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Aims: To calculate the relative distance between the incisive canal and maxillary central incisors using cone beam computed tomography (CBCT) and utilize the results in treatment planning in a clinical setting. Methods and Materials: A retrospective study was conducted on CBCT taken for other purposes in the Oral and Maxillofacial Radiology Department. All the quantitative measurements were performed between the incisive canal and both maxillary central incisors using CBCT on 61 subjects. The anterior-posterior measurements were taken on both sides and the average of both values was considered for the statistical analysis. All the linear measurements were performed on the axial plane at three different vertical reference points located on the sagittal plane. Statistical Analysis: The interexaminer reliability was tested by interclass correlation coefficient using two-way mixed and absolute agreement model. The comparison of linear measurement among each level was done by “Repeated measure ANOVA” and contrast method was used for pair-wise comparison when repeated measure analysis of variance (ANOVA) was significant. Results: The average anterior-posterior distance between the maxillary central incisor roots and the incisive canal measured was approximately 5–6 mm. The incisive canal width increases from the root apex level of maxillary central incisors (P3) to the oral opening level of the incisive canal (P1). Conclusions: The results of our study could be helpful in a clinical setting requires significant retraction of maxillary incisors or implant placement in maxillary anterior region.

Anterior teeth fracture is a common form of dental trauma that mainly affects children and adolescents. Maxillary incisors are the most commonly affected teeth. Loss of coronal tooth structure might affect esthetics and function. In recent decades, dentistry has shown many scientific and technological advances in restorative materials. However, no synthetic restorative material can replicate the natural tooth structure. Hence, the use of natural tooth as a restorative material has been suggested in literature and is termed as a biological restoration. The present case report represents the successful use of biological post and crown and was adequate with respect to adhesion, function, and esthetics with the follow-up period of 1 year. Hence, it may be concluded that the biological restoration, if feasible, is a cost-effective way to restore a damaged tooth with acceptable esthetics and tooth functions in the stomatognathic system.

Objective: To assess the labial and lingual alveolar bone thickness in adults with maxillary central incisors of different inclination by cone-beam computed tomography (CBCT). Methods: Ninety maxillary central incisors from 45 patients were divided into three groups based on the maxillary central incisors to palatal plane angle; lingual-inclined, normal, and labial-inclined. Reformatted CBCT images were used to measure the labial and lingual alveolar bone thickness (ABT) at intervals corresponding to every 1/10 of the root length. The sum of labial ABT and lingual ABT at the level of the root apex was used to calculate the total ABT (TABT). The number of teeth exhibiting alveolar fenestration and dehiscence in each group was also tallied. One-way analysis of variance and Tukey’s honestly significant difference test were applied for statistical analysis. Results: The labial ABT and TABT values at the root apex in the lingual-inclined group were significantly lower than in the other groups (p < 0.05). Lingual and labial ABT values were very low at the cervical level in the lingual-inclined and normal groups. There was a higher prevalence of alveolar fenestration in the lingual-inclined group. Conclusions: Lingual-inclined maxillary central incisors have less bone support at the level of the root apex and a greater frequency of alveolar bone defects than normal maxillary central incisors. The bone plate at the marginal level is also very thin. [Korean J Orthod 2015;45(5):245-252]

There are 3 types of crown shapes of the maxillary central incisors: type I-rectangular, type II-triangular and type III-oval. 250 study models of orthodontic patients of both sexes (125 males and 125 females) on the Dental Clinic in Nis were tested, with an attempt to determine the existence of variations in the crown shapes of maxillary central incisors. Gingival and incisal width and the crown height were measured by a digital nonius, as well as the proximal sides angle slope (Ø) according to Goose. Slightly more than a half of the examinees (52.40%) have a rectangular shape of the central incizor crown and a third (34%) has a triangular shape. Fewest examinees have an oval crown shape (13.60%). Similar distribution of crown shapes is found according to the examinees sex: a rectangular shape in 52% of boys and 52.80% of girls, a triangular shape in 36.80% of boys and 31.20% of girls and an oval shape in 11.20% of boys and 16% of girls. (Ø) angle is 7.56° in the total examinee sample, which coincides with the European population values. (Ø) angle is 6.95°in the triangular shape (6.51°in females and 7.39°in males); it is 8.20° in the oval shape (8.55° in females and 7.93° in males).

Background/purpose The Collum angle (the supplementary angle of the crown-root angle) of the maxillary central incisors is extremely important for patients who are undergoing orthodontic treatment and who are to receive an implant restoration. However, there is no report on the Collum angle in Taiwanese. Therefore, the purpose of this study was to evaluate the Collum angle of the maxillary central incisors in Taiwanese patients with different types of malocclusion. Materials and methods This study collected 124 samples of lateral cephalometric radiographs (38 radiographs from male patients and 86 from female patients). The age of sampled patients ranged 8–58 (mean, 19.9) years. Samples were divided into four groups according to the malocclusion type, and the Collum angle of the maxillary central incisors in each group was measured. A one-way ANOVA and the Scheffe test were used to compare whether or not the angle differed among the groups. Results The average value of the Collum angle was 6.1° ± 5.2° for class-I malocclusions, 5.3° ± 4.2° for class-II division-I malocclusions, 10.6° ± 4.4° for class-II division-2 malocclusions, and 5.6° ± 5.1° for class-III malocclusions. A statistical analysis showed that the Collum angle of the maxillary central incisors for patients with class-II division-2 malocclusions significantly exceeded values in the other three groups. Conclusion Compared to groups with other malocclusion types, the Collum angle of natural teeth for patients with class-II division-2 malocclusions was the greatest.

Fusion and gemination are developmental anomalies which are quite similar to each other but can be distinguished from each other if properly assessed. Fusion and gemination have been described as a result of developmental anomalies of dental tissues. The exact etiology is still unknown, but a genetic predisposition is suggested. This article highlights the importance of clinical and radiographic correlation in arriving at a definitive diagnosis.

Aim: The aim of this study is to evaluate the center of resistance of maxillary incisors during simultaneous intrusion and retraction. Subjects and Methods: In this study, the following steps were employed namely, (1) Preprocessing - the creation of geometric model, mesh generation and boundary conditions. (2) Postprocessing - the tooth movement and determination of center of resistance. Results: The center of the mid-sagittal plane approximately 6 mm apical and 4 mm posterior to a line perpendicular to the occlusal plane from the labial alveolar crest of the central incisor resistance for the maxillary four incisors was located within the. Conclusion: Finite element is a sound mechanical method of analysis as it was sufficient enough to provide insight into interactions between orthodontic forces, and dental tissues and reliability of this study. Further by using this study clinically, the center of resistance can be precisely located in single rooted tooth during orthodontic treatment.