April, 2009
Management of Impacted Teeth in the Orthodontic Practice
Dr. Mohamad Azhar Kharsa, DDS. PhD. Orth.
Introduction
Management of impacted teeth in the orthodontic practice is of paramount importance, as the existence of one (or more) impacted teeth may complicate orthodontic treatment and present dilemmas especially when inaccessibility or ankylosis are factors. The management of impacted teeth in orthodontic practice varies widely from extraction of the impacted tooth to forced orthodontic eruption. Orthodontic eruption varies between closed or open techniques that must be determined for each case. Materials and Methods: Ninety five impacted teeth in sixty two patients were followed with attention to the choice of technique and results. The approaches for handling the impacted teeth were open forced eruption, closed forced eruption and extraction when indicated. Bonding with self-cure orthodontic composite was used for eighty nine teeth, and light cure (40 second curing time) used on seven teeth. The purpose of this research is to discuss the prognosis of impacted teeth, the approach of orthodontic forced eruption and when to extract. This research also discusses the means of diagnosis of impacted teeth including periapical, panoramic and occlusal radiographs and even lateral cephalometric radiographs.
Conclusion
It is recommended that the decision regarding orthodontic forced eruption (closed or open), or extraction be based on evaluation of each independent case. Ankylosis, resorption, eruption failure and periodontal pockets are complications that need to be taken into account. Another complication can often be noticed is bonding failure, especially in closed force eruption. However, new bonding materials such as light cure composites along with improved technique for isolating the exposed tooth have helped to overcome this problem. Finally, the more precise the location and position of the impacted tooth is known, the easier the procedure becomes.
Managing impacted teeth in orthodontics is generally a choice between orthodontically forced eruption or extraction. Orthodontically forced eruption has two approaches: 1) Open eruption by doing a flap and leaving an open window to the tooth to allow traction or eruption. 2) Closed eruption by doing a flap, installing attachment components for orthodontically forced eruption, then closing the flap. The mechanics of orthodontically forced eruption is basically the same regardless of whether the eruption is open or closed. The decision of which technique is appropriate needs to be determined in consultation with the oral surgeon. The surgeon needs to evaluate access, flap shape and depth. Extraction may be indicated when the impacted dental tooth/teeth are either inaccessible, Figure 1. the tooth is a supernumerary, Figure 5. or when space deficiency is a major factor. Figure 6.
Materials and Methods
The aim of this study is to illustrate the factors in choosing the proper management procedures for impacted teeth. Management of impacted teeth varies from extraction, open exposure, closed orthodontic eruption or even “disregarding” the impacted tooth/teeth. Ninety five impacted teeth in sixty two patients were studied to identify the best management practice and compare the orthodontic eruption techniques according to prognosis after 12 to 24 months.
To outline impacted teeth management “for facilitation”, clinician may follow one of these procedures:
- Open exposure or open orthodontic eruption.
- Closed orthodontic eruption.
- Extraction of the impacted tooth/teeth.
- Disregard when orthodontic eruption or extraction is either impossible or destructive to vicinity anatomical structures and when impacted tooth/teeth is/are asymptomatic, as well.
Looking at the ninety five impacted teeth:
Sixty five were treated via the open eruption technique; a “window” was made, brackets “or buttons” bonded and traction placed. Five were disregarded; orthodontic treatment took place despite the existence of an impacted tooth.
Fourteen were extracted after “Space Analysis” indicated a severe lack of room, or because the tooth/teeth were supernumeraries. Eleven impacted teeth had been indicated for closed eruption technique, followed by the steps of orthodontic eruption.
Figure 1. Impacted Maxillary Right Canine: The case is indicated for extraction because of inaccessibility.
Figure 2. Previous case of Figure 1. after extraction.
Figure 3. Cephalometric Radiograph of Figure 1. case before extraction; this lateral cephalogram suggests a poor prognosis for this impaction.
Figure 4. Photograph of the same case as Figure 1. Figure 2. and Figure 3., after extraction had been done and orthodontic appliances was placed.
Figure 5. A mesodens “supernumerary tooth”, Case of 13 Y.O. male Pt.
Figure 6. A case of Retained deciduous mandibular left canine, with supernumerary tooth and impacted permanent canine. The permanent impacted canine, retained deciduous canine and supernumerary tooth are indicated for extraction in this case, because of space deficiency.
Extraction, closed or open orthodontically assisted eruption are not all the solutions of impaction in orthodontics, sometimes it is better to “disregard” the impacted tooth if it is asymptomatic, inaccessible and in vicinity of a vulnerable maxillofacial structure like the mandibular nerve or maxillary sinus Figure 7.
Figure 7. A horizontal asymptomatic supernumerary tooth close to the mandibular nerve. This impacted tooth has been ignored, and the patient has been treated as if the impacted tooth did not exist.
Tooth/Teeth Impaction is not exclusively an action “of nature” per se, sometimes impaction may happen as a consequence of trauma (tooth/teeth intrusion) Figure 8.
Figure 8. OPG of a female 10 year old patient exposed to anterior trauma in the age of 6.5 year old. The trauma caused exfoliation of the maxillary right central incisor, and a severe intrusion to maxillary right lateral incisor.
Figure 9. Photographs of Figure 8. patient before exposure of impacted upper right lateral incisor.
Figure
Figure 10. The impacted right lateral incisor, after exposure (Open Eruption Technique), and bracket installment.
Retained deciduous (and deciduous) teeth may hinder eruption of the adult successor due to pulp infection, pulp necrosis or early loss. Figure 11
Figure 11. Early loss of upper right deciduous Incisor delayed the eruption of its successor.
Open eruption technique may be an effective technique in cases with eruption delay due to early loss of deciduous tooth/teeth Figure 12.
Figure 12. Open Eruption Technique to assist the eruption of right central incisor. The first step of orthodontically assisted eruption is to gain access to the impacted tooth.
Figure 13. Second step is placement of a button, bracket or other attachment.
Figure 14. In the third step traction is placed, here by elastic chains.
Figure 15. In the fourth step shown here, the button has been replaced by abracket and attached directly to arch wire.
Figure 16. The final outcome is shown here after removal of the braces.
The steps or phases for orthodontically assisted eruption are:
- Gaining Access into Impacted Tooth/Teeth Figure 12.
- Button/Bracket Installment Figure 13.
- Impacted tooth/teeth traction by elastic chains/ligature wire Figure 14.
- Button “if existed” is replaced by a bracket; the installed bracket on the impacted tooth/teeth is/are attached directly into the arch wire Figure 15.
- Tooth/teeth is/are completely erupted and “Braces” Removed Figure 16.
Gaining access to the impacted tooth/teeth is of paramount importance for orthodontically assisted eruption; consequently, it is crucial that clinician be aware of a comprehensive treatment plan and thorough approach for each case.
The orthodontist is encouraged to discuss with the surgeon regarding the access:
- Should orthodontic eruption be open or closed?
- If open/closed eruption is indicated, is it labial or lingual/palatal?
Despite the myriad of classifications, nomenclatures or terminologies regarding orthodontic assisted eruption, the crucial point is just gaining access to the impacted tooth/teeth, then applying “traction”. Access to impacted tooth/teeth is sometimes a “borderline” situation between closed and open eruption especially when only a small embrasure exists that scarcely suffices for button or bracket placement Figure 17.
Figure 17. An “Open” Eruption Technique, palatally done, with a very small“window”.
Figure 18. Impacted upper left central incisor Figure 17. Case a. Upper photo before eruption. Case b. Lower photo after eruption.
Figure 19. Panoramic view of Figure 17. case before eruption.
Figure 20. Upper left central incisor has been successfully erupted, after mesodens surgical extraction, and placement of orthodontic traction.
In addition to gaining access, manipulation of the impacted tooth/teeth is of paramount importance as factors such as ankylosis, resorption or even a malpositioned axis may exist increasing the difficulties of the orthodontic eruption process Figure 21. Side effects and potential Complications of orthodontic eruption: The main side effects and complications of orthodontically assisted eruption are:
- Ankylosis.
- Resorption.
- Traumatization of nearby structures.
- “Collision” with the adjacent roots.
On the other hand, despite such hazards, clinical statistics show that occurrence of the above mentioned complications is not often important when appropriate precautions have been taken. Orthodontic Traction Forces should be low, continuous forces (below 90 g. in case of single roots teeth). Excessive force application can lead to resorption, Clinical evidence of excessive force can be seen clinically with “wiggle and sway” of the tooth/teeth in traction. Should the clinician encounter such an incident, the application of force should be stopped and the tooth/teeth fixed temporarily until periodontal movement returns to normal.
Figure 21. Upper left impacted canine. The axis of this tooth root is inclined to the distal labial aspects and the tooth is deeply embedded within the maxillary bone complicating the orthodontic eruption of this tooth.
Results
Looking at the ninety five impacted teeth:
Sixty five were treated via the open eruption technique; a “window” was made, brackets “or buttons” bonded and traction placed. Five were disregarded; orthodontic treatment took place despite the existence of an impacted tooth. Fourteen were extracted after “Space Analysis” indicated a severe lack of room, or because the tooth/teeth were supernumeraries. . Eleven impacted teeth had been indicated for closed eruption technique, followed by the steps of orthodontic eruption
It was noticed that light-cure bonding had better results than self-cure in forced eruption. It was also noticed that open eruption was “quicker”. On average it took 4 to 8 months to erupt the open cases. Closed technique had a longer time span of 5 -14 months for teeth to erupt. Open eruption was 1.23 times more rapid than closed eruption with a standard deviation of SD ≈ 0.58.
Conclusion
Treatment of impacted teeth varies widely from orthodontic eruption to extraction. However, it is crucial that every case be studied, planned and treated independently; as there is no “cook book” approach for all cases. The clinician is encouraged to analyze each case thoroughly, to anticipate all potential consequences and consider all possibilities to develop the best available treatment plan. It is important that a multi-disciplinary dental team approach is utilized to help insure successful treatment.
References
1. Becker A, Chaushu S. Long-term follow-up of severely resorbed maxillaryincisors after resolution of an etiologically associated impacted canine. Am JOrthod Dentofac Orthop. 2005, 127:650-4, quiz 754.
2. Becker A, Chaushu S. Impacted incisors and cuspids. Bullet Pacific Coast SocOrthod. 2004;76:27.
3. Chaushu S, Becker A, Zeltser R, Branski S, Vasker N, Chaushu G. Patients perception of recovery after exposure of impacted teeth: A comparison of closed-versus open-eruption techniques. J Oral Maxillofacial Surg. 2005;63:323-9.
4. Chaushu S, Becker A. The treatment of impacted teeth and the anatomy offailure. Bulletin of the Pacific Coast Society of Orthodontists, 2004;76:28-9.
5. Ziskind D, Sharon E, Hirschfeld Z, Becker A. Analysis of lateral toothmovement during forced orthodontic eruption. J Prosthet Dent. 2000;84:462-6.
6. Becker A. Early treatment for impacted maxillary incisors. Am J Orthod Dentofacial Orthop. 2002;121:586–587.
7. Bishara SE. Impacted maxillary canines: a review. Am J Orthod Dentofacial Orthop. 1992;101:159–171.
8. Tanaka E, Watanabe M, Nagaoka K, Yamaguchi K, Tanne K. Orthodontictraction of an impacted maxillary central incisor. J Clin Orthod. 2001;35:375–378.
9. Chaushu S, Zahavi T, Becker A. Forced eruption of maxillary incisor teeth fromthe lingual side. Quintessence Int. 2004;35:431-6.
10. Becker A, Chaushu S. Dental age in maxillary canine ectopia. Am J OrthodDentofacial Orthop. 2000;17:657-62.
11. Becker A, Brin I, Ben-Bassat Y, Zilberman Y, Chaushu S. Closederuptionsurgical technique for impacted maxillary incisors: a post orthodontic periodontalevaluation. Am J Orthod Dentofacial Orthop. 2002;122:9–14.
12. Holland DJ. The surgical positioning of unerupted, impacted teeth. Oral Surg Oral Med Oral Pathol. 1956;9:130–140.
13. Kolokithas G, Karakasis D. Orthodontic movement of dilacerated maxillarycentral incisor. Am J Orthod. 1979;76:310–315.
14. Lin YTJ. Treatment of an impacted dilacerated maxillary central incisor. Am J Orthod Dentofacial Orthop. 1999;115:406–409.
Contributed by:
Dr. Mohamad Azhar Kharsa, DDS. PhD. Orth
Senior Specialist Orthodontist Scientist Member of American Society of Laser Medicine and Surgery. Fellow of World Federation of Orthodontists. Fellow of Arab Orthodontic Society. PhD in Orthodontics from University of Medicine and Pharmacy “Victor Babes” of Timisoara, Romania. Member of Saudi Dental Society. Member of Saudi Orthodontic Society.
