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| 2010-22 |
| 22-1 |
ISSN (Print) 1013-9052
EISSN 1658-3558
The Saudi Dental Journal,
P.O. Box 52500,
Riyadh 11563,
Kingdom of Saudi Arabia
P.O. Box 52500,
Riyadh 11563,
Kingdom of Saudi Arabia
| Tel. |
966-1-467-7328 |
| Fax. |
933-1-467-7308 / 966-1-467-7534 |
| Email |
saudidj@ksu.edu.sa |
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Management and effects of mesiodens teeth on the upper central incisor
Ibrahim Awni Nashashibi, BDS, D Orth, RCS
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.
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