Detection and location of second mesiobuccal canal in permanent maxillary teeth: A cone-beam computed tomography analysis in a Taiwanese population.

OBJECTIVES: The aim of this study was to analyze the incidence, symmetry, concurrence of second mesiobuccal canal (MB2) and determine geometric relationships between each orifice of maxillary first and second molars by cone-beam computed tomography (CBCT) analysis. METHODS: A total of 216 qualified individuals' (503 teeth) CBCT image were enrolled in the present study. The consistency of bilateral symmetry and concurrent appearance of MB2 canals were analyzed among individuals with contralateral and adjacent molar teeth. The inter-orifice distances and angulations of first and second molars were also measured. RESULTS: The overall incidence of MB2 canal of maxillary molars was 39.2%, in which 45.9% and 32.3% in the first and second molars, respectively. The distribution of MB2 canal in contralateral molar teeth has significant gender difference in second molars (p = 0.024) while analyzing the frequency of MB2 canal appearing in contralateral molar pairs. The simultaneous occurrence of MB2 canal was 22.4% for contralateral molars, and the prevalence of concurrent appearance of MB2 canal in the adjacent molars was 43.4%. After adjusting for gender, age, and tooth type, the inter-orifice distances of mesiobuccal to palatal (odds ratios = 1.891) and to distobuccal (odds ratios = 1.448) canals, demonstrated significant differences between molars with and without MB2 canals. CONCLUSIONS: The clinical significance of the results presents critical information on the geometric features, including inter-orifice distances and angulations between each orifice in maxillary molar teeth. Further studies should be conducted to investigate the exact anatomic coordination between each orifice and its impact on access preparation and external crown morphology.

Relationship of the Incidence of C-shaped Root Canal Configurations of Mandibular First Premolars with Distolingual Roots in Mandibular First Molars in a Taiwanese Population: A Cone-beam Computed Tomographic Study.

INTRODUCTION: The aim of this study was to determine the prevalence of C-shaped canal configurations (CSs) and radicular grooves (RGs) in permanent mandibular first premolars (MPs) and to investigate the relevance of such complexities with the presence of distolingual roots (DLRs) in permanent mandibular first molars (MMs). METHODS: A total of 800 pairs of MPs and MMs were investigated using a cone-beam computed tomographic system (NewTom 5G; QR srl, Verona, Italy). The frequency and symmetry of DLRs in MMs along with the occurrence of RGs and CSs in examined MPs were evaluated. Multivariable logistic regression analysis was applied to examine the correlation between the CSs of MPs with the appearance of DLRs in MMs. RESULTS: In the examined teeth, 23.0% of MMs had a DLR, whereas 16.6% of MPs had RGs and 12.5% of MPs had C-shaped canals. Although the most common canal configuration in MPs is the single canal (74.1%), the other 25.9% still possess complicated root canals. Of these MPs that have different canal configurations, 54.6% had 2 canals, whereas 44.4% had CSs. Specifically, the CS showed a high prevalence of C3 morphologies at 98.9% followed by C1 at 1.1%. A corresponding and increasing frequency was noted in CSs and RGs of MPs and MMs with DLRs (P < .001). After adjusting for related categoric variables, the adjusted odds ratios for CSs of MPs in the bilateral DLR group compared with the non-DLR group was 3.294 (P < .001). CONCLUSIONS: This study showed an increased appearance of CSs in MPs when DLRs were present in MMs in the Taiwanese population.

The Presence of Distolingual Root in Mandibular First Molars Is Correlated with Complicated Root Canal Morphology of Mandibular Central Incisors: A Cone-beam Computed Tomographic Study in a Taiwanese Population.

INTRODUCTION: The aim of this study was to assess the prevalence of complicated root canals in permanent mandibular central incisors (PMCIs) and its correlation with the presence of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic imaging in a Taiwanese population. METHODS: A total of 400 patients (800 pairs of PMCIs and PMFMs) were qualified for further analysis. The prevalence of DLRs in PMFMs along with root canal configurations of PMCIs were assessed at subject and tooth levels. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMCIs with the existence of DLRs in PMFMs. RESULTS: The prevalence of PMFMs with DLRs and complicated root canal configurations in PMCIs was 23.0% and 15.6%, respectively. A significant difference in age (<50 years vs ≥50 years) was found for complicated root canal configurations in PMCIs. The most prevalent root canal system in PMCIs was Vertucci type I (84.4%) followed by type III (13.5%). A positive correlation between the presence of DLRs in PMFMs and complicated root canal configurations in PMCIs was noted. After adjusting for categoric variables including sex, age, and side, the odds ratios for the occurrence of complicated root canal configurations of PMCIs in the unilateral DLR group and the bilateral DLR group compared with the non-DLR group were 2.13 and 2.53, respectively. CONCLUSIONS: The concurrent appearance of DLRs in PMFMs and complicated root canal morphology in PMCIs is prominent in Taiwanese individuals.

The prevalence and distribution of radiopaque, calcified pulp stones: A cone-beam computed tomography study in a northern Taiwanese population.

BACKGROUND/PURPOSE: Presence of pulp stones increase the difficulty of locating canal orifice during endodontic treatment. This study aims to determine the prevalence of pulp stones in a northern Taiwanese population through analysis of cone beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 144 patients and 2554 teeth were used in the present study which were collected from a CBCT image archive. To determine the presence of pulp stones, images of pulp chamber and root canals were analyzed in the sagittal, axial and coronal planes and from the occlusal to apical direction. Correlations between pulp stones and gender, age, tooth type, dental arch or side were also examined. RESULTS: Of the 144 patients, 120 patients (83.3%) and 800 (31.3%) teeth were found to have one or more pulp stones through CBCT examination. Prevalence of pulp stones between dental arches and tooth types were significantly different (P < 0.001). Pulp stones were found to be the most prevalent in first molars (50.0%) and most scarce in first premolars (18.8%). There was no significant correlation between pulp stones and gender, increasing age, or dental sides. CONCLUSION: Pulp stones are more frequent in maxillary teeth compared to mandibular teeth. Pulp stones in molar teeth were significantly more common than premolars and incisors. CBCT could be a sensitive tool to detect pulp stones, especially simplifying identification of pulp stones in radicular pulp. Knowledge of pulp stones distribution can aid dentists in clinical endodontic treatment.

Complicated Root Canal Morphology of Mandibular Lateral Incisors Is Associated with the Presence of Distolingual Root in Mandibular First Molars: A Cone-beam Computed Tomographic Study in a Taiwanese Population.

INTRODUCTION: The aim of this study was to assess the root canal configurations in permanent mandibular lateral incisors (PMLIs) and the correlation between the root canal configurations of PMLIs with the appearance of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic (CBCT) imaging. METHODS: A total of 1200 CBCT images (300 patients) of PMFMs and PMLIs were investigated. The frequency and distribution of DLRs in PMFMs along with root canal configurations of PMLIs were assessed ipsilaterally and contralaterally. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMLIs with the appearance of a DLR in PMFMs. RESULTS: The prevalence of PMFMs with a DLR was 24.3%, and the incidence of complicated root canal configurations in PMLIs was 25.0%. The most prevalent root canal systems of PMLIs were Vertucci types I (75%) and III (23.0%). The incidence of complicated root canal configurations in PMLIs was 19.5% in the non-DLR group (ie, no DLR was found on either side of the PMFMs), 33.3% in the unilateral DLR (Uni-DLR) group (ie, a DLR was found in 1 of the PMFMs [the left or right side] and a DLR was not found on the other PMFM), and 39.8% in the bilateral DLR (Bil-DLR) group (ie, a DLR was found in both the right and left PMFMs). After adjusting for categoric variables including sex, age, and side, the odds ratios for the frequency of complicated root canal configurations of PMLIs in the Uni-DLR and Bil-DLR groups compared with the non-DLR group were 2.12 (P = .003) and 2.707 (P < .001), respectively. CONCLUSIONS: The simultaneous appearance of DLRs in PMFMs and complicated root canal configurations in PMLIs is prominent in Taiwanese individuals. Clinicians should be aware of the correlation between the anatomic variants of PMFMs and PMLIs, which are important before endodontic treatment.

Evaluation of Buccal Bone Concavity in the Esthetic Zone: A Cadaver Study.

PURPOSE: The primary aim of this study was to evaluate the buccal bone concavity position and depth in the anterior maxilla. The accuracy of cone beam computed tomography (CBCT) to measure the buccal bone concavity was also investigated. MATERIAL AND METHODS: Eleven fresh cadaver heads were used in this study. CBCT images were first acquired, on which the location and depth of the buccal bone concavity were measured in maxillary incisors and canines. After full-thickness mucoperiosteal flap reflection, the corresponding measurements were made directly on cadavers. The accuracy and correlations between direct and image-derived measurements were analyzed statistically. RESULTS: A total of 53 sites were measured. The mean depths were 2.88 ± 1.37 mm and 2.40 ± 1.29 mm (with direct and CBCT measurement, respectively). The deepest concavities were found in the lateral incisors sites (3.15 ± 1.32 mm). There was a statistically significant underestimation of the depth of concavity (0.2 to 0.6 mm) by CBCT. Nevertheless, there is a high statistical correlation (r = 0.8) between the direct and CBCT measurements. CONCLUSIONS: Within the limitations of this study, it can be concluded that buccal bone concavity is the most prominent at the lateral incisor sites. The CBCT readings were highly correlated but underestimated to the direct measurements.

Complicated Root Canal Configuration of Mandibular First Premolars Is Correlated with the Presence of the Distolingual Root in Mandibular First Molars: A Cone-beam Computed Tomographic Study in Taiwanese Individuals.

INTRODUCTION: The purpose of this study was to examine the frequency and bilateral consistency of distolingual roots (DLRs) in permanent mandibular first molars (PMFMs) and root canal configurations in PMFPs (permanent mandibular first premolars) and to determine the correlation between the root canal configurations of PMFPs with the appearance of DLRs in PMFMs. METHODS: A total of 932 cone-beam computed tomographic images of PMFMs and PMFPs were collected from 233 patients. The frequency and bilateral consistency of DLRs in PMFMs along with root canal configurations (root number and canal number) of PMFPs were recorded and evaluated ipsilaterally and contralaterally. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMFPs with the appearance of DLRs in PMFMs. RESULTS: The prevalence of PMFMs with DLRs was 24.7%, and the incidence of complicated root canal configurations of PMFPs was 26.6%. The incidence of complicated root canal configurations of PMFPs was 19.6% in the non-DLR group, 37.2% in the unilateral DLR group, and 44.7% in the bilateral DLR group. After adjusting for categoric variables including sex, age, and side, the odds ratios for the frequency of complicated root canal configurations of PMFPs in the unilateral DLR and bilateral DLR groups compared with the non-DLR group were 2.472 (95% confidence interval, 1.434-4.263; P = .001) and 3.392 (95% confidence interval, 1.976-5.823; P < .001), respectively. CONCLUSIONS: An increasing and corresponding trend between the presence of DLRs in PMFMs and complicated root canal configurations in PMFPs was noted in Taiwanese individuals. These results suggest that the clinicians should familiarize themselves with the anatomic variants of PMFMs and PMFPs before endodontic treatment.

Non-invasive evaluation of facial crestal bone with ultrasonography.

PURPOSE: Facial crestal bone level and dimension determine function and esthetics of dentition and dental implants. We have previously demonstrated that ultrasound can identify bony and soft tissue structures in the oral cavity. The aim of this study is to evaluate the accuracy of using ultrasound to measure facial crestal bone level and thickness. MATERIALS AND METHODS: A commercially available medical ultrasound scanner, paired with a 14 MHz imaging probe was used to scan dental and periodontal tissues at the mid-facial site of each tooth on 6 fresh cadavers. The alveolar crest level in relation to the cemento-enamel junction and its thickness on ultrasound images were measured and compared to those on cone-beam computed tomography (CBCT) scans and/or direct measurements on a total of 144 teeth. RESULTS: The mean crestal bone level measured by means of ultrasound, CBCT and direct measures was 2.66 ± 0.86 mm, 2.51 ± 0.82 mm, and 2.71 ± 1.04 mm, respectively. The mean crestal bone thickness was 0.71 ± 0.44 mm and 0.74 ± 0.34 mm, measured by means of ultrasound and CBCT, respectively. The correlations of the ultrasound readings to the other two methods were between 0.78 and 0.88. The mean absolute differences in crestal bone height and thickness between ultrasound and CBCT were 0.09 mm (-1.20 to 1.00 mm, p = 0.06) and 0.03 mm (-0.48 to 0.54 mm, p = 0.03), respectively. CONCLUSION: Ultrasound was as accurate in determining alveolar bone level and its thickness as CBCT and direct measurements. Clinical trials will be required to further validate this non-ionizing and non-invasive method for determining facial crestal bone position and dimension.

Geometric features of second mesiobuccal canal in permanent maxillary first molars: a cone-beam computed tomography study.

BACKGROUND/PURPOSE: Inadequacy to locate the second mesiobuccal canal (MB2) canal leads to the highest probability of endodontic failure in permanent maxillary first molars (PMFMs) and still remains a constant challenge for many clinicians. The aim of this study was to characterize the geometrical features between MB2 and other orifices of examined PMFMs using cone-beam computed tomography images. MATERIALS AND METHODS: A total of 108 teeth qualified in the cone-beam computed tomography image archives were enrolled in the present study. The intersecting point (T) was determined as the perpendicular line (h, altitude of triangle) projected from the vertex of the MB2 canal orifice to mesiobuccal canal orifice-palatal canal orifice line (MB1-P). We measured the geometric features of PMFMs with the MB2 canal, including the interorifice distances, area, altitude, and the ratio between the canal orifices. RESULTS: The average interorifice distance was found to be 1.91 ± 0.59 mm for MB1-MB2, 5.73 ± 0.66 mm for MB1-P, and 4.11 ± 0.79 mm for MB2-P, with significant gender difference for MB1-MB2 distance. For the MB1-T distance, a significant difference was found between genders (P = 0.02), with males averaging 1.78 ± 0.07 mm, and females 1.48 ± 0.11 mm. For the MB1-P distance, the majorities of both genders were found in the 20-40% cut-off. A portion of the males exhibited a tendency towards the 40-80% cut-off, while females shifted in the reverse direction towards the 0-20% cut-off. CONCLUSION: In clinical scenarios, these anatomical characteristics of the root canals system could be beneficial to locating the MB2 canal.

The Effect of Locally Delivered Statins on Treating Periodontal Intrabony Defects: A Systematic Review and Meta-Analysis.

BACKGROUND: Use of statins on adult patients with chronic periodontitis shows a positive effect on their periodontal status. However, effect of locally delivered statins on periodontal treatment has not yet been systematically analyzed. Hence, the present systematic review and meta-analysis aims to evaluate efficacy of statins on treating localized periodontal intrabony defects (IBDs). METHODS: An electronic search of three databases (PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature) between January 1, 1965 and March 1, 2016, and a hand search of peer-reviewed journals for relevant articles were performed. Controlled randomized clinical trials (RCTs) and prospective studies with data on comparison between adjunctive locally delivered statin use to mechanical scaling and root planing (SRP) and placebo in each group, with minimum 10 participants and follow-up period of at least 6 months, were included. RESULTS: Ten studies, eight RCTs and two prospective studies, were included. Each study included 15 to 105 patients between 25 and 55 years of age. Statistical results were recorded; weighted mean difference (WMD) and confidence interval (CI) were calculated; and meta-analyses were performed for defect fill, probing depth (PD) reduction, and clinical attachment level (CAL) gain in both statin and placebo/no treatment groups. Overall analysis of defect fill presented WMD of 1.37 mm (95% CI = 0.96 to 1.77; P <0.0001), PD reduction presented WMD of 1.76 mm (95% CI = 1.04 to 2.47; P <0.0001), and CAL gain presented WMD of 1.58 mm (95% CI = 0.89 to 2.28; P <0.0001). However, comparison presented considerable heterogeneity among studies. CONCLUSIONS: This systematic review and meta-analysis find that adjunctive use of locally delivered statins to mechanical SRP is beneficial to increasing bone fill percentage. Improved inflammatory and bleeding control as well as PD reduction and CAL gain are possible advantages to using these drugs in treating patients with periodontal IBDs.

Continued root formation after replantation and root canal treatment in an avulsed immature permanent tooth: a case report.

This case report describes the continued root formation following replantation and conventional root canal therapy of a traumatically avulsed open-apex tooth with suppurative apical periodontitis. A 7-year-old male patient had an avulsed upper left central incisor (tooth 21) replanted approximately 50 min after traumatic avulsion. A root canal procedure was initiated due to pulp necrosis and periapical abscess detected in the follow-up period. After endodontic treatment with calcium hydroxide (Ca(OH)(2)) dressing, a normal root length developed including an apical segment beyond the hard tissue barrier. Regeneration of the root occurred without pathology or ankylosis at 1-year of follow up.

Management of crown-root fracture tooth by intra-alveolar transplantation with 180-degree rotation and suture fixation.

Teeth with traumatic crown-root fractures extending subgingivally and involving the entire width of the tooth may have problems in endodontic isolation, periodontal maintenance, and restoration. A number of techniques, such as crown lengthening, and orthodontic or surgical extrusion, have been described for treatment of crown-root fractures. However, all of these techniques have limitations in terms of the extended time required for treatment, cost, and esthetic considerations. Intra-alveolar transplantation is an alternative treatment option in the management of complicated crown-root fractures. We describe a case of intra-alveolar transplantation with 180( degrees ) rotation and suture fixation. At 1-year follow-up, the replanted tooth has normal function and no obvious inflammatory root resorption on radiographic examination.

Floating retained root lesion mimicking apical periodontitis.

A case of a retained root tip simulating apical periodontitis on radiographic examination is described. The retained root tip, originating from the left lower first molar, floated under the left lower second premolar apical region mimicking apical periodontitis. It appeared as an ill-defined periapical radiolucency containing a smaller radiodense mass on radiograph. The differential diagnosis included focal sclerosing osteomyelitis (condensing osteitis) and ossifying fibroma. Upon exicisional biopsy, a retained root associated with granulation tissue was found. After 1-year follow-up, the patient was asymptomatic and the periradicular lesion was healing. Meanwhile, the associated tooth showed a normal response to stimulation testing.