Skeletal and Dental Morphological Characteristics of the Maxillary in Patients with Impacted Canines Using Cone Beam Computed Tomography: A Retrospective Clinical Study

The aim of this study is to analyze the skeletal and dentoalveolar morphological characteristics of the maxillary in subjects with a unilateral palatally impacted canine using Cone Beam Computed Tomography (CBCT). A retrospective clinical study was conducted of 100 adult patients divided into two groups: one consisting of patients with a unilaterally palatally impacted maxillary canine (GI), with the subgroups in the right and left hemiarches (GI-R and GI-L), and the second, without impacted canine, as the control group (CG). The CBCT measured skeletal variables (maxillary basal width and alveolar crest height) and dentoalveolar variables (inclination of the upper incisor, tooth lengths of incisors and canines, arch length, tooth size and bone dental discrepancy). In skeletal variables, statistically significant differences were found in alveolar crest height (ACH) in all groups and subgroups (p < 0.01). In the dentoalveolar variables, there were differences in the angle of the upper incisor (II) and lateral incisor length (LLIL) between the GI and GC and the angle of the upper incisor (II′), arch length (AL′) and arch length-tooth size discrepancy (ATD′) among the GI subgroups (p < 0.01). There are skeletal and dentoalveolar differences in patients with unilateral palatally impacted maxillary canines, with lower angular and linear measurements compared with patients without impaction.

Development of a Computational Tool for the Estimation of Alveolar Bone Loss in Oral Radiographic Images

The present study evaluated a newly developed computational tool (CT) to assess the alveolar bone space and the alveolar crest angle and compares it to dentist assessment (GT). The novel tool consisted of a set of processes initiated with image enhancement, points localization, and angle and area calculations. In total, we analyzed 148 sites in 39 radiographic images, and among these, 42 sites were selected and divided into two groups of non-periodontitis and periodontitis. The alveolar space area (ASA) and alveolar crest angle (ACA) were estimated. The agreement between the computer software and the ground truth was analyzed using the Bland–Altman plot. The sensitivity and specificity of the computer tool were measured using the ROC curve. The Bland–Altman plot showed an agreement between the ground truth and the computational tool in all of the parameters assessed. The ROC curve showed 100% sensitivity and 100% specificity for 12.67 mm of the alveolar space area. The maximum percentage of sensitivity and specificity were 80.95% for 13.63 degrees of the alveolar crest angle. Computer tool assessment provides accurate disease severity and treatment monitoring for evaluating the alveolar space area (ASA) and the alveolar crest angle (ACA).

Fracture Resistance in Non-Vital Teeth: Absence of Interproximal Ferrule and Influence of Preparation Depth in CAD/CAM Endocrown Overlays—An In Vitro Study

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.

Crown root fracture imaging on Cone Beam Computed Tomography

Objectives: This case report is aimed to describe the features of CBCT in assessing tooth fracture. Case Report: A 50-year-old man came with complaints of discomfort in the right lower jaw area, especially when used for chewing. The results of the percussion test were positive. CBCT examination showed that there was a radiolucent image of the enamel in the middle of the crown root to the 1/3 apical of the mesial and distal roots of tooth 47 which resembled a fracture line. The fracture line also appears to have reached the pulp. In addition, there is a well-defined radiolucent appearance with an irregular shape along the root from the buccal to lingual alveolar crest and accompanied by a decrease in the alveolar crest. The fracture that occurred in this case was from the enamel to the apical and involved the pulp, thus the radiodiagnosis on tooth 47 was a complicated crown root fracture with lateral periodontal cyst. Conclusion: CBCT can be used to help identify tooth fractures by obtaining a more accurate and useful value in differentiating conditions associated with fractures. CBCT provides data on the size and length of the fracture line and the size of the lesion.

Comparison of radiographic changes in the alveolar crest after extraction of fully and partially erupted premolars during orthodontic treatment: A retrospective analytical study

Background. The alveolar process plays an essential role in providing dental support and gradually disappears with tooth loss. Space deficiency can cause one premolar to remain semi-erupted adjacent to a fully-erupted premolar. During orthodontic treatment, each of these premolars can be extracted. This retrospective study aimed to compare radiographic changes of the alveolar crest due to orthodontic movements of fully-erupted and semi-erupted premolars into the extraction sites before and after treatment. Methods. The patients were divided into the fully-erupted premolar extraction (first) group and the semi-erupted premolar extraction (second) group. The distance between the cementoenamel junction (CEJ) and the alveolar crest, from the distal aspect of the canine to the mesial aspect of the first molar, was measured on panoramic radiographs of 78 patients (39 from each group) before and after treatment with a digital caliper. Changes in the alveolar crest were compared between the two groups. Finally, the height differences of the alveolar crest in mesial and distal aspects of the remaining premolars in both groups were calculated at the end of treatment. Descriptive statistical analyses and paired and independent t tests were used in the study. Results. The distance from the CEJ to the alveolar crest at mesial and distal aspects in the first group and the distal aspect of the extraction site in the second group increased significantly. However, changes at the mesial aspect were not significant in the second group. Comparing the alveolar crest height between the two groups and between the mesial and distal aspects of the remaining premolar tooth indicated no significant differences. Conclusion. No significant difference was observed between the extraction of a fully-erupted or semi-erupted premolar to obtain greater alveolar height.

Optimal sites for orthodontic anchor screw placement using panoramic images: risk of maxillary sinus perforation and contact with adjacent tooth roots during screw placement

Objectives This study investigated the safety of orthodontic anchor screw (OAS) placement by examining the morphology and degree of depression of the maxillary sinus adjacent to the alveolar bone between the maxillary molars. Methods We reviewed panoramic and CT imaging data of 25 patients. First, the morphology of the maxillary sinus adjacent to the alveolar bone between the maxillary molars on panoramic images was classified into three types: non-depressed sinus, funnel-like sinus depression, and sawtooth-like sinus depression. Then, the distance from the maxillary buccal bone to the maxillary sinus or to the maxillary lingual bone and the distance between the roots of the maxillary second premolar and first molar at heights of 5, 6.5, and 8 mm from the alveolar crest were measured on CT images and compared between the three sinus morphology groups. Results The sawtooth-like depression group had significantly smaller bone thickness than the other two groups, with mean thickness of < 4 mm at any height from the alveolar crest. The funnel-like depression and non-depression groups had mean bone thickness of > 8 mm at any height from the alveolar crest. Conclusions Sawtooth-like sinus depression had increased risk of maxillary sinus perforation, suggesting that OAS placement in this region should be avoided. In contrast, OAS placement between 6.5 and 8 mm from the alveolar crest is advisable in patients with funnel-like sinus depression and at a site > 8 mm from the alveolar crest in those with a non-depressed sinus.

Buccal Bone Thickness in Anterior and Posterior Teeth—A Systematic Review

(1) Background: Immediate dental implant placement has been a subject of great interest over the last decade. Here, information regarding the anatomy and bone thickness of the jaw prior to dental implant placement is crucial to increase the surgery’s success and the patient’s safety. The clinical premises for this approach have been controversially discussed. One of those heavily discussed premises is a buccal bone thickness of at least 1 mm thickness. This meta-analysis aims to systematically review buccal bone thickness (BBT) in healthy patients. Thus, the feasibility of immediate dental implant placement in daily practice can be assessed. (2) Methods: A search in the electronic databases was performed to identify articles reporting on BBT that was measured by computed tomography in adults. (3) Results: We were able to find 45 studies, including 4324 patients with 25,452 analyzed teeth. The analysis showed a BBT at the alveolar crest of 0.76 ± 0.49 mm in the maxillary frontal and of 1.42 ± 0.74 mm in the maxillary posterior region. In the mandible, the average measured values were similar to those in the maxilla (front: 0.95 ± 0.58 mm; posterior: 1.20 ± 0.96 mm). In the maxillary frontal region 74.4% and in the mandibular frontal region 61.2% of the crestal buccal bones showed widths <1 mm. (4) Conclusions: In more than 60% of the cases, the BBT at the alveolar crest is <1 mm in maxillary and mandibular frontal regions. This anatomic data supports careful pre-surgical assessment, planning of a buccal graft, and critical selection of indication for immediate implant placement, especially in the maxillary and mandibular frontal and premolar region.

Characteristics and Prevalence of Anterior Buccal Mandibular Depression Area in Cone Beam Computed Tomography Images

Summary Background/Aim: The purpose of this study was to assess the anterior buccal mandibular depressions (ABMD) prevalence and clinical characteristics at cone beam computed tomography images (CBCT). Material and Methods: 198 CBCT images with minimal depression between the mandibular molars were evaluated retrospectively. Presence and location of ABMD, its maximum depth, maximum width, cortical width, if any, alveolar crest width at maximum depth, the distance between maximum depth and alveolar crest apex and existing teeth in the relevant region were examined in cross-sectional views. Panoramic radiography of ABMD patients was evaluated for trabecular pattern and radiopacity to determine the area of interest. The possible lingual depression area on the maximum depth of ABMD slice was investigated and the same measurements for ABMD was performed. The presence of aperture / foramen in the ABMD area was also investigated. Results: The prevalence of ABMD was found as 43.43% where 82 cases were at bilateral side and 4 cases were only at left side. Lingual depression was observed in 20.7% right side and 30.2% left side of the ABMD cases. There was no statistically significant difference for maximum depth between different age groups. Most frequent location was observed in lateral and canine region (27.4%) followed by lateral-first premolar area (25.6%). Least frequent location was at canine-second premolar area (1.2%). Conclusions: ABMD is a lesser known area with a high prevalence observed on CBCT images. The detectability of the area on panoramic radiographs is limited. Clinicians should take into consideration ABMDs’ characteristics to avoid confusion with periapical pathologies. Failure to detect these areas before implant surgeries may cause complications. For this reason, it is important to be examined in detail for ABMD before surgery.

The effect of horizontal and vertical dimensions of the interproximal space on the existence of interdental papillae – A clinical study

The aim of the present study was to determine the existence of inter dental papilla according to the vertical dimension, horizontal dimension and the combined effects of the vertical and horizontal dimensions of the interproximal space on the existence of interdental papilla.182 interdental sites of 42 periodontitis patients undergoing open flap debridement were included in the study. The existence of interdental papilla was determined based on the Papilla Presence Index (PPI). The vertical dimension (VD) was measured from the alveolar crest to the contact point using UNC-15 probe. Horizontal dimension (HD) was measured from the mesial surface of the distal tooth and the distal surface of the mesial tooth at the level of the alveolar crest using castroviejocaliper. Statistical analysis was done by using independent ‘t’ test, Pearson’s Chi-square test and Trend Chi-square test. The existence of papilla was significantly higher in VD ≤ 5mm (91.5%) compared to VD &#62; 5mm (9.8%) [p&#60; 0.0001]. The existence of papilla was significantly higher in HD &#60; 2mm (97%) compared to HD ≥ 2mm (1.2%) [p&#60; 0.0001]. The contribution of both vertical dimension and horizontal dimension to the existence of papilla was about 61.6% and thus the existence of papilla may be influenced by various other factors (about 38.4%) which were not included in this study.The vertical and horizontal dimensions of the interproximal space gains significance in determining the existence of papilla and further research is needed to analyze the other factors influencing the papilla.