To examine root canal morphology of mandibular second premolars (Mn2P) of a mixed Swiss-German population by means of micro-computed tomography (micro-CT). Root canal configuration (RCC) of 102 Mn2P were investigated using micro-CT unit (µCT 40; SCANCO Medical AG, Brüttisellen, Switzerland) with 3D software imaging (VGStudio Max 2.2; Volume Graphics GmbH, Heidelberg, Germany), described with a four-digit system code indicating the main root canal from coronal to apical thirds and the number of main foramina. A total of 12 different RCCs were detected. 1-1-1/1 (54.9%) was most frequently observed RCC, followed by 1-1-1/2 (14.7%), 1-1-2/2 (10.8%), 1-2-2/2 (4.9%), 1-1-3/3 (3.9%), 1-1-1/3 (2.9%), 2-1-1/1 (2.9%) and less frequently 1-1-2/3, 1-2-1/2, 2-1-2/2, 1-1-2/5, 1-1-1/4 with each 1.0%. No accessory foramina were present in 35.3%, one in 35.3%, two in 21.6%, three and four in 2.9%, and five in 2.0%. In 55.9% Mn2Ps, accessory root canals were present in apical third and 8.8% in middle third of a root. Connecting canals were observed less frequently (6.9%) in apical and 2.9% in the middle third, no accessory/connecting canals in coronal third. Every tenth tooth showed at least or more than three main foramina. Almost two thirds of the sample showed accessory root canals, predominantly in apical third. The mainly single-rooted sample of Mn2Ps showed less frequent morphological diversifications than Mn1Ps.

Objective: This study aimed to investigate the morphology of maxillary lateral incisors (MxLI) using micro-computed tomography (micro-CT). Materials and methods: The root canal configurations (RCC) of maxillary lateral incisors (MxLI) of a mixed Swiss-German population were examined using micro-CT, 3D imaging, and a 4-digit system code indicating the main root canal from coronal to apical thirds and the main foramina number. Results: The most frequently observed RCC of MxLI were 1-1-1/1 (Vertucci I/Ve I, 80.0%), 1-1-2/2 (Ve V, 7.3%), 1-2-1/1 (Ve III, 6.4%), 2-1-1/1 (Ve II, 1.8%), and 1-1-1/2 (1.8%)(n = 110). Three additional RCC were observed less frequently (0.9%). The MxLI showed one physiological foramen in 89.1%, two in 9.1%, and seldom three (1.8%). Most accessory canals were identified in the apical third of a root (20.0%), and no accessory canals in 72.7% of the samples. Conclusions: Detailed information on the internal morphology of MxLI of a Swiss-German population is given. The most frequently observed RCC of MxLI is 1-1-1/1 (Ve I). However, accessory canals may occur in all apical thirds, and 20% of all teeth investigated showed a challenging RCC for clinical treatment. Clinical relevance: This study offers clinicians comprehensive data on MxLI morphology, emphasizing the significance of understanding varied RCC and accessory canal presence for improving root canal treatment outcomes. Over 25% of teeth exhibited complex RCC or accessory canals, influencing decisions during root canal treatment.

Objective: This study aimed to examine the morphology of maxillary canines (MxCs) by means of micro-computed tomography (micro-CT). Materials and methods: The root canal configurations (RCCs) of 97 maxillary canines of a mixed Swiss-German population were analyzed using micro-CT. After representing the internal morphology by 3-D software imaging, the RCC results were described using a four-digit system code indicating the main root canal from coronal to apical thirds and the main foramina number. Results: The most frequently observed RCCs of the MxC of the Swiss-German population were 1-1-1/1 (77.3%), followed by 1-1-1/2 (14.4%), 1-1-2/2 (4.1%), and finally 1-1-1/3 and 1-2-1/1 with 2.1% each. One physiological foramen was observed in 79.4% of the samples, two in 18.6%, and only 2.1% had three foramina. In 52.6% of the MxC samples, accessory and connecting canals were identified, with the majority located in the apical third of the root. Conclusions: This study contributes detailed information about the RCCs of MxC. The most prevalent RCC is 1-1-1/1, with accessory or connecting canals present in over half of the samples. However, it is noteworthy that in more than one-fifth of the examined samples, a particularly challenging RCC was observed. This should be considered when selecting treatment techniques. Clinical relevance: This study presents the root canal configurations in maxillary canines of a Swiss-German population and emphasizes the importance of influencing endodontic treatment decisions and outcomes.

Objectives: This systematic review analyzed the root canal morphology and configuration (RCC) of maxillary first premolars (Mx1Ps) and sex-specific differences based on existing literature. Methods: Registered in PROSPERO (CRD42023394460) and following PRISMA guidelines, systematic searches were conducted in five databases (Cochrane, Embase, LILACS, Scopus, MEDLINE via PubMed) using predefined MeSH terms. Additional studies were identified through cross-referencing. Studies on Mx1P RCCs were included, assessed using the AQUA tool. Data extraction focused on RCC prevalence, sex differences, root variations, and examination methods. Results: Of 865 studies, 86 were included, analyzing 31,325 teeth. The most common RCCs were 2-2-2/2 (IV, frequencies between 0.6–80.5%) and 1-1-1/1 (I, 1.1–72.0%). Mx1Ps primarily had two roots (7.1–96.2%) or one root (3.8–93.2%), with three-rooted variants being rare (0.4–6.5%). Males more frequently exhibited two- or three-rooted Mx1Ps with RCCs like 2-2-2/2 (IV; OR = 1.39 [1.22, 1.58]), and 1-1-3/3 (VIII; OR = 2.22 [1.59, 3.11]). Females showed higher frequencies of RCCs like 1-1-1/1 (I; OR = 0.71 [0.53, 0.96]), 2-2-1/1 (II; OR = 0.66 [0.57, 0.77]), 1-2-1/1 (III; OR = 0.70 [0.59, 0.83]), and 1-1-2/2 (V; OR = 0.81 [0.70, 0.95]). Conclusions: Mx1Ps predominantly have two roots and a 2-2-2/2 (IV) RCC. CBCT was the most used method, followed by staining and clearing. Clinicians should consider sex-specific and morphological variations.

Objective: Accurate knowledge of apical morphology is crucial for determining the correct working length and achieving an optimal seal, both of which are vital for long-term endodontic success. This review summarizes and evaluates the current literature on the physiological foramen, focusing on its diameter and the distance between the anatomical apex and the physiological foramen. Materials and Methods: A systematic literature search was conducted using the databases PubMed (via Medline), Embase, LILACS, and Scopus. Studies addressing the anatomy of the physiological foramen were selected based on predefined inclusion criteria. A total of 743 records were identified. After removing 103 duplicates, the titles and abstract of 640 records were screened, with 625 being excluded as irrelevant. Fifteen full texts were assessed and six excluded for not meeting inclusion criteria. Five additional articles were found through manual search. In total, 14 studies were included in the review. The risk of bias was assessed using the AQUA tool. Results: Considerable variation in the diameter of the physiological foramen was observed across the included studies, ranging from 0.15 mm to 0.43 mm depending on tooth type and location. Additionally, the distance between the anatomical apex and the physiological foramen varied from 0.1 mm to 1.2 mm. Conclusions: The results demonstrate considerable heterogeneity in the dimensions and position of the physiological foramen, with oval shapes occurring more frequently than round or irregular ones. Standardized definitions and consistent terminology are essential to improve comparability across studies and to enhance the clinical applicability of research findings. Recognizing these anatomical variations optimizes endodontic treatment outcomes and minimizes procedural errors.

Background/Objectives: The objective of this study was to investigate the internal morphology and root canal configurations (RCCs) of maxillary central incisors (MxCIs) in a Swiss–German population by means of micro-computed tomography (µCT). Methods: RCCs, main foramina, and accessory canals of MxCIs were examined using µCT and 3D imaging software. The root canal anatomy was classified according to three classification systems by Vertucci (Ve, 1984), Weine et al. (We, 1969), and Briseño-Marroquín et al. (Br, 2015). Results: The most common RCC observed among a total of 112 investigated single-rooted maxillary central incisors was Br 1-1-1/1 (97.3%, Ve I, We I), with a small percentage showing Br 1-1-1/2 (2.7%). One main foramen existed in 87.5% of the specimens, 8% had one accessory foramen, 3.5% had two, and a rare case had four accessory foramina (0.9%). Accessory root canals were mainly located in the middle and apical regions of the roots. Conclusions: Detailed insights into the root canal morphology of MxCIs in a Swiss–German population are provided. The predominant RCC was a simple root canal (Ve I, Br 1-1-1/1). However, accessory canals were detected in the middle and apical third in over 40% of the teeth examined. These anatomical features should be considered during endodontic treatment planning and execution.