Management of Impacted Maxillary Canines and Implant Placement: A Novel Classification System

Often called the “cornerstones of the dental arch,” canines play a crucial role in dental esthetics, function, and overall oral health. The management of impacted maxillary canines is not a solitary task but a collaborative effort among orthodontists, periodontists, prosthodontists, and oral surgeons. Each professional’s expertise is essential and integral to the process. Despite advancements in treatment, managing impacted canines remains a clinical challenge, particularly because of their high prevalence (2.9% to 20%) and varied orientations. Maxillary canines are second only to third molars in impaction rates, with impactions of these teeth occurring in a palatal position three to six times more often than buccally.^1-3

Maxillary canines enhance facial esthetics by supporting the upper lip and alar base over the canine eminences. Proper alignment, size, and shape of maxillary canines are essential for achieving an attractive smile and maintaining a correct smile line and proportionality among maxillary anterior teeth. Furthermore, these canines contribute significantly to dental functionality by facilitating the disocclusion of posterior teeth during movements and supporting overall dental health.⁴

Traditional management strategies for impacted canines often involve orthodontic repositioning or re-implantation, depending on numerous factors such as impaction position and severity and presence of ankylosis. When these methods are not feasible, surgical extraction followed by bone grafting and implant placement is a definitive option. The challenge increases, however, with diverse positions and orientations of impacted canines, which can complicate surgical interventions due to potential interference with adjacent teeth, risk of root resorption, and proximity to critical structures like the maxillary sinus or nasal cavity.^5-10

An innovative approach to overcome these challenges when conventional treatments fail includes implant placement. Using cone-beam computed tomography (CBCT)–based 3-dimensional (3D) printing technology, clinicians have effectively improved treatment planning to address problems like bone density and tooth exposure. This technology allows for the creation of a detailed 3D model of the patient’s teeth and surrounding structures, which can be used to plan the surgical procedure and ensure an optimal outcome. The 3D model provides a clear visualization of the impacted canine’s position, aiding in precise surgical planning and reducing the risk of complications. This approach has led to better outcomes in complex cases.¹¹ Three-dimensional printing of digital models, using standardized materials, creates personalized 3D objects through automated processes.¹²  

Materials and Methods

This article adheres to the CARE guidelines for case reports (www.care-statement.org). Patients were fully informed of all aspects of the study, including potential alternative treatment regimens, and gave their informed written consent. In this article, the authors introduce a novel classification system tailored to specific clinical presentations for impacted maxillary canines. The system is not just a tool, but serves as a comprehensive guide that breaks down various scenarios and effectively directs treatment strategies.  

The proposed classifications are based on case presentation and are as follows:

Class 1: Removal of the impacted canine can be achieved without damaging adjacent teeth, which is followed by implant placement. This approach is straightforward and effective when orthodontic methods are unsuccessful. 

Class 2: Extraction of the impacted canine risks damage to adjacent teeth. In these cases, implant placement is performed through the root portion of the impacted canine. 

Class 3: Extraction of the impacted canine is not feasible due to proximity to anatomical structures, ankylosis, or poor surgical access. A conventional bridge, therefore, is recommended in this scenario. 

Class 1: Extract the Impacted Canine and Replace It With an Implant 

This classification is diagrammed in Figure 1 through Figure 4. Case 1 depicts an example of this classification (Figure 5 through Figure 10).

Case 1: A 33-year-old female patient presented with a chief complaint of wanting to replace her missing maxillary right canine, tooth No. 6, because despite 2 years of orthodontic treatment, the tooth remained impacted. The tooth could not be aligned into the arch and was presumed ankylosed.

Diagnostic imaging, including a CBCT scan and a 3D-printed model, was used to evaluate the exact position of the impacted canine. The tooth was extracted surgically and bone grafting was performed simultaneously. A 4.1 mm x 12 mm bone-level implant (Straumann^® BL Implant, Straumann, Straumann.com) was placed 4 months post-extraction, and a screw-retained final restoration was delivered. The patient reported satisfaction with the esthetic and functional outcomes.

Class 2: Perform Implant Placement Through the Root Portion of the Impacted Canine

This classification is diagrammed in Figure 11 through Figure 13. Case 2 depicts an example of this classification (Figure 14 through Figure 17).

Case 2: A 42-year-old male patient presented with missing teeth Nos. 5 and 6. The impacted canine’s crown was positioned apically near teeth Nos. 7 and 8. After a discussion of the risks associated with extraction, including potential damage to adjacent teeth, the patient opted for implant placement through the root portion of the impacted canine. Two implants, 3.3 mm x 10 mm and 3.3 mm x 14 mm (Straumann^® BLT Implants), were placed in sites Nos. 5 and 6, respectively, and achieved primary stability and successful osseointegration without further grafting.

Class 3: Keep the Impacted Canine and Utilize a Conventional Bridge 

This classification is diagrammed in Figure 18 and Figure 19. Case 3 depicts an example of this classification (Figure 20 through Figure 22).

Case 3: A 69-year-old female patient presented with an impacted canine (tooth No. 6) and an existing four-unit bridge between Nos. 4 and 7. The patient’s previous dentist had advised against extraction of the impacted canine due to potential damage to adjacent teeth Nos. 4 and 5. The authors deemed implant placement through the crown of the impacted canine too complex and risky. The patient, therefore, continued with the existing conventional bridge, without implant treatment, maintaining functional and esthetic results.  

Discussion 

This article assesses outcomes related to the healing process, implant stability, and esthetic results of managing impacted maxillary canines. The present case reports, which can be compared with existing literature on the management of impacted canines, demonstrate the effectiveness and success of this individualized approach in complex scenarios. This success is not just a result, but can serve as a source of confidence and reassurance to dental practitioners. 

The case reports underscore the necessity of tailored implant treatment planning for impacted maxillary canines. An accurate diagnosis and patient-specific strategies are crucial, particularly when previous orthodontic treatments have been unsuccessful or extraction could pose serious risks. The classification system introduced in this article is aimed at helping clinicians effectively communicate treatment options and expected outcomes to patients, enhancing informed decision-making.

Advanced diagnostic tools such as CBCT and 3D-printed models are key factors to consider. These technologies allow precise visualization of the impacted canine’s position and assist in improving surgical planning. Practicing surgery on a 3D model can help identify potential complications, guide grafting procedures, and lead to better surgical outcomes. The principal advantage of using 3D-printed models is the opportunity to perform a preoperative rehearsal of the surgical procedure. Furthermore, their ability to render the surgical site and the spatial configuration of the impacted tooth in relation to contiguous anatomical structures enhances the surgeon’s ability to identify the most appropriate operative approach.

In class 1 cases, xenograft is used for bone augmentation procedures to increase bone volume and support implant placement. Xenografts are selected for their slow resorption rate, which helps preserve the volume of the augmented site over time.¹³

Research supports the feasibility of placing implants through impacted roots, showing survival rates similar to conventional implant placements. This method—intentional implant placement through the root of the impacted canine—has been notably effective, especially when traditional extraction and subsequent implant placement could compromise the health of nearby teeth or bone.¹⁴  

Davarpanah’s 2009 case series¹⁶ and later studies by Davarpanah and Amato offer valuable insights into guidelines for implant placement through impacted canines. They emphasize that meticulous surgical techniques and thorough planning are vital, particularly when adjacent structures are at risk.¹⁷

There is limited literature, however, on the survival rates of short implants, such as those measuring 4 mm and 6 mm, for replacing impacted canines.¹⁹ A systematic review and meta-analysis comparing splinted and non-splinted short dental implants found no significant difference in long-term survival rates.²⁰  

Conclusion 

The present case series highlights the value of a structured, evidence-based protocol for managing impacted maxillary canines in situations where orthodontic treatment is not feasible or is contraindicated. By integrating CBCT imaging and 3D-assisted diagnostic tools, clinicians can accurately evaluate the 3-dimensional position of the impacted canine, its proximity to adjacent anatomical structures, and the viability of implant-based rehabilitation. This enhanced precision not only can improve diagnostic confidence but also allows for predictable, minimally invasive, and patient-specific treatment planning. 

To summarize, the proposed classification system provides a practical framework to guide clinical decision-making:

Class 1: Removal of the impacted canine followed by grafting and implant placement. This traditional approach is indicated when the impacted canine can be safely removed without jeopardizing adjacent roots or vital structures. CBCT-guided planning enhances the accuracy of extraction, defect assessment, and graft volume estimation. Subsequent implant placement in a well-grafted site should result in a stable restorative platform and predictable esthetic and functional outcomes.

Class 2: Implant placement through the impacted canine. In selective cases, when the impacted tooth is ankylosed, exhibits severe dilaceration, or lies in a position that poses greater surgical risk upon removal, implant placement through the impacted canine can serve as a conservative and effective alternative. CBCT-based evaluation is essential to determine bone quality, implant trajectory, and the degree of tooth impaction to ensure primary stability and long-term success. This method reduces surgical morbidity while preserving surrounding structures.

Class 3: Avoidance of implant placement when removal poses excessive risk, and opt for prosthetic alternatives. When the impacted canine is near critical anatomical structures (eg, nasal floor, maxillary sinus, incisive canal) or threatens the integrity of neighboring roots, any attempt at removal or implant placement can be unsafe. In such instances, prosthodontic solutions, such as fixed partial dentures or resin-bonded prostheses, offer a reliable and minimally invasive alternative. This classification emphasizes that preserving adjacent teeth and anatomical safety must remain the highest priority.

Taken together, these treatment categories highlight the necessity of individualized treatment planning grounded in detailed radiographic assessment and interdisciplinary judgment. Depending on the situation, the combined use of surgical extraction, grafting, and/or implant placement or prosthetic rehabilitation facilitates each patient receiving the most appropriate and biologically sound intervention. This case series demonstrates that, when guided by high-resolution CBCT imaging and a 3D model along with a clear classification strategy, clinicians can achieve exceptional functional and esthetic outcomes while mitigating risks and preserving long-term oral health.  

ABOUT THE AUTHORS 

Dhevamadhini Sundar, BDS, MS 

Fellow, Liu Advanced Clinical Fellowship Program in Implant Dentistry, Ashman Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, New York 

Mauricio Lopez, DDS

Fellow, Liu Advanced Clinical Fellowship Program in Implant Dentistry, Ashman Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, New York

Chih Hao Shyu, DDS

Fellow, Liu Advanced Clinical Fellowship Program in Implant Dentistry, Ashman Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, New York

Yung Cheng (Paul) Yu, DDS

Clinical Associate Professor, Ashman Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, New York

Richard Trushkowsky, DDS

Adjunct Clinical Professor, Advanced Clinical Fellowship Program in Esthetic Dentistry, New York University College of Dentistry, New York, New York

Sang-Choon Cho, DDS

Clinical Associate Professor and Director, Liu Advanced Clinical Fellowship Program in Implant Dentistry, Ashman Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, New York 

Figures and Images

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Figure 1

Diagram of class 1 impacted canine: vertical position.

Figure 2

Diagram of impacted canine, surgical removal.

Figure 3

Fig 3. Diagram of implant placement.

Figure 4

Diagram of screw-retained single implant restoration.

Figure 5

Case 1, axial view of the CBCT to illustrate the tooth’s position relative to the adjacent teeth.

Figure 6

Photograph of the surgically removed impacted canine, sectioned into two pieces.

Figure 7

Photograph of the surgically removed impacted canine, sectioned into three pieces.

Figure 8

3D-printed model of the impacted canine, showing the orientation of the canine. The threshold of the CBCT scan was increased to visualize only the teeth anatomy.

Figure 9

Periapical radiographs showing delayed implant placement after graft maturation.

Figure 10

Final restoration: a single screw-retained implant restoration.

Figure 11

Diagram of class 2 impacted canine: horizontal position, close to adjacent root.

Figure 12

Diagram of intentional implant placement through the root of the impacted canine.

Figure 13

Diagram of the restoration.

Figure 14

Case 2, preoperative intraoral photograph, buccal view.

Figure 15

3D-printed model showing the location/position of the impacted canine.

Figure 16

Periapical radiograph showing intentional implant placement through the root dentin of the impacted canine.

Figure 17

Intraoral photograph showing a lateral view of provisional restoration.

Figure 18

Diagram of class 3 impacted canine: horizontal position, with the crown portion in the gap width.

Figure 19

Diagram of a fixed partial denture (fixed bridge) as a treatment of choice.

Figure 20

Case 3, preoperative periapical radiograph showing impacted canine.

Figure 21

CBCT image of the case, which had been restored with a four-unit bridge. The existing bridge was maintained.

Figure 22

Intraoral photograph showing lateral view of the existing four-unit bridge.