2021, Number 1
Dens invaginatus and associated maxillary cyst: follow up and interdisciplinary resolution
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ABSTRACT
Introduction: Dens invaginatus (DI) is a developmental dental abnormality in the early stages of tooth morph differentiation. It could be present with many clinical or radiographic characteristics with crown or root involvement. DI could lead to pulp necrosis and periapical infections or maxillary cysts. Objective: To report a case of an extensive maxillary cyst associated with DI, emphasizing the interdisciplinary treatment. Case report: A 26-year-old female with a painful tumor on the palate and oppression feeling presented to the consultation. She started an 8-month evolution and failed treatments without receiving a final diagnosis. After a clinical-radiographic study, a therapeutic approach was planned based on: 1) treatment of DI and cyst diagnosis, 2) cyst reduction by decompression, 3) follow-up and controls, and 4) removal of the remnant cyst and placement of bone substitute. A cystic lesion was observed related to the lateral incisor, presenting a coronal ID anomaly. Endodontic treatment of the incisor was performed, followed by a cystic decompression by surgical intervention and positioning of drainage. Clinical and radiographic controls showed a favorable evolution. Finally, a total cystectomy was done with the placement of a bone substitute. Conclusions: the early DI diagnosis avoids the formation of secondary lesions. If not accurately diagnosed, this condition could generate morbidity in patients. Therefore, interdisciplinary treatment should be considered to achieve successful results.INTRODUCTION
Dens invaginatus (also called dens in dente) is a rare multifactorial anomaly of dental development, produced in the early stages of morphodifferentiation, which might present in different clinical forms. Dens invaginatus (DI) term was introduced by Hallet, describing a dental invagination in which enamel is the center and dentin in the periphery.1,2 DI can be coronal (the most frequent) or radicular, depending on where intussusception is generated. The reported prevalence in adult teeth is between 0.3% and 10%; the most affected tooth is the lateral incisor, followed by the central incisor, premolars, canines, and molars, especially at the upper jaw.3
The depth of the invagination varies, from a slight elongation of the cingulum to a marked depth that may involve the dental apex. Related to this, DI are classified according to Oehlers as type I (the most frequent, 79%), confined to the crown; type II (15%), the invagination extends to the enamel-cementum junction, or without compromising the pulp tissue and type III (5%) which extends through the root, perforating its area.3,4 Radiographically, an invagination of enamel and dentin might extend to the pulp chamber, the root, and sometimes to the root apex. In most cases, this alteration is asymptomatic and therefore diagnosed as an accidental finding in routine dental practice. In other cases, a variable macroscopic morphology and color change of the involved element may suggest the presence of DI.
In those cases where DI generates a pulp condition, periapical lesions and/or maxillary cysts associated with this dental anomaly might coexist.5-7 Cases have been reported where maxillary cysts –in the absence of carious lesions– make a suspect that the condition's origin could be associated with dental anomalies such as ID. In most cases and reports, the lesions present osteolytic areas and close to the dental element that harbors the DI. Like the upper lateral incisor, the most common, the maxillary cyst usually appears clinically as an increase in volume, sometimes painful, on the palatal fibromucosa.8 In these cases, the diagnosis and treatment of the whole clinical picture is a real diagnostic challenge for the clinician.
This paper aims to report a clinical case of an extensive cyst generated by ID, lightening the endodontic-surgery treatment.
CASE REPORT
A 26-year-old female patient presented for consultation with a painful tumor lesion on the palate and a sensation of tightness in the left hemifacies. During the anamnesis, the patient reported having had the same lesion eight months earlier, which was treated with antibiotics, reversing the symptoms, but without receiving a specific diagnosis. The patient reported no clinically relevant systemic or family pathological history.
The intraoral examination revealed a slightly enlarged area in the palatal fibromucosa lateralized to the left, fluctuating, with a tendency to suppuration and pain on palpation. The provisional diagnosis was a palatal abscess, showing the upper right lateral incisor with a grayish coloration, negative pulp excitability test, and clinical suspicion of pulp necrosis. X-ray (periapical technique) showed a large radiolucent lesion in the cortex that extended beyond the areas confined to the problematic tooth (Figure 1).
In addition, as a relevant radiographic finding, a zone of radiodensity similar to dentin was observed at the level of the enamel-cementum junction, associated with an invagination of dental tissue circumscribed by a radiopaque area, compatible with DI.
An orthopantomography and a computed axial tomography showed a large lytic lesion in almost the entire left upper hemimaxilla without compromising the nasal cavity and maxillary sinus, whose anterior limit was in the corresponding central incisor sector and its posterior limit was delimited by the left first molar.
Figure 2 illustrates the different tomographic sections that allow observing the osteolytic image compatible with the cystic process. All the teeth involved showed an absence of signs of pathological rhizolysis and preserved pulp vitality, except for the left upper lateral incisor associated with DI. The clinical diagnosis was a maxillary inflammatory cyst associated with pulp necrosis of the upper lateral incisor.
Before planning together with specialists in the Area of Oral Medicine and Pathology, Endodontics, and Head and Neck Surgery, a therapeutic plan on four phases was programmed. 1) Treatment phase of the problematic tooth and lesion diagnosis. 2) Decompression phase. 3) Monitoring and control. 4) Removal of the lesion remnant and placement of bone substitute on a delayed basis.
- 1) Treatment of the involved tooth and lesion diagnosis phase: with radiographic and tomographic images, after treatment with antibiotics and having drained the palatal lesion, the root canal treatment of the involved tooth was done, and with rotatory instruments was eliminated the DI, both situations without inconvenience. Due to the endodontic-surgery inter-discipline, endodontic therapy was applied in two sessions, with an intermediate calcium hydroxide-based therapy. An expectant behavior was kept regarding the remaining dental elements compromised with the infectious. An incisional biopsy of the intraosseous lesion was immediately indicated. For this, a mucoperiosteal flap was made from the anterosuperior sector, trepanning, and preserving the vestibular cortex, incising 4 mm from the apex of the compromised tooth. An extensive bone cavity with liquid content was identified, covered by a capsule of difficult enucleation, which was partially extracted for histopathological study. Subsequently, the flap was replaced and sutured together with the placement of a silicone tube for decompressive purposes. The histopathological result revealed a maxillary inflammatory cyst. Figure 3A and 3B show the X-ray image of the drainage through which the patient flushed the cystic cavity. Figure 3C the tissue surrounding the catheter is normal in appearance. This photo was taken four months after initial placement during a device replacement procedure.
- 2) Decompression (conservative treatment phase): placing the drain device to allow washings of the cystic cavity. Initially, the washes were carried out by professionals calibrated for this purpose and later through the instruction to the patient on an outpatient basis. Drain and decompression maneuvers reduced the intracystic pressure generating relief and disappearance of the symptoms. The palatal abscess was remitted. Consequently, root canal treatment of the involved tooth and removal of DI with rotary instrumentation was finished.
- 3) Monitoring and control: monthly clinical and radiographic control was carried out. The patient continued with the washing on an outpatient basis for six months. Bone trabeculae formation and a notable lesion reduction (evident in the intraoral X-ray control) were observed near to the anteroposterior limits of the cystic lesion in the three and 6-month control (Figure 4).
- 4) Removal of the lesion remnant and placement of bone substitute on a delayed basis: after eight months of decompressive treatment, the patient requested a surgical lesion cleaning, so the cystic remnant was removed using general anesthesia. A mucosal flap extending from the right lateral incisor to the left second molar was done. After separating of the mucoperiosteum, the cystic bed was curetted; detachment of its capsule and placement of injectable synthetic bone substitute paste, composed of 55% dehydrated dicalcium phosphate, 45% tricalcium phosphate with bioconductive power to fill the collapsed bone after residual cystectomy, were performed (Figure 5 A and B). Next, the bone substitute was covered with a resorbable collagen membrane. Later, the drainage placed in the first diagnostic surgery was removed. Finally, the mucoperiosteal flap repositioned and sutured at separate points. The histopathological diagnosis of the enucleated lesion confirmed the initial diagnosis (inflammatory maxillary cyst).
- Figure 5C was obtained immediately after the placement of the bone substitute. A clinical and radiographic follow-up was carried out throughout its evolution with highly satisfactory results (Figure 5D shows the status of the problematic tooth and standard peri-dental tissues related to the bone substitute). To date, the patient has been under control for two years, observing the absence of recurrences and preserved pulp vitality of the previously involved pieces.
DISCUSSION
Different causes associated with DI development have been proposed. These include focal growth retardation, infection, the rapid proliferation of part of internal enamel epithelium in the dental papilla, increased localized external pressure, fusion of two dental germs, trauma, distortion and protrusion of the enamel organ during tooth development, and absence of signaling molecules for morphogenesis and, therefore, genetic factors.8,9
The tortuous anatomy of invaginate teeth makes dental tissue more susceptible to bacterial colonization and the subsequent carious lesions development, difficult to diagnose clinically. In addition, enamel and dentin may be defective, thin in proximity to the chamber, or simply absent. Therefore, the pulp tissue is exposed directly to the oral environment, causing its infection and subsequent necrosis. An aggravating clinical circumstance could be associated with a carious condition and its progress by communicating the invaginate portion of the palatal tooth surface with the oral cavity.10 In our case, a long-standing composite restoration could be seen in the proximity of the pulp chamber. However, the theory of clinically undetectable caries associated with the palatal portion of the DI could also be considered in the etiological analysis. Both situations, added to the presence of a DI with cameral involvement, could be the reasons that led to pulp necrosis.
Early diagnosis is a determining factor in the therapy to be used, preventive or restorative. In incipient stages, a composite sealant restoration is recommended under strict clinical-radiographic control to avoid future complications. In cases of pulp necrosis, such as the current case, endodontic therapy or a combination of endodontics and dental-maxillary surgery is necessary. In those cases where ID was previously endodontically treated, retreatment is usually unpredictable due to the difficulty of establishing working length and subsequent instrumentation. In consequence, in cases of apical-periapical affection with chronic abscesses without remission, apical surgery is indicated, with curettage and retrograde filling with bioceramic cement.11 Extraction would be the last option to consider.
In the case described, secondary to the present dental anomaly, an inflammatory cyst in almost the entire left upper hemimaxilla was diagnosed. Therefore, an incisional biopsy is recommended to establish the histopathological diagnosis in such extensive lesions.
Different diagnoses could be considered related to cystic lesions of the jaws. Despite keratocysts and ameloblastomas are not frequent in the anterior portion of the maxilla should be included in differential diagnosis and less aggressive cystic entities such as a nasopalatine cyst. That is why it is relevant to take material from one or several sectors of the lesion for subsequent histopathological analysis and obtain a certain diagnosis. This procedure allows planning the appropriate therapeutic approach in each case.
Conservative treatment is indicated for extensive cystic lesions in young patients. The decompressive technique proposed by Thoma (1958),12 used in the present case, consists of creating an open window in the cystic wall with the subsequent placement and fixation of a tube or stent. This technique aims to reduce the lesion volume while stopping the intracystic pressure, which also induces the formation of new bone. Furthermore, it provides better surgical access for subsequent enucleation with low postoperative morbidity, reducing the probability of infection and promoting healing. Another advantage of this technique is that it allows the pulp vitality of teeth related to the cystic cavity and the integrity of noble anatomical structures.13-15 Although the effects of decompression according to age are controversial, younger patients have been reported to have higher rates of cystic reduction.16 In our case, cystic decompression and surgical procedures carried out for almost a year determined a marked reduction in the size of the lesion, being able to show, throughout the radiographic follow-ups, new bone formation, especially at the anterior and posterior limits of the cyst (incisor sector and upper first molar).
Posterior enucleation, which is not always necessary in cases of endodontic-associated decompression, allows complete resolution of the case. Regenerative procedures should treat any bone defect that might arise. In large post-cystectomy surgical beds, it is advisable to use different modalities such as applying calcium phosphate, bone substitutes of different origins, hydroxyapatite, plasma rich in fibrin, etc. Subsequently, placing collagen membranes is helpful to avoid collapse of the mucoperiosteal flap, protect the bone filling material and prevent migration of the epithelium.17,18
In these cases, it is essential to carry out a strict clinical-radiographic follow-up to monitor the status of the affected bone, and the vitality of the teeth initially compromised with the cystic lesion.
CONCLUSION
Although DI is a rare dental anomaly, it can lead to clinical pictures that generate significant morbidity in patients, requiring major surgical interventions. Lateral incisors with clinical abnormalities in their coronal anatomy should always be carefully analyzed with a periapical X-ray to rule out possible developmental anomalies such as DI. The early DI diagnosis avoids the formation of secondary lesions. If not accurately diagnosed, this condition could generate morbidity in patients. Interdisciplinary treatment should be considered to achieve successful results.
REFERENCES
AFFILIATIONS
1 Cátedra de Estomatología "A", Facultad de Odontología, Universidad Nacional de Córdoba.
2 Cátedra de Endodoncia "B", Facultad de Odontología, Universidad Nacional de Córdoba.
3Servicio de Cirugía de Cabeza y Cuello, Hospital Italiano, Córdoba.
4Cátedra de Cirugía II "A", Facultad de Odontología, Universidad Nacional de Córdoba.
5Cátedra de Cirugía II "B", Facultad de Odontología, Universidad Nacional de Córdoba.
CORRESPONDENCE
Gerardo Marcelo Gilligan. E-mail: ggilligan@unc.edu.arReceived: Mayo 2020. Accepted: Mayo 2021.