Root canal therapy of maxillary molars with atypical canals:A report of three cases / 北京大学学报(医学版)

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 sys-tem 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 impor-tance 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 ca-nal orifices,thereby helping to locate the extra orifices.

The incidence of unfilled second mesiobuccal canals and periapical lesions in maxillary molars by cone-beam computed tomography E-VOL DX software

This study evaluated the incidence of unfilled second mesiobuccal (MB2) canals and periapical lesions in first maxillary molars using CBCT e-Vol DX software. Hence, 326 CBCT images of first maxillary molars of patients undergoing endodontic treatment were selected. The e-Vol DX software performed a retrospective review of these images, recording the presence or absence of MB2 canals, filling, and periapical lesions in first maxillary molars. Specific statistical analysis was performed at a 5% significance level. Unfilled MB2 canals were highly frequent in first maxillary molars and significantly associated with periapical lesions in the mesiobuccal root of these teeth (p<0.05). The CBCT e-Vol DX software effectively detected MB2 canals, and unfilled canals may be associated with periapical lesions.

Lesiones perirradiculares asociadas a primeros molares superiores tratados endodónticamente: estudio a través de tomografías computadas / Periradicular lesions associated with endodontically treated maxillary first molars: study through computed tomography

Objetivos: Estudiar con tomografías computadas de haz cónico (CBCT) las lesiones perirradiculares de primeros molares superiores tratados endodónticamente; evaluar la lo- calización y, en los que tenían lesión en la raíz mesiovestibu- lar (MV), evaluar la frecuencia del conducto MV2. Materiales y métodos: A partir de una muestra de 179 tomografías, que incluían primeros molares superiores, se seleccionaron y analizaron aquellas en las cuales estos ha- bían recibido un tratamiento endodóntico previo, presentaban lesiones perirradiculares y conservaban una restauración co- ronaria. Las variables analizadas fueron: la localización de áreas radiolúcidas compatibles con lesiones perirradiculares de origen endodóntico y la correlación entre diferentes loca- lizaciones y la calidad del tratamiento realizado (adecuado, defectuoso o sin tratamiento). Los datos fueron analizados mediante la prueba de chi-cuadrado y la prueba de Spearman. Resultados: De las 179 CBCT que incluían primeros molares superiores, 90 reunían las condiciones requeridas. La frecuencia de las lesiones perirradiculares fue significativa- mente mayor en la raíz MV al compararla con las raíces disto- vestibular y palatina (p<0,05). El conducto MV1 presentó un tratamiento adecuado en todos los casos. El conducto MV2 recibió un tratamiento adecuado en 4 casos (4,44%), defec- tuoso en 4 casos (4,44%) y no tratado en 82 casos (91,1%); con una diferencia estadísticamente significativa (p<0,05). Conclusiones: En la muestra analizada, la localización de lesiones perirradiculares postratamiento endodóntico en primeros molares superiores se encontró con mayor frecuencia asociada a la raíz mesiovestibular, donde en la mayoría de los casos el con- ducto MB2 no fue tratado o presentó un tratamiento defectuoso (AU)

Aim: To study with cone-beam computed tomography (CBCT) the periradicular lesions of maxillary first molars with endodontical treatment; to evaluate its localization and, in those with a mesiobuccal root (MB) injury, assess the fre- quency of the MB2 root canal. Materials and methods: From a sample of 179 tomog- raphies (CBCT) that included maxillary first molars, those in which they had received previous endodontic treatment, pre- sented periradicular lesions and had a coronary restoration were selected and analyzed. The analyzed variables were: localization of radiolucent areas compatible with periradic- ular lesions of endodontic origin and the correlation between different localizations and quality of the performed treatment (adequate, defective, or untreated). Data were analyzed by the chi-square test and the Spearman test. Results: Of the 179 CBCT that included maxillary first molars, 90 met the required conditions. The frequency of periradicular lesions was significantly higher in the MB root when compared with distobuccal and palatal roots (P<0,05). The MB1 canal presented an adequate treatment in all cas- es. The MB2 canal received adequate treatment in 4 cases (4.44%), a defective one in 4 cases (4.44%) and was untreated in 82 cases (91.1%). The differences among these frequencies were statistically significant (P<0.05). Conclusions: In the analyzed sample, the localization of periradicular lesions after endodontic treatment in maxillary first molars was associated more frequently with the mesio- buccal root in which in the majority of cases the MB2 canal was untreated or presented a defective treatment

Accuracy of cone beam computed tomography in assessing maxillary molar furcation involvement / 华西口腔医学杂志

OBJECTIVE@#This study aimed to assess the accuracy of cone beam computed tomography (CBCT) in detecting furcation involvement (FI) in maxillary molars.@*METHODS@#Thirty-one maxillary molars of 15 patients with generalized chronic periodontitis considered for furcation surgery were assessed. Clinical examination and CBCT were performed, and the FI degree was evaluated. Clinical and CBCT-based FI assessments were compared with intrasurgical data.@*RESULTS@#The agreement between clinical and intrasurgical assessments was weak in all sites, with a kappa of less than 0.4; the complete, overestimated, and underestimated agreement percentages were 42.0%, 24.7%, and 33.3%, respectively. The agreement between the CBCT and intrasurgical assessments was strong, with a ka ppa of 0.831; the complete, overestimated, and underestimated agreement percentages were 88.2%, 3.2%, and 8.6%, respectively. The agreement between both assessments was the highest in the buccal furcation entrance (κ=0.896), followed by that in the distopalatal (κ=0.822) and mesiopalatal (κ=0.767) furcation entrances.@*CONCLUSIONS@#CBCT images demonstrated high accuracy in assessing the horizontal bone loss of FI in maxillary molars.

Bilateral taurodontism in permanent maxillary first molar

Taurodontism is a dental anomaly caused due to the failure of Hertwig's epithelial sheath to invaginate at the proper horizontal level. A huge pulp chamber, displacement of the pulpal floor apically, and no constriction at the level of the cementoenamel junction are the key features representing a taurodontic tooth. This condition is most commonly associated with permanent molars. This clinical entity occurs in the form of an isolated, singular trait in majority of the cases. However, seldom, it may be associated with syndromes or ectodermal anomalies. The large and deep pulp chamber makes instrumentation of canals difficult, thereby challenging an endodontist. This case report describes the endodontic challenge faced in cases of taurodontism as well as the clinical steps involved in its successful endodontic management. Furthermore, it shows the typical presence of bilateral hypertaurodontism with respect to the maxillary first molar.

Distancia entre la raíz palatina del primer molar superior permanente y el piso del seno maxilar, obtenida mediante tomografía computarizada cone beam / Distance between the palatal root of the first permanent upper molar to the floor of the maxillary sinus, obtained by cone beam computed tomography

El conocimiento de las relaciones anatómicas entre el piso del seno maxilar y los ápices de dientes maxilares posteriores, es muy importante al planificar una terapia endodóntica o cirugías en molares maxilares. Este estudio tiene por objetivo, establecer la distancia existente entre el ápice de la raíz palatina del primer molar superior y el piso del seno maxilar, obtenida de una muestra de 61 tomografías volumétricas Cone beam. Se realizó un estudio observacional transversal, donde se procedió a medir la distancia entre el ápice de la raíz palatina del primer molar superior y el piso del seno maxilar en 61 tomografías volumétricas Cone Beam, obteniendo medidas de un total de 107 raíces palatinas de molares maxilares. Las imágenes fueron almacenadas en formato DICOM y analizadas con el software Sky View Dental Plan en un computador HP Compaq LA1951g Z600 y en su análisis estadístico se utilizó el Programa Stata 11.0. El promedio de distancia registrado entre el ápice de la raíz palatina del primer molar superior y el piso del seno maxilar fue de 1,2 mm. La mayor distancia fue de 12,5 mm y la menor de 0 mm. La medida de 0 mm se presentó en 48 casos y alcanzó al 44,9 % de la muestra. Es frecuente que los ápices radiculares se encuentren dentro del seno maxilar, condición que debe ser de conocimiento clínico, con el objetivo de prevenir al máximo accidentes y complicaciones en las terapias endodónticas.

The knowledge of the anatomical relationships between the floor of the maxillary sinus and the apices of the posterior maxillary teeth is very important when planning an endodontic therapy or surgeries in the area. The objective of this study is to establish the distance between the apex of the palatal root of the first maxillary molar and the floor of the maxillary sinus, in a sample of 61 cone-beam computed tomography. A crosssectional observational study was carried out. We proceeded to measure the distance between the apex of the palatal root of the first upper molar and the floor of the maxillary sinus in 61 conebeam computed tomography, obtaining measurements of a total of 107 first maxillary molar palatal roots. The images were stored in DICOM format and analyzed with the Sky View software and the Stata 11.0. for statistical analysis. The average distance recorded between the apex of the palatal root of the first upper molar and the floor of the maxillary sinus was 1.2 mm. The greatest distance was 12.5 mm and the smallest was 0 mm. The measurement of 0 mm was presented in 48 cases and reached 44.9 % of the sample. It is common for radicular apices to be located within the maxillary sinus. The clinician must know this condition to prevent accidents and complications in the endodontic therapies as much as possible.

Management of maxillary first molar with six canals using operating microscope

The purpose of this article was to highlight the importance of having a thorough knowledge about the root canal morphology. This case report highlights the unusual anatomy of a maxillary first molar with three mesiobuccal (MB) canals, two palatal canals, and one distobuccal canal which is extremely rare. The use of operating microscope was crucial, both for the detection and for the management of the additional canals. The use of surgical operating microscope and digital radiograph showed that MB root had Type 3-1 of Gulabivala classification and palatal canal showed Vertucci's Type II canal morphology This report describes and discusses the identification of variation in canal morphology of maxillary first molar and the use of latest adjuncts in successfully diagnosing and negotiating them.

An Unusual Occurrence Of Two Palatal Canals In Maxillary First Molar - A Case Report.

The endodontist should have a detailed and thorough knowledge of root canal anatomy to effectively perform endodontic treatment, negligence to which might lead to endodontic failures. Maxillary first molars show considerable variation in root canal anatomy with respect to number of roots and number of canals. Literature states that canal variations can reach up to 33% in maxillary first molars. There is an overall low prevalence (<2%) of anatomic variations in the palatal canal of maxillary molars among different populations. This case report deals with one such palatal canal variations in maxillary first molar with 4 canals: 2 separate palatal canals, mesiobuccal and distobuccal canal and its management.. Clinician awareness on careful assessment of extra palatal canal in maxillary molar teeth using conventional radiograph has been reinforced in this case report to achieve long term success in endodontic treatment.

Endodontic Management of Maxillary Molar With Six Root Canals - A Case Report.

The aim of the present case report is to describe the unusual root canal anatomy of maxillary first molar with six canals, three in mesiobuccal root, two in distobuccal root and one in palatal root. This article highlights the importance of modifying the access opening and magnification in location of the additional canal orifices.

Transoral removal of ectopic maxillary third molar situated superiorly to maxillary antrum and posteroinferiorly to the floor of orbit.

Only few cases of ectopic third molar in relation to the roof of maxillary sinus and posteroinferior to the floor of the orbit have been reported in the literature. The diagnosis is usually done by plain‑film radiography. “Caldwell‑Luc” operation or endoscopic procedures have been used for the removal of such type of ectopic tooth. We report a case of 46‑year‑old female patient who presented with pain, swelling and watering of eye due to the ectopic tooth. The trans oral removal (via “Caldwell‑Luc” operation) of the ectopic maxillary third molar situated superior to maxillary antrum and posteroinferior to the floor of orbit has been described in this case without any complication.

Evaluation of stress contours on a maxillary molar subjected to simulated tooth loads by finite element analysis technique

Forces applied by dental occlusion generate stresses which are transmitted to the surrounding bone via the periodontal ligament causing a tissue response. The purpose of this study was to evaluate the response of a maxillary molar under secondary trauma from occlusion by observing the changes in its stress patterns. In order to visualize the exact pattern of stress distribution, three dimensional finite element analysis models were developed. A force of 3 N, moment of 27 Nmm and a counter rotation moment of 15 Nmm were applied to simulate orthodontic forces. Stresses produced at the periodontal ligament-tooth interface on a maxillary molar model with normal bone height subjected to an orthodontic force were compared with molar models showing bone loss and analyzed using finite element analysis technique. As the bone loss increased, it was observed that, the concentration of stresses at the apical one-third of the tooth also increased and there was high tendency for tooth displacement. The results suggest that an alteration in the magnitude of forces applied may be necessary in teeth with an increased crown to root ratio to maintain a healthy periodontium.

Management of a maxillary first molar tooth with unusual mesiobuccal root anatomy

Sufficient knowledge on the root and root canal anatomy is essential for practicing root canal treatment. The mesiobuccal roots of maxillary molar teeth present an endodontic challenge due to their wide variability and complexity of their internal morphological landmarks. A review on the literature indicates that the prevalence of a third mesiobuccal root canal in the mesiobuccal root of maxillary molar teeth may reach 9%, and the root canal configuration usually is type XV (3-2). These reported data reveal the importance of absolute awareness for this anatomical aberration that requires special attention from dental practitioners while commencing root canal treatment in maxillary molar teeth. Hence, this article aims to report and describe the management of a maxillary first molar tooth with three mesiobuccal root canals, but with an unusual configuration.

Stress distribution in bone surrounding maxillary molar implants under different crown-to-fixture ratio: A 3D FEM analysis / 대한치과보철학회지

STATEMENT OF THE PROBLEM: Under anatomical limitations on maxillary posterior region, a poor crown-to root ratio acting on dental implants can result in undesirable stress in surrounding bone, which in turn can cause bone defects and eventual failure of implants. PURPOSE: The purpose is to compare stress distribution due to different crown-root ratio and effect of splinting between natural teeth and implants in maxillary molar area under different loads. MATERIAL AND METHODS: Analysis of stress arising supporting bone of the natural teeth and the implant was made with 3-dimensional finite element method. The model simulated naturel teeth was made with 2nd premolar and 1st molar in the maxillary molar region (Model T). The model simulated implants placed on same positions with two parallel implants of Straumann Dental Implant cemented abutment (Model I). Each model was designed in different crown-root ratio (0.7:1, 1:1, 1.25:1) and set cement type gold crown to make it non-splinted or splinted. After that, 300 N force was loaded to each model in five ways (Load 1: middle of occlusal table, Load 2: middle of buccal cusp, Load 3: middle of lingual cusp, Load 4: horizontal load to buccal cusp of anterior abutment only, Load 5: horizontal load to middle of buccal cusp of each abutment), and stress distribution was analyzed. RESULTS AND CONCLUSION: On all occasions, stress was concentrated at the cervical region of the implant. Under load 1, 2 and 3, stress was not increased even when crown-root ratio increases, but under load 4 and 5, when crown-root ratio increases, stress also increased. There was difference in stress values between natural teeth and implants when crown-root ratio gradually increases; In case of natural teeth, splinting decreased stress under vertical and horizontal loads. In case of implants, splinting decreased stress under vertical loads 1,2 and 3, but increased maximal stress under loads 2 and 3. Under horizontal loads, splinting decreased stress, however the effect of splinting decreased under load 5 than load 4. Furthermore, the stress was increased, when crown-root ratio is 1.25:1. CLINICAL IMPLICATIONS: This limited finite element study suggests that the stress on supporting bone may be increased under non-axial loads and poor crown-root ratio. Under poor crown-root ratio, excessive stress was generated at the cervical region of the implant, and decreased splinting effect for stress distribution, which can be related to clinical failure.

A rare case of paediatric pontine Glioblastoma presenting as a cerebellopontine angle otogenic abscess

We describe rare case of a 9-year old boy who presented with a two- week history of right ear discharge and mild fever. Contrast enhanced CT scan of the brain showed a lesion in the right cerebellopontine angle with mild enhancement mimicking early abscess formation. Involvement of the mastoid air cells pointing towards a radiological diagnosis of mastoiditis reinforced the diagnosis of an abscess. A magnetic resonance imaging (MRI) was planned for the patient but his conscious level deteriorated and patient slipped into coma warranting immediate surgical intervention. Intraoperatively, about 90% of the tumour was removed and the appearance of the tumour resembled that of an acoustic schwannoma but histopathology confirmed the diagnosis of a glioblastoma multiforme (GBM). MRI done post operatively showed lesion in the pons confirming the diagnosis of an exophytic pontine glioblastoma multiforme.

Sinus floor augmentation at the time of tooth removal / 대한치주과학회지

Rapid crestal bone resorption following maxillary tooth loss is further accentuated in the posterior regions because of pneumatization and enlargement of the maxillary sinuses. A treatment rationale that allows preservation and augmentation of vertical available bone at the time of posterior maxillary tooth extraction may offer numerous therapeutic benefits which are more short courses of therapy and no needs of additional surgical augmentation. The present study comprised 3 patients who had 4 posterior maxillary teeth with no evident bone between the tooth apex and sinus floor, as estimated through preoperative radiographic analysis. Sinus floor augmentation at the time of tooth extraction was chosen for the ltreatment of these patients. After the tooth was carefully extracted, the empty alveolus was thoroughly debrided and a trephine approach was performed. Particulated autogenous bone was gently pushed beyond the empty alveolus to elevate the sinus membrane using an osteotome. The distance between bone crest and sinus floor was radiographically estimated 4 months after the first procedure. Another procedure was then carried out to place the implants of 11 mm length without another augmentation procedure. All implant were clinically stable, with no sign of infection. The presented surgical procedure performed at the time of extraction of posterior maxillary teeth in close proximity to the sinus floor allowed placement of implants of proper length.

Dental infection presenting with ipsilateral parapharyngeal abscess and contralateral orbital cellulitis – A case report

A 43 year-old man presented with pain on the right tooth for three days duration. Computed tomography showed left orbital cellulitis and right parapharyngeal abscess. There was also evidence suggestive of a dental abscess over right upper alveolar region. Magnetic resonance imaging revealed left superior ophthalmic vein thrombosis. Emergency drainage of the right parapharyngeal abscess was performed. Right maxillary molar extraction revealed periapical abscess. Left eye proptosis markedly reduced after initiating heparin.

The treatment of scissors bite using maxillary molar retractor / 实用口腔医学杂志

In this paper,a maxillary molar retractor was introduced.It could control the direction of orthodontic force and provide a quick and easy solution for reposition of the tooth and correction of scissors-bite.

Study on the length,number and transverse shape of the root canals of the first maxillary molars in vitro / 实用口腔医学杂志

Objective:To investigate the root length,number and the transverse shape of first maxillary molars using root sectioning technique. Methods:100 isolated first permanent maxillary molars from above 20 years old patients were collected. The roots were cross-sectioned in three parts(superior 1/3,middle 1/3 and apex 1/3) after measuring the length of roots. The transverse shape of root canals were observed under the stereomicroscope.The number and shape of root in three parts of roots were recorded. Results:The length of lingual root,MB and DB of the first maxillary molar is (13.82?1.51) mm;(13.06?1.12) mm and (11.64?0.85) mm respectively; complex degree of MB and DB of the first marxillar molar is very high. 51% double roots in superior 1/3 of MB were found. Above 50% dual roots in the middle 1/3and apex 1/3 in the mesiobuccal root of first maxillar molar were recorded. Conclusion:Root number and transverse configuration in MB and DB of first maxillary molar varied in different parts of roots; There may be double root canals in medium 1/3 and apex 1/3 in MB of first maxillary molar when one line type canal in superior 1/3 was found.