Three-Dimensional Diagnosis and Surgical Management of Impacted Maxillary and Mandibular Canines in Pediatric Patients: A Case Series

Abstract

Impacted canines are very frequent, and their management is fundamental in aesthetics and functional occlusion. The planning and choice of an adequate surgical-orthodontic treatment for the discovery of impacted teeth is essential. Four clinical cases are presented that show the clinical and imaging considerations for diagnosis, treatment, and prognosis, with the description of surgical approaches with open, closed techniques and a combination of both, for impacted maxillary and mandibular teeth in pediatric patients. The follow-up has allowed correct management in the orthodontic traction of the impacted teeth with good periodontal health.

Introduction

A tooth is considered impacted when it has not emerged in the dental arch after the normal physiological date of eruption, its follicular sac is not connected to the oral cavity, and in some cases, it can be located in a bone crypt. The canines are the most frequently impacted teeth, after the third molars, they present an estimated prevalence that ranges between 1% and 4% with greater frequency in the female gender. ¹ Impacted mandibular canines are 10 times less common than maxillary canines. ² A study using computed tomography reported that 45.2% of impacted maxillary canines were found buccally, 40.5% were impacted palatally and 14.3% in the middle of the alveolus. ³ The canines play a fundamental role in the esthetics and function of the dental arch. The correct alignments of these dental organs are essential for the correct line of the smile, the adequate proportion of the anterior teeth, and the support of the general dentition. The maxillary canines in particular provide support to the upper lip and alar base and additionally have a great functional impact by providing disocclusion of the posterior teeth during excursive movements.

The etiological factors of impacted canines can be: genetic, local, and systemic, regarding the genetic factors are: heredity, poorly positioned dental germs, shortened arch length, and palatal cleft that affects the alveolar bone. Local factors include: dental arch discrepancies (lack of space), prolonged retention or an early loss of primary canine, insufficient primary canine root exfoliation/resorption, ankylosed permanent canine, cysts or neoplasms, root dilacerations, maxillary lateral incisor agenesis, changes during the phase of lateral incisor root formation. Systemic factors include endocrine deficiency and febrile diseases, untreated canines can cause tooth misalignment, root resorption of adjacent teeth, infections, and cystic changes. ⁴

The diagnosis and location of impacted teeth are one of the great challenges in surgical practice, it is necessary to carry out an adequate analysis based on the evaluation of radiographic images. Conventional radiographs are available, including periapical, panoramic, and occlusal radiographs, however, the use of 2-dimensional images can show the presence of unerupted teeth, but makes any analysis difficult by not allowing details such as the exact location of these teeth, the impact on adjacent teeth/structures, and the anatomy of the roots. With technological advances, 3-dimensional (3D) measurements using computed tomography (CT) allow obtaining images that provide information that is not available with conventional radiographs. CT is a fundamental tool for evaluating impacted canines, allowing for a correct and accurate diagnosis through the precise visualization of their location, angulation, and depth. Additionally, this instrument allows for the analysis of important anatomical structures such as bone cortical thickness and establishes the relationship between the impacted canine and the roots of adjacent teeth, as well as early identification of root resorption, which are determining factors for the proper design of surgical and orthodontic treatment plans and the estimation of the prognosis for clinical care. ⁵ In the case of impacted canines, root resorption in adjacent teeth is a primary concern, and diagnostic accuracy in identifying this type of complication is significantly improved through the use of 3-dimensional modalities. ⁶ The periodontal approach for impacted and impacted teeth also called exposure or surgical discovery, involves the management of bone, connective and epithelial tissues; uses certain periodontal plastic surgery techniques that can be adapted to reach impacted teeth with the following objectives: direct access to the clinical crown, sufficient osteomucosal release for attachment to orthodontic appliances, the emergence of the tooth in space. ¹ The purpose of the article is to present 4 clinical cases of pediatric patients who attended the Periodontology Postgraduate Clinic of the University of Guadalajara referred by the Orthodontics Postgraduate to perform exposures of impacted canines with different surgical techniques.

Case Series

Clinical Case 1

A 12-year-old male patient, right molar class I and left class II due to a deviated midline and not established right canine class, Angle class II, attends the Periodontics Postgraduate clinic due to retained tooth #13 (maxillary right canine; Figure 1a and b). Both in the panoramic radiograph and the tomographic sections, the presence of the tooth toward the buccal is identified (Figure 1c and d). Written informed consent was obtained from the patient’s legally authorized representative, both for the clinical procedure and for the use of the information for academic and publication purposes. The technique used for the exposure was the apical reposition flap, by the buccal. Mesial and distal releasing incisions and an incisal located incision were made to release the canine and apically displace a band of keratinized tissue, the flap was reflected, pericoronal tissue was removed (Figure 1e), and a metal orthodontic button was placed on the crown. Next, traction was performed using metallic ligature and elastic thread on the 0.016 × 0.022 base archwire, and the NITI15” open coil spring was left inactivated to maintain space. The flap was repositioned apically and sutured with polyglactin (APG) 4-0 simple stitches (Figure 1f). After 10 days the sutures were removed. At a 9-month follow-up, the advancement of the impacted canine position is identified (Figure 1g and h).

Figure 1.

Photographs of case 1 #13 (maxillary right canine) retained: (a) initial photo right lateral view, (b) occlusal view, (c) panoramic radiograph, (d) tomographic sections, (e and f) surgical procedure, (g) photograph at 9 months follow-up frontal view, and (h) follow-up photograph right side view.

Clinical Case 2

A 14-year-old female patient, Angle class III attends the Periodontics postgraduate clinic, presenting bilateral retention of #13 (maxillary right canine) and #23 (maxillary left canine; Figure 2a and b). In the images and tomographic analysis, the presence of both palatal teeth was observed, identifying #23 a more posterior position (Figure 2c and d). Written informed consent was obtained from the patient’s legally authorized representative, both for the clinical procedure and for the use of the information for academic and publication purposes. The technique used for the exposure of both canines was the combination of the open and closed technique for #23 and only closed for #13. In the surgical intervention, the full-thickness flap from the first premolar to the first premolar was reflected, in the pericoronal tissue and when locating the canines, an ostectomy was performed to uncover them (Figure 2e). At the time, it was decided to make a window to improve access to #23, orthodontic appliances were placed on both teeth, chain in #13, the flap was repositioned, it was sutured with APG 4-0 simple stitches (Figure 2f). For both, a chain traction technique was performed from the bracket to the base arch. In #13 a 0.019 × 0.025-gage steel chain was started on the base archwire, once it was pulled to the archwire, the technique was changed to an extrusion set on a new 0.019 × 0.025-gage archwire. Until the proper leveling is achieved. Regarding #23, we waited for its eruption to progress, and then it was pulled toward the buccal. At 5 months of follow-up, the advancement of the position of the maxillary canines is identified (Figure 2g and h).

Figure 2.

Photographs of case 2 bilateral retention of #13 (maxillary right canine) and #23 (maxillary left canine): (a) initial photo lateral frontal view, (b) occlusal view, (c and d) tomographic slices, (e and f) surgical procedure, (g) photograph 5 months after follow-up frontal view, and (h) follow-up photograph occlusal view.

Clinical Case 3

A 14-year-old female patient, Angle class II (Figure 3), attends the Periodontology postgraduate clinic due to impacted teeth #23 (maxillary left canine), #33 (mandibular left canine) and #43 (mandibular right canine) because they are clinically absent (Figure 3a and b). The imaging analysis, the panoramic radiography and the CT, the presence of the dental organs is identified, the 3 are inclined and toward the buccal of the alveolar process, #33 is found apical of the anterior teeth, with poor prognosis for orthodontic alignment, therefore the possibility of extracting was proposed (Figure 3c and d). Written informed consent was obtained from the patient’s legally authorized representative, both for the clinical procedure and for the use of the information for academic and publication purposes. Due to the clinical and tomographic characteristics observed, it was decided to select the combined surgical technique as the treatment of choice. Exposures were scheduled in 2 surgeries. In the first intervention, for the lower canines, a full-thickness flap was reflected buccally from #34 (mandibular left first premolar) to #44 (mandibular right first premolar) until the canines were exposed. Clinically, the hopeless prognosis of #33 is corroborated, so it was decided to extract it at that time, and 0.25 g of Bio-Oss^® (Geistlich Pharma AG, Wolhusen, Switzerland) bone and ¼ of ACE collagen membrane (ACE Surgical Supply Co., Brockton, MA, USA) were placed, a metallic orthodontic button was placed in #43 and a chain elastic for later traction, the flap was sutured with APG 4-0 simple stitches (Figure 3e). In the second intervention, a buccal approach was performed for #23, a flap was reflected until it was exposed with liberators to expose the canine, a metal button and elastic chain were placed, and the apical flap was moved to be sutured with APG 4-0 simple stitches (Figure 3f). At 1 month of follow-up, the advance of the position in #23 and #43 (Figure 3g and h).

Figure 3.

Photographs of case 3 retention of #23 (maxillary left canine), #33(mandibular left canine) and #43 (mandibular right canine): (a) initial photo frontal view, (b) occlusal view, (c) panoramic radiograph, (d) tomographic section, (e) surgical procedure of #43, (f) surgical procedure of #23, (g) frontal view follow-up photograph a month, and (h) occlusal view follow-up photograph.

Clinical Case 4

A 16-year-old female patient, molar and canine class I on the right side and unestablished Angle Class I left canine relationship, presents dental absences of #21 (maxillary left central incisor), #22 (maxillary left lateral incisor) and #23 (maxillary left canine) which is why she was referred to the Periodontics postgraduate clinic (Figure 4a and b). Radiographic and tomographic analysis revealed these apically retained teeth (Figure 4c and d), #23 tilted to the right, #21 and #22 in a horizontal position, with a poor prognosis for orthodontic alignment, as discussed below, and with the patient, the possibility of extractions. Written informed consent was obtained from the patient’s legally authorized representative, both for the clinical procedure and for the use of the information for academic and publication purposes. Due to the clinical and tomographic characteristics observed, it was decided to select the closed surgical technique as the option of choice. At surgery, a full-thickness buccal flap with liberators was reflected to gain access to the 3 teeth to the apical position (Figure 4e). Once discovered, the poor prognosis of #22 was clinically corroborated, so it was decided to extract to improve the prognosis of the other teeth, and metal buttons were placed on #21 and #23. The flap was repositioned, sutured with APG 4-0 simple points, (Figure 4f) and orthodontic traction was performed in a 0.017 × 0.025 arch utilizing a closed elastic chain. At 7 months it was identified that only #23 managed to lower the arch, a periapical radiograph was taken, and it was noted that the orthodontic abutment became unglued, which is why #21 does not lower (Figure 4g). A new tomography was indicated (Figure 4h), confirming that #21 is still retained, it was decided to re-enter surgically with the same technique and place a new button (Figure 4i and j), healing was checked for 2 weeks postoperatively (Figure 4k and l).

Figure 4.

Photographs of case 4 retention of #21(maxillary left central incisor), #22 (maxillary left lateral incisor) and #23 (maxillary left canine): (a) initial frontal view photo, (b) occlusal view, (c) panoramic radiograph, (d) tomographic section, (e and f) surgical procedure, (g) periapical radiograph in where it is noted that the button was detached from the front of the tooth and (h) new tomography, (i and j) surgical reentry 7 months after the first intervention, frontal views, and (k and l) healing at 2 postoperative weeks.

Discussion

Management of impacted canines is important in terms of function and esthetics. These interventions generally allow these dental organs an adequate eruption in the dental arch, so correct orthodontic management is essential. This article presents 4 clinical cases with different surgical-orthodontic approaches in the treatment of impacted canines, where multidisciplinary management is crucial since it involves early periodontal surgical management in pediatric patients.

Radiographic analysis plays a fundamental role in the diagnosis and treatment of impacted canines. Conventional radiographs, including periapical, panoramic, and occlusal radiographs are helpful in diagnosis, however, they lack an accurate evaluation. CT provides 3-dimensional reconstruction in different planes with precise analysis to detect the position of the impacted canines and provides additional information on the adjacent teeth. ⁵ Recent studies have validated that CT-based interpretations offer significantly higher diagnostic accuracy and observer reliability compared to conventional 2D radiography for impacted canines, as demonstrated by Hajeer et al ⁷ Alqahtani, ⁸ in their prospective study, showed that CT was the diagnostic radiograph of choice for most orthodontists, improving the level of confidence regarding canine location, the presence of root resorption, and treatment planning, avoiding damage to essential anatomical structures during the surgical approach. The 3D localization of maxillary impacted canines using CT has been proven to match gold-standard in-vivo readings with high precision, far exceeding the capabilities of 2D methods, according to Alfailany et al ⁹ In the report of these 4 cases, thanks to the tomographic evaluation, the following were observed: not very complex positions as in case 1; case 2 showed differences in the position of both canines, which determined the type of approach; while in case 3 the position of each retained tooth, as well as its relationship with the neighbors, was decisive in establishing the hopeless prognosis of #33; For its part, case 4 presented greater complexity due to the location and involvement of more than one retained tooth; the 3-dimensional analysis through tomography provided us with the exact location of the retained teeth, which helps us with pre-surgical planning.

The location of the impacted canine, buccal or palatal, influences the technique for exposing the clinical crown to place orthodontic appliances for tooth traction to the planned position. Surgical techniques to expose impacted canines are classified into open and closed procedures. Regarding buccal impaction, Kokich in 2004 ¹⁰ proposed 3 interventions: gingivectomy, apical reposition flap, and closed eruption techniques. The choice depends on the labiolingual position, the vertical position relative to the mucogingival junction, the mesiodistal position, and the amount of keratinized tissue. In an impacted canine with a coronal position and an adequate band of keratinized tissue (2-3 mm), it is feasible to use any technique. When the impacted canine is located apically at the mucogingival and mesiofacial junction at the root of the lateral incisor, the indicated technique is an apical repositioning flap; additionally, this procedure is indicated in the case of little keratinized tissue around the impacted canine. This technique was chosen for cases 1, 3, and 4 of this article, due to the position of the impacted canines and to preserve keratinized tissue, after 9, 3, and 7 months of follow-up respectively, between 3 and 4 mm of keratinized tissue around each pulled canine. Buccally impacted canines are considered more difficult to control for adverse periodontal outcomes and require special attention in the selection of the least invasive surgical technique. ¹⁰

The closed technique is indicated if the dental organ is deeply impacted apically to the mucogingival line ¹⁰ as it is in case 4 (#22). The follow-up of dental movements is of vital importance, due to the possibility that some of the orthodontic accessories may become detached in the traction process, as in case 4. The reason for which it was decided to re-enter surgically to re-place the attachment with the same surgical technique due to the position of the canine and to control the orthodontic traction, it was indicated to take X-rays every 3 months. These types of clinical complications, such as attachment detachment and the consequent need for reoperation, are extremely important; repeated surgery increases the risk of surgical intervention and unfavorable healing, as well as patient anxiety, which can compromise adherence to treatment. In this same context, it is essential to try to minimize possible failures in the adhesion of traction attachments through adequate moisture control during cementation, correct exposure of the clinical crown, and last but not least, ensuring quality in the selection of adhesive materials and always verifying the stability of the attachment prior to flap replacement. Therefore, we suggest a constant periodic evaluation, both clinical and radiographic, in order to have a follow-up of the movements and not compromise the dental replacement in the planned place.

Regarding palatal impaction, open and closed techniques can be used to perform the exposure. The open intervention consists of removing the tissue over the impacted tooth, placing orthodontic appliances, and covering the area with a surgical dressing for 10 days. The main advantage of the open technique is the short surgical duration; however, the disadvantages include painful and prolonged post-surgical recovery. ¹¹ The closed technique consists of reflecting a full-thickness flap, removal of the follicle, placement of orthodontic appliances in the exposed crown, and finally, the flap is sutured back to its original place. The main advantages of the closed technique are fewer post-surgical complications, faster recovery, and reduced post-surgical pain. In case 2, the open technique was used for #23 and closed in #13, the latter was considered by the position of the canines identified in the tomography and additionally, a window was made in one of the canines to improve access. to it for orthodontic traction. In the closed surgical technique for both buccal or palatal impaction, it is possible, in addition to ostectomy in the bone tissue that covers the dental organ, to remove pericoronal tissue using periodontal curettes. ¹² Regarding the results of the treatment, there is no evidence that one technique is more efficient than the other, which coincides with our results in case 2. While CT provides superior diagnostic precision for localized impactions, the choice between surgical techniques must be evidence-based, especially regarding the velocity of tooth movement and periodontal outcomes, which have been extensively reviewed by Mousa et al ¹³

The decision to extract impacted canines or adjacent teeth may be considered appropriate due to the presence of certain clinical, tomographic, and/or biomechanical factors of the tooth in question that compromise proper orthodontic alignment. Some of the criteria supporting this decision include marked dilaceration of the roots, apical location too deep, lack of space in the alveolar arch, unfavorable relationship with the roots of adjacent teeth, and/or associated pathological lesions.^4,14,15 In the present clinical case 3, tooth #33 was deeply and unfavorably inclined and was located apically to the mandibular alveolar process in a space that was too small for clinical management. Furthermore, imaging showed a high possibility of alteration to adjacent teeth. These characteristics together would lead to questionable and unfavorable orthodontic treatment in impacted mandibular canines. On the other hand, in case 4, the severe apical and horizontal position of tooth #22, as well as its inadequate location in front of the adjacent retained teeth (#21 and #23), could biomechanically compromise orthodontic alignment.

Determining factors in hindering the traction of impacted teeth are considered: the horizontal position, the patient’s age, the height or depth of the tooth, and the buccal-palatal position.^16,17 Regarding age, these 4 cases presented relative advantages as they were young individuals who were still in development and growth phases, however, in the clinical evaluation when considering the feasibility of treatment in cases 3 and 4, the deep position, as well as their relationship with neighboring teeth, compromised #33 and #22, respectively, so it was decided to extract them.

Conclusion

The management of impacted canines requires a multidisciplinary approach that allows a correct and stable alignment of these teeth within the dental arch, with an adequate band of keratinized tissue, as well as the care of neighboring teeth and structures. The success of the impacted canine procedure is based primarily on careful planning with the correct radiographic examinations that allow greater precision, adequate access to the clinical crown through a specific surgical technique, the presence of healthy supporting tissues, and good positioning in the arch.

Supplemental Material

sj-docx-1-gph-10.1177_30502225261422143 – Supplemental material for Three-Dimensional Diagnosis and Surgical Management of Impacted Maxillary and Mandibular Canines in Pediatric Patients: A Case Series

Supplemental material, sj-docx-1-gph-10.1177_30502225261422143 for Three-Dimensional Diagnosis and Surgical Management of Impacted Maxillary and Mandibular Canines in Pediatric Patients: A Case Series by Giovanna Victory-Rodríguez, Alondra C. Ruiz-Gutiérrez, Mari Luz Muro-Jiménez, Juan José Varela-Hernández, Adrián Fernando Gutiérrez-Maldonado, María Fernanda Landero-álvarez, Mario Alberto Alarcón-Sánchez, Artak Heboyan and Sarah Monserrat Lomelí-Martínez in Sage Open Pediatrics