Tonetti MS, Greenwell H, Kornman KS. Staging and grading of periodontitis: Framework and proposal of a new classification and case definition. J Clin Periodontol. 2018; 45:S149-Ss61
Ramachandra SS, Mehta DS, Sandesh N Periodontal probing systems: a review of available equipment. Compend Contin Educ Dent. 2011; 32:71-77
Matthews DC, Tabesh M. Detection of localized tooth-related factors that predispose to periodontal infections. Periodontology 2000. 2004; 34:136-150 https://doi.org/10.1046/j.0906-6713.2003.003429.x
Ghivari S, Patil AC, Patil S Interdisciplinary management of an isolated intrabony defect. Case Rep Dent. 2014; 2014 https://doi.org/10.1155/2014/672152
Malhotra N, Gupta VV, Ramachandra SS. Diagnosis: the difficult part!. Dent Update. 2016; 43
Ercoli C, Tarnow D, Poggio CE The relationships between tooth-supported fixed dental prostheses and restorations and the periodontium. J Prosthodont. 2021; 30:305-317 https://doi.org/10.1111/jopr.13292
Ababneh KT, Taha AH, Abbadi MS The association of aggressive and chronic periodontitis with systemic manifestations and dental anomalies in a jordanian population: a case control study. Head Face Med. 2010; 6 https://doi.org/10.1186/1746-160X-6-30
Hans MK, Srinivas RS, Shetty SB. Management of lateral incisor with palatal radicular groove. Indian J Dent Res. 2010; 21:306-308 https://doi.org/10.4103/0970-9290.66627
Zhu J, Wang X, Fang Y An update on the diagnosis and treatment of dens invaginatus. Aust Dent J. 2017; 62:261-275 https://doi.org/10.1111/adj.12513
Western JS, Gupta VV, Ramachandra SS. Salvaging a periodontally compromised and endodontically involved three-rooted mandibular first molar with cervical enamel projection. Compend Contin Educ Dent. 2019; 40:172-177
Romeo U, Palaia G, Botti R Enamel pearls as a predisposing factor to localized periodontitis. Quintessence Int. 2011; 42:69-71
Faria AI, Gallas-Torreira M, Lopez-Raton M. Mandibular second molar periodontal healing after impacted third molar extraction in young adults. J Oral Maxillofac Surg. 2012; 70:2732-2741 https://doi.org/10.1016/j.joms.2012.07.044
Al-Hezaimi K, Naghshbandi J, Simon JH, Rotstein I. Successful treatment of a radicular groove by intentional replantation and Emdogain therapy: four years follow-up. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009; 107:e82-85 https://doi.org/10.1016/j.tripleo.2008.11.012
Versiani MA, Cristescu RC, Saquy PC Enamel pearls in permanent dentition: case report and micro-CT evaluation. Dentomaxillofac Radiol. 2013; 42 https://doi.org/10.1259/dmfr.20120332
Maddalone M, Rota E, Amosso E Evaluation of surgical options for supernumerary teeth in the anterior maxilla. Int J Clin Pediatr Dent. 2018; 11:294-298 https://doi.org/10.5005/jp-journals-10005-1529
Reddy KV, Nirupama C, Reddy PK Effect of iatrogenic factors on periodontal health: an epidemiological study. Saudi Dent J. 2020; 32:80-85 https://doi.org/10.1016/j.sdentj.2019.07.001
Saed SM, Ashley MP, Darcey J. Root perforations: aetiology, management strategies and outcomes. The hole truth. Br Dent J. 2016; 220:171-180 https://doi.org/10.1038/sj.bdj.2016.132
Ilday NO, Celik N, Dilsiz A The effects of overhang amalgam restoration on levels of cytokines, gingival crevicular fluid volume and some periodontal parameters. Am J Dent. 2016; 29:266-270
Ramachandra SS, Hans MK, Shetty SB. Vertical root fracture – a diagnostic dilemma. Dent Update. 2010; 37
Lin YT, Huang YL, Chang SH, Hong HH. Sequelae of iatrogenic periodontal destruction associated with elastics and permanent incisors: literature review and report of 3 cases. Pediatr Dent. 2011; 33:516-521
Dubey KN, Garg S, Atri R. Diagnosis and osseous healing of a lateral periodontal cyst mimicking a deep unusual interdental pocket in a young patient. Contemp Clin Dent. 2010; 1:47-50 https://doi.org/10.4103/0976-237X.62526
Lee AHC, Neelakantan P, Dummer PMH, Zhang C. Cemental tear: literature review, proposed classification and recommendations for treatment. Int Endod J. 2021; 54:2044-2073 https://doi.org/10.1111/iej.13611
Pompura JR, Sandor GK, Stoneman DW. The buccal bifurcation cyst: a prospective study of treatment outcomes in 44 sites. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1997; 83:215-221 https://doi.org/10.1016/s1079-2104(97)90008-1
Livada R, Shiloah J, Anderson KM, Callahan WR. Managing a lateral periodontal cyst with bone graft: a computed tomography assessment 18 months postoperatively. Compend Contin Educ Dent. 2017; 38:e5-e8
Pedercini A, Weitz DF, Heyse JD Cemental tear: an overlooked finding associated with rapid periodontal destruction. A case series. Aust Dent J. 2021; 66:S82-S87 https://doi.org/10.1111/adj.12844
Kocak Oztug NA, Ramachandra SS, Lacin CC, Alali A, Carr A. Regenerative approaches in periodontics. In: Hosseinpour S, Walsh LJ, Moharamzadeh K (eds). Cham, Switzerland: Springer; 2021
Ramachandra SS, Rana R, Reetika S, Jithendra KD. Options to avoid the second surgical site: a review of literature. Cell Tissue Bank. 2014; 15:297-305 https://doi.org/10.1007/s10561-013-9395-8
An isolated periodontal pocket is a perplexing clinical entity that usually poses a diagnostic challenge to the oral health professional. Although periodontal pockets are easy to detect, they can be easily missed during a routine clinical examination. The broad range of aetiological factors that can result in an isolated periodontal pocket makes identifying the cause difficult. The aetiology can be as simple as an overhanging restoration or food impaction due to open interproximal contacts, to more complex and uncommonly occurring presentations, such a palato-radicular groove or cemental tears. Although previous classifications proposed by the American Academy of Periodontology and European Federation of Periodontology have discussed this topic under different headings, an explicit classification on isolated periodontal pockets based on aetiology is currently missing. Isolated periodontal pockets are easily undiagnosed, with associated cases presenting with substantial destruction necessitating complex multidisciplinary treatment. This article highlights the various causes of an isolated periodontal pocket, and provides a systematic and easy clinical aetiology-based classification. The proposed classification categorizes isolated periodontal pockets into those occurring due to: (1) developmental anomalies of the teeth; (2) iatrogenic causes; and (3) pathological conditions. Further studies are essential to validate this classification.
CPD/Clinical Relevance: Early detection of easily missed isolated periodontal pockets is of clinical value during initial screening to avoid delayed diagnosis and treatment.
Article
A comprehensive periodontal examination, with assessment of the risk factors, helps in identifying the extent of periodontitis (localized or generalized) and in determining the stage and grade of periodontitis.1 Measurement of pocket depth and clinical attachment loss using periodontal probes are the most important means to diagnose periodontitis.2 Periodontal pockets are easily detected in generalized periodontitis cases; however, in a few situations, periodontal pockets are associated only with an isolated tooth or a particular location on a tooth's surface. The detection of isolated periodontal pockets may be easily missed during initial screening or dismissed as having minimal diagnostic value, both by general dental practitioners and specialists.3 The aetiology of an isolated periodontal pocket can be restorative, endodontic, prosthodontic, periodontic or a combination of these, resulting in delayed diagnosis and treatment.3 Numerous individual case reports4 and short communications/letters to editors5 are published where the diagnostic significance of isolated periodontal pockets are discussed. Previous classifications proposed by the American Academy of Periodontology and the European Federation of Periodontology have broadly discussed this topic under different headings.6 Additionally, previous reviews have stressed prosthodontic considerations and the potential of the dental prosthesis with subgingival margins causing gingivitis and periodontitis.3,7 However, an explicit classification for isolated periodontal pockets is needed. The authors define an isolated periodontal pocket as a pathologically deepened gingival sulcus, or a periodontal pocket of more than 4 mm in depth with bleeding on probing in a localized area or site, with an aetiology unique to that site. This narrative review summarizes the relevant literature regarding isolated periodontal pockets, including their causes, commonly involved sites, and treatment. The review also proposes an aetiology-based classification for isolated periodontal pockets.
Methodology
A literature search was performed using the PubMed, MEDLINE, EBSCO and OVID databases with the keywords ‘isolated periodontal pocket’/’localized periodontal pocket’/‘isolated periodontitis’ from 1950 to 2021. Upon initial screening, if the article contained information about isolated periodontal pockets/periodontitis, the complete article was downloaded, and relevant information was analysed by the authors (NM and SR). If the reviewer of the article felt that the title and the abstract of the article did not provide sufficient information, the complete article was obtained and reviewed.
Aetiological classification of isolated periodontal pockets
Based on the aetiology, isolated periodontal pockets can be classified into those resulting from:
Developmental anomalies of the teeth;
Iatrogenic causes; and
Pathological causes.
Table 1 summarizes the proposed aetiological classification of the isolated periodontal pockets, listing their common causes, with a broad treatment plan.3,6,7 The article also briefly discusses the clinical presentation, pathogenesis and treatment plan for these aetiological factors.
Causes
Commonly seen in
Broad treatment plan
1
Isolated periodontal pockets due to developmental anomalies of the teeth
On the maxillary and mandibular anterior teeth. Can occur in the cervical, middle and apical third of the roots
Scaling and root debridement, endodontic treatment, regenerative periodontal therapies and intentional replantation. Extraction for teeth with poor prognosis
On the buccal aspect of the mandibular first and second molars in children
Surgical enucleation of the cyst
Isolated periodontal pockets due to developmental anomalies of the teeth
The presence of dental developmental anomalies can cause isolated periodontal pockets. Ababneh et al reported the frequent presence of dental anomalies including dens invaginatus, dens evaginatus, or peg-shaped lateral incisors among aggressive (16%) and chronic periodontitis (15%) patients compared to the controls.8 The dental anomalies further included palatal radicular grooves (PRG),9 dens in dente,10 cervical enamel projections,11 extra-buccal cusps,12 enamel pearls,13 impacted teeth,14 and lateral or accessory pulpal canals.15 Developmental defects of the teeth or altered variations in the shape of the teeth may result in a niche for plaque accumulation or difficulty in maintenance of oral hygiene.3,6 This results in localized advanced periodontal destruction at the involved surface of the tooth, creating an isolated periodontal pocket.6,7 The next section of the article briefly discusses the various developmental anomalies leading to isolated periodontal pockets.
Palatal radicular grooves (PRG)
These grooves are developmental anomalies that occur due to the infolding of the enamel organ and the epithelial sheath of Hertwig, found on the maxillary incisors and specifically on the palatal root surface of the maxillary lateral incisors.5,9 The grooves begin from the cingulum area of the incisors and extend to different distances down the root, especially along the distal root surface.9 Deep periodontal pockets are associated with moderate and severe grooves.5
Depending on the involvement of pulpal and periodontal tissue, cases of PRG can be associated with pain, loss of vitality, swelling and suppuration. This groove acts as a locus for plaque accumulation and can result in a severe localized periodontal defect. Figure 1 shows a PRG associated with a maxillary central incisor. Infection from the periodontium can enter into the pulp space via accessory canals or lateral canals, resulting in involvement and/or non-vitality of the pulp. Radiographically they are seen as a radiolucent parapulpal line running adjacent to the root canal along the involved root surface (usually distal aspect).9 Scaling and root debridement is followed by elevation of a mucoperiosteal flap for degranulation and exposure of the radicular groove. Radiculoplasty is performed, followed by sealing of the groove with biomaterials.9
Figure 1.
(a) A deep isolated periodontal pocket was traced to the palatal radicular groove on the palatal aspect of the maxillary right central incisor. (b) The entire length of the probe could be inserted in the periodontal pocket. (c) A deep pocket was also observed on the mesiolabial aspect of the maxillary right central incisor. Additionally, the involved incisor showed distolabial migration with midline diastema.
Dens-in-dente
Dens-in-dente is a developmental anomaly that occurs due to the infolding of the enamel and dentin or an accentuation of the lingual pit of an incisor, especially the maxillary incisors.10 Although this condition most frequently results in endodontic problems due to the possibility of early pulpal involvement,10 occasionally, the condition can also result in localized periodontitis.10 Treatment for these lesions involves prophylactic or preventive sealing of the invagination, endodontic surgery, periapical surgery and intentional replantation if required.
Cervical enamel projection (CEP)
The CEPs, especially the Grade III CEPs are covered by enamel and are correlated with periodontal destruction in the furcation regions of the molars.11 CEP lacks a connective tissue attachment, which makes the area more susceptible to periodontal breakdown and increases the chances for rapid bone loss in the furcation leading to the development of isolated furcation involvement, which may be clinically seen as an isolated periodontal pocket.11 The treatment of the lesion involves elevation of a mucoperiosteal flap, followed by radiculoplasty and regenerative periodontal therapy to address the associated periodontal defects (Figure 2)
Figure 2.
(a) A periodontal abscess was noted on the buccal aspect of the mandibular right first molar. (b) Periodontal probing revealed an isolated periodontal pocket. (c) shows presence of a CEP in relation to buccal furcation (revealed following abscess drainage). Reproduced with kind permission of the publishers, BroadcastMed LLC, of Western et al.11
Extra buccal cusp
Extra buccal cusps noticed on the posterior teeth, especially on the molars are known as ‘Bolk cusps’.12 The additional cuspal areas provide a niche for the accumulation of plaque and calculus, which may predispose to dental caries and periodontitis (Figure 3). These areas will result in the formation of an isolated periodontal pocket.
Figure 3.
(a) An extra buccal cusp (red arrow) attached to the buccal surface of the maxillary second molar, which acts as an area for accumulation of bacterial deposits leading to periodontitis and dental caries. (b) The magnified area from the other angle, where dental caries can be appreciated.
Treatment of these cases depends upon whether these additional cusps have pulp or pulp-like structures within them.12 If additional cusps have pulp within them, before altering the structure of these teeth, intentional endodontic therapy and restorative treatment are indicated.
Enamel pearls
Enamel pearls are isolated 0.3–2 mm globules of enamel located on the root surfaces, especially on the furcation areas of the maxillary second and third molars.13 These globules may contain dentine and pulp tissue.13 The exposure of an enamel pearl to the pocket environment provides an amenable environment for increased bacterial contamination. The patient may complain of chronic discomfort in the related tooth.16 The examination may reveal an extensive localized periodontal breakdown in the form of isolated pockets and alveolar bone loss. In symptomatic cases, treatment includes root debridement, odontoplasty and regenerative periodontal procedures, if required.13
Supernumerary and impacted teeth
The presence of supernumerary teeth often results in these teeth being placed in unusual locations in the dentition.17 This creates difficulties in the maintenance of oral hygiene, which may result in the accumulation of plaque and calculus leading to localized periodontitis or isolated periodontal pockets.18 It can be accompanied by malalignment and mobility of adjacent teeth. The supernumerary teeth associated with periodontal pockets include the paramolars (Figure 4), distomolars, and mesiodens.19 Removal of the supernumerary teeth is the treatment of choice.17
Figure 4.
(a) The paramolar acting as a niche for plaque accumulation resulting in an isolated periodontal pocket. (b) Extraction of the paramolar, followed by root debridement resolved the periodontal infection. (c) The bone loss distal to mandibular right second molar (red arrow). The presence of an impacted third molar prevented the maintenance of good oral hygiene around the third molar and in this case resulted in an isolated periodontal pocket on the distal aspect of the mandibular second molar.
Impacted teeth may cause difficulties in maintenance of oral hygiene of the adjacent teeth leading to localized periodontitis of the neighbouring teeth. Retention of the third molars can result in a deterioration of the periodontal health of the adjacent mandibular second molars (Figure 4b).14 Faria et al reported improvement in the periodontal health of the mandibular second molars following removal of the impacted third molars.14
Isolated periodontal pockets due to iatrogenic reasons
Iatrogenic incident/mishap occurring during dental treatment can also injure the surrounding periodontium resulting in a periodontal pocket.20 Reddy et al reported a significant impact on the periodontal status of the teeth following the placement of overhanging interproximal restorations in 100 patients.20 Isolated periodontal pockets can result due to iatrogenic factors such as vertical root fractures,21 perforation of the tooth during endodontic therapy or post and core preparation,22 defective restorations23 and the use of inappropriate orthodontic forces.6 Iatrogenic factors can establish a connection between the periodontium and the oral cavity through the gingival sulcus resulting in an isolated periodontal pocket.
Perforations
An endodontic perforation is an artificial opening in the tooth or its root, created during entry to the canal system or by a biological event such as pathological resorption or caries that results in communication between the root canal and the periodontal tissues.22. Root perforations account for almost 10% of all failed endodontic cases.22
The success of perforation repair is highly dependent on the periodontal status because the main complication is secondary inflammation of the periodontal ligament, with eventual infection and formation of osseous defects, which compromises healing significantly.22 Any open (communicating) defect located near the gingival sulcus can cause inflammation with loss of epithelial attachment and periodontal pocket formation.22 Furcal and cervical perforations affect the sulcular attachment and are associated with epithelial down growth and subsequent periodontal defect.22 Location/position of perforation defect and closing the defect on an immediate basis leads to favourable healing and a better prognosis.22
Figure 5.
(a) A deep isolated periodontal pocket is seen along the mandibular first premolar. Multiple periodontal abscesses can also be noted. (b) Intra-oral peri-apical radiograph shows a halo-like radiolucency or J-shaped radiolucency around the endodontically treated mandibular premolar. The mandibular first premolar was used as an abutment for the replacement of mandibular second premolar and first molar. The excessive forces then placed on the mandibular first premolar resulted in a vertical root fracture. Courtesy of Ramachandra et al.24
Vertical root fractures (VRFs)
Longitudinally oriented fractures of the root (commonly in buccolingual orientation), extending from the root canal to the periodontium are known as VRF.21,24 Although, most VRF are complete,21 both incomplete and complete VRF tend to form deep, isolated periodontal pockets.21,24
Patients complain of a long history of variable discomfort or soreness, mild to moderate degree of pain, associated with localized long-standing infection. Multiple or double sinus tracts are common.24 VRFs commonly present with deep, narrow, isolated periodontal pockets in the presence of otherwise normal attachment. Deep probing depths in two positions on opposite sides of the infection is almost pathognomonic for the presence of VRF.21,24 The presence of a ‘halo-like’ radiolucency running around the whole of the tooth is a classic sign of a VRF. VRFs in endodontically treated teeth occur either from excessive force during the obturation, or weakening of the tooth because of excessive removal of the tooth structure. In non-endodontically treated teeth, incomplete root fractures may be attributed to the force exerted by an intracoronal restoration. VRFs usually involve the gingival sulcus and thus provide a pathway for the ingress of bacteria, their metabolites and other irritants.5 The resulting chronic inflammation and alveolar bone loss predispose to pocket formation at the site of the fracture line. Multirooted teeth can be successfully treated with root amputation or hemisection, by resecting the fractured root.21 However, for single-rooted teeth, extraction is often the treatment of choice.
Overhanging restorations and fixed prosthesis beneath the finish lines
Clinical studies have in the past reported on a link between overhanging restorations and periodontal or alveolar bone destruction.23 Owing to improper application and non-confinement of these biomaterials (amalgam, composite and glass ionomer cement) within the dental structures,23 an overhang results, which encroaches upon the supracrestal connective tissue resulting in an isolated periodontal pocket. In a fixed prosthesis, especially if the prosthesis has finish lines placed subgingivally for aesthetic reasons, there are possibilities for compromising oral hygiene, resulting in encroachment of supracrestal connective tissue attachment. If periodic professional maintenance is not performed in these regions, plaque accumulation may lead to localized periodontitis or isolated periodontal pockets.
The patient may complain of dull, continuous pain and discomfort that increases gradually over time. An over-contoured and/or over-extended restoration is observed at the proximal region with an isolated periodontal pocket. Furthermore, an intra-oral peri-apical radiograph would show an overhang restoration encroaching on the underlying interdental bone. Treatment in these cases may involve removal of the overhang or total replacement of the restoration, with or without periodontal flap surgery and regenerative periodontal procedure.
Orthodontic treatment
Localized periodontal destruction has been reported in cases where elastic bands used to close a midline diastema have migrated/slipped subgingivally and not realized until localized periodontal destruction or even tooth loss has occurred.25 In certain circumstances, the application of excessive orthodontic forces may cause non-vitality of teeth. Eventually, the pulpal infection may pass through the lateral canals into the periodontal ligament space leading to isolated periodontal pockets (Figure 6). Commonly observed signs and symptoms of isolated periodontal destruction in these cases include pain, increased pocket depths along the path of the slipped elastic band in the interproximal area, vertical or arc-like bony destruction where the elastic band was present, radiographic root convergence, crown divergence and isolated pyogenic granuloma like growths in the interdental area. The treatment includes the surgical or non-surgical removal of the dislodged elastic bands.25
Figure 6.
(a) A deep isolated periodontal pocket and periodontal abscess was seen on the buccal aspect of the mandibular first molar in a 20-year-old girl undergoing orthodontic treatment. (b) Intra-oral peri-apical radiograph of the region showed widened periodontal ligament space with radiolucency at the apices (black arrows). Scaling and root debridement with adjunctive antimicrobials resolved the abscess and isolated periodontal pocket. Vitality tests showed that the tooth was non-vital, and (c) endodontic therapy was performed.
Isolated periodontal pockets due to pathological conditions
Certain pathological conditions, such as a lateral periodontal cyst,26 cemental tears27 and buccal bifurcation cysts28 can also result in isolated periodontal pockets.
Lateral periodontal cysts
A lateral periodontal cyst is a non-keratinized, non-inflammatory developmental cyst occurring adjacent or lateral to the root of a tooth.29 These cases are usually present between the maxillary lateral incisor and canine, however, these cysts can occur between any teeth.26 Although in many cases, lateral periodontal cysts do not communicate with the gingival sulcus, the cyst can enlarge until it communicates with the adjacent crevicular epithelium, thus establishing an isolated periodontal pocket.29 Alternatively, the crevicular epithelium in the gingival sulcus could migrate apically until it communicates with an existing lateral periodontal cyst.29 The lateral periodontal cyst is treated by enucleation with or without regenerative periodontal therapies based on the associated bony defects.29
Cemental tears
A cemental tear is a specific type of root fracture involving complete or partial detachment of the cementum from the cementodentinal junction or along the incremental line within the cementum.30 Cemental tears can occur in both unexposed as well as exposed cementum, in vital and non-vital teeth in equal proportions and at the cervical, middle, or apical third of the root. More commonly observed in males involving the incisors and premolars.30
The usual presentation is a rapid localized site-specific periodontal breakdown, including isolated periodontal pocket formation or alveolar bone destruction. The separated cementum fragment initiates a localized attachment loss,30 which may be asymptomatic with a 6–10 mm isolated periodontal pocket observed on the involved surfaces of a tooth. The presence of a hard, immovable, ledge-like projection on the root surface near the base of the pocket, felt during probing is characteristic of cemental tears.27,30 If the detached cementum becomes exposed to the oral cavity, pain, swelling, and exudation can occur. On the radiographs, a deep vertical defect with a slender, narrow foreign body/object lying parallel to the involved root surface is noticed.27,30 Trauma either acute (localized injury from hard foods or toothpicks), chronic (tensional forces due to occlusal overloading) or idiopathic (gouging or separation of cementum due to overzealous instrumentation or subsequent to tissue regeneration procedures) can be the cause of cemental tears.27 Treatment includes removal of the traumatic forces resulting in potential repair and reattachment of the broken fragments. The successful therapeutic approach includes scaling and root debridement, open flap debridement,27 retrieving the cementum fragment by mechanical instrumentation with or without elevating a flap, and possible use of regenerative therapies.27
Buccal bifurcation cysts
A buccal bifurcation cyst is an inflammatory odontogenic cyst commonly occurring in the buccal surface of the mandibular first and second molars of children. Deep periodontal pockets are noted on the buccal surface of the mandibular molars.28 Pompura et al reported the majority of the buccal bifurcation cysts in molars and the lesion extended from the buccal bifurcation to the tooth apex.28 Following surgical enucleation of the cysts, the teeth were saved and complete healing was observed radiographically.28 Surgical enucleation is the treatment of choice with developing succedaneous permanent teeth being unaffected.28
Discussion
This article discusses the various potential causes for isolated periodontal pockets under three main headings: (1) developmental anomalies of the teeth; (2) iatrogenic factors; and (3) pathological factors. Treatment for these isolated periodontal pockets involves early identification of the cause of the lesion and subsequent treatment to eliminate the cause of pocketing. In advanced cases, where the isolated periodontal pocket is associated with bone defects, periodontal regenerative therapies could be considered. Considering the high predictability of success for bone grafting31 and soft tissue grafting procedures,32 periodontal hard and soft tissue defects can be successfully treated, especially if identified early.4,11,15 The complexity of the treatment also depends on the advanced nature of the lesion or the pocketing involved.11
As the role of plaque control is well documented in eliminating supragingival microbial components and gingival inflammation, presence of deep periodontal pocket due to various aetiological factors leads to further colonization by bacteria and periodontal destruction.6 Therefore, accurate diagnosis and elimination of aetiological factors is important for management of periodontal pockets.3
This article also proposes an aetiology-based classification of isolated periodontal pockets. First, isolated periodontal pockets caused due to developmental anomalies of the teeth are directly or indirectly related to the area turning into a niche for accumulation of plaque and calculus.3,8 This results in the apical migration of the junctional epithelium resulting in isolated periodontal destruction and attachment loss6,7 or creation of a communication between the pulpal space and the periodontium.9 Secondly, iatrogenic factors including excessive application of force or trauma/perforation caused due to dental procedures, may result in communication between the oral cavity and the periodontium leading to isolated periodontal pockets.25,27 Thirdly, isolated periodontal pockets due to pathological reasons are a result of either the pathology extending to the periodontium or the junctional epithelium (periodontium) slowly proliferating towards the pathology.29
Strengths and limitations
This manuscript has couple of strengths. First, to the authors' knowledge, this report is an initial attempt at summarizing the main causes of isolated periodontal pockets in a systematic manner. Our article has tried to categorize various factors/causes leading to one specific clinical feature (isolated periodontal pocket), contrary to American Academy of Periodontology and European Federation of Periodontology classification which discusses factors causing periodontitis in general. Secondly, this classification incorporates the possibility of pathological conditions causing isolated periodontal pockets, which has not been included in previous classifications. However, this review has couple of limitations as well. First, many of the causes for isolated periodontal pockets (for example cervical enamel projections, vertical root fractures or palatal radicular grooves) are comprehensive review topics by themselves. However, this review does not describe in detail each of the causes of isolated periodontal pockets. Secondly, the classification needs to be validated in terms of the percentage of cases and the treatment rendered.
Conclusion
Isolated periodontal pockets can occur due to a variety of reasons and the multidisciplinary nature of these reasons could delay their diagnosis. Clinicians therefore need to be aware of the possible causes of isolated periodontal pockets, identify them early and treat them to improve their prognosis.
