Aesthetic and functional rehabilitation of missing teeth in growing patients with mini-implants: a contemporary approach

Growing patients with missing teeth in aesthetically prominent areas pose a challenge in restoration of the same. Fracture of anterior teeth in these age groups is very common and often requires removal of the affected tooth. After the decision to maintain the space in the dental arch is made, some other factors have to be borne in mind before restoration of the space. Continuing growth of the alveolar bones, questionable cooperation of the patient and aesthetics are deciding factors that may limit the treatment options. The effective use of mini-implants for space preservation, alveolar bone width maintenance and aesthetics represents an elective way of successfully treating such cases. The aim of this article is to describe as well as highlight the advantages and ease of the procedure with the help of two clinical cases.

Using Cone-Beam Computed Tomography to Assess Changes in Alveolar Bone Width around Dental Implants at Native and Reconstructed Bone Sites: A Retrospective Cohort Study

The aim of this study was to use a cone-beam computed tomography (CBCT) to assess changes in alveolar bone width around dental implants at native and reconstructed bone sites before and after implant surgery. A total of 99 implant sites from 54 patients with at least two CBCT scans before and after implant surgery during 2010–2019 were assessed in this study. Demographic data, dental treatments and CBCT scans were collected. Horizontal alveolar bone widths around implants at three levels (subcrestal width 1 mm (CW1), subcrestal width 4 mm (CW4), and subcrestal width 7 mm (CW7)) were measured. A p-value of < 0.05 indicated statistically significant differences. The initial bone widths (mean ± standard deviation (SD)) at CW1, CW4, and CW7 were 6.98 ± 2.24, 9.97 ± 2.64, and 11.33 ± 3.00 mm, respectively, and the postsurgery widths were 6.83 ± 2.02, 9.58 ± 2.55, and 11.19 ± 2.90 mm, respectively. The change in bone width was 0.15 ± 1.74 mm at CW1, 0.39 ± 1.12 mm at CW4 (p = 0.0008), and 0.14 ± 1.05 mm at CW7. A statistically significant change in bone width was observed at only the CW4 level. Compared with those at the native bone sites, the changes in bone width around implants at reconstructed sites did not differ significantly. A significant alveolar bone width resorption was found only at the middle third on CBCT scans. No significant changes in bone width around implants were detected between native and reconstructed bone sites.

Autogenous Bone and Bioactive Glass around Implants Placed Simultaneously with Ridge Splitting for the Treatment of Horizontal Bony Defects: A Randomised Clinical Trial

Objective. To compare using autogenous bone with or without bioactive glass in ridge splitting of horizontal bone defects combined with simultaneous implant placement. Materials and Methods. In control group, bone expansion was performed and autogenous bone was used to augment the intercortical bone defect. In study group, autogenous bone was mixed with bioactive glass (1 : 1 in volume). In both groups, the implants were inserted simultaneously with ridge splitting. Six months following implant insertion, bone width and height were evaluated. Statistical analysis utilizing paired Student’s t-test was used for comparing results within the same group, whereas independent samples t-test was used for intergroup variables comparison. Results. The mean bone width and labial and mesiodistal crestal bone height values were increased significantly in both groups from baseline to 6 months postoperatively. Comparing the two groups showed nonstatistical significant difference regarding the labial crestal bone loss, while the ridge width gain values were significantly higher in the study group than in the control group. The mesiodistal bone loss was significantly higher in control group than in study group. Conclusion. Autogenous bone was mixed with bioactive glass (1 : 1 in volume) to fill intercortical defect created after ridge splitting to decrease peri-implant bone resorption associated with autogenous bone alone. This trial is registered with clinical trial registration: NCT04814160.

Morphological changes of the anterior alveolar bone due to retraction of anterior teeth: a retrospective study

Backgroud To analyze the morphological changes of the anterior alveolar bone after the retraction of incisors in premolar extraction cases and the relationship between incisor retraction and remodeling of the alveolar base represented by points A and B displacements. Methods Pre- (T0) and post-treatment (T1) lateral cephalograms of 308 subjects in the maxilla and 154 subjects in the mandible who underwent the orthodontic treatment with extraction of 2 premolars in upper or lower arches were included. Alveolar bone width and height in both the maxillary and mandible incisor area were measured at T0 and T1 respectively. By superimposing the T0 and T1 cephalometric tracings, changes of points A and B, and the movement of the incisors were also measured. Then the correlation between incisor movement and the displacements of points A and B was analyzed. Results The alveolar bone width (ABW) showed a significant decrease in both maxilla and mandible (P < 0.001) except the labial side of the mandible (P > 0.05). The alveolar bone height (ABH) showed a significant increase in the labial side of maxilla and a significant decrease in the lingual side of maxilla and mandible. A strong positive correlation was verified between incisor movement and position changes of points A and B in both horizontal and vertical directions. Conclusions Anterior alveolar bone width and height generally decreased after orthodontic treatment. Incisor retraction led to significant position changes of points A and B. The decrease of anterior alveolar bone due to significant incisor retraction should be taken into account in treatment planning.

Measurement of inter radicular bone width in different growth patterns for determining safe zone for placement of miniscrew implants – A cone beam computed tomography study

To measure the inter-radicular spaces in both arches for miniscrew implant placement and to determine the most reliable sites using CBCT. A CBCT radiograph was taken for 75 subjects that met with inclusion criteria. They were divided into 3 categories- Hypodivergent, average, and hyperdivergent group. Images were calibrated by using software and printed as a film. Interradicular space on the right side of the jaw was measured in the sagittal plane after assuming the jaw to be symmetrical. Bucco-lingual and mesiodistal width were measured up to desired bone levels. In vertical growth pattern, in posterior maxilla highest mesiodistal width between 2nd premolar and 1st molar at 7mm. In the mandible, it was between the 1st and 2nd molar at 11mm. In horizontal growth pattern, in posterior maxilla highest mesiodistal width between 1st and 2nd premolar, and mandible it was between 1st and 2nd molar at 11mm. In average growth pattern, in posterior maxilla highest mesiodistal width between 2nd premolar and 1st molar and 1st molar at 7mm. In the mandible, it was between the 1st and 2nd molar at 11mm. The importance of the relationship between the growth pattern and the availability of inter radicular space may aid the clinician in planning appropriate surgical sites for miniscrew implant placement.

Case Report: Postmortem bone histomorphometric analysis in a 38-year-old Japanese man with immobilization osteoporosis because of orthostatic hypotension related to amyloid light chain amyloidosis

We performed a postmortem bone histomorphometric analysis of iliac bone on a 38-year-old man who had been bedridden for the nine months before his death because of orthostatic hypotension and severe malnutrition related to amyloidκ-light-chain amyloidosis. Cancellous bone volume was greatly decreased, with a trabecular bone volume to total bone volume ratio of 6.77% (normal value, 19.56% ± 5.62%). Trabecular thinning was also apparent, with a trabecular thickness of 78.9 μm (normal value, 131.3 ± 28.1 μm), although the trabecula was still preserved. Cortical bone width was normal, although areas of porosity area were clear throughout the cortical bone. Our findings indicate that immobilization-related osteoporosis may be closely associated with loss of cancellous bone.

Defining Critical Glenoid Bone Loss in Posterior Shoulder Capsulolabral Repair

Background: Although critical bone loss for anterior instability is well defined, a clinically significant threshold of posterior bone loss has not been elucidated. Hypothesis: Patients with failed arthroscopic posterior shoulder capsulolabral repair will have increased posterior glenoid bone loss with a defined critical threshold. Study Design: Case control study; Level of evidence, 3. Methods: Athletes older than 18 years with unidirectional posterior instability treated with arthroscopic repair were evaluated at 2-year minimum follow-up. Failure was defined as revision surgery, American Shoulder and Elbow Surgeons (ASES) score of <60, or subjective stability score of >5. Magnetic resonance imaging (MRI) measurements from 19 patients with failed arthroscopic posterior shoulder capsulolabral repair were compared with 56 patients whose surgery was successful. MRI measures included glenoid version, labral version, glenoid width, labral width, percentage bone loss using the circle technique, labral height, percent subluxation, and recently described measures of defect slope, bone loss angle, and defect length. The P value threshold was set at .05, and a multivariable logistic regression analysis was performed for evaluation of risk of surgical failure. Results: Smaller glenoid width and greater percentage glenoid bone loss (25.5 ± 0.68 mm vs 28.8 ± 0.47 mm; P < .001; 6.8% ± 0.64% vs 4.6% ± 0.43%; P = .008) were seen in those patients with failed surgery. There was no difference in glenoid version or other measurements between the failures and nonfailures. A cutoff of 11% glenoid bone loss resulted in a 10.4 times statistically higher surgical failure rate, while a 15% bone loss resulted in a 24.4 times statistically higher failure rate. Six patients had >11% bone loss (range, 11.1 to 19.3) and 1 patient had >15% bone loss. Conclusion: Risk factors for failure of arthroscopic posterior shoulder capsulolabral repair include smaller glenoid bone width and greater percentage of glenoid bone loss. A threshold of 11% posterior glenoid bone loss implicated a 10 times higher surgical failure rate, while a threshold of 15% led to a 25 times higher surgical failure rate. Surgical failure of posterior capsulolabral repair, however, is relatively rare as it is an overall successful intervention.

Histomorphometric Evaluation of Socket Preservation Using Autogenous Tooth Biomaterial and BM-MSC in Dogs

This study is aimed at assessing the dimensional alterations occurring in the alveolar bone after premolar extraction in dogs with histomorphometric and histological analysis. After atraumatic premolar extraction, tooth-derived bone graft material was grafted in the extraction socket of the premolar region in the lower jaws of six dogs in two experimental groups. In the second experimental group, BM-MSCs were added together with the graft. The control was left untreated on the opposite side. After twelve weeks, all six animals were sacrificed. Differences in alveolar bone height crests lingually and buccally, and alveolar bone width at 1, 3, and 5 mm infracrestally, were examined. Histologic study revealed osteoconductive properties of tooth biomaterial. A statistically significant difference was detected between the test and control groups. In the test groups, a reduced loss of vertical and horizontal alveolar bone dimensions compared with the control group was observed. Tooth bone graft material may be considered useful for alveolar ridge preservation after tooth extraction, as it could limit the natural bone resorption process.