Mandibular Lateral Incisors Research Articles

Evaluation of the dimensional alternation of the alveolar bone in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography

The alveolar bone is an essential consideration when planning treatment for patients with tooth agenesis. This study evaluated the changes in the alveolar bone and adjacent teeth in patients with a congenitally missing mandibular lateral incisor using cone-beam computed tomography. Twenty-three nonorthodontically treated adults with a unilateral congenitally missing mandibular lateral incisor were the missing group (M group). The control group (C group) consisted of 23 nonorthodontically treated adults with normal occlusion and no missing teeth. First, the difference in the arch perimeter between the groups was compared at the cementoenamel junction (CEJ) level and the root apex (RA) level. Next, the root divergence of the anterior teeth in the M group was observed. Finally, the alveolar bone thickness ratio was compared between the M and C groups at different vertical levels. The arch perimeter was significantly decreased in the M group at the CEJ and RA levels (P<0.05). Root divergence was observed adjacent to the missing site (P<0.0001). There were a reduction in total and cancellous cortical alveolar bone thickness (ABT) ratios at the 3-, 6-, and 9-mm positions (P<0.05). The buccal cortical ABT ratios decreased at the 3-and 6-mm positions. The lingual ABT ratio increased at the 9-mm position (P<0.05). The congenitally missing mandibular lateral incisor caused a reduction in the arch perimeter in the CEJ area and the RA area. The root divergences were observed in the teeth adjacent to the missing areas. A significant decrease in the buccal cortical bone and cancellous bone was observed in the missing area.

Issue Information

The two gubernaculum tracts (GTs) of two successional teeth related to fused deciduous teeth were fused into one. Figure A and B show the fused GT of the mandibular canine and lateral incisor. Figure C and D show the fused GT of the maxillary central incisor and lateral incisor. Further details can be seen in the article by Oda et al. in this issue. image

Salivary Gene Expression of RANK, RANKL, and OPG in Type 1 Diabetes Mellitus and Periodontal Disease Patients.

The relationship between type 1 diabetes mellitus (T1DM) and periodontal disease may exhibit by the alteration of bone metabolism. However, evidence for this relationship is scarce and inconclusive. Thus, the aims of the present study were to investigate salivary receptor activator of nuclear factor kappa-β (RANK), receptor activator of nuclear factor kappa-β ligand (RANKL), osteoprotegerin (OPG) gene expression and the RANKL:OPG ratio in T1DM and non-T1DM. Secondary objective was to determine the relationships of RANK, RANKL and OPG gene expression to clinical parameters of T1DM and periodontal disease. Twenty patients with T1DM and twenty age-matched non-T1DM were recruited. Clinical periodontal parameters were measured. Total RNA was isolated from non-stimulated saliva, and the relative gene expressions of RANK, RANKL, OPG and RANKL:OPG ratio were determined by quantitative real-time polymerase chain reaction. The T1DM group had significantly higher mean periodontal parameters than the non-T1DM group, while the mean plaque scores of both groups were not significantly different. There was a trend of higher relative gene expression of RANK, RANKL, and the RANKL:OPG ratio and lower expression of OPG in T1DM group but no statistic significant different when compared to non-T1DM. In the T1DM group, RANKL:OPG correlated with the percentage of bleeding sites, whereas RANK, RANKL, and HbA1c levels correlated with pocket depth. Bone metabolisms demonstrating by decreased OPG gene expression and upregulated of RANK, RANKL, RANKL:OPG with higher pocket depth and bleeding in T1DM may play an important role in periodontal destruction in T1DM.

Endodontic management of biradicular mandibular canine and mandibular lateral incisor with a missed canal: A rare case report

Endodontic treatment may sometimes fail due to complex morphological features of the teeth. Mandibular lateral incisor and canine usually contains one root with a single root canal. Two rooted mandibular canine with two canals are rare. This paper illustrates a case report of a biradicular mandibular canine and mandibular lateral incisor with two canals.

Complete transposition of mandibular lateral incisor–canine (Mn.I2.C): A rare clinical case

A permanent tooth that grows and emerges from the same location of the dental arch as the other permanent teeth is a rare event. Unilateral transposition has been reported more often than bilateral transposition, with the left side of the body being affected more frequently than the right. With a frequency rate of 0.03 percent, the Mn.I2.C transposition is the rarest of all transpositions. In this unusual case report on a mandibular lateral incisor-canine transposition, dento-alveolar concerns such as arch length disparities and tooth material differences are addressed (Mn.I2.C).

Variability and Patterning in Permanent Tooth Dimensions among Four Ethnic Groups from the North-eastern States of India.

Methods The study was a comparative cross-sectional study among four different ethnic groups of North-east India among the age group of 20-30 years. Dimensions of the maxillary and mandibular teeth were measured with a digital Vernier calliper using the dental casts of 50 male and 50 female subjects from each of the four ethnic groups under study. The data were statistically analyzed using a Student's t-test and one-way analysis of variance. Statistical significance was set at p < 0.05. Results The tooth dimensions of all four ethnic groups were significantly lower than the standard values except for the MD dimension of the maxillary second molars of the Singpho group (9.13 mm vs. 9.0 mm); mandibular central incisors of the Meitei group (5.01 mm vs. 5.0 mm); and mandibular lateral incisors of the Meitei, Ao, and Singpho groups (>standard value of 5.5 mm) and BL dimension of the mandibular first premolars of the Meitei and Ao groups (>standard value of 7.5 mm); mandibular second premolars of the Meitei and Singpho groups (>standard value of 8.0 mm); and mandibular second molars of the Ao group (10.04 mm vs. 10.0 mm). In some instances, the comparative analysis revealed group variations in different tooth dimensions among the four ethnic groups (p < 0.05). Conclusion Variations were observed in the tooth dimensions among the four ethnic groups and within the same population. Unlike other parts of India, the North-eastern population belongs to a distinct ethnic race of indigenous people of East Asia, Southeast Asia, and the Arctic region of North America. Hence, population-specific data for India's North-eastern region are necessary for forensic odontology, dental anthropology, routine dental practice, and effective treatment planning.

Radicular Dens in Dente: Review of the Literature with Report of a Rare Case in a Child

Introduction: Dens invaginatus is an extremely rare developmental disturbance that can occur in primary, permanent, or supernumerary teeth due to invagination of the enamel organ into the dental papilla during tooth development. The clinical recognition of the radicular variant of dens in the dente is challenging as it is mostly asymptomatic with a normal-appearing clinical crown and is incidentally discovered in radiographs. Case presentation: This report describes a case of the radicular variant of dens in dente that involved the mandibular lateral incisor in an 8-year-old child. The affected tooth was symptomatic and was extracted as a part of treatment. Conclusion: Although the present case required extraction since it was associated with periapical infection, in other cases, treatment may be rendered with appropriate restorative/endodontic procedures with a keen intent to avoid sacrificing the involved tooth as has been reported earlier and reviewed herein.

ERUPTED COMPOUND ODONTOMA IN PATIENT WITH SEIZURES: A CASE REPORT

Erupted odontomas are rare in the oral cavity. During the intraoral examination of a 17-year-old girl in investigation of Dravet syndrome, psychogenic nonepileptic seizures, and psychotic disorder, an enamel-like tissue exposed in gingiva was identified. The lesion size was around 2 mm, localized between the right permanent mandibular lateral incisor and canine teeth. Periapical radiography revealed a radiopaque image of irregular tooth-like structures, suggesting the presence of an erupted compound odontoma. The lesion was surgically removed under infiltrative anesthesia, without the need for a flap. Four small tooth-like structures were removed and the specimens were sent for histopathologic analysis, confirming the hypothesis of compound odontoma. The procedure was achieved without complications or need of patient sedation. Twenty days after the surgery, there was satisfactory healing of tissue in the operated region. Erupted odontoma are rare. The patient follows her treatments with the team. Erupted odontomas are rare in the oral cavity. During the intraoral examination of a 17-year-old girl in investigation of Dravet syndrome, psychogenic nonepileptic seizures, and psychotic disorder, an enamel-like tissue exposed in gingiva was identified. The lesion size was around 2 mm, localized between the right permanent mandibular lateral incisor and canine teeth. Periapical radiography revealed a radiopaque image of irregular tooth-like structures, suggesting the presence of an erupted compound odontoma. The lesion was surgically removed under infiltrative anesthesia, without the need for a flap. Four small tooth-like structures were removed and the specimens were sent for histopathologic analysis, confirming the hypothesis of compound odontoma. The procedure was achieved without complications or need of patient sedation. Twenty days after the surgery, there was satisfactory healing of tissue in the operated region. Erupted odontoma are rare. The patient follows her treatments with the team.

CRACKED TOOTH SYNDROME ONE YEAR AFTER HEAD AND NECK RADIOTHERAPY

The left lateral mandibular incisor (tooth 32) of a patient with base of tongue cancer submitted to adjuvant radiotherapy (RT) was assessed during mouth conditioning protocol and followed up 1, 3, 6, 9, and 12 months post-RT. Enamel craze lines (ECL) were assessed using a pen-sized cordless transillumination device. ImageJ software was used to analyze the number and size of ECLs before and 1 year post-RT. The tooth measured 8.8 mm. Analysis 1 year post-RT revealed a 100% increase in the number of ECLs (from 8 to 16). All existing ECLs increased in size. The largest ECL measured 8.46 mm and the smallest was 0.76 mm. Seven of 8 new ECLs appeared on the tooth cervical area. Results support ECL as part of the initial spectrum of radiation-related caries (RRC). Increased ECLs revealed weakened tooth structure post-RT. Dentists should be aware of the presence of ECL in patients with head and neck cancer post-RT to promote prevention and early diagnosis and management of RRC. The left lateral mandibular incisor (tooth 32) of a patient with base of tongue cancer submitted to adjuvant radiotherapy (RT) was assessed during mouth conditioning protocol and followed up 1, 3, 6, 9, and 12 months post-RT. Enamel craze lines (ECL) were assessed using a pen-sized cordless transillumination device. ImageJ software was used to analyze the number and size of ECLs before and 1 year post-RT. The tooth measured 8.8 mm. Analysis 1 year post-RT revealed a 100% increase in the number of ECLs (from 8 to 16). All existing ECLs increased in size. The largest ECL measured 8.46 mm and the smallest was 0.76 mm. Seven of 8 new ECLs appeared on the tooth cervical area. Results support ECL as part of the initial spectrum of radiation-related caries (RRC). Increased ECLs revealed weakened tooth structure post-RT. Dentists should be aware of the presence of ECL in patients with head and neck cancer post-RT to promote prevention and early diagnosis and management of RRC.

An Observational Study on Root Canal Morphology of Mandibular Incisors in a Dental College Hospital

INTRODUCTIONAdditional canals are frequent findings in radicular morphology of the mandibular incisors. Finding additional canals and their obturation significantly improve the prognosis of endodontic treatment. Cone Beam Computed Tomography (CBCT) best visualize all canals and their configurations. The study assessed root canal anatomy of mandibular incisors on CBCT images of the patients. MATERIAL AND METHODSAn observational cross-sectional study was carried during July-October 2021 on 42 CBCT images of the patients visiting Kantipur Dental College and Hospital. The samples were selected using convenience sampling presenting with bilateral mandibular central and lateral incisors. Root canals and their configurations were assessed on 168 teeth. The presence of unilateral or bilateral additional root canal was recorded and chi-square test was used to test its association with gender (p &lt; 0.05). RESULTThe prevalence of additional canal was 27.4% in mandibular incisors. Bilateral symmetrical distribution of extra canal in mandibular central and lateral incisors were 36.3% and 41.6% respectively. There was a significant association between the presence of extra canal and gender in both central incisors (p-value 0.019) and lateral incisors (p-value 0.009). Type I canal configuration was most prevalent (72.6%) followed by Type III (22.6%). CONCLUSIONThe prevalence of double canals in mandibular incisors is 35% in male and 4% in female samples confirming the male predominance. Bilaterally symmetrical occurrence of double canal is evident up to 41%. CBCT evaluation helps in the visualization of missing root canals during endodontic therapy.

Anatomical Evaluation of Root and Root Canal Morphology of Permanent Mandibular Dentition among the Saudi Arabian Population: A Systematic Review.

This study aimed to conduct a compendious review of root canal morphology of “permanent mandibular teeth in different regions of Saudi Arabia” to obtain a large sample representing the total population. A detailed search through the databases Web of Science, Scopus, and PubMed was conducted following the PRISMA guidelines. The data were analyzed based on the following inclusion criteria: original full-length original articles that reported the variables of interest “(number of roots, number of canals, Vertucci's classification system and C-shaped canals or mid-mesial canals)” of the mandibular teeth and conducted on Saudi subjects. The retrieved data were presented as frequencies and percentages. The results revealed that 56.6% of mandibular central incisors had one canal and Vertucci type I (56.6%), while 57.4% of the mandibular lateral incisors had one canal, with Vertucci types I and III most frequent. In mandibular canines, 91.8% had one canal and 8.2% had two canals. Most of the mandibular first premolars had one root (86.6%), while almost all mandibular second premolars (91.5%) had one canal, and 96.9% had Vertucci type I configuration. Among the mandibular first molars, three and four canals were prevalent in 58.7% and 40.6%, respectively. The majority of mesial roots had Vertucci type IV (60.6%), and most of distal roots had Vertucci type I (72.2%). Most of the mandibular second molars had three canals (87.3%) and showed Vertucci type IV (39.4%) canals for mesial roots and Vertucci type I (95.6%) for distal roots. The C-shaped canals were seen in 8% of first premolars and 9.8% of second molars. The middle mesial canal was found in 4.2% and 0.4% of first and second molars, respectively. This review could represent “the population of Saudi Arabia as the included samples were combined from different regions of the country.” Some variations were noticed within the same group of teeth from different regions. However, the overall results of combined samples were comparable to the other international studies.

Comparative evaluation of the fracture resistance of reattched fragments using three different retentive methods: An in vitro study

: Traumatic injuries to the anterior teeth are one of the most difficult and perplexing problems faced in the paediatric dentistry. Coronal fracture of the anterior teeth is a common form of dental trauma that mainly affects the maxillary and mandibular incisors. Fragment reattachment has been the preffered technique among clinicians because it has several advantages over the composite restorations such as it is a conservative procedure, maintains original tooth contours, translucence and incisal edge wears at similar rate to adjacent teeth.: To compare and evaluate the fracture resistance of reattached fragments using three different methods.Forty sound permanent mandibular central and lateral incisor were selected and mounted in self-cure acrylic resin. The teeth were sectioned with a diamond disc 3mm short of the incisal edge and they were randomly divided into four groups (n=10). Group I – simple reattachment, group II- internal dentinal groove, group III – vertical groove with fiber reinforced post placement, group IV – overcontouring done before the reattachment procedure. The force required to fracture the specimen were recorded using an onscreen calibration tool of the universal testing machine. The results were statistically analyzed.: The results showed that group I, group II and group IV required lesser force to fracture when compared with group III.: The group restored with fiber reinforced post showed the highest value of fracture strength while the simple reattachment had the lowest value.

Cone-beam CT analysis of the correlation between incisor root resorption rate and tooth movement index in adult patients with fixed orthodontics appliance

Objective: To analyze the correlation between the root resorption rate and tooth movement of the maxillary and mandibular incisors before and after orthodontic treatment in adult patients using cone-beam CT (CBCT), and to explore the related factors that affect the apical root resorption. Methods: In this retrospective study, 23 adult patients with classⅠor class Ⅱ division 1 malocclusion [2 males and 21 females, mean age (23.4±6.3) years, treatment time (2.1±0.7) years] who received orthodontic treatment with fixed appliance in Department of Oral & Cranio-Maxillofacial Surgery, Shanghai Ninth People's Hospital from January 2017 to June 2021 were enrolled. Full-column CBCT examination was performed before and after treatment. A three-dimensional model was established to observe and record the volume of the maxillary and mandibular central and lateral incisors before and after treatment. The change of the incisal edge, the angle of rotation of the incisal edge, and the direction of the long axis of the tooth were also measured. The root resorption in each tooth before and after treatment was compared, and the root resorption rate was calculated. Pearson correlation analysis was performed on the root absorption rate before and after treatment with age, treatment time and tooth movement. Results: After treatment, the tooth volume of the maxillary and mandibular central and lateral incisors decreased significantly (P<0.01). The root absorption volumes were (20.2±6.0) mm3 and (11.2±4.7) mm3 in maxillary central and lateral incisors, and (14.7±4.6) mm3 and (14.8±5.0) mm3 in mandibular central and lateral incisors, respectively. The root absorption rates were (9.49±1.75)% and (9.13±3.24)% in maxillary central and lateral incisors, and (8.56±3.43)% and (9.13±3.24)%, in mandibular central and lateral incisors, respectively (F=0.56, P=0.640). The root resorption rate of maxillary central incisors had a weak positive correlation with the change of sagittal distance of incisal edge (r=0.36, P=0.015). The root resorption rate of mandibular central incisors had a moderate positive correlation with the vertical movement distance (r=0.48, P=0.001). The root resorption rate of mandibular lateral incisors was weakly positively correlated with the vertical movement of incisal edge and the treatment time (r=0.35, P=0.016; r=0.34, P=0.021), and was moderately positively correlated wit the change of sagittal movement of incisal edge (r=0.44, P=0.002). Conclusions: During orthodontic treatment, both maxillary and mandibular incisors had a certain degree of root resorption, which was related to sagittal and vertical movement of the incisors and the time of orthodontic treatment.

Study of cross-sectional morphology of root canals in Tibetan mandibular incisors by micro-computed tomography

Objective: To study the cross-sectional morphology of root canal system of Tibetan mandibular incisors by micro-CT. Methods: From October 2019 to October 2020, one hundred and thirty-six mandibular incisors were collected from Tibetan patients [(51.9±16.4) years old, range from 25 to 80 years] who underwent teeth extraction due to severe periodontitis at the Department of Stomatology, Tibetan Hospital of Traditional Tibetan Medicine, including 84 mandibular central incisors and 52 mandibular lateral incisors. These teeth were scanned at 23 μm voxel size resolution. Root lengths from cemento-enamel junction (CEJ) to apex of mandibular incisors were measured. According to the length, the root was divided as cervical 1/3, middle 1/3 and apical 1/3, and the numbers of root canals were recorded simultaneously. The major diameter, minor diameter, and dimension were measured per millimeter in cross section for mandibular incisor with single root canal, and the ratio of major diameter to minor diameter (Dmax/Dmin) as well as roundness were calculated for morphological analysis. The diversions and conversions from CEJ to apex in cross section were recorded for mandibular incisor with multiple root canals. Results: For mandibular central incisors with single root canal, the Dmax/Dmin was highest in middle 1/3 of the root [1.99 (1.31, 2.79)], which was significantly higher than cervical 1/3 and apical 1/3 (P=0.010, P=0.003). The roundness was least in middle 1/3 [0.47 (0.31, 0.66)], which was significantly lower than cervical 1/3 and apical 1/3 (P=0.010, P=0.001). For mandibular central incisor with multiple root canals, the highest incidence of multiple root canals was 40.5% (34/84), and mainly detected in middle 1/3 of the root [32.1% (27/84)]. For mandibular lateral incisor with single root canal, the roundness was greatest in apical 1/3 of the root [0.61 (0.49, 0.71)], which was significantly higher than cervical 1/3 (P=0.001) and middle 1/3 (P=0.001). The highest incidence of multiple root canals was 34.6% (18/52), all of which were detected in apical 1/3. Conclusions: In Tibetan mandibular central incisors, the cross-sectional morphology of root canals was long and narrow in middle 1/3, and multiple root canals were more likely to be found here. In Tibetan mandibular lateral incisors, the cross-sectional anatomy of root canal was relatively close to circle in apical 1/3, but the shape was still so irregular that one root canal may divide into two here.

Three-dimensional digital evaluation of tooth symmetry and volume in patients with missing and peg-shaped maxillary lateral incisors

This study aimed to evaluate the 3-dimensional tooth crown symmetry and the crown volumes of maxillary and mandibular teeth in patients with unilateral or bilateral missing or peg-shaped maxillary lateral incisors. Six groups were established for the possible clinical variations in patients with unilateral missing or peg-shaped maxillary lateral incisors, bilateral presence of these tooth anomalies, and a control group (CG) with normal lateral incisors. The study was conducted on digital dental models of 132 patients. The morphologic symmetry of the antimere teeth was investigated using 3-dimensional deviation analysis. Volumes of contralateral teeth were compared within and among groups for the maxilla and mandible. Furthermore, volumes of teeth were compared in missing and peg-shaped quadrants and quadrants of CG. Intergroup differences were tested using one-way analysis of variance and Kruskal-Wallis tests, whereas paired t and Wilcoxon tests were used for parametric and nonparametric variables, respectively, for intragroup comparisons. Significant deviations in symmetry of antimere teeth were not detected (P>0.05). The volumes of mandibular central and lateral incisors in missing or peg-shaped lateral incisor groups were smaller than in the CG (P<0.05). Per quadrant analysis, volumes of the maxillary central incisor and mandibular central incisors, canines, and first molars in quadrants with missing or peg-shaped lateral incisors were smaller than in the control quadrants (P<0.05). Neither unilateral nor bilateral presence of missing or peg-shaped maxillary lateral incisors affected the morphologic symmetry of antimere teeth but did affect tooth volume, especially in the mandibular arch.

Multidisciplinary approach for aesthetic rehabilitation in gummy smile and fluorosis: a case report

Background: Teeth, gingiva and lips are the three interrelated primary components in aesthetic dentistry. These combinations warrant a multidisciplinary approach for planning and predictable treatment outcome. Objective: The aim of this article is to describe the multidisciplinary approach for aesthetic rehabilitation involving gingivectomy and minimally invasive tooth preparation with porcelain laminate veneer (PLV) restorations and resin bonded bridge. Case: A 25-year-old female patient attended with existing space between maxillary anterior teeth post orthodontic treatment and missing mandibular anterior teeth. Intraorally, patient had uneven interdental spacing in between 13 to 23, missing 31 and 32, with merging and irregular opacities suggestive of enamel fluorosis appearance. The zenith lines were asymmetrical with short clinical crowns and disharmonious teeth axes. To optimize the aesthetic outcome and overall smile appearance, gingivectomy was performed after confirmation of biologic width. Eight weeks after healing, PLV restorations were delivered from 13 to 23, and zirconia resin bonded bridge were used to restore missing mandibular lateral incisors. Conclusion: The present case illustrates the sequential and predictable approach for management of gummy smile and fluorosis. An alternative treatment modality such as electrocautery may enhanced the smile and obtain positive outcome.

Association of Non-Syndromic Hypodontia with Skeletal Malocclusion in Orthodontic Patients

Background: Hypodontia is one of the frequently observed dental anomalies in which dentofacial esthetics, phonetics, mastication, self-esteem and quality of life can be adversely affected. Awareness of disproportionate tooth number is important and must be considered by orthodontists while making treatment plans to achieve proper occlusion, overbite, and overjet, in order to restrain oral health deterioration. The aim of this study was to determine the frequency of non-syndromic hypodontia in orthodontic patients and its association with skeletal malocclusion. Methods: This retrospective case-series was conducted at the department of Orthodontics, Sharif Medical &amp; Dental College. It involved screening the records of orthodontic patients from last 5 years from October 2017 – October 2021, consisting of standardized good quality orthopantomograms and lateral cephalograms. Patient files with incomplete records, any craniofacial syndrome and/or previous history of tooth loss were excluded. Non-syndromic hypodontia and skeletal malocclusion was recorded along with demographic data, in predesigned proforma. Results: Out of 244 orthodontic patients, 18 patients (7.37%) had non-syndromic hypodontia. Moreover, 63 teeth were missing in 18 patients of NSH. Maxillary arch (52.4%) and upper left quadrant (28.6%) were found to be more frequently affected. The difference of non-syndromic hypodontia among dental arches, quadrants and skeletal malocclusion was statistically significant while for genders it was insignificant. Conclusion: Non-syndromic hypodontia was significantly associated with skeletal malocclusion, highlighting their genetic etiology. Most commonly absent tooth was maxillary lateral incisor followed by mandibular second premolar and lateral incisor. Keywords: congenitally missing tooth, dental anomaly, dentofacial esthetics, genetic etiology, skeletal malocclusion

Analysis of Root Canal Anatomy of Mandibular Permanent Incisors in Saudi Subpopulation: A Cone-Beam Computed Tomography (CBCT) Study.

This study aimed to evaluate the root canal anatomy of central and lateral mandibular incisors in a Saudi population using cone-beam computed tomography (CBCT). Overall, 1370 CBCT images of central (687) and lateral (683) mandibular incisors of Saudi patients who attended the Dental College at King Saud University in Riyadh were examined. The number of roots and canals, canal configuration types, symmetry between bilateral incisors, and the effect of gender and age were determined. For data analysis, the chi-square test was applied, and the p value was set at ≤0.05. Only one tooth had two roots, and 41% of mandibular incisors had two canals. The most common canal configuration type observed was type I (58.83%), followed by type III (28.24%). Type V was more common in men (8.31%) than women (3.9%). Bilateral symmetries were higher in the mandibular central incisors regarding the root and canal numbers and the canal configuration types (100, 100, and 97.92%, respectively) than in the lateral incisors (99.69, 98.16, and 97.24%, respectively). The 21–40 age group showed a higher proportion of teeth with more complicated root canal anatomy than the other age groups. More than one canal in mandibular incisors is a common finding in the Saudi subpopulation, with the type III canal configuration as the most common type.

Evaluation of canal configuration and frequency of second canal in mandibular lateral incisor using Cone Beam Computed Tomography (CBCT)

Objective: To categorize root canal configuration according to Vertucci’s classification and determine the frequency of second canal in mandibular lateral incisors of Pakistani subpopulation (Karachi based) by using Cone Beam Computed Tomography.&#x0D; Study Design: Cross sectional study.&#x0D; Place and Duration of Study: Out-patient department of Oral and Maxillofacial Surgery and the department of Radiology at Dow University of Health Sciences, Karachi Pakistan, from Jan to Jul 2019.&#x0D; Methodology: Study was conducted on 160 extracted permanent mandibular lateral incisors. After extraction, teeth were randomly arranged in wax models and imaged via CBCT. Each tooth sample was analyzed in axial and sagittal sections. The images were investigated by two blinded examiners and data on canal morphology was recorded.&#x0D; Results: The frequency of single canal mandibular incisors was recorded as 107 (66.9%) whereas 53 (33.1%) of teeth showed two canals. Females presented with a higher frequency of two canalled incisors, although the results were statistically insignificant. The most prevalent canal anatomy detected was Type I (105, 65.6%) followed by Type III (33, 20.6%), Type II (12, 7.5%) and Type V (10, 6.3%). Mandibular lateral incisors presenting with two canals anatomy, Type III (32, 97%) morphology was most commonly detected followed by Type II (12, 100%) and Type V (9, 90%).&#x0D; Conclusion: CBCT scans are an effective tool for identification of root canal morphology. Mandibular lateral incisors most frequently presented with Type I canal anatomy whereas incisors with two canals most frequently presented with Type III configuration.

Mandibular incisors with two canals are associated with the presence of the distolingual root in mandibular first molars: a cone-beam computed tomographic study

BackgroundThis study aimed to evaluate the root canal configurations and the association between mandibular first molars and distolingual root (DLR) and mandibular incisors using cone-beam computed tomography (CBCT).MethodsMandibular first molars and incisors were evaluated using CBCT images of 150 patients. Mandibular first molars were classified according to the presence or absence of DLR. The curvature of the DLR was evaluated using Schneider’s method in buccolingual and mesiodistal orientations. The angle of the mesiolingual–distolingual–distobuccal canal orifices (ML–DL–DB) was evaluated at the pulpal floor level. The mandibular central and lateral incisors were classified as either single canal or two canals. The association between the root canal system of the mandibular first molar and mandibular incisors was evaluated. Data were analyzed using the Chi-square test, Student’s t-test, and odds ratios from binary logistic regression. The significance level was set at 5%.ResultsThe frequency of mandibular first molars with DLR was 27.0% and that of mandibular incisors with two canals was 25.8%. The curvature of the DLR was 37.1° in the buccolingual orientation and 10.4° in the mesiodistal orientation. The angle of ML–DL–DB was 79.0°. The presence of two canal systems in mandibular incisors was associated with the presence of DLR in the mandibular first molar (left central incisors: p = 0.001, odds ratio = 4.25; left lateral incisors: p < 0.001, odds ratio = 3.8; right central incisors: p = 0.003, odds ratio = 3.86; right lateral incisors: p = 0.001, odds ratio = 3.44) but not with the curvature of the DLR or angle of the ML–DL–DB orifice (p > 0.05).ConclusionsThe mandibular first molar showed a high incidence of separate DLRs. It was confirmed that DLR in the mandibular first molar is highly associated with the presence of two-canal system in the mandibular incisors. This association can aid clinicians in successful endodontic treatments.