A Rare Root Canal Configuration of Bilateral Maxillary First Molar with 7 Root Canals Diagnosed Using Cone-beam Computed Tomographic Scanning: A Case Report

Introduction

The complexity of the root canal system of maxillary molars presents a constant challenge in the diagnosis and treatment of these teeth. This case report describes the importance of a surgical operating microscope and cone-beam computed tomographic (CBCT) imaging.

Methods

Root canal treatment of a left maxillary first molar with 3 roots and 7 canals was successfully performed. Seven canals were identified with the help of a surgical operating microscope and CBCT imaging. CBCT images also confirmed the 3 roots and 7 canals in the right maxillary first molar.

Results

CBCT images confirmed a type IV canal pattern in the distal and palatal root, whereas the mesial root had a type VIII canal pattern.

Conclusions

The use of a surgical operating microscope and CBCT imaging helps the clinician to diagnose unusual anatomy of a tooth and facilitate successful endodontic treatment.     

C-shaped Maxillary Permanent First Molar: A Case Report and Literature Review

Introduction

The C-shaped configuration is rare in the upper first molar.The purpose of this article is to present 2 cases diagnosed during endodontic therapy and perform a literature review of this anatomy in the upper first molar.

Methods

Endodontic therapy was performed by using a dental operating microscope and a cone-beam computed tomography analysis for better understanding of this anatomy. A literature search was conducted to identify and compare all the published cases of C-shaped upper first molar.

Results

Before the cases reported in this article, only 5 cases were available in the published literature. Three different types of C-shaped configurations in the upper first molar have been presented.

Conclusions

The C-shaped maxillary first molar is a rare anatomic configuration. The use of the dental operating microscope may help in the endodontic therapy of these cases. Three types of C-shaped configurations have been reported; the fusion of the distobuccal root with the palatal root appears to be the most usual one.     

Internal Resorption of Multiple Posterior Teeth in a Patient Diagnosed with Hyperparathyroidism: A Case Report

This case reports a 46-year-old man with end-stage renal disease and internal resorption (IR) affecting multiple posterior teeth. IR involves odontoclast’s removal of dentin within pulp chambers and root canal space. Typically, asymptomatic until detected on radiographs, IR is relatively rare, so the etiology and pathogenesis are poorly understood. Patients’ radiographs with cone-beam computed tomography revealed extensive IR in multiple premolars and all remaining molar teeth. Blood tests and hormonal assay measured elevated phosphorus and parathyroid hormone levels consistent with secondary hyperparathyroidism. Histopathology showed highly vascularized and inflamed pulp tissues with numerous odontoclast-like multinucleated giant cells along dentinal walls and in resorption lacunae. Immunohistochemistry showed that multinucleated giant cells and adjacent mononuclear precursors stained strongly for tartrate-resistant acid phosphatase like osteoclasts. Extraction of crown-root fractures and endodontic treatment with crown restorations for all IR teeth effectively arrested disease progression at 9 months’ follow-up. Elevated parathyroid hormone from secondary hyperparathyroidism that promotes bone osteoclast activity may also stimulate odontoclasts causing IR.     

Use of Cone-beam Computed Tomography to Evaluate Root Canal Morphology and Locate Root Canal Orifices of Maxillary Second Premolars in a Chinese Subpopulation

Introduction

The aim of this study was to investigate root canal morphology and locate root canal orifices of maxillary second premolars in a Chinese subpopulation using cone-beam computed tomographic imaging.

Methods

A total of 392 cone-beam computed tomographic images of maxillary second premolars were obtained from 238 patients who required a preoperative assessment for implant surgery or orthodontic treatment. The number of roots and root canals and root canal configuration were investigated and categorized using Vertucci's criteria. The distance between the root canal orifice and the anatomic apex and the distance between root canal orifices in those teeth with 2 root canals were measured and evaluated. The Fisher exact test was used to analyze the correlation between the number of roots and sex.

Results

Among the 392 teeth, 86.5% (n = 339) had 1 root; 45.4% (n = 178) of the teeth had 1 root canal, and 54.3% (n = 213) had 2 root canals that ranged from type II–type V. The majority of teeth with 2 root canals showed a type IV canal configuration (n = 79, 20.2%) followed by type II (n = 64, 16.3%), type III (n = 45, 11.4%), and type V (n = 25, 6.4%). Only 1 tooth had 3 root canals. No significant difference was found between the number of roots and sex (P > .05). Among the 213 teeth with 2 root canals, the most frequent distribution of the distance between the root canal orifice and the anatomic apex was 5–10 mm (n = 157). The distance between the 2 orifices of 189 teeth was 1–4 mm.

Conclusions

The frequency of teeth with 2 root canals was high in maxillary second premolars. The internal morphology of teeth with 2 root canals was variable. This study provided useful information about the root canal morphology of maxillary second premolars in a Chinese subpopulation.     

Clinically Relevant Dimensions of 3-rooted Maxillary Premolars Obtained Via High-resolution Computed Tomography

Introduction

This study aimed to characterize the dimensions of a selection of 3-rooted maxillary premolars through high-resolution computed tomographic analysis considering measures of clinical interest for root canal treatment, such as root wall thickness, canal diameters, and distances between 2 canals in fused roots and between the root apex and foramen.

Methods

Fifteen 3-rooted human maxillary premolars extracted for therapeutic reasons were individually scanned using a high-resolution desktop high-resolution computed tomographic system. Starting from the apical foramen, the selected cross-sectional images corresponding to each millimeter of the roots were evaluated. Measures of clinical interest were determined using Image J software (version 1.41; National Institutes of Health, Bethesda, MD).

Results

Root wall thickness as thin as 0.4 and 0.6 mm was detected in the apical portion of buccal and palatal roots, respectively. In the cervical portion, buccal roots had narrower root walls (0.817–1.670 mm) compared with palatal roots (1.361–2.720 mm). In all thirds, the palatal canal was wider compared with the mesiobuccal and distobuccal canals. In the buccopalatal direction, all roots had thicker root walls toward the furcation, whereas in the mesiodistal direction the mesiobuccal and distobuccal roots had the thinnest walls along their distal and mesial aspects, respectively. Both buccal canals revealed dentin apposition 2 mm from the canal orifice, resulting in cervical constriction. Generally, the distance between the root apex and the foramen was greater in distobuccal roots in comparison with the others with a tendency for foramina to be eccentric.

Conclusions

Three-rooted premolars are a clinical challenge not just because of their low frequency and difficulties regarding diagnosis and root canals access but also because of their fragile roots. These phenomena are critical in terms of the amount of dentin removed during the preparation of root canals and during post space preparation.     

Treatment of an Acute Apical Abscess in a Patient With Autoimmune Hepatitis Taking Alendronate: A Case Report

IntroductionThe aim of this study was to report a patient's clinical case who was diagnosed with severe apical abscess and with autoimmune hepatitis (AIH) using immunosuppressive drugs and bisphosphonate.MethodsA 32-year-old man of black African descent urgently sought dental surgery because of an increase in volume in the right genic region and a nuisance in the region of the lower right second premolar when chewing. After intraoral and radiographic clinical examination, the patient was diagnosed with pulp necrosis and an acute apical abscess. Because he had AIH and was taking corticosteroids and bisphosphonate (alendronate), he was submitted to endodontic therapy as a minimally invasive treatment, considering his systemic state.ResultsAfter 3 years of follow-up treatment with periapical and tomographic radiographic control, bone repair of the periapical region of the tooth was observed.ConclusionsThrough this report, we can infer that it is possible to reverse the condition of a periapical lesion in a tooth with an acute apical abscess and necrotic pulp in an AIH patient who is using alendronate without the need for more invasive procedures and that would put at risk the patient's general and oral condition in the postoperative period.     

下颌第二磨牙近中3根管1例

本文报道罕见近中3根管,远中双根管的下颌第二磨牙1例。     

Two Palatal Root Canals in a Maxillary Right Second Molar： One Case Report

牙根和根管的数目不是固定不变的,文献报道表明牙齿尤其是上颌磨牙根管存在着解剖变异。但是,上颌第二磨牙发生腭根双根管的可能性很低。在本文中,作者报道了一例右上颌第二磨牙腭根双根管的解剖变异。由于可能存在的上颌第二磨牙腭根管解剖变异,所以临床医生在牙髓病治疗过程中应注意术前对患牙进行影像学分析,术中可借助牙科手术显微镜等可视手段寻找可能存在的腭根解剖变异。     

锥体束CT对上颌第一磨牙近中颊根管形态的研究

目的：通过锥体束CT（cone--beam computed tomography,CBCT）成像系统分析上颌第一磨牙近中颊根根管形态及第二（second mesiobuccal,MB2）根管的发生率。方法：选择95名进行CBCT扫描的患者,共计180颗上颌第一磨牙,观察近颊根根管形态、MB2根管的发生率、左右侧发生比率及男女发生比率差异。结果：上颌第一磨牙近颊根管形态以Ⅲ型为主,MB2根管发生率为79．4％,左右侧发生比率无统计学差异（P=0．846）,男性发生率明显高于女性（P=0．043）。结论：上颌第一磨牙近颊根MB2根管的发生率较高,可通过CBCT有效的发现MB2根管,为临床诊疗提供依据。     

Endodontic treatment of a taurodontic premolar with five canals

Taurodontism is a morpho‐anatomical abnormality in the shape of a tooth. An enlarged pulp chamber, apical displacement of the pulpal floor and no constriction at the level of the cemento‐enamel junction are the characteristic features. Special care is required in all aspects of endodontic treatment of a taurodontal tooth, including identifying the orifice, canal exploration, cleaning, shaping and obturation of the root canal. This case report describes the successful endodontic treatment of a taurodontic mandibular second premolar with five root canals.     

Reparative Endodontic Treatment of a Perforating Internal Inflammatory Root Resorption: A Case Report

The aim of this case report was to present a reparative treatment approach of an extensive internal inflammatory resorption with a lateral perforation and apical and lateral inflammatory lesions. Only the necrotic coronal part of the pulp was removed, and the vital pulp tissue within the resorption cavity and the apical part of the root canal was left uninstrumented. Bleeding was induced, and the blood clot was covered with mineral trioxide aggregate. Hard tissue repair and healing of the apical lesion could be observed in the 3-year recall.     

Misdiagnosis of a Nasopalatine Duct Cyst: A Case Report

Introduction

Nonendodontic lesions misdiagnosed as pathoses of endodontic origin are often referenced in the literature. One of the most frequent nonodontogenic cysts of the oral cavity, the nasopalatine duct cyst (NPDC), can be misdiagnosed as endodontic in nature.

Methods

A case is presented in which a patent NPDC was originally diagnosed as a sinus tract with subsequent endodontic nonsurgical retreatment and eventual extraction before endodontic consultation.

Results

After surgical treatment, a histopathologic diagnosis of an NPDC was confirmed.

Conclusions

If diagnosed incorrectly, inappropriate endodontic treatment of a NPDC may be initiated to include unnecessary extraction. An increased understanding of anatomy, the use of appropriate diagnostic tests to include cone-beam computed tomography imaging, and key examination techniques to distinguish endodontic lesions from nonendodontic pathoses are imperative for an accurate differential diagnosis and appropriate treatment outcome.     

Regenerative Endodontic Treatment with Orthodontic Treatment in a Tooth with Dens Evaginatus: A Case Report with a 4-year Follow-up

Dens evaginatus is a developmental tooth anomaly in which an extra cusp or tubercle protrudes on the occlusal surface of the tooth along with some pulpal tissue. Because of the fragile nature of the protrusion, these teeth are often at risk of pulpal exposure. When this occurs in an immature tooth, regenerative endodontic treatment may be a good treatment approach to promote root formation. There is limited literature that documents the occurrence of orthodontic treatment in teeth that have undergone regenerative endodontic therapy using triple antibiotic paste. Here we present a case of an immature premolar tooth with dens evaginatus that was diagnosed with pulp necrosis and chronic apical abscess. The tooth was treated with regenerative endodontic treatment; after which, the patient received orthodontic treatment with fixed appliances for 2 years. The tooth responded favorably to the regenerative endodontic treatment and orthodontic tooth movement. Clinically and radiographically, all the follow-up examinations revealed an asymptomatic tooth with evidence of periapical healing with stunted root development. The tooth remained asymptomatic even after 4 years. The regenerative endodontic procedure (REP) was successful in treating an immature permanent premolar with pulp necrosis and apical periodontitis with dens evaginatus. In this case, the tooth treated with an REP responded to orthodontic treatment similar to the nonendodontically treated teeth. Further studies are recommended to clarify the precise effects of orthodontic treatment on teeth treated with an REP.     

The Incidence of Second Mesiobuccal Canals Located in Maxillary Molars with the Aid of Cone-beam Computed Tomography

Introduction

Many endodontic treatment failures in maxillary molars result from missed second mesiobuccal (MB2) canals. An MB2 canal orifice is present in as many as 95% of maxillary molars, but these canals are not always located during endodontic procedures. Additional tools, such as cone-beam computed tomographic (CBCT) imaging, may be needed to locate these canals in maxillary molars. Hence, the aims of this study were to investigate the frequency of use of CBCT imaging during the treatment of maxillary molars and to evaluate the influence of its use on the detection of MB2 canals.

Impact of Three Radiographic Methods in the Outcome of Nonsurgical Endodontic Treatment: A Five-Year Follow-up

Introduction

The periapical film radiograph (PFR) and digital periapical radiograph (DPR) techniques have some limitations in the visualization of small periapical lesions (PLs) when compared with cone-beam computed tomography (CBCT). However, the evidence supporting their effectiveness is very limited. This retrospective longitudinal cohort study evaluated the outcome of endodontic treatments measured/monitored by PFR, DPR, and CBCT during a 5-year follow-up and also determined the prognostic factors that influenced treatment success.

Methods

A total of 132 teeth (208 roots) with vital pulps received endodontic treatment. The periapical indexes with scores ≥2 for PFR and DPR and ≥1 for CBCT indicated the presence of PLs. Prognostic factors were determined by bivariate and multivariate analyses. Statistical significance was defined at a P level <.05.

Results

CBCT detected a higher number of PLs (18.7%, n = 39 roots), followed by DPR (7.7%, n = 16 roots) and PFR (5.7%, n = 12 roots). Likewise, CBCT was more sensitive than PFR and DPR in detecting deficiencies in extension and density of the root canal filling (P ≤ .001). Of the 17 prognostic factors evaluated, 4 were significantly associated with poor outcome to the treatment (P < .05): root canal curvature, disinfection of gutta-percha, presence of missed canals, and the quality of definitive coronal restoration.

Conclusions

The success outcome of endodontic treatment after 5 years in teeth with vital pulps varied with each radiographic method: 94.3%/PFR, 92.3%/DPR, and 81.3%/CBCT.     

Cone-beam Computed Tomographic Scans in Comparison with Periapical Radiographs for Root Canal Length Measurement: An In Situ Study

Introduction

The primary aim of this study was to compare the precision of root canal length determination on cone-beam computed tomographic (CBCT) scans and periapical radiographs (PAs) with the actual root canal length. The secondary aim was to examine the influence of tooth type on root canal length measurements as assessed on CBCT scans and PAs.

Methods

In total, 40 root canals of 33 teeth (molars, premolars, canines, and incisors) out of 5 dentate maxillas of human cadavers were included. Root canal length measurement was performed by a consensus panel (2 examiners) on CBCT scans (3D Accuitomo 170; J Morita, Kyoto, Japan) and digital PAs. After straight-line access opening, a #15 file was fixated in every root canal at the length measured on CBCT scans. All teeth were extracted, and the root canal containing the file was uncovered. Measurements made on images taken with a digital camera (AxioCam; Carl Zeiss, Sliedrecht, The Netherlands) linked to a stereozoom microscope (Stemi SV6, Carl Zeiss) were used as the actual root canal length.

Results

When all roots were examined together, it was not clear which method is better for all types of teeth. For root canals of anterior teeth, there was no significant difference between the 2 methods. For root canals of posterior teeth, CBCT images gave results significantly closer to the actual root canal length in comparison with PAs (t value = −1.96; critical value is 1.74 with a significance level of 0.05).

Conclusions

Root canal length measurements of posterior maxillary teeth were more accurate when assessed by CBCT images than PAs.     

Preserving the Neurovascular Bundle in Targeted Endodontic Microsurgery: A Case Series

Endodontic microsurgery encompasses the use of microscopy, specialized instruments, and advanced imaging with cone-beam computed tomographic (CBCT) imaging. This treatment modality results in high clinical success rates and facilitates the enucleation of osteolytic lesions, the resection of apical root canal complexities harboring persistent bacterial biofilms, and the evaluation of possible root defects and fractures. However, there is the risk of injury to important anatomic structures, particularly when treating posterior teeth. Neurovascular bundles are among these structures at risk for injury. Fortunately, high-resolution CBCT scans can be used to detect these structures that are known to have a high anatomic variability. In addition, CBCT information can be combined with high-resolution intraoral scans to plan, design, and fabricate surgical guides to be used in a targeted endodontic microsurgery (TEMS) approach. We report 3 cases with previous endodontic treatment having persistent apical periodontitis that were treated with TEMS to avoid damage to the neurovascular bundles at risk of injury. In the first case, the palatal root of tooth #14 was adjacent to the greater palatine artery. In the second case, the mental nerve exited through 2 separate foramina close to the predictive osteotomy site for the mesial root of tooth #19. In the third case, the posterior superior alveolar artery was in close proximity to the mesiobuccal root of tooth #14. Collectively, these cases illustrate the diagnostic value of CBCT imaging for detecting neurovascular bundles and the use of TEMS to mitigate the risk of injury to these important structures. Thus, the combination of CBCT imaging and TEMS can potentially minimize the risk of intraoperative complications and postoperative sequelae while increasing the predictability of endodontic microsurgeries in complex cases.     

Resolution of maxillary sinus mucositis after endodontic treatment of maxillary teeth with apical periodontitis: a cone-beam computed tomography pilot study

Introduction

Apical periodontitis (AP) is an inflammatory response that can affect the maxillary sinus. This study characterized maxillary sinus mucositis adjacent to teeth with AP and assessed its resolution after endodontic treatment.

Methods

Thirty maxillary sinuses in subjects (n = 29) who had AP associated with maxillary posterior teeth were imaged with cone-beam computed tomography (CBCT). When mucositis was detected, its resolution was assessed with CBCT scanning 3 months after treatment, and periapical healing was assessed using the periapical index (PAI) after 6 months.

Results

Excluding 5 sinuses obscured by sinusitis, mucositis was detected in 14 of 25 sinuses (56%). Nonsignificant inverse association was observed between the mucosal lining thickness and the distance from the sinus to root apices with AP. Four noncompliant subjects were discontinued. Three months after treatment, mucositis was fully resolved in 3 of 10 subjects (30%), partially resolved in 3 of 10 subjects (30%), unchanged in 3 of 10 subjects (30%), and worsened in 1 subject (10%). Six months after treatment, 6 of 10 subjects (60%) had reduced PAI scores classified as healed or healing. The subject with expanded mucositis at 3 months was not healing at 6 months.

Conclusions

Within the limited sample of this pilot study, CBCT imaging revealed a lower-than-expected prevalence of mucositis adjacent to teeth with AP. Fully resolved mucositis was not common 3 months after endodontic treatment, suggesting that in specific cases it might linger beyond 3 months after the elimination of the endodontic infection. Because of the low statistical power, the association between the resolution of mucositis and periapical healing could not be explored.     

Guided Endodontic Access in Maxillary Molars Using Cone-beam Computed Tomography and Computer-aided Design/Computer-aided Manufacturing System: A Case Report

The aim of this study was to describe a guided endodontic technique that facilitates access to root canals of molars presenting with pulp calcifications. A 61-year-old woman presented to our service with pain in the upper left molar region. The second and third left molars showed signs of apical periodontitis confirmed by the cone-beam computed tomographic (CBCT) scans brought to us by the patient at the initial appointment. Conventional endodontic treatment was discontinued given the difficulty in locating the root canals. Intraoral scanning and the CBCT scans were used to plan the access to the calcified canals by means of implant planning software. Guides were fabricated through rapid prototyping and allowed for the correct orientation of a cylindrical drill used to provide access through the calcifications. Second to that, the root canals were prepared with reciprocating endodontic instruments and rested for 2 weeks with intracanal medication. Subsequently, canals were packed with gutta-percha cones using the hydraulic compression technique. Permanent restorations of the access cavities were performed. By comparing the tomographic images, the authors observed a drastic reduction of the periapical lesions as well as the absence of pain symptoms after 3 months. This condition was maintained at the 1-year follow-up. The guided endodontic technique in maxillary molars was shown to be a fast, safe, and predictable therapy and can be regarded as an excellent option for the location of calcified root canals, avoiding failures in complex cases.     

Relationship between the Surgical Access Line of Maxillary Posterior Teeth and the Maxillary Sinus Floor

IntroductionThe aim of this study was to use cone-beam computed tomographic imaging to investigate the relationship between the surgical access line (SAL) of maxillary posterior teeth and the maxillary sinus floor (MSF) in endodontic microsurgery.MethodsCone-beam computed tomographic scans of 190 subjects with clear and integrated maxillary posterior teeth and sinus floors on both sides were evaluated. The correlation of the average distance between the SAL and the MSF with age was analyzed. Three types of relationships between the SAL and MSF were classified. The minimum vertical distance between the SAL and the MSF for the type 1 relationship was measured.ResultsA total of 1134 teeth, including 758 premolars and 376 first molars, were evaluated. The average distance between the SAL of maxillary posterior teeth and the MSF increased with age, except in the 31- to 40-year-old group. The highest rates of the SAL touching the MSF and protruding into the maxillary sinus occurred among first molars at 25.6% and 8.1%, respectively. For the type 1 relationship, the mean distance from the SAL of the first and second premolars and the first molar to the MSF was 7.11 ± 4.40, 4.92 ± 3.69, and 4.76 ± 3.61 mm, respectively.ConclusionsKnowledge of the relationship between the SAL and the MSF of maxillary posterior teeth could provide an important reference for surgeons to evaluate surgical difficulty and decrease the risk of maxillary sinus perforation.