View more from Listerine
Switch to Dark theme

References

Dalessandri D, Parrini S, Rubiano R, Gallone D, Migliorati M. Impacted and transmigrant mandibular canines incidence, aetiology, and treatment: a systematic review. Eur J Orthod. 2017; 39:161-169
Mupparapu M. Patterns of intra-osseous transmigration and ectopic eruption of mandibular canines: review of literature and report of nine additional cases. Dentomaxillofac Radiol. 2002; 31:355-360
Manne R, Gandikota C, Juvvadi SR, Rama HRMR, Anche S. Impacted canines: etiology, diagnosis, and orthodontic management. J Pharm Bioallied Sci. 2012; 4:234-238
Rodríguez SAA, Rodríguez SDM, Hatem GR, Fernández OH. Surgical approach of transmigrated mandibular canine preserving midline of the mandibular symphysis: report of a case. J Dent Maxillofacial Res. 2018; 1:53-55
Bhullar MK, Aggarwal I, Verma R, Uppal AS. Mandibular canine transmigration: report of three cases and literature review. J Int Soc Prev Community Dent. 2017; 7:8-14

Technique Tips: Surgical Extraction of a Transmigrant Mandibular Canine: Description of a Minimally Invasive Technique

From Volume 47, Issue 4, April 2020 | Pages 376-377

Authors

Jenny Girdler

MChD/BChD BSc, MFDS RCS (Ed), PGDip Prim Dent Care, PGCert Clin Teach

DCT in Oral and Maxillofacial Surgery Aintree University Hospital, Liverpool

Articles by Jenny Girdler

Valerie Ornsby

BDS, FDS RCSEng

Associate Specialist in Oral and Maxillofacial Surgery and Specialist in Oral Surgery

Articles by Valerie Ornsby

Stephen Chadwick

BDS, FDS RCS, MSc, MOrth RCS, MA, FDS(Orth) RCS, FDS(Orth) RCPS

Consultant Orthodontist, Department of Oral and Maxillofacial Surgery, Countess of Chester Hospital, Liverpool Road, Chester, CH2 1UL, UK

Articles by Stephen Chadwick

Article

A minimally invasive technique is described for the surgical removal of an unusual oral surgery challenge: the impacted, transmigrant mandibular canine. The technique involves removing the bone around the crown of the impacted tooth. Traction holes and multiple axial sections are performed to deliver the canine. Conservative surgery is possible through a minimal access bony window, preserving bone in the mental region and reducing the risk of damage to adjacent teeth. Impacted mandibular canines are uncommon, with incidence ranges between 0.92%–5.1%.1 Transmigration is a rare anomaly in which an unerupted tooth crosses the midline by more than 50%.2 Mandibular canine transmigration has an incidence range from 0.1–0.31%.1

Treatment strategies for transmigrated mandibular canines include radiographic monitoring, autotransplantation, exposure, orthodontic alignment and surgical extraction. The most common treatment is extraction, with reported complications including trismus, inflammation, pain, haematoma and bony defects.3

The minimally invasive technique described is an approach to the surgical extraction of a Type 2 transmigrated mandibular canine2 (Figures 1 and 2). This categorizes horizontally impacted canines near the inferior border of the mandible below the apices of the incisors. This technique gains access through a small bony window and involves repeated axial sectioning.

Figure 1. Orthopantomogram showing a Mupparapu Type 2, horizontally impacted, transmigrated mandibular right permanent canine.
Figure 2. Cone beam computed tomography showing the ectopic lower right permanent canine lying horizontal and below the apices of the anterior teeth. The crown is below the apex of the LL3, and the root is below the apex of the LR4.

Operations near the symphysis can change facial contour and aesthetics. The technique described reduces the amount of bone removal required around the impacted canine with the potential to improve patient outcomes.

Surgical technique

A vestibular semilunar incision was made and a mucoperiosteal flap raised, exposing the cortical bone in the symphysis region. A pericoronalostectomy was carried out, exposing the crown of the impacted mandibular canine (Figure 3).

Figure 3. Intra-operative view following the pericoronalostectomy, tooth exposure and coronectomy.

The canine was decoronated, leaving the root in situ. A traction hole was drilled into the coronal third of the root with a tungsten carbide surgical fissure bur. A Cryer elevator was placed inside the hole and rotated to allow more of the root to slide into the small bony window crypt. The root was horizontally cross-sectioned, and another traction hole placed for the elevator. This process was repeated through the minimal access bony window, until the whole tooth was extracted (Figure 4). Haemostasis and primary suture closure were achieved.

Figure 4. View of the extracted LR3, showing the multiple axial sections and traction holes.

Case reports in the literature describe bone removal beyond the coronal aspect of the transmigrated canine in order to visualize the root surface and create application points for elevation.4,5

Limitations of the technique include ankylosed mandibular canines, which may not slide into the bony crypt with a traction force alone, however, further research is required to evaluate this. It is also operator sensitive, and there will be an initial learning phase before consistent results can be delivered.

Conclusion

This effective technique encourages preservation of bone around the surgical site, which is particularly important in the symphysis region due to the important aesthetic and functional implications. In theory, it may reduce the risk of iatrogenic damage to adjacent teeth, prevent the need for bone grafting and reduce post-operative inflammation and pain. Further studies are needed to investigate these outcomes and compare them to more invasive techniques.