**3. Surgical exposure techniques**

### **3.1. Exposure technique for a palatally-impacted canine**

The surgical technique used to expose a palatally-impacted canine is relatively uncomplicated. After local anesthesia, a window is made in the palate at the site where the crown of the impaction is anticipated to be using an electrosurgery knife; the electrosurgery knife is used to remove the tissue overlying the tooth. Then, the palatal mucoperiosteum is dissected off the bone and discarded. The bony covering of the tooth is removed with a rose bur and handpiece under copious saline irrigation. The follicular tissue is scraped off the palatal surface of the crown and removed. The cavity is enlarged if necessary by further soft tissue and/or bone removal as required to expose the entire palatal or buccal surface of the impaction (depending on the orientation of the impaction). The cementoenamel junction is left undisturbed. After hemostasis, the tooth is dried and after acid etching and resin bonding a bracket is fixed to the labial or palatal surface of the crown; then the wound is packed using periodontal dressing.

Alternatively, orthodontic brackets may be bonded 3 to 7 days postoperatively by the ortho‐ dontist (instead of intraoperatively). Seven to 10 days postoperatively 50 to 60 g elastic traction is applied (Fig.4).

**Figure 4.** A palatally-impacted canine is exposed through a round window and a bracket is attached to the palatal sur‐ face of the crown.

#### **3.2. Exposure technique for a buccally-impacted canine**

Buccally-oriented impacted canines are generally easier to treat. The surgical technique used to expose a buccally-oriented impacted canine after local anesthesia, includes reflection of a small trapezoid flap at the site where the crown of the impaction is anticipated using a scalpel and no.15 blade. The underlying bone is removed using a round bur and handpiece. Then, the follicle is removed exposing the crown. The flap is then repositioned apically at the CEJ of the impaction and sutured in the vestibule leaving the crown exposed for bracket bonding. In due time the tooth erupts (or is forced to erupt) bringing attached gingiva along with it (Fig. 5).

**Figure 5.** A buccally-impacted canine is exposed through a trapezoid flap sutured apically so that it erupts along with the attached gingiva; a bracket has been attached and elastic traction has been applied.

Follicular enlargement or cystic change around an impacted canine should be sought and this factor is taken into consideration when planning treatment for impacted canines. However, this per se does not mean that the impacted canine must be extracted (discussed later in this chapter).5,6

### **3.3. Severely-displaced impacted maxillary canine**

nent canine is risky because the canine may be fused and defy forced eruption. Thus, in such cases it should be attempted to expose and move the impaction before the premolar is extracted. If the impacted tooth responds favorably to forced eruption then the premolar is

The surgical technique used to expose a palatally-impacted canine is relatively uncomplicated. After local anesthesia, a window is made in the palate at the site where the crown of the impaction is anticipated to be using an electrosurgery knife; the electrosurgery knife is used to remove the tissue overlying the tooth. Then, the palatal mucoperiosteum is dissected off the bone and discarded. The bony covering of the tooth is removed with a rose bur and handpiece under copious saline irrigation. The follicular tissue is scraped off the palatal surface of the crown and removed. The cavity is enlarged if necessary by further soft tissue and/or bone removal as required to expose the entire palatal or buccal surface of the impaction (depending on the orientation of the impaction). The cementoenamel junction is left undisturbed. After hemostasis, the tooth is dried and after acid etching and resin bonding a bracket is fixed to the labial or palatal surface of the crown; then the wound is packed using periodontal dressing.

Alternatively, orthodontic brackets may be bonded 3 to 7 days postoperatively by the ortho‐ dontist (instead of intraoperatively). Seven to 10 days postoperatively 50 to 60 g elastic traction

**Figure 4.** A palatally-impacted canine is exposed through a round window and a bracket is attached to the palatal sur‐

Buccally-oriented impacted canines are generally easier to treat. The surgical technique used to expose a buccally-oriented impacted canine after local anesthesia, includes reflection of a small trapezoid flap at the site where the crown of the impaction is anticipated using a scalpel

extracted.

is applied (Fig.4).

face of the crown.

**3. Surgical exposure techniques**

96 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**3.1. Exposure technique for a palatally-impacted canine**

**3.2. Exposure technique for a buccally-impacted canine**

Sometimes the impacted canine is displaced in the jaws; this is often due to a pathologic lesion most commonly a dentigerous cyst (Fig. 6).

**Figure 6.** Impacted canine displaced high up in the maxilla adjacent to the orbital floor due to a dentigerous cyst.

In such cases the exposure has to be made through the mucosa. Impediments (cyst, tumor, teeth, fibrosis etc.) must be removed, sent to the pathologist and the tooth be given time to descend (Fig.7).

When the tooth is accessible in the vestibule it is then exposed and bonded (Fig. 8). [18]

After 2 years the tooth was finally in the dental arch (Fig. 9).

**Figure 7.** The tooth has descended after cyst removal.

**Figure 8.** The tooth has descended 3-4 cm and brought into occlusion.

**Figure 9.** The canine tooth has been brought into the dental arch. (Orthodontist: Dr. Jabari)

#### **3.4. Severely-displaced impacted mandibular canine**

In such cases the exposure has to be made through the mucosa. Impediments (cyst, tumor, teeth, fibrosis etc.) must be removed, sent to the pathologist and the tooth be given time to

When the tooth is accessible in the vestibule it is then exposed and bonded (Fig. 8). [18]

After 2 years the tooth was finally in the dental arch (Fig. 9).

98 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**Figure 7.** The tooth has descended after cyst removal.

**Figure 8.** The tooth has descended 3-4 cm and brought into occlusion.

descend (Fig.7).

A cyst may also displace an impaction in the mandible to a great extent. Enucleation of the cyst without extraction of the impacted tooth may be indicated for children and adolescents if the involved tooth is strategic. There may be swelling in the vestibular area of the mandibular canine region. A common cause is a dentigerous cyst. Aspiration of the lesion must be performed first; in many cases, aspiration reveals a clear yellow fluid in dentigerous cysts. Next, the entity must be confirmed by a pathologist. In our case, excisional biopsy was performed under local anesthesia via a submarginal mucoperiosteal trapezoid flap reflected from the right canine tooth to the left premolar from below the attached gingiva; the cystic lesion was removed after it was separated from the bone and incised off the tooth surface using a #15 scalpel. The flap was sewn in the vestibule, which left the crown exposed for bracket bonding. Orthodontic treatment was started 2 weeks postoperatively. (Figs. 10 and 11).

**Figure 10.** Orthopantomogram of an impacted canine displaced to the inferior border of the chin by a large dentiger‐ ous cyst of the mandible extending from the right canine to the left first premolar tooth

.

**Figure 11.** Lateral cephalogram obtained at the same time.

The canine was brought into occlusion orthodontically within 4 years (Figs. 12 and 13). [19]

**Figure 12.** Orthopantomogram 4 years after surgery. The tooth has been brought into occlusion after surgical exposure and orthodontic guidance; the vitality of all of the teeth has been preserved.

Surgical Exposure and Orthodontic Alignment of Impacted Teeth http://dx.doi.org/10.5772/58956 101

**Figure 13.** Lateral cephalogram obtained at the same time. This bone has healed in the chin.

**Figure 14.** Oral view (Orthodontist Dr. Masoud Seifi).

.

**Figure 11.** Lateral cephalogram obtained at the same time.

100 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

The canine was brought into occlusion orthodontically within 4 years (Figs. 12 and 13). [19]

**Figure 12.** Orthopantomogram 4 years after surgery. The tooth has been brought into occlusion after surgical exposure

and orthodontic guidance; the vitality of all of the teeth has been preserved.

#### **3.5. Impacted teeth associated with benign tumors**

The surgical technique used to expose an impacted tooth associated with a benign tumor is similar. Aspiration of the lesion is negative for fluid. An excisional biopsy under local anes‐ thesia is done. A trapezoid flap is reflected from the mesial and distal aspects of the involved tooth. The lesion is completely removed after separating the capsule from the bone and excising it off the canine tooth surface. Minimal bone removal in the bed of the lesion is done with a rose bur. Clinically, nothing is left attached to the tooth surface. The wound is irrigated and the flap is sutured apically leaving the crown exposed for bracket bonding. Orthodontic treatment is started 1-2 weeks postoperatively depending on the case (Figs. 15 and 16). [6]

**Figure 15.** A 13-year-old female with an impacted left mandibular canine tooth and a relatively well-defined radiolu‐ cent lesion (AOT) on the mesial aspect spanning the length of the crown and root. Care was taken not to devitalize the tooth.

**Figure 16.** The 3-year postoperative radiograph showing complete bone formation and canine alignment (Orthodont‐ ist: Dr. H.A. Shafeie).

Such cases require periodic follow-up after completion of treatment. Our cases had no recurrences to date.

### **4. Conclusion**

The decision to expose or remove a bone-impacted permanent tooth is based on clinical and radiographic information as well as surgical and orthodontic judgment.
