teeth which causes delayed eruption
of permanent upper central incisor. Early detection and removal of
supernumerary teeth is of importance to avoid such complications.1-5
Mesiodens6 can be
detected in the maxillary midline, usually present as single, in pairs or multiple
supernumerary teeth.7 !t can affect one or both
central incisors.8 They are mostly conical in shape and poorly
formed.9 Sometimes they resemble the normal teeth (supplemental
teeth). These are mostly seen in the premolar region. Paramolars are
supplemental teeth seen in the end of the arch.
Supernumerary teeth occur due to hypergenesis of the
epithelial cord, hereditary, developmental defects as cleft lip and palate, and
atavism.
In Saudi Arabia, the frequency of supernumerary teeth is
2.3% without sex difference,10 3.1% in
Canada,11 and 1.7% in Denmark.12 All studies agree that the anterior maxilla is
the area predomin antly involved,13 and that
there is no significant dif ference in the distribution of unilateral and
bilateral supernumerary teeth.14
Supernumerary teeth can prevent the eruption of central
incisors. They can cause bodily displacement, median diastema or torsiversion
which is usually associated with the inverted type of mesiodens.13 Supernumerary teeth can be involved with other
problems as multiple impaction of teeth, compound odontoma, cyst, and root
resorption of the adjacent teeth.14
Assessment and Management of the
Effects of Supernumerary Teeth
A. Radiographic
Assessment
In routine analyses of supernumerary teeth, radiographs
required are periapical, orthopan tomogram, and lateral skull radiograph.
When suspecting a supernumerary tooth, an extra radiograph will
help the diagnosis; an upper occlusal film will clarify the presence or absence
of the supernumerary teeth. A lateral skull radiograph will assist in
determining the depth and height of the supernumerary tooth.
B. Clinical
Assessment
Careful and detailed clinical examination
will be valuable in detecting the reason for an unerupted central incisor.
Certain clinical features, as retention of the deciduous central incisor,
bulging of the soft tissue on the labial or palatal mucosa, or loss of space in
the arch will be observed.
Rotation of the central incisor is usually caused by the
presence of mesiodens. The degree of rotation depends on the position, depth
and angulation of the unerupted mesiodens. Erupted mesiodens will cause median
diastema and displacement of one or both of the centra! incisors.
The following four cases will illustrate complica tions
resulting from the presence of mesiodens.
1. Impaction of upper central incisors and space loss in the
dental arch.
Case A:
A 10-year-old Saudi girl was referred for orthodontic
treatment complaining of delayed eruption of the left central incisor. Clinical
exami nation showed a labial bulge of the labial mucosa, lack of space, and
absence of deciduous incisors. Routine radiographic analysis, with the
assistance of upper anterior occlusal film (Fig. a1), revealed the presence of
a supernumerary tooth which was preventing the incisor from normal eruption.
The first stage of treatment was to
regain space by using the
Edgewise technique. Compressed open coil spring was used to create space. The
second stage was surgical removal of the supernumerary tooth and exposure of
the upper central incisor.
The latter was brought to the arch by light forces.
The central incisor was retained for three months by a fixed
appliance before debanding and chang ing the retaining fixed appliance to a
Hawaly retainer. The height of the clinical crown of the exposed central
incisor (Fig. a2), which was longer than its adjacent incisor, was adjusted.
Case B:
A 9 1/2-year-old Saudi girl presenting a skeletal class III
malocclusion, bilateral crossbite, defi ciency in the growth of the maxilla,
skeletal open-bite, steep gonial angle, and unerupted right cen tral incisor.
Radiographic examination revealed a mesiodens which was removed surgically to
avoid any complication to the neighboring teeth.
The bilateral crossbite was treated by using diffe rential
expansion forces created from quadhelix expansion arch which helped the forward
growth vector of the maxilla and created enough space to accommodate the
impacted central incisor (Fig.
bl). Surgical exposure of the central incisor was performed, and a
pre-angulated central incisor bracket was bonded by pre-tongue bracket. The
tooth was ligated by a ligature wire (Fig. b1,) and then moved occlusally by
using light force from elastic thread
followed by round nitinol wire 0.016 inch and rectangular nitinol wire 0.017 X
0.022
inch.
The tooth was brought to correct position in the arch within
eight months and was kept in fixed retention for four months (Fig. b2). Other
correc tive procedures to treat the different anomalies will be taken in consideration
later on.
2. Mesiodens tooth causing median
diastema and displacement of the central incisors.
Case C:
An 11-year-old Saudi boy complained of the eruption of an
extra tooth in the anterior region causing esthetic and functional problems
(Fig.
cl). The right central incisor was in anterior cross-bite; the left was
displaced labially. The mesiodens was erupted between them creating a distance
between the incisors (Fig. cl). The mesiodens was extracted and a fixed
Edgewise appliance was fit ted. The displaced central incisors were aligned
and the space closed (Fig. c2). When the upper canines erupted, the upper arch
was debanded.
The treatment time took 18 months plus extra three months in
retention. The final result showed Class I incisor relationship with good
alignment between the central incisors.
3. Mesiodens causing rotation of the central incisor.
Case D:
An 8 1/2-year-old girl was referred for severe rotation of
the upper right central incisor. Routine radiograph revealed the presence of a
mesiodens (Fig. d1).
The mesiodens was removed surgically. The patient was under
supervision to evaluate further self derotation. Ten months later, slight
improve ment was observed. Fixed appliance was fitted to the anterior region
to rotate the central incisor. The treatment was completed after 6 months plus
nearly 10 months of retention. One year later (Fig. d2), it showed stable
result.
Significant delay in the eruption of the maxillary
incisor(s) suggests the presence of supernumerary teeth.12, 15, 16 Surgical removal of the supernumer
ary tooth will accelerate the eruption of the unerupted central incisor to its
ordinary position without any orthodontic treatment.1-5 If the roots of the central incisor are
completed, the eruption force will be affected and orthodontic correction is
necessary as shown in Cases A and B.s
Some authors prefer to delay the surgical
removal of the supernumerary tooth to avoid injury of the developing root
structure until the root is completed. In Cases A and B, lack of space was
associated with an unerupted central incisor. After thorough investigation of
the cause of lack of space, due to drifting of the neighboring teeth, as in
Case A, or due to basal jaw discrepancies, as in Case B. The first step is to
create enough space for the tooth to erupt,
As is common in such cases, the clinical crown of treated
impacted central incisor, as in Cases A and
B, is longer than its adjacent tooth. Such discre pancy is due to
"window type" surgical exposure and the distance in which the impacted central
incisor was moved. Minor periodontal surgery decreases such discrepancy.
In Case C, a supplemental supernumerary tooth was removed
and the displaced central incisor moved to its ordinary position after closure
of the diastema. The result was esthetically and func tionally satisfactory.
Some operators extract the central incisor and the supplemental supernumer ary
tooth which is built up with composite filling material or is crowned. This
type of treatment has cosmetic and functional disadvantage in the long term
management.
In Case D, the mesiodens was removed before the roots of the
central incisors were closed. This was beneficial to stabilize the final result
and to pre vent relapse which is, otherwise, common where teeth are rotated.
All case reports support the idea of early surgical removal
of the mesiodens tooth to decrease the degree of displacement or rotation of
the unerupted tooth. Satisfactory function and esthetic results will be
obtained with proper consideration of surgical, periodontal and orthodontic
principles17,3,4 in the treatment of patients with super
numerary teeth.
- Bodenham RS. The treatment and prognosis of unerupted maxillary incisors associated with the presence of super numerary teeth. Br Dent J 1967;123:173-177.
- Munn D. Unerupted incisors. BrJOrth 1981;8:39-42.
- Thomas KH. Oral Surg 3rd ed. St. Louis: CV Mosby Co 1958: 395-398.
- Duncan WK, Ashraf MH, Meister F. Jr. et al. Management of the non-erupted maxillary anterior tooth. J Am Dent Assoc 1983;106(51:640-644.
- Gangiaiosi TJ. Management of a maxillary permanentincisor. J Am Dent Assoc 1982; 105:812-814.
- DiBiase DD. Midline supernumeraries and eruption of maxillary central incisors. Transactions of the British Society for the Study of Orthodontics. 1969:83-88.
- Rosenthaler H, Quinn PD, Rose LF. Surgical orthodontic management of an unerupted maxillary incisor. J Am Dent Assoc 1979;98(5):731-733.
- Herter-Greaven CW. Bilaterally impacted supernumerary central incisors. Oral Surg 1974;38(2):332-333.
- Gotoff AM, Stern M. Surgical and orthodontic management of an unerupted maxillary permanent incisor, J Am Dent Assoc 1974;89(4):897-899.
- Locht S. Panoramic radiographic examination of 704 Danish children aged 9-10 years. Community Dent Oral Epidemiol 1980;8:3 75-380.
- Howard RD. The unerupted incisor, a study of the postoperative eruptive history of incisors delayed in their eruption of supernumerary teeth. Transactions of the British Society for the Study of Orthodontics. 1981:30-40.
- Bolk L.Die veberzahnlinger oberen incisiven de menschen. Deutsche Monatsch Zahnh 1931;35:185.
- Tay F, Pang A,Yuen S. Unerupted maxillary anterior supernumerary teeth.A.S.D.S. J Dent Child I984;51(4):289-294.
- Talbot WR. Multiple dental anomalies. Oral Surg 1980;49:380.
- Gardiner JH. Supernumerary teeth. Transaction of the British Society for the Study of Orthodontics. 1961:15-25.
- Ruprecht A,Batniji S, El-Newehi E.The incidence of supernumerary teeth. Ann Dent 1984;43(2)18-21.
- Castaldi CR, Bodnarchuk A, MacRae PD. et al. Incidence of congenital anomalia in permanent teeth in a group of Canadian children aged 6-9. J Can Dent Assoc 1966;32:154-159.
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