|Year : 2013 | Volume
| Issue : 2 | Page : 114-119
Syndesmocorono-radicular tooth: An endo-perio challenge
Rhythm Bains1, Vivek Kumar Bains2, Kapil Loomba3, Kavita Verma4, Anju Loomba5
1 Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, King George's Medical University, Saraswati Dental College and Hospital, Lucknow, Uttar Pradesh, India
2 Department of Periodontology, Saraswati Dental College and Hospital, Lucknow, Uttar Pradesh, India
3 Department of Conservative Dentistry and Endodontics, Career Post Graduate Institute of Dental Sciences and Hospital, Lucknow, Uttar Pradesh, India
4 Department of Conservative Dentistry and Endodontics, Saraswati Dental College and Hospital, Lucknow, Uttar Pradesh, India
5 Department of Dental Care Clinic, Lucknow, Uttar Pradesh, India
|Date of Web Publication||11-Feb-2014|
Vivek Kumar Bains
Department of Periodontology, Saraswati Dental College and Hospital, Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Syndesmocorono-radicular tooth consist of palatoradicular groove that represents anomalous morphology and is the predisposing factor for developing localized chronic periodontitis and pulpal necrosis. This clinical report discusses diagnosis and endodontic-periodontal treatment of maxillary central incisor with palatoradicular groove that begins in the central fossa, crosses cingulum and extends a variable distance onto the root. Both endodontic and periodontal surgical therapy is required for treatment of pulpal pathosis, correction of osseous defect, pocket elimination and groove correction depending on the extent and depth of the radicular groove.
Clinical Relevance to Interdisciplinary Dentistry
- Endodontic failure may occur due to communication of palatal groove with pulp cavity. Such anomaly often predisposes to periodontal defects, severe bone destruction or combined endodontic-periodontal lesions.
- Interdisciplinary treatment modalities used in the present case reports emphasizes on the team approach management consisting of both endodontist and periodontist.
Keywords: Endo-perio lesion, palatoradicular groove, periodontitis
|How to cite this article:|
Bains R, Bains VK, Loomba K, Verma K, Loomba A. Syndesmocorono-radicular tooth: An endo-perio challenge. J Interdiscip Dentistry 2013;3:114-9
| Introduction|| |
Palatoradicular groove,  an anatomical variation that is more often found in maxillary lateral incisors, is characterized by a developmental groove, which usually begins in the central fossa, crosses cingulum and extends a variable distance onto the root. ,,,, Kovacs called tooth with palatoradicular groove as syndesmocorono-radicular tooth. He brought attention to a significant feature associated with the groove; the alteration of the level of the cementoenamel junction where the groove passes from the crown to the root. Evidence of this anomaly in prehistoric and medieval eras has also been reported.  Other synonyms for such tooth anomaly are radicular anomaly,  palatogingival groove,  distolingual groove,  radiculolingual groove,  cinguloradicular groove,  palatal groove.  Such an anomaly that often creates the dilemma in diagnosing and treating endo-perio lesions, ,, may be the outcome of an infolding of the enamel organ and epithelial sheath of Hertwig  or an effort of the tooth germ to form another root. , It may be bilateral, or two grooves can occur on a single tooth on facial and palatal surface or can also be observed in teeth with talon cusp.  Radicular groove may vary in extension and depth. A study by Peikoff et al.  suggested that endodontic failure may occur due to communication of groove with pulp cavity. Such anomaly often predisposes to periodontal defects, severe bone destruction  or combined endodontic-periodontal lesions. 
This paper discusses the clinical report of maxillary central and lateral incisors, with palatoradicular groove that causes severe periodontal destruction and has been treated by both endodontic and periodontal therapy. Thorough knowledge of such cases amongst dental practitioners must be emphasized for precise diagnosis and treatment, leading to increased success rate in clinical practice.
| Case Reports|| |
This was a case report of a 17 year old, systemically healthy, non-smoker male patient who reported to the Department of Periodontics with the chief complaint of continuous pus discharge from upper anterior palatal region along with dull pain on chewing for past 1 year. There was no history of trauma. Clinical examination revealed probing depth of 11 mm and pus discharge on palpation from palatal gingival sulcus of 11 (maxillary right central incisor), together with the presence of a palato-radicular groove extending apically beyond the cervical line. No tooth mobility was present.
Radiographic examination revealed a radiolucent area at the middle third along mesial side of root of 11 [Figure 1]a. On vitality testing using the electric pulp tester (Parkell Electronics Division, New York, USA) tooth 11 was found to be non-vital, whereas tooth 12 (maxillary right lateral incisor), 21 (maxillary left central incisor) and 22 (maxillary left lateral incisor) were vital. Results were further verified by cold test, using ice sticks.
|Figure 1: (a) Radiograph of tooth 11 showing radiolucency in middle third of root (b) radiograph of tooth 11 after root canal treatment (c) photograph showing residual calculus in radicular groove of tooth 11 (d) photograph showing osseous defect and palatoradicular groove in 11 (e) 9 months follow-up radiograph of tooth 11|
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The condition was diagnosed as pulp necrosis associated with localized chronic periodontitis resulting from palato-radicular groove. Treatment plan comprised of thorough scaling, root planning and root canal therapy followed by periodontal surgery for the treatment of pocket elimination and groove repair. Access opening was done under rubber-dam isolation after local anesthesia. After pulp extirpation and working length determination, the canal was prepared using step back method up to ISO size 50 using K files (Dentsply Maillefer, Switzerland), irrigated with 3% sodium hypochlorite and the access cavity was temporarily sealed with cavit (3M, ESPE). Calcium hydroxide was placed as intracanal medicament. On a subsequent visit after 7 days, the patient was asymptomatic and pus discharge had ceased, the tooth was obturated with Gutta-percha cones and AH Plus sealer using cold lateral compaction technique. The access cavity was sealed with glass ionomer cement (Fuji II, GC Corporation, Japan) [Figure 1]b.
At 1 week after the endodontic therapy, periodontal flap surgical procedure was performed. Following nasopalatine nerve block, full thickness mucoperiosteal flap was reflected from the palatal aspect of tooth 12, 11, 21 and 22. A small circumferential bony defect surrounding the palatal and mesial aspect of 11 was revealed, that extended apically into a localized bony destruction along the radicular groove [Figure 1]c. The bony defect was debrided of the granulation tissue, the residual calculus present in the radicular groove was removed and it was traced for its depth and extent after thorough root planning [Figure 1]d. The radicular groove was then sealed with glass ionomer cement (Fuji I, GC Corporation, Japan) after conditioning with 10% polyacrylic acid for 10 s. Hydroxyapatite graft material (G-Bone, Modified Hydroxyapatite Granules; Average Particle size 0.4-0.9 mm; SURGIWEAR, Shahjahanpur, India) was mixed with saline and placed into the deep bony defect. The flap was later on readapted and stabilized with sling sutures and Coepak (GC America INC., Alsip, IL, USA) was applied on operative area. Written post-operative instructions were given to the patient and analgesic (ibuprofen 400 mg thrice a day) was prescribed for 3 days. 0.2% chlorhexidine mouth rinse was also instructed for 1 week. Sutures were removed 7 days after the surgical procedure. Patient responded well to the periodontal surgery with uneventful healing and was asked to maintain meticulous oral hygiene and care. Patient remained asymptomatic 9 months after treatment, with a significant reduction in probing pocket depth at the site from 11 mm to 3 mm and is still under active follow-up [Figure 1]e.
The another case is about a systemically healthy non-smoker 16-year-old male patient reported to the Department of Periodontics with the chief complaint of continuous pus discharge from palatal aspect of upper anterior region for more than 1½ year. The patient had been to the general dental practioner 6 months ago, who could not be specific in diagnosing the problem and performed scaling and root planning together with antibiotics and analgesics that helped him in relieving the problem but only for few weeks. There was no history of trauma or spontaneous pain and clinical examination revealed probing depth of 10 mm and pus discharge on palpation from palatal gingival sulcus of 12 (maxillary right lateral incisor). No mobility was present and the tooth was not sensitive to percussion. Radiographic examination revealed a radiolucent area at the middle third along mesial side of root of 12 [Figure 2]a. Close examination of the tooth in question showed a palatogingival groove crossing the cingulum and cervical line and extending further apically. On vitality testing using electric pulp tester (Parkell Electronics Division, New York, USA) and ice sticks, tooth 12, 11 (maxillary right central incisor), 13 (right maxillary canine), 21 (maxillary left central incisor) and 22 (maxillary left lateral incisor) responded within the normal range.
|Figure 2: (a) Radiograph of tooth 12 showing radiolucency in middle third of root (b) photograph showing osseous defect in relation to tooth 12 (c) radiograph of tooth 12 after root canal treatment (d) 6 months follow-up radiograph of tooth 12|
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The condition was diagnosed as periodontal abscess associated with localized chronic periodontitis resulting from palatoradicular groove. Treatment plan comprised of scaling, root planning and periodontal surgery for treatment of periodontal abscess, pocket elimination and groove repair. Peridontal surgery was performed under local anesthesia using nasopalatine nerve block. Full thickness mucoperiosteal flap was reflected from the palatal aspect of tooth 11, 12 and 13. A small circumferential bony defect surrounding the palatal and mesial aspect of lateral incisor was revealed that extended apically into a localized bony destruction along the radicular groove. Granulation tissue was removed from the bony defect and after complete debridement the radicular groove was traced for its depth and extent [Figure 2]b. The groove was shallow but extended apically into localized bony defect. Odontoplasty was done for correction of the radicular groove using diamond wheel and flame shaped stone at slow speed. Then, hydroxyapatite graft material (G-Bone, Modified Hydroxyapatite Granules; Average Particle size 0.4-0.9 mm; SURGIWEAR) was mixed with saline and placed into the deep bony defect; flap was later on readapted and stabilized with sling sutures and Coe-pak (GC America INC., Alsip, IL, USA) was applied on operative area. Written post-operative instructions were given to the patient and analgesic (ibuprofen 400 mg thrice daily) was prescribed for 3 days. 0.2% chlorhexidine mouth rinse was instructed for 1 week. Sutures were removed 7 days after the surgical procedure. Patient was instructed to maintain meticulous oral hygiene and was recalled after every 4 weeks and on subsequent visit vitality tests were performed to check the status of the pulp. Patient responded well to the periodontal surgery and healing was uneventful.
On follow-up 8 weeks after periodontal surgery, patient was relieved of pus discharge but reported sensitivity to hot and cold in relation to 12 and on clinical examination, it was found to be slightly sensitive to percussion. Response to electric pulp tester was not conclusive for 12 however 11, 13, 21 and 22 responded within normal range. To confirm the results, cold test using ice sticks was performed in which tooth 12 showed immediate responses which lingered on even after removal of the stimulus. Persistent tenderness and progressive thermal sensitivity was suggestive of stressed pulp  and intentional endodontic therapy was planned. Access opening was done under rubber-dam isolation after local anesthesia. After pulp extirpation and working length determination, the canal was prepared using crown down method up to ISO size 45 using K files (Dentsply, Switzerland) and irrigated with 3% sodium hypochlorite and the access cavity was provisionally sealed with Cavit (3M, ESPE). Intracanal medicament used was calcium hydroxide. After 1 week, the canal was obturated with cold lateral compaction of Gutta-percha and AH plus sealer. The access and coronal part of palatoradicular groove was sealed with glass ionomer cement (Fujii II, GC Corporation, Japan) [Figure 2]c. Patient remained asymptomatic when he last reported 6 months after the root canal treatment [Figure 2]d with a significant reduction in probing depth from 10 mm to 3 mm.
| Discussion|| |
Syndesmocorono-radicular tooth comprises of palatoradicular groove with the prevalence that ranges from 12% to 21% in both lateral and central maxillary incisors  and 6.3-14% in lateral incisors alone, as given by Brabant;  however other reports suggest frequency of occurrence in lateral incisors of about less than 2%,  4.4%  and 5.6% respectively.  In the present clinical report of anomalous morphology, the palato-radicular groove was found to be the predisposing factor for developing localized chronic periodontitis and pulpal pathosis.
Primary etiologic agent in periodontal disease is bacterial plaque and various secondary factors that may influence its course and act as predisposing factors consist of calculus; anatomic anomalies, including enamel projections, root grooves and concavities; over-hanging margins; habits; food impaction; and host response etc. ,,, Developmental malformations like palato-radicular groove becomes contaminated once the epithelial attachment is breached and a self-sustaining infrabony pocket is formed along its course,  as this conduit provides a nidus or an ideal plaque trap for accumulation of bacterial biofilm which may cause localized periodontal destruction and pulpal changes. ,,,,,,, Gao et al.  in their study have reported bacterial access to pulp space through accessory canals connecting the pulp in the depth of the groove. Area of bone destruction may follow the course of groove and sometimes a tear drop-shaped radiolucency may be evident radiographically.  However, in some cases radicular lingual groove may present as a radiolucent parapulpal line on radiographs.  In both the present cases, radiolucency in middle-third of the root may represent the apical extent of the palato-radicular groove and the associated pathology. Clinicians should be careful while diagnosing such cases as initial radiographic appearance of this kind without vigilant clinical correlation can be misinterpreted as internal/external resorption or fenestration.
Both pulp vitality test and presence of deep periodontal probing depth further helps in establishing the diagnosis. Seldom, electric pulp testing results may be inconclusive and in that case pulp vitality tests should be repeated or other tests like cold tests can often be preferred for differentiating reversible and irreversible pulpitis and in identifying the teeth with necrotic pulp. ,,
Pulpal pathosis herein represents retrograde nature of the lesion that was secondarily involved after localized periodontal destruction ,, Furthermore, odontoplasy performed for the correction of radicular groove may have resulted in the stressed pulp condition, a clinical concept that describes pulps that have received repeated previous injury and survived with diminished responses and lessened repair potentials.  On critical appraisal of the endo-perio lesions, Rotsein and Simon  have suggested that secondary endodontic involvement after periodontal therapy is possible through lateral canals and dentinal tubules that may be opened following curettage, scaling or surgical flap procedures. Pulpal inflammation and necrosis may be the result of microorganisms being pushed into the area during periodontal treatment when blood vessel within the lateral canal may be severed by a curette.  Prognosis of syndesmocorono-radicular tooth depends on depth, location and extension of the palato-radicular groove. Shallow groove, entirely within the crown or terminating at cervical line usually would not have deep osseous defects or pulpal pathology and can be managed easily, but the same is not true if the groove is deep and extends apically below cervical line.  Treatment of such cases usually involves comprehensive management that mainly focuses on abolition of primary etiologic agent (microbial biofilm) by eliminating the groove and endodontic therapy for pulpal pathosis together with periodontal surgical management for successful treatment of deep osseous defects and elimination of deep periodontal pocket. Cases of palato-radicular groove have been managed successfully by odontoplasty, composite, amalgam, glass-ionomer cement and mineral trioxide aggregate and the corrective modality can be influenced by its depth and extent. ,,, Liji and Rameshkumar  reported the use of biodentine, a new tricalcium silicate based dental cement to seal the groove.
A study by Schäfer et al.  demonstrated the healing capacity of groove related periodontal defect after surgical curettage without filling the groove with any material. In the present clinical scenario radicular groove treatment both by odontoplasty and glass ionomer cement was found to be successful. Odontoplasty and saucerization in conjunction with peridontal therapy and endodontic treatment if involved pulpally, is helpful for management of lesions associated with shallow radicular grooves. ,,,
Reports suggest epithelium and connective tissue adherence to glass-ionomer cement during the healing process  and have supported it for antibacterial effect, chemical adhesion to tooth structure and good sealing ability. , In addition, periodontal therapy including scaling root planning, complete debridement after full thickness flap elevation of the osseous defect and filling the bone defect by hydroxyapatite crystals, promotes regeneration by osteoconduction.  Jahn  has suggested that hydroxyapatite acts as an amphoteric ion exchanger. Selective accumulation of calcium and phosphate ions occurs as a consequence of the negative charges on the hydroxyapatite surface that leads to the formation of more apatite and stimulates the formation of new bone. The excellent bonding between new bone and calcium phosphate implants has been characterized in detail by various investigators.  Minegishi et al.  suggested that in contrast to control sites, downgrowth of junctional epithelium never extended to the base of the defect but stayed at the coronal portion of implanted hydroxyapatite granules which were encapsulated with dense connective tissue. Role of platelet rich plasma in osseous regeneration of such cases has also been suggested.  Al-Hezaimi et al.  in their study have reported successful treatment of radicular groove by the combination of endodontics, intentional replantation and Emdogain therapy in maxillary lateral incisor of a 15-year-old girl and Liji and Rameshkumar  reported the use of biodentine to seal the radicular groove and platelet rich fibrin as a regenerative material.
Interdisciplinary treatment modalities used in the present case reports emphasize on the team approach management consisting of both endodontist and periodontist. Additional investigations including pulp sensibility tests, cone beam computed tomography and transgingival probing or sounding under local anesthesia, may further be helpful in establishing accurate assessment of the pulpal condition and bone destruction pattern. Once correctly diagnosed, both endodontic therapy and periodontal surgical therapy may be required for treatment of pulpal pathosis, correction of osseous defect, pocket elimination and groove correction depending on the extent and depth of the radicular groove. The current reports confer to the treatment of pathosis associated with palato-radicular groove by combined endodontic-periodontal therapy in patients who showed clinically significant reduction in probing pocket depth with uneventful clinical and radiographic healing.
| Conclusion|| |
Following conclusions can be drawn from the presented clinical reports:
- Although rare, palato-radicular groove may be responsible for retrograde pulpitis and localized chronic periodontitis in maxillary incisors
- Detailed history, thorough clinical examination, recognition, understanding and correlation of the clinical features with radiographic interpretation along with diagnostic tests confirm the presence of such lesions
- Once correctly diagnosed, both endodontic and periodontal surgical therapy may be required for treatment of pulpal pathosis, correction of osseous defect, pocket elimination and groove correction depending on the extent and depth of the radicular groove
- Recent advances in diagnosis, regeneration and adhesive dental materials further help clinicians in achieving beneficial results.
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[Figure 1], [Figure 2]