Assessment of the relationship between labial gingival thickness and the underlying bone thickness in maxillary anterior teeth by two digital techniques

This study aimed to noninvasively assess the relationship between the labial gingival thickness (GT) and the underlying bone thickness (BT) of maxillary anterior teeth by two digital techniques. A total of 30 periodontally healthy participants with 172 maxillary anterior teeth were enrolled. GT and BT were measured at 2, 4 and 6 mm apical to the cemento-enamel junction (CEJ) by two digital techniques: M1—cone-beam computed tomography (CBCT) and M2—digital intraoral scanning (DIS) combined with CBCT. The Pearson's correlation coefficient was calculated to determine the correlation between GT and BT. A significant negative correlation was identified between GT and BT at 2 mm apical to the CEJ for central incisors (CI), lateral incisors (LI), and canines (CA) both by M1 and M2, while a weak negative correlation at 4 mm apical to the CEJ was observed by M1 for CA. No significant correlation was found at other sites by both M1 and M2. The labial BT was < 1 mm in most cases (85% of CI; 97% of LI; and 90% of CA). Within the limitation of this study, it was concluded that GT and BT seemed to be negatively correlated at 2 mm apical to the CEJ. Therefore, caution is warranted when implant restoration at the esthetic area of the anterior teeth.

Mini-Implant-Assisted Simultaneous Torquing Extrusion Retraction Spring for Ectopic Canines

Orthodontic management of ectopic canines is quite challenging and time consuming due to the presence of thin buccal cortical bone. Sectional mechanics provide distal and extrusive force on canine but without any torque control. So, palatal root torquing during canine retraction is needed to increase the buccal cortical bone thickness and to avoid bone dehiscence and gingival recession. This article describes an innovative spring which provides 3-dimensional control by simultaneous retraction, extrusion, and torquing of ectopic canine.

Protective Effects of Omega-3 Fatty Acid on Salt Induced Microscopic Changes in Femur of Female Sprague Dawley Rats

Osteoporosis is a major risk factor for fracture affects an enormous number of people of both genders worldwide. Objectives: To evaluate the shielding effect of omega-3 fatty acids on high salt induced histological findings in femur of rats. Study Design: Randomized Control Trial. Methodology: Female rats (n=30) were divided into three groups. Group A recieved high salt diet (8%NaCl) while group B recieved omega-3-treated salt loaded diet receiving 260 mg/kg body weight with 8% NaCl solution (8 weeks), control group received standard diet. Tissue from mid shaft and proximal end of femur was obtained to study the osteoblast number, mid cortical bone thickness and trabecular bone architecture. Statistical analysis: SPSS software, v 21 analyzed data. Results: Protective effects were seen in Omega-3 fatty acid supplemented experimental group B with increase in osteoblast number, mid cortical bone thickness and increase in microstructure of trabeculae. Conclusion: We concluded that dietary nutrient like omega-3 fatty acid is a helpful tool in eliminating adverse effects of salt on bones by enhancing osteoblastic activity thus reducing its remodeling. Keywords: Bone, Osteoblast, Omega-3 fatty acid, Salt and Trabeculae.

Localized, time-dependent responses of rat cranial bone to repeated mild traumatic brain injuries

While it is well-established that bone responds dynamically to mechanical loading, the effects of mild traumatic brain injury (mTBI) on cranial bone composition are unclear. We hypothesized that repeated mTBI (rmTBI) would change the microstructure of cranial bones, without gross skull fractures. To address this, young adult female Piebald Viral Glaxo rats received sham, 1x, 2x or 3x closed-head mTBIs delivered at 24h intervals, using a weight drop device custom built for reproducible impact. Skull bones were collected at 2 or 10 weeks after the final injury/sham procedure, imaged by micro computed tomography and analyzed at predetermined regions of interest. In the interparietal bone, proximal to the injury site, modest increases in bone thickness was observed at 2 weeks, particularly following 3x mTBI. By 10 weeks, 2x mTBI induced a robust increase in the volume and thickness of the interparietal bone, alongside a corresponding decrease in the volume of marrow cavities in the diploe region. In contrast, neither parietal nor frontal skull samples were affected by rmTBI. Our findings demonstrate time- and location-dependent effects of rmTBI on cranial bone structure, highlighting a need to consider microstructural alterations to cranial bone when assessing the consequences of rmTBI.

Influence of Voxel Size on CBCT Images for Dental Implants Planning

Objective This study was developed to evaluate the influence of voxel size on bone measurements for implant planning. Materials and Methods The research was performed by using edentulous synthetic human mandibles with different levels of bone resorption. For each mandible, height and bone thickness were measured with a digital caliper. The PaX-i3d device was used to acquire the volumes of the five mandibles, with 50kVp, 4 mA, and a voxel size of 0.08 mm. After the acquisition, the images were reconstructed in the software CS three-dimensional Imaging, with four different sizes of voxels: 0.1, 0.2, 0.3, and 0.4 mm. All volumes were analyzed by a single evaluator who performed measurements to obtain bone height and thickness, using the reference points that were considered in obtaining the gold standard. The data were analyzed by ANOVA with a significance level of 5%. Results There was no significant difference in the measurements obtained with different voxel sizes, both for bone height measurements and bone thickness. There was no statistically significant difference in measurements in thickness in comparison to the gold standard. Conclusion When necessary, to measure height and bone thickness, it is possible to recommend voxel images of larger size (0.40 mm) without compromising the quality of the patient's clinical planning.

Anatomical Patterns of the Nasopalatine Canal and Incisive Foramen in an African Setting – a Cross-sectional Study

Purpose: Surgical procedures revolving around the anterior maxilla are of great interest due to their debilitating facial aesthetics and nerve injury effects if complications arise. Hence, sufficient knowledge concerning the morphology and morphometry of the nasopalatine canal (NPC) and incisive foramen (IF) is necessary to prevent such complications from arising. Materials and Methods: Measurements of the NPC and the IF were carried out on 150 CBCT scans. The maxillary bone thickness anterior to the NPC was measured at 3 levels. Independent t-test and chi-square test were performed to determine the presence of sexual dimorphism. Results: The presence of one Stenson’s foramen was most prevalent. The mean length of NPC was 13.21 ± 3.25 mm with significantly longer canals in males. The most prevalent shape of NPC was cylindrical in sagittal view and a single canal in coronal view. The mean angulation of NPC was 118.42° to the horizontal plane. The average dimensions of the IF were 3.53 mm and 3.07 mm in the anteroposterior and mediolateral diameter respectively while the most common shape was round. The anterior maxillary bone was thicker in males and generally reduced in thickness from the anterior nasal spine superiorly towards the alveolar crest inferiorly. Conclusion: This study highlights the anatomical characteristics of the NPC and IF, with significant sexual dimorphism observed regarding the number of Stenson’s foramina, length of NPC, shapes of the NPC and IF as well as alveolar bone thickness anterior to NPC.

Cortical bone thickness of the distal radius predicts the local bone mineral density

Aims The distal radius is a major site of osteoporotic bone loss resulting in a high risk of fragility fracture. This study evaluated the capability of a cortical index (CI) at the distal radius to predict the local bone mineral density (BMD). Methods A total of 54 human cadaver forearms (ten singles, 22 pairs) (19 to 90 years) were systematically assessed by clinical radiograph (XR), dual-energy X-ray absorptiometry (DXA), CT, as well as high-resolution peripheral quantitative CT (HR-pQCT). Cortical bone thickness (CBT) of the distal radius was measured on XR and CT scans, and two cortical indices mean average (CBTavg) and gauge (CBTg) were determined. These cortical indices were compared to the BMD of the distal radius determined by DXA (areal BMD (aBMD)) and HR-pQCT (volumetric BMD (vBMD)). Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC) were used to compare the results and degree of reliability. Results The CBT could accurately be determined on XRs and highly correlated to those determined on CT scans (r = 0.87 to 0.93). The CBTavg index of the XRs significantly correlated with the BMD measured by DXA (r = 0.78) and HR-pQCT (r = 0.63), as did the CBTg index with the DXA (r = 0.55) and HR-pQCT (r = 0.64) (all p < 0.001). A high correlation of the BMD and CBT was observed between paired specimens (r = 0.79 to 0.96). The intra- and inter-rater reliability was excellent (ICC 0.79 to 0.92). Conclusion The cortical index (CBTavg) at the distal radius shows a close correlation to the local BMD. It thus can serve as an initial screening tool to estimate the local bone quality if quantitative BMD measurements are unavailable, and enhance decision-making in acute settings on fracture management or further osteoporosis screening. Cite this article: Bone Joint Res 2021;10(12):820–829.