CHAPTER 2
Exposure and Bonding of an Impacted Tooth

Neil C. Kanning,¹ Scott A. Curtice,² and Christopher J. Haggerty³

¹Private Practice, Kanning Orthodontics, USA

²Department of Oral and Maxillofacial Surgery, Naval Medical Center San Diego, San, Diego, California, USA

³Private Practice, Lakewood Oral and Maxillofacial Surgery Specialists, Lees Summit; and Department of Oral and Maxillofacial Surgery, University of Missouri–Kansas City, Kansas City, Missouri, USA

A method of facilitating the eruption of severely impacted and/or malpositioned teeth with orthodontic guidance.

Indications

1. Appropriate arch length to accommodate the impacted tooth within the alveolar arch
2. Appropriate interdental space for the incorporation of the impacted tooth within the alveolus
3. Erupted or impacted tooth on the contralateral side of the arch to provide appropriate symmetry
4. Appropriately developed impacted tooth with no associated malformations or pathology

Contraindications

1. When repositioning impacted teeth will create a structural weakness in the roots of adjacent teeth
2. When other structures (i.e., adjacent roots, supernumerary teeth, and odontomas) are in the path of the anticipated distraction vector
3. Impacted teeth that appear malformed or associated with pathology

Technique

1. Local anesthesia is administered in the form of blocks and infiltration. Subperiosteal injection into the area of the anticipated mucoperiosteal flap will hydro-dissect the tissue and aid in hemostatic flap reflection.
2. Primary teeth in the path of distraction and/or functioning as a space maintainer are extracted.
3. A crestal incision is created within the area of the edentulous space or extraction site of the retained deciduous tooth. Incisions are designed to bisect the attached tissue overlying the alveolar ridge. This will allow the impacted tooth to be distracted through keratinized tissue and will lead to optimal periodontium supporting the tooth.
4. A full-thickness mucoperiosteal flap is raised, with or without distal releasing incisions depending on the access needed to locate the impacted tooth (see Figure 2.6 in Case Report 2.1 and Figure 2.16 in Case Report 2.2).
5. The impacted tooth is frequently identified as an area with a bulge and/or by the identification of the dental follicle. Thin superficial bone overlying the impacted tooth can be removed with a periosteal elevator (see Figure 2.16 in Case Report 2.2). If significant bone removal is required to expose the clinical crown of the impacted tooth, a small round bur with copious irrigation is utilized.
6. Once the clinical crown of the impacted tooth is exposed, the dental follicle is removed with cautery (see Figure 2.7 in Case Report 2.1 and Figure 2.17 in Case Report 2.2). Cautery allows for quick and easy removal of the follicle and greatly adds to hemostasis.
7. If needed, local anesthesia containing a vasoconstrictor can be injected into the surrounding tissue and around the clinical crown of the tooth to aid in hemostasis.
8. A suction tip is placed at the tooth–bone interface to further enhance hemostasis and to aid in the creation of a dry field. A dry field is paramount to ensuring that the composite adheres and has a strong bond.
9. Once a dry field is established and maintained, the bracket is placed toward the incisal or occlusal tip of the impacted tooth in the position of the ideal vector for the distraction of the tooth into the space created by the orthodontist or within the space created by the extraction of the primary tooth.
10. Once the bracket is secured in the appropriate position, the chain attached to the bracket is tested with cotton pliers or pickups to ensure a strong bond between the composite and the impacted tooth. Excessive composite flange is removed with a round bur with copious irrigation.
11. The chain is secured to the orthodontic archwire with 4-0 silk sutures. Excessive chain links are removed in order to minimize slack within the chain (see Figure 2.11 in Case Report 2.1 and Figure 2.18 in Case Report 2.2) as excessive chain slack can lead to bracket detachment.
12. The area is closed primarily with interrupted 4-0 chromic sutures (see Figure 2.13 in Case Report 2.1).

Figure 2.1. Orthopantomogram demonstrating retained primary teeth c and h and impacted teeth #6 and #11.

Figure 2.2. Cone beam computed tomography sagittal view demonstrating the palatal position of tooth #6.

Figure 2.3. Cone beam computed tomography sagittal view demonstrating the palatal position of tooth #11.

Figure 2.4. Occlusal view of impacted teeth #6 and #11.

Figure 2.5. 14-year-old patient in full orthodontics with c and h acting as space maintainers for impacted teeth #6 and #11.

Figure 2.6. Extraction of primary teeth c and h. Crestal incision and reflection of full-thickness mucoperiosteal flaps to expose teeth #6 and #11. The flaps are not connected within the midline in order to preserve the integrity of the incisive canal and of its contents.

Figure 2.7. Removal of the dental follicles and surrounding bone to expose the clinical crowns of teeth #6 and #11.

Figure 2.8. Placement of acid etch on impacted teeth #6 and #11.

Figure 2.9. A low-profile mesh bracket is utilized to attach to the impacted teeth (Cusp-Lok Chain and Mesh, Xemax Surgical Products, Inc., Napa, CA, USA). The mesh allows for greater adherence of the composite to the bracket, and the low-profile design helps to prevent external forces from displacing the bracket.

Figure 2.10. A very small amount of composite is utilized, as excessive composite does not aid in adherence and creates a plaque trap.

Figure 2.11. The bracket is bonded to impacted tooth #11, excessive composite has been removed with a round bur, additional gold chain links have been removed to eliminate potential slack, and the chain has been secured to the orthodontic wire with 4-0 silk sutures.

Figure 2.12. Gold chains secured to the orthodontic archwire using 4-0 silk sutures.

Figure 2.13. Bilateral palatal flaps are closed with interrupted 4-0 chromic sutures placed over the primary canine extraction sites and within the interproximal embrasures.

Postoperative Management

1. Analgesics are prescribed based on the invasiveness of the procedure.
2. Antibiotics are not routinely prescribed.
3. Patients return to their normal activities the next day.
4. Orthodontic traction should begin as soon as possible after exposure, typically between 5 and 21 days post exposure. Immediate traction is initiated for teeth that have been luxated to address ankylosis.

Complications

Early Complications

1. Bleeding: Often from not identifying bleeding tissue on closure. Alternatively, since most expose and bond patients are very young, this may represent an underlying, undiagnosed coagulation disorder.
2. Bracket detachment: From inadequate moisture control during the use of composite. It is important to reattach the bracket within 72 hours before extensive healing of the mucoperiosteal flap occurs.
3. Infection: Rare. Treated with antibiotics and oral rinses such as Peridex. If an abscess is identified on examination or with radiographs, an incision and drainage procedure is indicated.

Late Complications

1. Bracket detachment: Frequently due to an ankylosed tooth or excessive force by the orthodontist.
2. Failure of tooth movement (ankylosed tooth): Treatment options include re-exposure of the impacted tooth with more aggressive bone removal, attempted luxation of the tooth with a dental elevator, and the creation of a bony tunnel through the alveolus to facilitate movement. Care should be taken during surgical exposure to avoid trauma to the cementoenamel junction (CEJ) and the periodontal ligament. Damage to these structures may result in potential periodontal defects and subsequent ankylosis. If the above fails, consider tooth removal and closure of the space via orthodontic means or with a dental implant.
3. Periodontal defects: Less likely with conservative flap elevation, the use of orthodontic brackets, conservative bone removal around only the clinical crown, and distracting the impacted tooth through attached keratinized gingiva. Utilizing a bonded bracket to engage the impacted tooth instead of ligating a steel wire around the CEJ will discourage periodontal defects and promote a more optimal periodontal result.

Key Points

1. Radiographs allow the operator to know the exact position of the impacted tooth, its labial or lingual-palatal position, any interferences caused by other structures (i.e., adjacent teeth roots, supernumerary teeth, or odontomas), and whether the tooth is malformed or associated with a pathologic condition. Radiographs should include any combination of orthopantomograms, periapical films, occlusal films, and/or cone beam computed tomography (CBCT) imaging. When utilizing periapical and occlusal films, it is important to understand Clark's rule (i.e., the SLOB rule, for “same lingual; opposite buccal”).
2. Communication with the orthodontist is important prior to the ligation of the bracket. Having a clear concept of the overall orthodontic treatment plan and the eruption vectors will lead to more precise bracket placement and ideal treatment outcomes.
3. Some orthodontists prefer to have the expose and bond procedure completed several weeks prior to the placement of full orthodontics. In these instances, the impacted tooth is exposed and bonded, and the silk suture is tied around the teeth adjacent to the site where the tooth will be distracted. For example, for an impacted maxillary canine, the silk suture is tied below the CEJ of the adjacent lateral incisor.
4. The more vertically upright the impacted tooth is positioned, the higher the success rate for distraction into the alveolus and the less chance of ankylosis.
5. Incisions are always crestal. All incisions are designed to bisect the attached tissue overlying the alveolar ridge. This will allow the impacted tooth to be distracted through keratinized tissue and will lead to optimal periodontal support of the tooth. Incisions placed within alveolar mucosa may lead to the eruption of the impacted tooth through unattached tissue and compromise the periodontal support of the tooth once it is aligned within the alveolus.
6. Adequate clinical crown exposure and a dry field are keys to the success of the bonding of the composite to the impacted tooth. It is also paramount to select a composite specifically designed for orthodontic bonding.
7. The bracket should be placed so that when the chain is activated by the orthodontist, the vector of the chain pull coincides with the anticipated path of eruption of the impacted tooth. The bracket should also be placed close to the incisal or occlusal tip of the impacted tooth in order to give the orthodontist optimal control over the movement of the tooth.
8. Orthodontic traction should begin as soon as possible after exposure, but no later than 3 weeks post exposure. Immediate traction should be initiated for teeth that have been luxated to address ankylosis.
9. The technique described above is often referred to as the closed eruption technique because the technique involves full flap closure after exposure and bonding of the bracket to the impacted tooth. Alternatively, an open eruption technique can be employed. The open eruption technique is primarily utilized for palatally impacted maxillary canines when there is concern of adjacent root resorption from the vector of distraction from a closed technique. The open eruption technique involves creating an incision that bisects the attached mucosa and removing sufficient bone to expose the clinical crown of an impacted tooth just as in the closed eruption technique. Next, the flap is repositioned over the impacted tooth, and a perforation is created within the tissue overlying the impacted tooth's clinical crown. The tissue perforation is packed with a surgical packing (typically, a periodontal pack; Coe-Pak, GC American Inc., Alsip, IL, US) or an appliance (a cleat, bracket, or chrome steel crown), and the tooth is allowed to erupt autonomously to the level of the occlusal plane.

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Case Reports

Case Report 2.1. Palatally positioned impacted teeth. A 14-year-old female presents with impacted teeth #6 and 11 and retained primary teeth c and h. The patient has been in full orthodontics for 9 months in order to align teeth and alleviate anterior crowding. (See Figures 2.1 through 2.13.)

Case Report 2.2. Labially positioned impacted tooth. A 15-year-old female presents with failure of spontaneous eruption of tooth #11. The patient has been in full orthodontics for 6 months and has already lost all of her primary dentition. The orthodontist has created sufficient space for the orthodontic redirection of tooth #11. (See Figures 2.14, 2.15, 2.16, 2.17, and 2.18.)

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Figure 2.14. Orthopantomogram demonstrating vertically erupting tooth #6 and impacted tooth #11.

Figure 2.15. Cone beam computed tomography sagittal view demonstrating the labial position of tooth #11.

Figure 2.16. Crestal incision and reflection of a full-thickness mucoperiosteal flap to expose tooth #11. A periosteal elevator has been used to locate the tooth by removing a small piece of thin overlying bone.

Figure 2.17. Removal of the dental follicle and surrounding bone to expose the clinical crown of tooth #11.

Figure 2.18. Placement of bracket, removal of excessive composite flash, removal of excess chain links, and securing the chain to the orthodontic archwire with 4-0 silk sutures.

References

1. Caminiti, M.F., Sandor, G.K., Giambattistini, C. and Tompson, B., 1998. Outcomes of the surgical exposure, bonding and eruption of 82 maxillary canines. Journal of the Canadian Dental Association, 64, pp. 576–59.
2. Chaushu, S., Becker, A., Zeltser, R., Branski, S., Vasker, N. and Chaushu, G., 2005. Patient's perception of recovery after exposure of impacted teeth: a comparison of closed versus open eruption techniques. Journal of Oral and Maxillofacial Surgery, 63, pp. 323–9.
3. Kurol, J., Erikson, S. and Andreasen, J.O., 1997. The impacted maxillary canine. In: J.O. Andreasen, J.K. Petersen and D. Laskin, eds. 1997. Textbook and color atlas of tooth impactions. Copenhagen: Munksgaard.
4. Kokick, V.G., 2010. Preorthodontic uncovering and autonomous eruption of palatally impacted maxillary canines. Seminars in Orthodontia, 16, 205–11.