| Abstract|| |
Palatogingival groove is a rare developmental anomaly involving the lingual surface of the maxillary incisor and resulting in severe endodontic and periodontal lesions. This case report describes a multidisciplinary approach for the combined management of the endodontic and periodontal problems for successful rehabilitation of the involved tooth. Cone-beam computed tomography (CBCT) helped in correct diagnosis of the lesion and hence enabled effective treatment.
Keywords: CBCT, glass-ionomer cement, palatogingival groove, thermoplasticized gutta-percha
|How to cite this article:|
Rajput A, Talwar S, Chaudhary S, Khetarpal A. Successful management of pulpo-periodontal lesion in maxillary lateral incisor with palatogingival groove using CBCT scan. Indian J Dent Res 2012;23:415-8
Palatogingival groove is a rare developmental anomaly of maxillary central and lateral incisors and is associated with periodontal pockets and bone loss, which may lead to pulpal necrosis. Its prevalence is 2.8%-8.5%, , the occurrence varying in different populations and subpopulations. It is most commonly seen in the maxillary lateral incisors and less frequently in the central incisors.
|How to cite this URL:|
Rajput A, Talwar S, Chaudhary S, Khetarpal A. Successful management of pulpo-periodontal lesion in maxillary lateral incisor with palatogingival groove using CBCT scan. Indian J Dent Res [serial online] 2012 [cited 2019 Oct 14];23:415-8. Available from: http://www.ijdr.in/text.asp?2012/23/3/415/102243
The etiopathogenesis of palatogingival groove has not been fully elucidated. The palatal groove is thought to represent an infolding of the enamel organ and Hertwig's root sheath, leading to an external defect adjacent to the gingival crevice.  However, more recently, the etiopathogenesis has been related to the recent concept of alteration of genetic mechanisms.  The groove provides the site or pathway for bacteria to penetrate into the periodontal ligament area, resulting in a periodontal pocket along the length of the groove.  Necrosis of the adjacent pulp tissue can develop because of the presence of irritants in an area that is separated from pulp tissue by only a thin layer of enamel and dentine or cementum. 
Careful clinical and radiographic examination is necessary for correct diagnosis and treatment planning in such cases. Because of the two-dimensional limitations of radiographs, they are not sufficient to understand the complex anatomy of root canal system in such an anomaly. This has given palatogingival groove a reputation for being difficult to diagnose. However, with the advent of cone-beam computed tomography (CBCT), early diagnosis and timely treatment has become possible.
This case report describes the successful endodontic and periodontal management of palatogingival groove present in a maxillary lateral incisor with the use of CBCT. A combined treatment approach involving both endodontic therapy and periodontal surgical management resulted in adequate periodontal healing and resolution of the associated periradicular radiolucency.
| Case Report|| |
A 20-year-old patient reported with the chief complaint of pain, discoloration, and mobility in relation to tooth 12 for the last 3-4 months. Periodontal examination revealed an around 10-mm pocket associated with a deep palatoradicular groove in relation to the maxillary right lateral incisor on its lingual surface [Figure 1]. The tooth was discolored gray-black and revealed a negative response to an electronic pulp tester (Parkell Electronics Division, New York, USA), confirming the diagnosis of a nonvital pulp. There was neither caries nor any history of trauma in relation to the concerned tooth. Thus, it appeared likely that pulp necrosis had occurred secondary to the deep periodontal defect occurring as a result of the palatoradicular groove. An intraoral periapical radiograph revealed a periapical lesion with a bony defect [Figure 2]. Since bilateral occurrence of the palatoradicular groove is possible, tooth 22 was also examined, but no evidence of a palatoradicular groove was found after sulcular probing and radiography.
|Figure 1: Preoperative photograph showing presence of periodontal pocket associated with palatogingival groove|
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|Figure 2: Preoperative radiograph of maxillary left lateral incisor showing the palatogingival groove with periapical radiolucency|
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Gutta-percha tracing into the periodontal pocket revealed direct communication of the periodontal pocket with the periapical area, thus confirming that the problem was primarily periodontal and secondarily endodontic in nature. Extension of the groove along the root was not clear either clinically or on radiography; on angulated x-ray views it simulated a two-rooted lateral incisor. To clarify these doubts and to establish a definitive diagnosis, we decided to refer the patient for a three-dimensional CBCT of tooth 12. CBCT demonstrated the complex anatomy of tooth 12 and showed that the groove extended till the root apex, in this manner bifurcating the root into two halves, with each having a different apex in the axial planes [Figure 3]. The pulp chamber was found to be in intimate association with the groove. CBCT revealed the presence of a 'C' shaped sheet of pulp tissue surrounding the bifurcation coronally, extending from mesial to distal along the palatal aspect of the tooth.
|Figure 3: CBCT axial section demonstrating the complex anatomy of 12 with invagination extending from mesial to distal along the palatal aspect of 12|
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After taking the patient's consent, combined a combined endodontic-periodontal treatment approach was planned. Access opening was done in the usual manner except that the width of the opening was slightly increased to enable access to the bifurcation area and thus both the apices. Working length was taken [Figure 4] and the canals were cleaned and shaped using K-files, 3% sodium hypochlorite, 2% chlorhexidine, and normal saline, after which calcium hydroxide (UltraCal XS™, Ultradent Products, Inc., South Jordan, UT) was packed in both the canals for 1 week. The access opening was sealed with intermediate restorative material (IRM) (Dentsply Caulk, Milford, DE) and the tooth was reduced out of occlusion. Thermoplasticized gutta-percha (Thermafill Plus™) was used to obturate both the canals, and the access cavity was finally sealed in with glass-ionomer cement (Fuji II™; GC Corporation, Tokyo, Japan) [Figure 5].
The patient was reviewed after 1 week, when periodontal flap surgery was performed to eliminate the pocket and groove simultaneously. A full-thickness mucoperiosteal flap was reflected on the palatal aspect of the maxillary right lateral incisor. On reflection, an advanced circumferential bony defect was found, which surrounded the palatal, mesial, and distal aspect of lateral incisor. Granulomatous tissue was removed from the bony defect and the palatoradicular groove was traced to the apex. Following root-planing, the groove was conditioned with 10% polyacrylic acid, isolated with cotton pledgets, and sealed with light-cured glass-ionomer cement (Fuji I™; GC Corporation) [Figure 6]. Hydroxyapatite graft material (Perio Bone G ® ; Top Notch-Health Care Products, Aluva, Kerala, India) was mixed with saline and placed into the deep bony defect. The flap was readapted and stabilized with sling sutures and the wound site covered with non-eugenol periodontal dressing (Coe- Pak™; GC Inc., Alsip, IL, USA). Postoperative instructions were given and a 0.12% chlorhexidine gluconate rinse was prescribed. The patient was prescribed antibiotics (ornidazole + ofloxacin) and analgesics (ibuprofen) for 5 days. The dressings and sutures were removed 10 days after surgery so as to stabilize the graft material.
|Figure 6: (a) Surgical photograph showing the presence of palatogingival groove (b) Surgical photograph showing the groove restored with GIC|
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The patient was recalled after 1 week and then in the first, second, third, sixth, twelfth, and eighteenth month postoperatively for follow-up. During these visits radiographs were taken for evaluation of the endodontic and periodontal status. Discoloration was masked with direct composite veneer. After 2 months, the pocket probing depth had reduced from 10 mm to 4.0 mm and between the sixth month and the eighteenth month it remained at 3.5 mm. There was no exudate or bleeding on probing. Mobility was reduced to within physiological limits. The 18-month follow-up radiograph [Figure 7] demonstrated excellent bone fill of the osseous defect.
|Figure 7: Periapical radiograph demonstrating excellent periradicular healing|
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| Discussion|| |
The complex anatomy of palatogingival groove calls for detailed knowledge of the dental root's internal morphology for successful planning of endodontic therapy. Periapical radiographs provide 2-D images of anatomic structures, and the superimposition of adjacent tissues may obscure the true nature of palatogingival groove and the extent of periodontal damage. CBCT is an x-ray imaging approach that provides high-resolution 3-D images. It is especially useful in endodontics for identification of anatomic features and variations of the root canal system. In this particular case, the use of CBCT proved to be of great advantage as it demonstrated the dimensions of groove, its communicating nature, the site of bifurcation, the volume of bone loss and, thus, the approximate amount of graft required for filling the defect. 
Due to the abnormal anatomical configuration, the palatogingival groove poses technical difficulties in its clinical management. When no visible communication exists between the groove and the pulp cavity, treating the groove as a separate entity and preserving the vitality of the pulp is a recommended treatment approach. Endodontic treatment was done in this case as the tooth had become nonvital due to the chronic long-standing involvement of the periodontium because of the presence of communicating channels between the groove and the pulp chamber, which facilitated bacterial penetration, causing the pulp tissue to undergo inflammation, degenerative changes, and eventual pulp necrosis.
The groove was associated with severe periodontal breakdown and extensive periapical lesion, necessitating surgical intervention. The periapical pathosis in this case was primarily due to the infected periodontium. However, it was not known how long the root canal had been infected prior to the patient developing symptoms. Mechanical debridement of the primary root canal was difficult, but the combination of chemo-mechanical instrumentation and the use of calcium hydroxide were found to be an effective method for eliminating bacteria. The use of a warm gutta-percha technique helped to obturate the root canal system, as it was possible to compact the softened material into the major irregularities within the root canal system. 
The problem encountered in the management of a tooth that presents with a palatal groove relates to the inability to adequately treat the tooth periodontium and resolve the associated localized periodontal defect. It is important to note that it is the ability to adequately treat the associated periodontal defect that ultimately determines the prognosis of these teeth. This case report describes successful management of a maxillary lateral incisor with a deep palatal groove and associated periodontal and pulpal involvement using a combined endodontic and periodontic treatment approach. With this management approach there was improvement in periodontal ligament attachment and periradicular healing as assessed on the 18-month follow-up radiograph.
| Conclusion|| |
CBCT meets a much needed diagnostic imaging need in dentistry. With a collaborative management of the complex root canal system and the significant developmental anomaly in this case, periodontal ligament attachment and periradicular healing were evident both clinically and radiographically on follow-up.
| References|| |
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Department of Conservative Dentistry and Endodontics, Maulana Azad Institute of Dental Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]