Palatogingival groove – a silent killer: Treatment of an osseous defect due to it

Abstract

A male patient of 21 years of age reported to the Department of Periodontology and Implantology with a chief complain of pus discharge in both right and left upper lateral incisors. On clinical examination a deep pocket of about 10–14 mm was noticed in both lateral incisors. Radiographic interpretation shows a teardrop-shaped radiolucency in both the laterals giving suspicion of palatogingival groove, which was later discovered and treated surgically.

INTRODUCTION

Palatogingival groove or radicular lingual groove (RLG) is a developmental anomaly that occurs as developmental infoldings of the inner enamel epithelium and Hertwig's epithelial root sheath (HERS), involving primarily maxillary lateral incisors. RLG formation presumably represents an aborted attempt to represent an additional root.[1] According to Kogon's investigations, the groove can be found in cingulum, followed by lateral fossa, cementoenamel junction, and root in decreasing order. He also found that most common location is in the midpalatal area of lingual surface followed by distal and then mesial.[2]

The presence of RLG does not always indicate the development of pathology. In most cases the epithelial attachment remains intact across the groove. Once the attachment is breached, a self-containing pocket forms along the length of the groove or by gingival irritation secondary to microbial plaque retention.[3] The attachment may be breached due to endodontic involvement. Inflammation can progress from an apical lesion coronally along the groove, causing a primary endodontic/secondary periodontic lesion.[4] If inflammation spreads to the pulp through defects in the groove or involvement of apex, a primary periodontic/secondary endodontic lesion develops.[4]

Goon et al. suggested a classification, which represents two types of RLGs, simple and complex.[5] The simple RLGs do not communicate with the pulp and represents a partial unfolding of HERS, while complex RLGs communicate directly with the pulp and groove that extend the length of the root. In rare cases, the groove may lead to minor accessory root, which may contain a root canal.

CASE REPORT

A 21-year-old male patient reported to the Department of Periodontology and Implantology of S.P.P.G.I.D.M.S., Lucknow (UP), India, with a chief complaint of pus discharge from right and left upper lateral incisors. On clinical examination, a localized gingival inflammation was present with soft edematous tissue with the accumulation of plaque and calculus. Periodontal examination depicts a deep tubular periodontal pocket depth ranging between 14 mm on the right and 10 mm on the left lateral incisors [Figure 1], grade I mobility was present in both the lateral incisors. On radiographic examination, a tear-shaped radiolucency was present with localized bone loss in both the lateral incisors [Figure 2]. The patient does not have any caries and history of trauma IRT 12 and 22. Both 12 and 22 show an extensive bone loss and deep periodontal probing depth. This extensive amount of bone loss along with the above findings at the age of 21 years gives a suspicion of palatogingival groove, which on careful examination was discovered on both the lateral incisors [Figure 3]. The groove was present on distal aspect on both the laterals shown with the help of gutta-percha points.

Figure 1.

Probing depth of 14 mm in 12 and 10 mm in 22

Figure 2.

Radiograph of 12 and 22 showing tear-shaped radiolucency

Figure 3.

Palatogingival groove IRT 12 and 22

Treatment

Aim of the treatment

To correct the osseous defect along with correction of palatogingival groove.

Method

Phase one therapy followed by an endodontic treatment was planned and root canal was done in both the lateral incisors. After completion of a root canal and curettage of deep periodontal pocket surgery was planned. Surgery was done in two appointments for both the lateral incisors.

Complete extraoral and intraoral mouth disinfection was done with betadine, local anesthesia was administered (xylocaine 2% with epinephrine 1:80,000). A crevicular incision was given along with the vertical incision in respect to (IRT) both 12 and 22 [Figure 4] and the full-thickness flap was raised [Figure 5]. A defect was curetted and cleaned and a clear groove was visible after flap reflection [Figure 6]; and after this, the groove was corrected with a taper fissure bur [Figure 7]; and after correction, a smooth surface develops [Figure 7] followed by root planning and root conditioned with tetracycline [Figure 8]. The defect was filled with bone graft (bioactive ceramic composite granules with 50% bioactive glass, 50% synthetic hydroxyapatite) [Figure 9] followed by a resorbable barrier membrane placement (periocol) [Figure 10]. The flap was replaced and sutures [Figure 10] followed by a periodontal pack [Figure 11].

Figure 4.

Crevicular incision along with vertical IRT 12 and 22

Figure 5.

Full-thickness flap was raised IT 12 and 22

Figure 6.

Defect was cleaned IRT 12 and 22 also showing groove

Figure 7.

Groove was corrected with bur IRT 12 and 22

Figure 8.

Smooth surface after correction of grooves IRT 12 and 22

Figure 9.

Root conditioning done with tetracycline IRT 12 and 22

Figure 10.

Bonegraft placed IRT 12 and 22

Figure 11.

Resorbable membrane placed IRT 12 and 22

Postoperative

The patient was asymptomatic postoperatively and sutures were removed after 7 days. Patient was recalled after 3 months, which shows pocket depth reduction to 5 mm IRT 12 and 4 mm IRT 22 [Figure 12] along with bone formation IRT 12 and 22 [Figures Figure 13–15].

Figure 12.

Sutures placed IRT 12 and 22

Figure 13.

Coe-pack was given IRT 12 and 22

Figure 15.

Postoperative after 3 months

Figure 14.

Postoperative after 3 months

DISCUSSION

Numerous articles in the literature describe the palatoradicular groove as a morphological defect associated with central/lateral incisors.[6] These defects usually occur on the lingual surface of the midpalatal, mesial, or distal region of the tooth.[2,3] It can extend apical to the root.[6] However, in our case it was present in distal surface of lateral incisor and reaches up to apical one-third of the root surface. The first large survey of the incidence of PRG in extracted teeth was conducted by Everett and Kramer.[7] Although this anomaly was prevalent in humans during the megalithic era,[8] it was not addressed in the dental literature until recently.[9] Developmental folding may result in defects that can provide a pathway for pulpal pathology. Radicular groove can create periodontal and pulpal pathology, but they may be difficult to identify as an etiological factor; however, in our case there was pulpal involvement for which root canal treatment was done IRT to 12 and 22. A few reports have demonstrated the relationship between PRGs and localized periodontitis using standard periodontal indices.[10] Our case also shows a periodontal involvement, which was depicted as a bone loss IRT to both laterals.

Radicular groove develops with the alteration in the growth of the inner enamel epithelium and Hertwig's epithelial root sheath and involves primarily the maxillary lateral incisors.[11] It has a similarity to dens invaginatus; however, it differs from it in such a way that dens invaginatus occurs due to an unfolding of the epithelium (resulting in a groove), rather than an invagination (resulting in a circular opening).[11]

Recognizing RLGs as the initiator of pathology can often be difficult, patient may present with pulpal involvement in teeth that have no caries or history of trauma[12,13] periradicular abscess, also present in our case. Several authors have reported cases in which patients with pathological involvement received delayed or improper treatment, since RLGs were not diagnosed.[12–14] Conversely, the patient may demonstrate periradicular abscess formation in teeth with vital pulps.

Symptomatic patient may report with concurrent episodes of pain and swelling on the palate adjacent to the groove. Before the final diagnosis, one should look for periodontal abscess, vertical root fracture, juvenile periodontitis,[7] or patent nasopalatine duct.[15]

CONCLUSION

A palatogingival groove is a hazard for periodontal as well as endodontal problems. Most of the time goes undiagnosed but if looked out carefully and treated in a proper way may solve out both periodontal and endodontal problems.