Mean Bone Density in Interadicular Areas of Maxilla among Patients Visiting Dental Unit of a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Introduction: A close relationship occurs between the type of bone density and the success of orthodontic mini-implant. The aim of this study was to find out the mean bone density in interradicular areas of the maxilla among patients visiting dental unit of a tertiary care centre. Methods: A descriptive cross-sectional study was performed at the Department of Orthodontics and Dentofacial Orthopedics at a tertiary care centre from 15 January 2022 to 28 June 2022 after taking ethical approval from the Institutional Review Committee (Reference number: UCMS/IRC/175/21). Data was collected from scan reports obtained with a computed tomography scanner. Bone density was measured at 6 mm height from the alveolar crest. Convenience sampling was done. Point estimate and 95% Confidence Interval were calculated. Results: Out of 70 patients, mean bone density at interradicular areas of maxilla was 992.31±204.20 HU (944.46-1040.13, 95% Confidence Interval). Between central and lateral incisor 50 (71.44%) had D2 type of bone density. Conclusions: The mean bone density in inter radicular areas of the maxilla among patients visiting the dental outpatient department was similar to other studies done in similar settings. Keywords: bone density; prevalence; prostheses and implants.

Comparison of Changes in Intraoral Dynamic Space (Donders Space) with Myofunctional Therapy in Skeletal Class II Division 1 Malocclusion: An In Vivo Study.

AIM: To evaluate the changes in the intraoral dynamic space with myofunctional therapy in skeletal class II division 1 malocclusion using three-dimensional digital volume tomography (3D-DVT). MATERIALS AND METHODS: The study type is observational and the duration of intervention was 3 years. Dental casts obtained from 20 samples of 11-14 years age-group were collected and 3D-DVT scans were performed prior to and after the myofunctional therapy. The parameters depicting the arch perimeter, arch width, arch length, arch shape, and arch volume on dental cast were used in the study using several linear and volumetric measurements. All parameters were compared before and after myofunctional therapy using t-test. RESULTS: The Intraoral volume before myofunctional therapy (T0) was 5.59 mL and after myofunctional therapy (T1), it was 7.22 mL. Significant changes were seen in intraoral volume, arch perimeter, arch length, and intercanine and intermolar arch width and the arch shape. Linear and volumetric measurements were increased after myofunctional therapy. CONCLUSION: Myofunctional appliances lead to an expansion in the anteroposterior and sagittal direction thus increasing the Donders space and leading to proper formation of dental arches and proper positioning of the teeth. CLINICAL SIGNIFICANCE: Myofunctional therapy is an effective method of increasing arch width, length, and volume. This therapy can be used in routine practices in young children with constricted arch and improvement in facial esthetic.

Evaluation and comparision of the shear bond strength of rebonded orthodontic brackets with air abrasion, flaming, and grinding techniques: an in vitro study.

AIM: To evaluate and compare in vitro the shear bond strength of rebonded orthodontic brackets among the three most frequently used rebonding methods--sandblasting, direct flaming, and grinding with a green stone bur. The surface characteristics of new and rebonded bracket bases were also compared using scanning electron microscopy (SEM). METHODS: The sample used in the present study comprised 60 extracted human premolars bonded with brackets. The sample was divided into three groups (each n = 20; sandblasting, direct flaming, and grinding with a green stone bur). SEM was used to compare the surface characteristics of the new and rebonded bracket bases for all three groups. RESULTS: The Z test for the direct flaming and grinding groups revealed statistically significant bond strength (P < .05). The ANOVA test for all three groups showed P < .05, which is statistically significant. SEM for the sandblasting method showed well-defined retentive areas. CONCLUSION: When rebonding brackets, sandblasting the bracket base yields the highest bond strength.