Treatment of pre-eruptive intracoronal resorption: A systematic review and case report.

BACKGROUND/
PURPOSE: Pre-eruptive intracoronal resorption (PEIR) is usually detected accidently in radiographs. However, treatment modality is still not reported systematically. The current study aimed to conduct a systematic review of the treatment modality of PEIR case reports and to report a case on the preservation of a vital pulp with surgical exposure in permanent maxillary canine.
MATERIALS AND METHODS: We systematically searched case reports from PubMed/MEDLINE, EMBASE, and Web of science databases. The treatment modality, suspected etiology, and follow up periods were collected from each study and reviewed by two authors independently.
RESULTS: The initial search identified 100 studies. After the title/abstract screening, 37 articles received a full-text reading; and finally, 24 articles (29 patients and 37 affected teeth) were selected for the final review. Among the 24 unerupted teeth, surgical opening and restoration treatment of PEIR was chosen as a high priority for treatment options (n = 9, 36%). Among the 13 erupted teeth, restoration was applied for the prevention such as developing in size and fracture (n = 4, 31%).
CONCLUSION: According to this systematic review, treatment modalities were based on the progressive nature of the lesion size and eruption state to establish the optimal approach for each patient. Clinicians should take into account the eruption status, lesion progression, the size of the lesion, and the degree of pulp involvement.

Introduction

Pre-eruptive intracoronal resorption (PEIR) of the teeth is usually detected accidently in radiographs. Lesions are typically found in dentin of unerupted teeth and close to the dentinoenamel junction., The defect is generally located on the central or mesial portion of the crown. However, lesions sometimes involve the pulp and can cause symptoms such as swelling and pain., The prevalence of PEIR has been determined to be 2–8% by subject and 0.6–2% by tooth, primarily affecting the mandibular first premolar and second and third molars. Usually, a single tooth is affected in an individual, with nearly half of the lesions extending to more than two-thirds of the dentin thickness.

Although this condition was first reported in 1941, the etiology of PEIR remains unclear because only a small number of studies have been conducted on it. No association was found between PEIR and sex, race, medical conditions, systemic factors, or fluoride supplementation., From a histological viewpoint of PEIR, multinucleated giant cells, osteoclasts, and chronic inflammatory cells have been described as related factors in some case reports. This evidence suggests that the process in PEIR involves resorption of calcified dental tissue.,

Regardless of suspected etiology, the clinician who discovers a radiolucency associated with an unerupted tooth is faced with a dilemma. Should the clinician wait until the tooth erupts to initiate treatment or intervene surgically to arrest this phenomenon? Or should the tooth be extracted surgically? There are many different treatment modalities of PEIR that depend on extent of the lesion at the time of discovery and anticipated eruption time of the affected tooth. The objective of this paper is to present a systematic review of treatment modalities of PEIR and to present a case report on vital pulp preservation in permanent dentition.

Materials and methods

We followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for this systematic review.

Search strategy

A systematic search was conducted without limits, including studies published in or before July 2019. The authors independently searched PubMed/MEDLINE, Web of Science, and EMBASE. A combination of Medical Subject Heading (MeSH) and full-text search term were used: (“pre-eruptive” OR “intracoronal”) AND (“tooth resorption"[MeSH Terms] OR Tooth Resorption[Text Word] OR “radiolucency”) AND (“case reports"[Publication Type] OR “case reports"[All Fields]). Keywords in EMBASE were (‘pre-eruptive’ OR intracoronal) AND ‘tooth disease’ AND ‘case report.’ The search strategy in the Web of Science was (“pre-eruptive” OR “intracoronal”) AND (resorption) AND (case report).

Selection criteria

The studies were initially selected based on title and abstract according to the following inclusion criteria:

Case report related to PEIR

Published in English

Articles without an abstract or those without an adequate description were included for full-text evaluation. Eligibility was confirmed after evaluation of the full text based on previously defined exclusion criteria (i.e., duplicates, editorials, commentaries, retrospective study, and comparative study).

Screening process

The two reviewers (VNT Le and DW Lee) performed the search and selection process (finished on 30 July 2019). After initial screening of titles and abstracts, full-text articles were analyzed, and differences between the reviewers were resolved through discussion.

Results

Literature search

Electronic searches identified 100 publications (Fig. 1). The initial search yielded 39 available titles in PubMed/MEDLINE, 42 in EMBASE, and 19 in Web of Science. After eliminating duplicates, titles and abstracts were screened in the remaining 48 articles, resulting in exclusion of 11 articles. The full text of the remaining 37 articles was reviewed, and unrelated (n = 4) and retrospective studies (n = 9) were excluded. The remaining 24 articles (29 cases with 37 affected teeth) were included in our qualitative analyses.

Figure 1

Flow diagram for identification of relevant studies.

Study characteristics

The main characteristics of all included studies are shown in Table 1. Included studies were published between 1988 and 2018, had range of patient age from 19 months to 14 years, with no sex predilection. All cases were diagnosed on radiographs, such as panoramic (n = 14, 48.3%),,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 periapical (n = 8, 27.6%),,,,19, 20, 21, 22 and bitewing (n = 7, 24.1%),,23, 24, 25, 26, 27 with 24 unerupted teeth and 13 erupted teeth.

Table 1

Study characteristics of the included studies.

Case	Author (year)	Age/Sex	Tooth	Diagnostic method	Eruption status	Treatment	Suspected etiology	Note (Histologic, impressive findings)	Follow-up
									Period	Status
1	Ilha et al.9 (2018)	8 yFemale	#36	Panoramic radiograph	Unerupted	Surgical exposureRestoration (GIC + Composite)	NR	Delayed eruption of the affected tooth	18 m	Asymptomatic
2	De Souza et al.1 (2017)	10 yMale	#35	Panoramic radiograph	Unerupted	Monitoring eruptionRestoration (Composite)	Ectopic eruption		12 m	Asymptomatic
3	Schwimmer et al.3 (2017)	19 mFemale	#74	Periapical radiograph	Erupted	RCT	NR		1w7 m	Good healingAsymptomatic
4	Manmontri et al.10 (2017)	8 y 8 m	#37	Panoramic radiograph	Unerupted	Monitoring (periodic intraoral and extraoral radiographs)	NR	Nine years of follow-upSupporting theory: progressive resorption of PEIR may cease or decelerate after tooth eruption	2y3m3y4m6y4m	Partially eruptedAsymptomaticCompletely eruptedAsymptomaticNo changes clinically or radiographically in the PEIR-affected tooth
5	Omar et al.23 (2015)	11 yNR	#37	Bitewing	Unerupted	Surgical exposureMTA direct pulp capping + cotton pellets + IRMIRM and cotton pellets were removed + Composite	NR		8w3m8w3y3m8w	AsymptomaticNormal root developmentAsymptomaticNormal root developmentAsymptomatic
6	Spierer and Fuks24 (2014)	6 yMale	#46	Bitewing	Unerupted	Surgical exposureRestoration (Glass monomer lining + GIC)	Minute gaps in enamel formation	Connective tissue, bone and granulation issue	3w3m3w1 y	Good healingAsymptomaticNormal root developmentAsymptomatic
7	Czarnecki et al.19 (2014)	4 y 3 mFemale	#46	Periapical radiograph	Unerupted	Surgical exposureRestoration (GC sealant)CHX rinse	NR		8w2 m20 m30 m35 m44 m	AsymptomaticUnremarkableNo change size of the defect, caries-free
8	Brunet-Llobet et al.20 (2014)	12 yMale	#37	Periapical radiograph	Unerupted	Extraction	NR	Inflamed myxomatous tissue, plump stellate fibroblast, hyalinized connective tissue, inflammatory cells, predominantly neutrophils, lymphocytes, and plasma cells
9	Wong and Khan11 (2014)	12 yFemale	#37	Panoramic radiograph	Unerupted	Extraction	NR	No evidence of pulpal inflammation
10	Ari12 (2014)	12 yMale	#35	Panoramic radiograph	Erupted	RCTRestoration (Composite)	NR		NR
11	Counihan and O'Connell8 (2012)	10 yFemale	#45	Panoramic radiograph	Unerupted	Monitoring eruptionRestoration (indirect pulp cap + GIC + Composite)	NR	Histological examination was inconclusive due to small sample size and contamination of the sample with oral bacteria	NR
12	Counihan and O'Connell8 (2012)	6 yFemale	#46	Bitewing	Partially erupted	Monitoring eruptionConservative approach + monitoring annually	NR		5 y	VitalAsymptomaticNo evidence of caries
13	Counihan and O'Connell8 (2012)	12 yFemale	#37	Panoramic radiograph	Partially erupted	Extraction	NR	Pulpal surface with osteoclast-like giant cells and granulation tissue
14	Hata et al.21 (2007)	8 y 6 m10 y 11 m	#11#42#35	Periapical radiographPeriapical radiographPeriapical radiograph	EruptingEruptedUnerupted	Partial pulpotomy with calcium hydroxide + GICCompositeGingivectomyRestoration (calcium hydroxide liner + Composite)Extraction of the primary second molarRestoration (calcium hydroxide liner + GIC)	External resorption	Ps taken at age 11 years showed normal root formation	2 m3 y	AsymptomaticNormal pulp vitalityNormal periodontal tissue
15	Davidovich et al.13 (2005)	11 yFemale	#37	Panoramic radiograph	Unerupted	Surgical exposureRestoration (Glass monomer lining + GIC)Restoration removalPartial pulpotomy (calcium hydroxide + IRM + Amalgam)	NR	The radiolucent area underneath the restoration	1w3m1w9m1w	Fibrin healing tissueErupted, gingivitisAsymptomaticNormal appearanceContinued root development
16	McEntire et al.25 (2005)	9 yFemale	#35	Bitewing	Unerupted	MonitoringRestoration (Composite)	Ectopic positioning		5 y	Asymptomatic
17	Moskovitz and Holan26 (2004)	6 y 2 mFemale	#47	Bitewing	Partially erupted	MonitoringRestoration (Calcium hydroxide liner + IRM)	A small aperture of the enamel surrounding the lesion		5y8m6y9m	No increase in size of the radiolucent defectAsymptomatic
18	Dowling et al.4 (1999)	11 yFemale	#33	Periapical radiograph	Erupted	RCTRestoration (porcelain veneer)	Idiopathic external resorption	Crown: granulation tissuePulp: chronic inflammation	NR
19	Kupietzky27 (1999)	12 yMale	#35	Bitewing	Erupted	Indirect pulp capping + Amalgam restorationComposite	NR	Amalgam was removed	8 mNR	NR
20	Seow14 (1998)	14 yFemale	#15#26#34#35#38#45#47	Panoramic radiograph	Unerupted	NR	A small or sealed external opening through which resorption cells had gained entry into the dentin during initial development of the tooth		NR
21	Savage et al.15 (1998)	11 yFemale	27	Panoramic radiograph	Erupted	Surgical extraction	Idiopathic external resorption	No evidence of dental cariesA thin dentin bridge separated pulp from the resorption defect, pulpal response was minimal with very few inflammatory cells
22	McNamara et al.16 (1997)	11 yMale	#37	Panoramic radiograph	Unerupted	Surgical extraction	External resorption	The extensive lesion was caused by external resorption
23	Seow and Hackley6 (1996)	2 y 6 mFemale	#75	Periapical radiograph	Erupted	Extraction	Localized developmental aberration of dentin	No dental cariesNo communication was noted between pulp and resorption area, pulp and outer surface, or resorption area and outer surface
24	Seow and Hackley6 (1996)	11 yFemale	#47	Periapical radiograph	Unerupted	Surgical exposureRestoration (calcium hydroxide liner + GIC)The tooth was re-covered with the mucosal flap for spontaneous eruption	Communicating channels between exterior and resorptive areas	Normal dental follicleUninflamed tissueReduced enamel epithelium	9 m2 y 9 m	EruptedVital, intact restorationNormal root developmentNormal pulp vitality and occlusal function
25	Holan et al.17 (1994)	12 yMale	#43	Panoramic radiograph	Erupting	Restoration (calcium hydroxide liner + composite)	Reduced enamel epithelium of the unerupted tooth (Invasion of the crown by vascular connective tissue)		6 m	Normal root developmentAsymptomatic t
26	Holan et al.17 (1994)	13 yMale	#37	Panoramic radiograph	Unerupted	Surgical exposureRestoration (calcium hydroxide liner + IRM)			6 m3 y 9 m	EruptedAsymptomaticAsymptomatic Normal root development
27	Holan et al.17 (1994)	11 yFemale	#45	Bitewing	Erupted	Restoration (calcium hydroxide liner + composite)			6 y	Asymptomatic
28	Ignelzi et al.18 (1990)	12 y 9 mMale	#47	Panoramic radiograph	Unerupted	Surgical exposureRestoration (lining calcium hydroxide + Zinc oxide and eugenol)SuturePulp therapy + stainless steel crown	NR	Eruption appeared imminent, and destruction to the crown was extensive	2w2 m5 m1 y2 y 6 m	AsymptomaticGood healingAsymptomaticAsymptomaticAsymptomaticNormal root developmentAsymptomaticNormal root development
29	Brooks22 (1988)	10 yFemale	#45	Periapical radiograph	Unerupted	MonitoringRestoration (lining calcium hydroxide + composite)	NR		1 m6 m	EruptedApical root-end closureAsymptomatic

Abbreviations: NR: Not reported, RCT: Root canal treatment, GIC: Glass ionomer cement, IRM: Intermediate restorative material (reinforced zinc oxide eugenol), MTA: Mineral trioxide aggregate.

Treatment modality and follow-up

Among the 24 unerupted teeth, the reviewed treatment options were surgical exposure and restoration due to large and developing lesions (n = 9, 36%),,,,17, 18, 19,,, no reports (n = 7, 28%), monitoring and restoration due to small and static lesions (n = 4, 16%),,,, extraction due to large lesion, unrecoverable residual, extensive pulpal involvement, or benefit of orthodontic treatment (n = 3, 16%),,, and observation due to small and static lesion without restoration (n = 1, 4%).

Among the 13 erupted teeth, the reviewed treatment options were restoration due to prevention such as developing in size and fracture (n = 4, 30.7%),,, root canal therapy (n = 3, 23.1%),,, extraction due to an abscessed primary tooth, large lesion, or unrecoverable residuals (n = 3, 23.1%),,, monitoring and restoration due to prevention such as developing in the thickness of resorptive dentin and fracture (n = 1, 7.7%), surgical exposure and restoration due to large and developing lesions (n = 1, 7.7%), and observation due to small and static lesions (n = 1, 7.7%).

Regarding conservative approaches (without extraction), the follow-up period ranged from 2 months to 6 years 9 months. With long-term follow-up, there was no apparent variation of prognoses regardless of approach.

Suspected etiology

Most studies mentioned that the etiology seemed to remain unclear. Some etiologies were theorized as ectopic eruption,, external resorption,,,14, 15, 16, and developmental abnormality of the tooth.,,

Case report

A 9-year-10-month-old girl was referred to the Department of Pediatric Dentistry, Jeonbuk National University Dental Hospital, Jeonju, Jeonlabukdo, South Korea by a dentist at a local dental clinic, with a chief complaint of gingival swelling, bleeding, and pain when brushing or touching the right maxillary canine. Her past medical history was unremarkable. There was no known specific dental history (including trauma or infection of the maxilla and teeth). The patient did not have a family history of a genetic disorder.

Intraorally, gingival swelling and bleeding were observed at the area of right maxillary canine. A clinical examination revealed an eruption hematoma. A panoramic radiograph revealed a delayed eruption of the right maxillary canine. Further periapical radiograph revealed a well circumscribed radiolucent lesion of two-thirds of the dentin thickness that extended over the dentinoenamel junction (Fig. 2). Given the position of lesion, clinical history radiographic examinations, and the features supported a diagnosis of a PEIR.

Figure 2

During the first visit on #13. (A) Eruption hematoma. (B) Panoramic radiograph: a delayed eruption. (C) Periapical radiograph: a circumscribed radiolucent lesion.

For unerupted right maxillary canine, we made a treatment plan including surgical exposure and restoration.

After the patient's parents agreed to the treatment plan, surgical opening was performed under local anesthesia. The cavity of the lesion showed a gray irregular and friable fragment of soft tissue without infected dentin (Fig. 3A). The dentin area inside the crown was resorbed by this tissue (Fig. 3B). After curettage of the tissue, no pulp exposure was found and the defect was restored by interim glass ionomer (Fig. 3C). A biopsy sample of the removed tissue was sent for histopathological examination, which revealed nonspecific chronic inflammation with hemorrhagic necrosis. This result supports distinction of PEIR from dental caries.

Figure 3

Treatment of #13. (A) Surgical exposure of crown. (B) Tooth preparation. (C) Glass ionomer cement. (D) Surgical suture.

After nine months, the right maxillary canine remained asymptomatic. The tooth showed a negative response to percussion, physiological mobility, and normal response to hot and cold stimuli. A periapical radiograph revealed normal root development without infection. Therefore, resin restoration was performed to recover the appearance and function of the canine.

After the two years follow-up examination, the tooth was asymptomatic and completely erupted with normal root development. Occlusal adjustment was performed to ensure functional occlusion and restoration longevity (Fig. 4).

Figure 4

Follow-up after treatment. One year follow-up: (A) intra-oral clinical photograph, (B) periapical radiograph. Two years follow-up: (C) intra-oral clinical photograph, (D) periapical radiograph, (E) panoramic radiograph.

Discussion

Overall, we found that no protocol is currently available for treatment of PEIR. Based on our systematic review, the majority of authors considered conservative therapy as a treatment of PEIR. In seven studies, extraction was performed because of large lesions,,,, extensive pulpal involvement or benefit of orthodontic treatment, and abscessed primary tooth. Since early intervention was not performed in these cases,,,,,, the lesion progressed, leading to extraction.

In this study, according to its progressive nature based on lesion size, PEIR lesions can be divided into two major types: static,,,,, and developing.,,,,,11, 12, 13,15, 16, 17, 18, 19, 20, 21,,, Most previous treatment plans were based on lesion size. For static cases, many authors chose the conservative option by monitoring without treatment until the tooth erupted,,,, since the lesion was asymptomatic and static. This group of authors suggested that the clinician should monitor development of the lesion through periodic radiographic examination. When a lesion increased in size, as in developing cases, treatment should be provided immediately to avoid the complication related to pulp as well as fracture.,

Clinically, not only the size of the PEIR lesion, but also the eruption state is critical for treatment planning. After initial detection of PEIR, the clinician can use periodic radiographic examinations to monitor the size of the lesion to create a restorative treatment plan. However, when eruption has occurred, restoration is indicated, as the lesion progresses rapidly and becomes symptomatic.,,,,

Generally, PEIR of a developing and unerupted tooth have been discovered only through radiographic examination. This type of atypical resorption process is proceeded at a slow pace until the exposure of the crown to the oral cavity. However, once the tooth erupts through the gingiva, cariogenic microorganisms invade and progress into the dentin via the resorbed area, and the extensive size of the lesion makes it distinguishable., In our case report, permanent maxillary canine was unerupted. The swelling and inflammation of the gingival tissue implied that it was likely to be progressive due to penetration of bacteria externally. Therefore, we performed the treatment as soon as possible. We surgically exposed the right maxillary canine and restored with glass ionomer. This method of treatment is generally recommended for most cases as soon the lesion is diagnosed radiographically.,,,,, Waiting until full emergence of the crown to achieve curettage may allow the resorption to extend to the pulp with complications from infection.

Our study is the first systematic review investigating the treatment modalities of PEIR. However, most case reports lack histological analyses of lesions, which supports the diagnosis of PEIR.,,,8, 9, 10,12, 13, 14,16, 17, 18, 19,,23, 24, 25 Although the etiology of each case is not clear, a review of treatment modalities helps to create a treatment plan for clinical management. The period of follow-up of included case reports is heterogeneous, from 2 months to 6 years 9 months. This leads to difficulty in evaluating the effect of treatment modalities by meta-analysis.

In conclusion, from the present systematic review, it can be concluded that surgical opening and restoration treatment are considered high priority (36%) as a treatment option for PEIR. Second, most treatment plan was based on progressive nature of the lesion size and eruption state to establish the optimal approach for each patient.

Declaration of Competing Interest

The authors declare no conflict of interest.