[Root canal therapy of maxillary molars with atypical canals: A report of three cases]

Maxillary molar with three roots and 3 to 4 canals is a common occurrence. However, in addition to common root canal anatomy, there may be significant differences in the number, distribution, and morphological structure of root canals. The success of root canal treatment is dependent on ensuring that all the intricate details associated with it are meticulously followed. Failure to locate all canals could have a negative effect on the treatment as it may lead to initiation or continuation of periapical pathology. Missed canals were the main reason for patients reporting back for nonsurgical root canal retreatment. Moreover, the bacteria residing in such canals could also result in persistence of symptoms. Root canal anatomy is complex, and the recognition of anatomic variations could be a challenge for clinicians. This article presents three cases of endodontic management of maxillary molars with atypical canal morphology. In the three cases of this study, the patients underwent cone beam computed tomographic (CBCT) examination before root canal treatment. The CBCT images revealed that the maxillary molars in case 1 and case 2 had 5 canals. Case 1: 2 mesiobuccal (MB, MB2), two distobuccal (DB and DB2), and one palatal canal. Case 2: 2 mesiobuccal (MB, MB2), one distobuccal (DB), and two palatal canals (MP and DP). In case 3, CBCT scan slices showed that the maxillary first molar presented as a C-shaped root canal with a rare tooth anomaly of taurodontism. Although C-shaped root canals were most frequently seen in the mandibular second molar, they might also appear in maxillary molars. A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars. Case 3 described the fusion between mesiobuccal and palatal roots of the maxillary first molar, forming a C-shaped mesiopalatal root canal. The above cases suggest that endodontists should always be aware of aberrancies in root canal system apart from the knowledge of normal root canal anatomy. CBCT as a means of diagnosis can be helpful for identifying and managing these complex root canal systems. This case series also highlights the importance of magnification and illumination. Through using an endodontic microscope, clinicians can identify root canals that are difficult to locate or overlooked with normal vision. A correct access opening is a most important step to locate and negotiate the orifices of root canals. The use of ultrasonic tips can refine the access cavity and allow controlled and delicate removal of calcifications and other interferences to the canal orifices, thereby helping to locate the extra orifices.

Can maxillary molar dimensions predict the presence of the second mesiobuccal canal?

OBJECTIVE

To evaluate the potential of maxillary molar dimensions as predictors of the presence of the second mesiobuccal (MB2) canal.

METHODS

Micro-computed tomography scans were obtained from 47 maxillary molars, out of which 26 had the MB2 canal. The distance between root canals, extension of the canals, and thickness of surrounding dentin were obtained from axial images at the furcation level, 3 mm from the apex, and 5 mm from the apex. The association between the measurements and the presence of the MB2 canal was assessed using multiple logistic regression and odds ratio.

RESULTS

At the furcation level, the bucco-palatal extension of the MB1 canal significantly decreased the chance of the presence of the MB2 canal. Regarding the thickness of surrounding dentin measurements, the mesial and distal aspects of the MB1 canal at 3 mm from the apex were statistically significant to decrease and increase the chance of presence of the MB2 canal, respectively. Regarding the extension of the canals, only buccal-palatal extension seems to decrease the chance of the presence of the MB2 canal.

CONCLUSION

The presence of the MB2 canal in the mesiobuccal root of maxillary molars is associated with the bucco-palatal extension and surrounding dentin thickness of the first mesiobuccal canal, and seems to be unrelated to the dimensions of the distobuccal and palatal roots.

Guidance and rationale for the immediate implant placement in the maxillary molar

Objectives

While the reliability of immediate implant placement in the maxillary molar has been discussed, its significance is questionable. There have been no guidelines for case selection and surgical technique for successful treatment outcomes of immediate maxillary molar implants. Therefore, in this study, we classified alveolar bone height and socket morphology of the maxillary molar to establish guidelines for immediate implant placement.

Materials and Methods

From 2011 to 2019, we retrospectively analyzed 106 patients with 148 immediate implants at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Inclusion and exclusion criteria were applied, and patient characteristics and treatment results were evaluated clinically and radiologically.

Results

A total of 29 tapered, sand-blasted, large-grit, and acid-etched (SLA) surfaces of implants were placed in 26 patients. The mean patient age was 64.88 years. Two implants failed and were reinstalled, resulting in a 93.10% survival rate. Fluctuating marginal bone level changes indicating bone regeneration and bone loss were observed in the first year following installation and remained stable after one year of prosthesis loading, with an average bone loss of 0.01±0.01 mm on the distal side and 0.03±0.03 mm on the mesial side.

Conclusion

This clinical study demonstrated the significance of immediate implant placement in maxillary molars as a reliable treatment with a high survival rate using tapered SLA implants. With an accurate approach to immediate implantation, surgical intervention and treatment time can be reduced, resulting in patient satisfaction and comfort.

Clinical, radiographic characterizations and complications of maxillary molar in a periodontitis population: a retrospective study based on CBCT radiography

OBJECTIVE

This study was aimed to delineate the clinical, CBCT radiographic characteristics, and complications of maxillary molar in a periodontitis population.

MATERIALS AND METHODS

Medical records and CBCT images were utilized to identify adult patients with periodontitis in a tertiary referral dental hospital between June 2019 and December 2020. CBCT scan images were used to characterize the detailed bone thickness, absorbing height, and position of maxillary molar as well as their associated conditions. All relevant descriptive epidemiological data, clinical information, radiographic details, and associated complications were recorded and statistically analyzed.

RESULTS

According to the above criteria, 577 eligible periodontitis patients were enrolled and defined as research cohort here with mean age 45 ± 4.8 years. Male patients outnumbered females with a gender ratio of 1.23:1. Our results demonstrated that the bone loss of maxillary first molar was more serious than that of second molar with tooth position symmetry. The occurrence of various complications (periodontal abscess, pulp lesions, furcation lesion, and mucosal thickening) was significantly correlated to periodontal-related clinical parameters of maxillary molar.

CONCLUSIONS

Our results demonstrated the more serious bone loss of maxillary first molar with tooth position symmetry. The occurrence of various complications was significantly correlated to periodontal-related clinical parameters. Our findings offer valuable information concerning the clinical, radiographic characteristics, and complications of maxillary molar in a periodontitis population.

CLINICAL RELEVANCE

These findings are beneficial for clinicians to comprehensively understand the bone status, pathogenesis, and clinical management of maxillary molar in periodontitis.

Retreatment of a C-shaped maxillary second molar: case reports and literature review

The root canal systems of maxillary second molar (MSM) variations are complicated, especially the prevalence of fused roots and consequent merged and C-shaped canals, which represent a clinical challenge because canal configurations can be irregular and unpredictable. The purpose of this article was to present 2 cases with a C-shaped configuration diagnosed during root canal retreatment and perform a literature review of this MSM anatomy. Case 1 reports that two palatal root canals fused into a C-shaped configuration that finally formed an apical foramen, which was classified as Type D. Case 2 reflects the fusion of the distobuccal canal and palatal canal into a C-shaped configuration and the configuration was Type C, which was first reported in a case report. Nonsurgical retreatments were proposed and conducted. Evaluation at a 24-month recall revealed that the two patients were symptom-free, and radiographic examination revealed normal periapical tissue. This report serves to remind clinicians of the complexities of the root canal system and that possible anatomic variation should always be anticipated when formulating an effective root canal treatment plan. The use of CBCT imaging coupled with an operative dental microscope will be helpful in locating and identifying supernumerary canals when a preoperative periapical radiograph shows signs of a fused-rooted MSM.

Endodontic management of a fused left maxillary second molar and two paramolars using cone beam computed tomography: A case report

BACKGROUND

Fused teeth usually involve several complications, such as the development of caries in the groove between fused crowns, tooth impaction, diastemas, aesthetic and periodontal problems, and pulpal pathosis, due to the complex anatomical structure of fused teeth. A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis. With the advent of cone-beam computed tomography (CBCT), accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained, and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information. Therefore, we utilize CBCT data herein to generate a digital model for the infected region in a patient, and this model enables us to better plan the management of his case.

CASE SUMMARY

This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis. The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar. No caries or other defects were identified in these teeth, and a normal response to a pulp electric viability test was observed. With the aid of CBCT and digital model technology, we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars. Therefore, we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure; furthermore, the vital pulp was retained, and good treatment outcomes were observed at the 24-month follow-up.

CONCLUSION

This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth.

A cone-beam computed tomography study of the prevalence and location of the second mesiobuccal root canal in maxillary molars

Objectives

This study aimed to investigate the incidence and location of the second mesiobuccal root (MB2) canal in maxillary molars with the aid of various measuring points and lines using cone-beam computed tomography (CT).

Materials and Methods

A total of 205 images of patients who underwent cone-beam CT examinations between 2011 and 2015 as part of their dental diagnosis and treatment were included. There were 76 images of the maxillary first molar and 135 images of the maxillary second molar. Canal orifices were detected at −1 mm from the top of the pulpal floor on cone-beam CT images. Image assessment was performed by 2 observers in reformatted image planes using software. Assessments included measurement of the distance between the MB1 and MB2 canals, and the angles between the lines connecting the MB1-MB2 and distobuccal (DB)-palatal (P) canals. The data were analyzed using the student's t-test.

Results

The prevalence of the MB2 canal was 86.8% in the first molar and 28.9% in the second molar. The angle between the lines connecting the MB1-MB2 and DB-P canals was 2.3° ± 5.7° in the first molar and −3.95° ± 7.73° in the second molar. The distance between the MB1 and MB2 canals was 2.1 ± 0.44 mm in the first molar and 1.98 ± 0.42 mm in the second molar.

Conclusions

The angles between the lines connecting the MB1-MB2 and DB-P canals was almost parallel. These findings may aid in the prediction of the location of the MB2 canal orifice.

Determination of alveolar bone height according to the relationship between molar teeth and maxillary sinus

PURPOSE

This study aims to analyze alveolar bone height (ABH) in the maxillary molar area according to the anatomical relationship between maxillary sinus and maxillary molar teeth via cone beam computed tomography images.

METHODS

In 330 patients, 660 maxillary first molar (M1) and 648 maxillary second molar (M2) were evaluated. ABH measurements were made as to the shortest distance between the furcation midpoints of maxillary molars and the lowest point of the sinus floor. After the measurement, the positions of the maxillary molar teeth relative to the maxillary sinus were classified into four categories as type 1, 2, 3, and 4.

RESULTS

ABH measurements in males were significantly higher than females (p < 0.05), but there were no differences between sides (p > 0.05). There were significant differences between types of both M1 and M2 for ABH, and the longest ABH was measured in type 1 (p < 0.05). Type 3 was the most common among 1308 maxillary molars teeth followed by type 1, type 2, and type 4.

CONCLUSION

Determination of the relationship between maxillary molar teeth and the maxillary sinus and analysis of ABH according to this relationship may help plan endodontic treatment, apical surgery, and immediate implant therapy and prevent their complications.

The MB3 canal in maxillary molars: a micro-CT study

OBJECTIVES

To assess the internal and external morphologies of the mesiobuccal (MB) root of maxillary molars presenting a third root canal (MB3), using micro-computed tomography (micro-CT).

MATERIAL AND METHODS

Two-hundred and sixty-five extracted maxillary first and second molars with different root configurations were imaged in a micro-CT scanner at 19.6-μm pixel size. Sixteen teeth presenting MB3 canal were selected and evaluated regarding root configuration, minimal dentine thickness 2 mm under the furcation area, canal configuration of the MB root, MB3 canal morphology (location, independent or confluent orifice, and anatomy types), and the apical anatomy (aspect ratio, number of accessory canals and foramina, presence of isthmus, and independent MB3 foramen).

RESULTS

Overall, a high variability in canal configuration was detected in the MB root. MB3 canal was observed in 10 maxillary first molars and 6 maxillary second molars (n = 16). Minimal dentine thickness related to the MB3 canal at the coronal third was smaller than that of the MB1 canal. A complex internal anatomy comprising 13 different root canal configurations was observed. A high number of independent MB3 orifices at the pulp chamber floor was observed in the first molars (7 out of 10 teeth), while most of the specimens (n = 14) showed a confluent anatomy of the MB3 canal. A varied number of accessory canals and foramina were observed. At the apical third, isthmus could be observed in 6 specimens, while an independent MB3 foramen was present in 37.5% of the MB roots.

CONCLUSIONS

MB3 canal is a rare anatomical variation present in maxillary first and second molars. Its presence can be associated to a complex internal anatomy of the MB root which includes the presence of isthmuses and multiple accessory canals and foramina at the apical third, but also a thin dentine thickness at the coronal third and a confluent anatomy of the MB3 with the other main canals.

Investigating the anatomical relationship between the maxillary molars and the sinus floor in a Chinese population using cone-beam computed tomography

Background

The anatomical relationship between the root apices of maxillary molars and the maxillary sinus floor (MSF) is important for the treatment of dental implantations and endodontic procedures. In this study, the detailed anatomical relationships between the root apices of maxillary molars and the MSF were studied in a Chinese population using CBCT.

Methods

We collected the CBCT data files of patients who visited the stomatology outpatient clinic in Shanghai Fifth People’s Hospital, Fudan University from January 1, 2017 to January 1, 2019 and measured the following items: the distance between the molar root apices and the MSF, the thickness of the mucosa and cortical bone of the MSF closest to the root apices, and the angle between the buccal and palatal roots.

Results

The shortest distances between the root apices and the MSF were 1.57 ± 3.33 mm (the mesiobuccal root of the left second molar) and 1.61 ± 3.37 mm (the mesiobuccal root of the right second molar). Apical protrusion over the inferior wall of the sinus most often occurred in the mesiobuccal root of left second molar (frequency, 20.5%). The mucosa of the MSF was thinnest at the distobuccal root of the right second molar (1.52 ± 0.85 mm), the cortical bone of the MSF was thinnest at the mesiobuccal root of the right second molar (0.46 ± 0.28 mm), and the angle between the buccal and palatal roots ranged from 12.01° to 124.2° (42.36 ± 24.33 °).

Conclusions

Among the root apices of the maxillary molars, the mesiobuccal root apex of the left second molar was closest to the MSF, and it had the highest incidence of protrusion into the sinus. The unique anatomical relationship between the maxillary molars and the MSF in this Chinese population is critical for treatment planning for dental implantation or endodontic procedures.

Parastyle cusp: A rare morphologic variant of maxillary second molars

Human jaws and teeth show a high diversity in the morphology, which varies from individual to individual. The variation in the morphologic feature is of great importance in the forensic field for identification. A tubercle or an accessory cusp is rare but is usually seen in the mandibular molar buccal aspect. From a forensic odontologist's point of view, the features though rare and unusual are useful for identification of the victim as well as criminal. The article presents three cases showing this rarest morphologic variation, i.e., the presence of a parastyle on a permanent maxillary second molar.

The morphology of maxillary first and second molars analyzed by cone-beam computed tomography in a polish population

BACKGROUND

The success of endodontic treatment is greatly affected by the location of the root canals. The purpose of this study was to evaluate the root and canal morphology of permanent maxillary first and second molars in a Polish population using cone-beam computed tomography scanning.

METHODS

Cone-beam computed tomography (CBCT) scans of maxillary first and second molars the maxilla were examined. The number of roots and root canals, and the frequency of additional canals (MB2) in the mesiobuccal root canals were determined. The results were subjected to statistical analysis using the chi-square test or the chi-square test with Yates' correction.

RESULTS

A total of 112 CBCT images of maxillary first (n = 185) and second molars (n = 207) from 112 patients were analyzed. All the maxillary first molars had three roots (100%). The majority of maxillary second molars had three roots (91.8%), 5.8% had two roots and 2.4% had one root. A statistically significant difference was observed between the numbers of roots in the maxillary first and second molars (p < 0.01). A statistically significant difference was also found in the distribution of the number of canals in the maxillary first and second molars (p < 0.001). The majority of maxillary first molars had four root canals (59.5%), while 40.5% had three root canals. Most maxillary second molars had three root canals (70%). Additional canals (MB2) in the mesiobuccal roots were detected significantly more frequently in the maxillary first molars than the second molars (p = 0.000) and more frequently in men than in women (p < 0.05). A higher prevalence of two canals in the mesiobuccal roots in maxillary second molars occurred in patients aged between 31 and 40 years than in patients aged between 21 and 30 years. In the maxillary first molars, the prevalence of the MB2 canal in the mesiobuccal root was almost equally distributed in the two age groups (21-30 and 31-40 years).

CONCLUSION

Within the limitations of this study, it can be concluded that there are differences in the number and configuration of roots and root canals between maxillary first and second molars in the studied patients of a Polish population.

Distalization of Maxillary First Permanent Molar by Pendulum Appliance in Mixed Dentition Period

Introduction

Mesial drifting of molar teeth in maxillary arch is corrected by movement of the molars distally. In addition to traditional distal movement techniques, such as extraoral force application and removable appliances, various intra-arch devices have been introduced since 1980s. These intra-arch appliances have nearly eliminated the need for patient cooperation.

Case report

The purpose of this paper is to report a case of 10-year-old male patient with loss of space in maxillary molar teeth treated by intra-arch appliance-pendulum appliance by distalization of maxillary first permanent molar teeth. Distaliza-tion of the permanent molar teeth helped in proper eruption of second premolar teeth without any extensive treatment procedures.

Conclusion

In the present case report, the treatment of developing malocclusion was corrected by utilizing the concept of interceptive orthodontics. Hence, correction of space loss in mixed dentition period using pendulum appliance can eliminate the fixed orthodontic therapy.

How to cite this article

Paranna S, Shetty P, Anandakrishna L, Rawat A. Distalization of Maxillary First Permanent Molar by Pendulum Appliance in Mixed Dentition Period. Int J Clin Pediatr Dent 2017;10(3):299-301.

Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study

Purpose:

The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth.

Materials and Methods:

One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18–45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I), then under magnification with the aid of operating microscope (Stage II) and finally with the combined use of operating microscope and selective dentin removal (Stage III).

Results:

MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I–III, respectively.

Conclusion:

This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals.

The location and accessibility of the second mesiobuccal canal in maxillary first molar

OBJECTIVES

The purpose of this study was to examine the location and accessibility of the second mesibuccal canal in maxillary first molar of a Turkish sub-population.

METHODS

Presence and accessibility of the MB2 canal in 110 extracted maxillary first molars was examined with unaided vision, dental loups and the DOM. To characterize the geometrical location of MB2 canals, photographs of pulp chambers were obtained.

RESULTS

With the unaided vision, 58 MB2 canal orifices and after evaluation with the dental loup, DOM an additional 28 MB2 canal orifices were detected. In 65 molars, the MB2 canal orifices was located 0.87 mm distally and 1.73 mm palatally to the main mesiobuccal canal and in the remaining 21 molars was 0.72 mm mesially and 1.86 mm palatally.

CONCLUSIONS

Presence of second mesiobuccal canal was similar to the other studies but in a Turkish sub-population it originates mainly distal to the main MB canal.