Invest Clin 59(4): 339 - 351, 2018 https://doi.org/10.22209/IC.v59n4a05
Canine Transmigration: Seven Case Reports.
José Rubén Herrera-Atoche, Ileana Paolina Gómez-Medina, Iván Daniel Zúñiga-Herrera, Laura Beatriz Pérez-Traconis, Mauricio Escoffié-Ramírez and Gabriel Eduardo Colomé-Ruiz
Facultad de Odontología, Universidad Autónoma de Yucatán. Yucatán, México.
Corresponding author: José Rubén Herrera-Atoche, Calle 61-A No. 492-A Costado Sur del Parque de la Paz por Avenida Itzáes, Col. Centro, 97000. Mérida, Yucatán, México. Telephone: +52 999 9240508 Ext. 117. Fax: 52 999
9239253. E-mail: jose.herrera@correo.uady.mx
Transmigración de caninos: Presentación de siete casos clínicos.
Invest Clin 2018; 59 (4): 339 - 351
Recibido 23-04-2018 Aceptado 27-09-2018
A tooth is considered to be in transmi- gration “when its eruption pattern has been altered and the tooth has been displaced to the opposite side of the arch, with at least half of the crown crossing the midline” (1). Trans- migration is an infrequent eruption anomaly that occurs in an estimated 0.1 to 0.41% of patients, depending on the population (1- 6). It is generally more frequent in women (1, 4) and the mandibular canines are the most af- fected (1), although it has also been reported in the maxillary canines (5, 7).
Patients with transmigrated teeth can also exhibit other associated anomalies, such as supernumerary teeth, agenesis, and impacted teeth (5, 7, 8). A genetic origin
may explain transmigration (5, 9), although other causes are known: blockage of erup- tion routes by supernumeraries or odonto- mas (2, 10); cysts (2, 8); anomalies of the
lateral incisors (2); and problems of space (premature loss of deciduous teeth, reten- tion of the deciduous canine, crowding or spacing) and abnormal emerging patterns such as ectopic eruption (8).
Transmigration is diagnosed using ra- diographs, especially panoramics, because some transmigrated teeth can be found quite far from their normal location within the dental arch (2, 11, 12). Mupparapu (2002) developed a classification for transmigrating mandibular canines based on a review of 127 cases in the literature (4). The classification uses five transmigration patterns. Type 1 is a canine in a mesio-angular position cross- ing the mandibular midline, be it labial or lingual to the incisors, with the crown cross- ing the midline. Type 2 is a horizontally im- pacted canine near the mandible’s inferior margin, but below the incisor apexes. Type 3 is an erupting canine that is mesial or distal to the opposite canine. Type 4 is horizontal
impaction of the canine near the mandible’s inferior margin, below the apexes of the op- posite premolars or molars. Finally, type 5 is a vertical canine on the midline, but with its axial axis crossing the midline; it is classi- fied at this level independent of its eruption status. Type 1 transmigrations are the most frequent and type 5 the least (4).
Options for treating this dental anomaly include surgical removal, autotransplants, and surgical exposure with orthodontic traction (1, 2, 13). In many cases, no treatment is ap- plied and the condition is simply monitored with periodic radiographs; however, as with any impacted tooth, there is a risk of cyst develop- ment or damage to neighboring structures, such as the roots of adjacent teeth (7, 11).
As a further contribution to the diag- nosis and treatment of this condition, seven clinical cases are presented, including each patient’s clinical condition and the treatment plan developed for each case. Of the seven pa- tients, four (57.14%) were male and the aver- age age was 17.14 years ± 4.9 (the youngest was 12 years old and the oldest was 25 years old). A total of eight canines were transmi- grated (seven mandibular and one maxillary), with four on each side (the maxillary canine was on the left). Of the seven mandibular ca- nines, three were type 1 and four were type 2.
Only three of the eight canines (37.5%) were extracted; the remaining five were monitored. Of the mandibular canines, two of the three type 1 canines (66.67%) were extracted, and one of the four type 2 canines (75%) was extracted. Five of the seven pa- tients (71.42%) exhibited associated dental anomalies, the most frequent being super- numerary teeth (n=3), followed by impac- tion of other teeth (n=2); one patient had three associated anomalies (Table I).
Male, 12 years old. Clinical examination revealed that the inferior left canine was the only primary tooth still present (Fig. 1). The panoramic radiograph showed that the 3.3 was in a type 1 transmigration (Fig. 2A). The cone beam computed tomography (CBCT) showed that the crown of the transmigrated canine was very close to the adjacent incisors’ roots (Figs. 2 B and C). Despite the recom- mendation for surgical removal or even orth- odontic traction, the parents chose not to treat the transmigrated tooth and instead to follow up with periodic radiographs.
Female, 15 years old. As with Case 1, the inferior left canine was the only primary tooth remaining in the mouth (Fig. 3). The radio- graph showed that the 3.3 exhibited a type 2 transmigration (Figs. 4, A and B). The tooth
DESCRIPTIVE INFORMATION ON SEVEN DENTAL TRANSMIGRATION CASES
Sex | Age | Type | Affected teeth | Associated Dental Anomalies | Treatment | |
Case 1 | M | 12 | 1 | 3.3 | Monitor | |
Case 2 | F | 15 | 2 | 3.3 | Monitor | |
Case 3 | F | 18 | 2 | 4.3 | Supernumeraries | Monitor |
Case 4 | M | 25 | 2 | 2.3, 4.3 | Microdontia | Monitor |
Case 5 | M | 12 | 2 | 4.3 | Supernumeraries | Extraction |
Case 6 | M | 22 | 1 | 3.3 | Impaction, Root Reabsorption | Extraction |
Case 7 | F | 16 | 1 | 4.3 | Agenesis, Supernumeraries, Impaction | Extraction |
E) Lower occlusal view.
C) CBCT sagittal slice.
E) Lower occlusal view.
was located closer to the mandible edge than in Case 1, precluding the use of orthodontic traction, and it was decided to monitor the tooth. Dental protrusion was the initial rea- son for the appointment, and the patient re- quested orthodontic treatment of this condi- tion. Because the 3.3 was far from the roots of the neighboring teeth, the orthodontist decided there would be no risk in moving teeth in this zone. To correct the protrusion, the first premolars were extracted (except for quadrant 3 since the 3.3 was transmigrated). The 3.3 would not be restored in this treat- ment since the 3.4 would take its place. The 1-year follow-up panoramic x-ray showed no significant changes (Fig. 4C).
Female, 18 years of age. The inferior right primary canine was still present (Fig. 5). Radiography showed that the 4.3 was in type 2 transmigration and showed the pres- ence of at least three supernumerary teeth near the 4.3 (Fig. 6, A and B). The patient was
referred to a maxillofacial surgeon to evalu- ate the possibility of surgical extraction, but the proximity of the 4.3 to the mandible edge made this possibility untenable. As in Case 2, the space between the transmigrated tooth and its neighbors allowed for orthodontic manipulation. The option of opening a space and rehabilitating the transmigrated canine was offered to the patient, who accepted. The 2-year follow-up panoramic x-ray showed no significant changes (Fig. 6C).
Male, 25 years of age. Both the 2.3 and 4.3 were absent, with corresponding gaps, and the
2.2 was microdontic (Fig. 7). The radiograph showed that both missing teeth were in trans- migration (Fig. 8A) and the inferior one was a type 2 transmigration. The patient decided on monitoring for both teeth to allow orthodontic treatment to open the spaces and then restore the errant canines to their places. The 2.5-year follow-up panoramic x-ray showed no signifi- cant changes (Fig. 8B).
E) Lower occlusal view.
E) Lower occlusal view.
Male, 12 years of age. During clinical examination in preparation for orthodontic treatment, the inferior right primary ca- nine was found to be present (Fig. 9). The radiograph showed the 4.3 to be in type 2 transmigration and that a supernumerary tooth was reabsorbing the root of the previ- ously-mentioned primary canine (Fig. 10A). After the treatment options were explained, the patient decided for surgical removal of the 4.3. A restorative dentist found that the supernumerary tooth had a crown and root sufficiently large to be used in a fixed pros- thesis. It could therefore be maintained and treated with prosthetics instead of using a
dental implant or bridge. The primary 4.3 was extracted and a space opened for future restoration using orthodontics (Fig. 10B).
Male, 22 years of age. This patient was missing various teeth. He requested a treat- ment evaluation during which the 1.3, 3.3, and 3.6 were found to be absent (Fig. 11). The patient indicated that the 3.6 had been extracted due to dental caries. The radio- graph showed that the 1.3 was impacted and that the 3.3 was in type 1 transmigration. In addition, the 2.2 exhibited root resorption of half the root. The distal face was more se- vere, suggesting that during eruption the 2.3
E) Lower occlusal view.
E) Lower occlusal view.
had damaged the adjacent root (Fig. 12A). Due to the proximity of the 3.3 to the incisor roots, it was suggested that it be removed, to which the patient agreed (Fig. 12B). Orth- odontic treatment of the 1.3 was initiated to later surgically expose it and move it into the dental arch.
Female, 16 years of age. The 1.5, 2.1,
3.5, 4.3, and 4.5 teeth were missing, and the inferior right primary canine and two prima- ry second molars were still present (Fig. 13). The radiograph showed that the 4.3 was in type 1 transmigration, the 1.5, 3.5, and 4.5 exhibited agenesis, and the 2.1 was impacted and had an associated supernumerary tooth
(Fig. 14A). The simultaneous presence of supernumeraries and agenesis is a very rare (0.33%) condition known as concomitant hypo-hyperdontia (14). As in Case 6, the 4.3 was near the roots of neighboring teeth and the CBCT revealed a lesion that extended from the right deciduous canine to the left lateral incisor, almost as if showing the path that the transmigrated canine had followed (Fig. 14, B-D), so it was extracted. The 2.1 was surgically exposed and a post attached to it to allow its movement with orthodon- tics. The gap for the 1.5 was to be closed using orthodontics, but the spaces for the inferior premolars were to be maintained for later rehabilitation with dental implants (Fig. 15).
E) Lower occlusal view.
Dental transmigration is a complex phe- nomenon with various treatment options. The risks and benefits of each possible treat- ment need to be evaluated before deciding on which treatment to pursue. Derived from our experience in dealing with these seven cases, Table II displays the advantages and disadvantages of each approach that we rec- ommended to our patients. Of the seven cas- es reported here, the patients chose either monitoring/observation or extraction; this is similar to the choices made in four previ- ously reported cases (15). None of the pa- tients opted for orthodontic traction, possi- bly due to its difficulty, risks, and treatment time. This paper recommends investigating
if the Mupparapu classification might help in choosing among the treatment options for these patients.
Regarding diagnosis, CBCT is recog- nized as the best method to evaluate im- pacted teeth (2). However, there is not a consensus regarding the reasons that would justify CBCT as the first-line tool to evalu- ate this condition (16) and even less support for using CBCT for transmigrated canines. Some authors claim that the use of CBCT is indicated when: a) conventional radiogra- phy does not provide sufficient information (17); b) it is important to have a precise lo- cation and a tridimensional position of the impacted canine (16); and c) it is necessary to evaluate the root resorption of adjacent teeth (16- 18). Since all the subjects in this
ADVANTAGES AND DISADVANTAGES OF EACH TREATMENT OPTION IN DEALING WITH CANINE TRANSMIGRATION
Treatment option | Advantages | Disadvantages |
Orthodontic traction |
|
|
Surgical removal |
|
|
Radiographic monitoring |
|
|
report were orthodontic patients, the diag- nostic was done with a routine panoramic x-ray; two of them had CBCT scans, which in those cases allowed a better view of the tooth location and assessment of the health condition of adjacent structures, just as the literature review suggests.
In contrast to previous reports (1, 4), most of the cases presented here were male patients. The patient age ranged from 12 to 25 years of age, indicating that transmi- gration is present even in younger patients, even though their teeth have had less time to migrate through the bone and cross the midline.
Transmigrated mandibular canines were present in all seven cases, which coincides with the literature, but a transmigrated max- illary canine was also present. The patient with the affected maxillary canine (Case 4) exhibited inferior transmigration and was the only patient with a double transmigration. Superior canines are rarely (0.2%) involved in transmigration (19), possibly because the space between the oral cavity roof and the na- sal cavity floor is less than that in the man- dible. Also, the roots of the superior incisors are longer than those of the inferiors, further reducing the available space and making transmigration less likely (5).
Based on the Mupparapu (2002) clas- sification (4), 42.85% of the mandibular ca- nines presented here were type 1 and 57.15% were type 2; this is the inverse of the expect- ed pattern since type 1 transmigration is the most frequent. Even though the present sam- ple was small, it suggests the possibility that the sample population’s ethnicity could have some effect on type frequency. Samples from a much broader range of ethnic groups would be needed to determine if this is the case.
In terms of chosen treatment, most of the type 1 transmigrations presented here were treated by extraction, whereas almost all the type 2s were kept under observation. The fact that the type 2 transmigrated teeth were closer to the mandible edge is the main reason that they were not extracted. Also
of note is that none of the transmigrated canines were treated with orthodontics, al- though many of the patients were treated with orthodontics and/or restoration to resolve the malocclusion caused by the ab- sence of the transmigrated canine. This as- pect is important to consider when discuss- ing treatment planning and cost with dental transmigration patients.
Most of the patients (71.42%) exhibited other dental anomalies in addition to transmi- grated canines. Supernumeraries were present in three cases: two were associated with the transmigrated teeth and the third was associ- ated with an impacted superior central incisor. Some studies indicate that supernumeraries can block other teeth and cause impaction (3), which could make it one of the etiologi- cal causes of transmigration (10). The pres- ence of genetic anomalies, such as microdon- tia and dental agenesis (20), could support the idea that transmigration has a hereditary component (5, 9); Case 7, with three associ- ated anomalies (including concomitant hypo- hyperdontia), is a clear example of this.
Finally, the seven cases presented here confirm that dental transmigration is a com- plex condition, the resolution of which de- mands interdisciplinary analysis because it commonly requires surgical, orthodontic, and/ or dental restoration treatments. Even when the final decision is to monitor the transmi- grated tooth, patients still undergo treatment to rehabilitate the missing tooth and often to resolve other associated dental anomalies.
This article does not contain any stud- ies with human or animal subjects performed by the any of the authors.
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