SRM Journal of Research in Dental Sciences

: 2018  |  Volume : 9  |  Issue : 2  |  Page : 87--90

Palatogingival groove: A diagnostic and treatment challenge

Prashanth Prakash1, Soumya Raveendran1, Ramya Raghu2, Keerthi Venkatesan1,  
1 Department of Conservative Dentistry and Endodontics, Thai Moogambigai Dental College and Hospital, Dr. MGR Educational and Research Institute University, Chennai, Tamil Nadu, India
2 Department of Conservative Dentistry and Endodontics, Bangalore Institute of Dental Sciences and Hospital, Bengaluru, Karnataka, India

Correspondence Address:
Prashanth Prakash
No. 24, Montieth Road, Egmore, Chennai - 600 008, Tamil Nadu


This article presents a case report of a maxillary lateral incisor with a palatogingival groove extending up to the middle third of the root. Despite the poor prognosis, management of the defect was successfully carried out with combined endodontic and periodontal therapy.

How to cite this article:
Prakash P, Raveendran S, Raghu R, Venkatesan K. Palatogingival groove: A diagnostic and treatment challenge.SRM J Res Dent Sci 2018;9:87-90

How to cite this URL:
Prakash P, Raveendran S, Raghu R, Venkatesan K. Palatogingival groove: A diagnostic and treatment challenge. SRM J Res Dent Sci [serial online] 2018 [cited 2021 May 8 ];9:87-90
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Palatogingival groove (PGG) is an anatomic malformation of developmental origin usually found on the lingual aspect of the roots of maxillary incisor teeth.[1] In 1968, Lee et al. initially reported their presence.[2],[3],[4] Such grooves start in the cingulum region, proceeding apically toward and beyond cementoenamel junction and may terminate at various levels in the root. They can also provide a route for bacterial invasion to the pulp.[5],[6],[7] There are two types of PGG based on depth: simple or complex.[8],[9] The etiopathogenesis describes the groove to be a morphological defect which arises from the infolding of the enamel epithelium and Hertwig's epithelial root sheath during odontogenesis.[2],[6],[10] This funnel-shaped defect can provide a nidus for plaque accumulation and subsequent inflammation.[5] PGG can be diagnosed clinically by periodontal probing which determines its extent. Radiographic diagnosis may exhibit a parapulpal line along the root canal. Treatment options for mild defects include saucerization of the groove followed by sealing it with a restorative material, and a combination of endodontic and periodontal therapy is indicated for moderate-to-complex grooves.[11]

 Case Report

A female patient aged 45 years reported with a chief complaint of discolored tooth in the upper left anterior region with mobility. The medical history was noncontributory. There was no history of trauma or previous dental treatment in the maxillary anterior region.

On examination, it was found that the maxillary left lateral incisor was discolored and was slightly extruded. The tooth also exhibited Grade 2 mobility. Further examination revealed a groove in the lingual aspect of the maxillary left lateral incisor arising from the cingulum [Figure 1]a. On palatal periodontal probing, there was a deep pocket which measured 9 mm [Figure 1]b and [Figure 1]c.{Figure 1}

Radiographic examination revealed periradicular and periapical radiolucency in relation to the maxillary left lateral incisor [Figure 1]d.

Sensibility testing with cold test using Endo-Ice Refrigerant Spray (Coltene/Whaledent, Inc., Mahwah, NJ, USA)[12] revealed negative response in the left lateral maxillary incisor (#22).

The diagnosis was: nonvital (#22) with a palatogingival groove.

The treatment was done in two phases:

At the first appointment, the endodontic phase was started. After prophylaxis and removal of localized calculus, endodontic access was prepared under local anesthesia and rubber dam isolation. Canal length was measured using Root ZX apex locator (J Morita Manufacturing, Kyoto, Japan) and confirmed using radiographs. Cleaning and shaping of the canal was carried out using Ni-Ti ProTaper system (Dentsply Maillefer, New York, PA, USA) along with a lubricant: Endoprep-RC (Mediclus, Chungcheongbuk-do, Republic of Korea) in a crown-down manner to size F3.[6] The canal was debrided using copious irrigation with 5.25% sodium hypochlorite.[6]

Calcium hydroxide medicament (RC Cal, Prime Dental Pvt. Ltd., Mumbai, India) was placed within the root canal for 7 days.

At the second appointment, calcium hydroxide was removed with copious saline irrigation. Final rinsing was done with 5.25% sodium hypochlorite and 17% ethylenediaminetetraacetic acid (Deo Smear-Off, Azure Lab, Kerala, India).[6] The tooth was obturated using lateral compaction technique with gutta-percha and AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). The access cavity was temporarily restored with zinc oxide eugenol cement (Cavit G) [Figure 2].{Figure 2}

At the third appointment, periodontal phase treatment was done.

Under local anesthesia, a full-thickness mucoperiosteal surgical flap was elevated from the palatal aspect to gain access to the PGG. The PGG was found to be extending up to the mid-third of the palatal aspect of the root [Figure 3]a. Scaling and root planing was performed over the groove to eliminate calculus and debris. The granulation tissue was curetted out using Gracey curette numbers 1, 2 and 5, 6 (Hu-Friedy Manufacturing Co., Chicago, IL, USA).{Figure 3}

Minimal widening of PGG was done using a straight fissure bur and at slow speed [Figure 3]b. Chemical conditioning was done using 10% polyacrylic acid for 20 s and type 2 conventional glass ionomer cement (Fuji 2; GC Corporation, Tokyo, Japan) was used to seal the groove.[5] [Figure 3]c. The area was kept isolated from blood and tissue fluids during the entire procedure. After the cement had set, the localized bony defect was substituted with bone graft material (Spongious bone substitute; Geistlich Pharma AG, Wolhusen, Switzerland)[5] [Figure 3]d. The flap was approximated and sutured [Figure 4]a. The tooth was splinted with an orthodontic wire for 1 week [Figure 4]b.{Figure 4}

The patient was instructed on postsurgical precautions and maintenance protocol, which included rinsing with 0.12% solution of chlorhexidine twice a day for 5 weeks.


The maxillary lateral incisor region is an area of embryologic hazard. Several anomalies can occur in this area such as dens in dente, peg-shaped laterals and congenitally missing lateral incisors. One such developmental anomaly is the PGG or radicular lingual groove.[13] The groove is formed during odontogenesis by the infolding of the enamel organ or the Hertwig's epithelial root sheath.[14],[15] It has also been described as an attempt by the developing tooth germ to divide into a main root and a minor accessory root.[2],[6],[10] Withers et al. evaluated 2099 maxillary incisors and reported that 2.33% presented with a PGG, of which 94% were present in the maxillary lateral incisors.[16] Some other authors have also reported an incidence of PGG in 4.6% of maxillary incisors, of which 5.6% were seen in the maxillary lateral incisor teeth.[16],[17] These radicular grooves vary in depth, length, location, and complexity.[11] It is estimated that 58% extend >5 mm apically from cementoenamel junction.[16]

This article presents a case of a PGG involving the palatal surface of a maxillary left lateral incisor tooth. The groove was found to be extending from cingulum to the middle third of the root. On periodontal probing, the pocket which was associated with the groove measured 9 mm. Since this groove acts as a medium for plaque formation, a communication may be formed between the root canal system and the periodontium.[6] The accessory foramina and lateral canals which are present along the groove are also additional means of bacterial invasion of the pulp.[15],[18]

Clinically, the tooth with PGG may present with either:

A primary perio lesionA primary perio lesion with a secondary endo lesionA true combined lesion in long-standing cases.

In combined lesions, lateral and periapical bone loss may be evident.

In most cases, a primary periodontal lesion with secondary involvement of the pulp is present [6] as seen in this case.

This condition can also be misdiagnosed as a periodontal abscess clinically and a vertical root fracture or as an additional canal radiographically.[7]

Treatment modalities depend on the severity of the endo-perio lesion due to the complexity of communication between the periodontal environment and root canal system.[4],[19]

Therefore, the prognosis of teeth varies according to the location of the groove, the extent and accessibility of the periodontal defect, depth, and length of the groove (shallow/deep or long/short).[6],[12],[20] In this case, management of the defect was carried out in two phases: endodontic phase and periodontal phase. Since the pulp was necrotic, endodontic root canal therapy was performed followed by elevation of flap to expose the PGG. Widening of the groove was done to eliminate bacterial plaque and calculus and to prevent bacterial recolonization. The groove was sealed to enhance regeneration of periodontal attachment and bone and to eliminate the pocket.[5] Materials such as composite and amalgam have been used to fill the PGG.[21] In our study, glass ionomer cement was chosen as adhesion to the dentin is better and it also enhances epithelial and connective tissue attachment. Recently, mineral trioxide aggregate is also used for this purpose, but it has a disadvantage of getting washed off from the transgingival defect in the presence of moisture.[5]

Guided tissue regeneration principles can also be used by placing a mechanical barrier to allow periodontal ligament, cementum, and bone to regenerate.[22],[23] The tooth presented with Grade 2 mobility; therefore, splinting was done for 1 week to immobilize the tooth and to optimize the healing outcome. Although there was an option to extract the tooth and place a replacement, we chose to save the tooth since it was in an esthetic zone.[4]


Endodontic and periodontal therapy proved to be successful, although the tooth presented with poor prognosis. Accurate diagnosis and adequate treatment with the help of improved diagnostic aids and regenerative materials can help in saving teeth with such anomalies.

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.


The authors deny any conflicts of interest related to this study.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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