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Year : 2017  |  Volume : 20  |  Issue : 6  |  Page : 479-481
Accessory branch of canalis sinuosus mimicking external root resorption: A diagnostic dilemma

1 Department of Conservative Dentistry, Endodontics and Aesthetics, Manubhai Patel Dental College and Hospital, Vadodara, Gujarat, India
2 Department of Conservative Dentistry, Endodontics and Aesthetics, Sumandeep Vidyapeeth, K. M. Shah Dental College and Hospital, Vadodara, Gujarat, India

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Date of Submission26-Nov-2016
Date of Decision15-Nov-2017
Date of Acceptance20-Nov-2017
Date of Web Publication15-Jan-2018


The aim of this study was to recognize the importance of canalis sinuosus in Endodontics. A 60-year-old male patient reported with the chief complaint of pain and swelling in upper front tooth region for 2 weeks with a history of trauma 21 years back. Clinical examination revealed fractured tooth 21 (maxillary left central incisor) with an associated sinus tract. Radiographic examination revealed diffuse periapical radiolucency in relation to tooth 21 and external resorptive defect in apical third of the root of tooth 11 (maxillary right central incisor). Cone-beam computed tomography advised to plan surgical treatment for the same disclosed the presence of an anatomic variation of canalis sinuosus. The location and course of this canal illuded as a resorptive defect, which is a very rare occurrence. This led to a change in diagnosis with relation to tooth 11 and treatment plan was formulated accordingly.

Keywords: Anatomic variation; anterior superior alveolar nerve; canalis sinuosus; cone-beam computed tomography; root resorption

How to cite this article:
Shah PN, Arora AV, Kapoor SV. Accessory branch of canalis sinuosus mimicking external root resorption: A diagnostic dilemma. J Conserv Dent 2017;20:479-81

How to cite this URL:
Shah PN, Arora AV, Kapoor SV. Accessory branch of canalis sinuosus mimicking external root resorption: A diagnostic dilemma. J Conserv Dent [serial online] 2017 [cited 2022 Dec 3];20:479-81. Available from:

   Introduction Top

Numerous unnamed accessory foramina have been described in the jaws, especially in the anterior palate,[1] lateral to the lingual foramina and lingual aspect of the mandible.[2] The size and morphology of these foramina are extremely variable due to which they can be misinterpreted as apical pathosis.

The most prominent anatomical structure within the premaxillary region is the nasopalatine canal.[3] It carries the nasopalatine nerves and vessels, which supply the anterior teeth and the adjacent soft tissues. This region is also traversed by a lesser known but often present bony canal called canalis sinuosus (CS).[4] This canal branches from the lateral face of infraorbital canal, close to its midline;[5] runs forward and downward to the inferior wall of the orbit, medially bent to the anterior wall of the maxillary sinus, follows the lower margin of the nasal aperture, and opens next to the nasal septum in front of the incisive canal.[6] CS contains the anterior superior alveolar (ASA) nerve and corresponding vessels.[7]

Limited knowledge among the practitioners, insufficient literature in the textbooks, and failure of conventional radiography to properly display these anatomical configurations may cause them to remain unnoticed.

This report describes a rare case of superimposition wherein the opening of an accessory canal was mimicking a resorptive defect in the apical third of the root of tooth 11.

   Case Report Top

A 60-year-old male patient presented to the department of conservative dentistry and endodontics with pain and intermittent episodes of swelling in upper front tooth region for 2 weeks. The patient had a history of trauma in the same region 21 years back. Extraoral examination showed no remarkable findings. Intraoral examination revealed sinus tract associated with fractured tooth 21 [Figure 1]a and [Figure 1]b.
Figure 1: (a) Clinical assessment of sinus tract with relation to tooth 21, (b) radiographic image of sinus tract tracing, (c) radiographic image taken with a straight horizontal angulation suggestive of a resorptive defect with relation to tooth 11 (red arrow), (d) radiographic image taken with a distal horizontal angulation suggestive of an external resorptive defect, present on the palatal side of tooth 11 (red arrow), (e-g) axial sections showing the presence of nasopalatine canal (yellow arrow), accessory canal in relation to tooth 11 (red arrows) and tooth 21 (blue arrow), (h-j) sagittal sections of the anterior maxilla showing the presence of accessory canal with relation to tooth 11 (red arrows), (k-m) coronal sections of the anterior maxillary region showing the presence of nasopalatine canal (yellow arrow) and accessory canal in relation to tooth 11 (red arrows)

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Pulp vitality tests were negative for the teeth 11 and 21. Intraoral periapical (IOPA) radiograph revealed diffuse periapical radiolucency in relation to tooth 21. A well-defined radiolucency in relation to the root of tooth 11 was apparent on the IOPA radiograph which was suggestive of resorption [Figure 1]c. Another IOPA radiograph was taken with a different horizontal angulation [Figure 1]d, which hinted towards the presence of an external root resorption defect since the site of lesion moved with the change in horizontal angulation. Cone-beam computed tomography (CBCT) scan was advocated to plan the management of resorptive defect on tooth 11 (scan parameters: field of view – 8 cm × 4 cm, kVp – 120, mA – 5, effective exposure time – 7 s).

In the CBCT scan, no resorptive defect was evident with relation to tooth 11. However, a well-corticated bony canal, located palatal to the root of tooth 11, was observed. Similar structure was also observed on the distopalatal aspect of the root of tooth 21, but its cortical border was not well delineated [Figure 1]e,[Figure 1]f,[Figure 1]g,[Figure 1]h, [Figure 1]i,[Figure 1]j,[Figure 1]k,[Figure 1]l,[Figure 1]m.

It was inferred that the opening of this accessory canal behind the palatal aspect of tooth 11 superimposed on the root surface and was earlier interpreted as a resorption defect. Based on the previous literature reporting similar anatomic structure, this accessory canal can be identified as an “accessary branch of CS.”[8] Hence, the final diagnosis was concluded as pulpal necrosis for tooth 11 and chronic periapical abscess for tooth 21 and root canal treatment was planned for both the teeth.

   Discussion Top

The clinical implications of accessory canals and foramina are often overlooked in clinical procedures. The presence of these anatomical variations can be discovered preoperatively on imaging and has a direct influence on the planning and success of the treatment. Frederic Wood Jones was the first who described an accessory bony canal carrying ASA nerve and vessels. Owing to its double-curved course, the term CS was coined by him.[4]

In the present case, a wide accessory canal was observed extending from the floor of nasal cavity to a foramen located mesiopalatal to the tooth 11 with a diameter of 2.1 mm. The exit profile and orientation of the accessory canal led to a circular radiolucency superimposed on the root of tooth 11 on the IOPA.

Although CS has been identified previously on IOPA,[9] it is difficult to locate it on conventional radiography as evident in the present case with respect to tooth 21. This could be due to small diameter of the canal, porous cortical layers, and variable course. CBCT is advantageous in such case scenarios as it clearly delineates these delicate findings.[10]

The present case is a rare occurrence where superimposition of the anatomic variation of CS mimicked the apical resorptive defect with relation to tooth 11. A misdiagnosis in this case could have led to unnecessary surgical intervention of the tooth.

   Conclusion Top

This case reinforces the fact that anatomical variations can be misleading and require a detailed evaluation to fulfill the treatment needs. In what appeared to be a simple diagnosis, a CBCT advised for treatment planning leads to an accurate diagnosis and discovering the unexpected.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

de Oliveira-Santos C, Rubira-Bullen IR, Monteiro SA, León JE, Jacobs R. Neurovascular anatomical variations in the anterior palate observed on CBCT images. Clin Oral Implants Res 2013;24:1044-8.  Back to cited text no. 1
Angelopoulos C. Cone beam tomographic imaging anatomy of the maxillofacial region. Dent Clin North Am 2008;52:731-52, vi.  Back to cited text no. 2
Mraiwa N, Jacobs R, Van Cleynenbreugel J, Sanderink G, Schutyser F, Suetens P, et al. The nasopalatine canal revisited using 2D and 3D CT imaging. Dentomaxillofac Radiol 2004;33:396-402.  Back to cited text no. 3
Jones FW. The anterior superior alveolar nerve and vessels. J Anat 1939;73:583-91.  Back to cited text no. 4
Neves FS, Crusoé-Souza M, Franco LC, Caria PH, Bonfim-Almeida P, Crusoé-Rebello I, et al. Canalis sinuosus: A rare anatomical variation. Surg Radiol Anat 2012;34:563-6.  Back to cited text no. 5
Wanzeler AM, Marinho CG, Alves Junior SM, Manzi FR, Tuji FM. Anatomical study of the canalis sinuosus in 100 cone beam computed tomography examinations. Oral Maxillofac Surg 2015;19:49-53.  Back to cited text no. 6
Warwick R, Williams PL. Gray's Anatomy. 35th ed. Edinburgh: Longman; 1973.  Back to cited text no. 7
Torres MG, de Faro Valverde L, Vidal MT, Crusoé-Rebello IM. Branch of the canalis sinuosus: A rare anatomical variation – A case report. Surg Radiol Anat 2015;37:879-81.  Back to cited text no. 8
Shelley AM, Rushton VE, Horner K. Canalis sinuosus mimicking a periapical inflammatory lesion. Br Dent J 1999;186:378-9.  Back to cited text no. 9
von Arx T, Lozanoff S, Sendi P, Bornstein MM. Assessment of bone channels other than the nasopalatine canal in the anterior maxilla using limited cone beam computed tomography. Surg Radiol Anat 2013;35:783-90.  Back to cited text no. 10

Correspondence Address:
Priyal Naresh Shah
Manubhai Patel Dental College and Hospital, Vishwajyoti Ashram, Near Vidyakunj School, Munjmahuda, Vadodara - 390 011, Gujarat
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JCD.JCD_375_16

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