2023 NESO Cup Poster Competition

2023 NESO Cup Poster Competition


Ultrasound Characterization of Alveolar Bone Changes During Orthodontic Tooth Movement

Ashleigh Alex1, Michelle Skelton1, Scott Noh1, Sunil Wadhwa1, Seung Song2
1Division of Orthodontics, College of Dental Medicine, Columbia University, New York, New York. 2Division of Prosthodontics, College of Dental Medicine, Columbia University, New York, New York.

Objectives: The aim of this pilot study is to observe patients undergoing orthodontic treatment via fixed appliances and to utilize ultrasound sonography to quantify the amount of
vertical bone loss on the facial surface of the maxillary anterior teeth.

Methods: This study examined 10 orthodontic patients who were starting orthodontic treatment for any type of malocclusion with the straight wire appliance. Ultrasonography was
performed on the facial surface of the maxillary anterior teeth at the time of baseline and at 1 month. The distance from the inferior base of the bracket to the tip of the facial crestal bone was
measured directly on the ultrasound. Measurements were made by three independent investigators.

Main Results: A significant decrease in facial vertical bone level from Baseline to Visit 1 of 0.20mm was observed. There was a significant, high, and positive degree of Intraexaminer and
Interexaminer correlations. Data & Statistics: A t-test was performed to evaluate mean change in bone loss across patients from month 1 relative to their baseline visit. A Pearson correlation coefficient to evaluate Intraexaminer and Interexaminer reliability was performed.

Conclusions: In our sample size of 10, we found that there is a significant decrease in the facial vertical bone level from Baseline to Visit 1 of 0.20mm. These findings can be used to help power
larger sample size studies which examine the vertical bony changes seen with specific movements of teeth, such as flaring or intrusion.

The effect of Object’s Boundary Geometry & Off-Center Location: 3D CBCT Measurements

Arash Poursattar Bejehmir DDS1, Anita Gohel BDS, PhD2, Melih Motro DDS, PhD3
1. Postgraduate Student, Orthodontics & Dentofacial Orthopedics, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA  2. Professor, Department chair, Oral & Maxillofacial Diagnostic Sciences, University of Florida, College of Dentistry, Gainesville, FL 3. Clinical Associate Professor, Orthodontics & Dentofacial Orthopedics, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA

Objectives: CBCT images has been used increasingly to segment and measure airway and bony head and neck structures’ volumes for orthodontic & orthognathic purposes. A specific subclass of partial volume defect (exponential edge-gradient effect (EEGE)), by which, volumetric measurement of objects with sharp contours and abrupt geometry transformation in the borders may increase errors. Also, “Halation defects” may cause higher resolution at the center of the volume and considerably more distortion at the periphery of scanned volumes and reduce the model accuracy.

Methods and materials: 5 different 3D-printed objects as gold standards (cuboid, solid cylinder, large rectangular cube, cone, and a hollow cylinder) with different boundary geometries were scanned with a i-CAT Next Generation Scanner. Objects were positioned centrally or peripherally in the field of view. DICOMs were imported to Mimics (1), Invesalius (2), Amira-Avizo (3), Analyze (4) ITK-SNAP (5), and InVivo (6) softwares for semi-automatic segmentation with interactive thresholding method.

Results & Statistics: A high observer agreements ((ICC >0.99) obtained. The mean absolute percentage errors for softwares 1,2,3,4,5, and 6 were -0.07%, -0.02%, -0.22%, -0.03%, -0.04%, and -0.08%, respectively. Measured volumes were not statistically related to applied software (F(5,144)=0.018, p=1). Centrally vs. peripherally positioning did not differ the measures (P>0.05). A Kruskal-Wallis statistics showed significant differences between error precents for various objects (χ2(4) = 46.67, p = 0.001) with a mean rank error percent of 66.2,73.83,44.10, 74.73 and 118.63 for cuboid, solid cylinder, large cube, cone, and hollow cylinder, respectively.

Conclusions: Parasagittal vs. sagittal position of objects (e.g., symphysis vs. condyles) and sharp boundaries vs. round borders (e.g., knife edge crestal bone vs. condylar head) did not increase the error. However, air interface is a significant source of inaccuracy.

Ovariectomies and Artificial Female Sex Hormones in Orthodontic Tooth Movement

Stefani Berry, Paul Emile Rossouw, Abdul Basir Barmak, Shaima Malik

University of Rochester Eastman Institute for Oral Health, Rochester, NY

Objective: The objective is to compose a systematic review in order to assess how ovariectomies or the administration of artificial female sex hormones affects orthodontic tooth movement (OTM) with fixed appliances.

Materials and Methods: An electronic search of indexed databases was completed without language or time restrictions up to and including June 2022. The following eligibility criteria was utilized: (i) prospective original controlled clinical studies; (ii) experimental studies on animal models; (iii) subjects undergoing orthodontic therapy with fixed appliances; (iv) clearly defined control groups not undergoing ovariectomy or administration of artificial female sex hormone; and (v) studies with experimental groups receiving the intervention of interest (ovariectomy or artificial female sex hormone administration). Review articles, letters to the editor, case reports, case series, commentaries, cross sectional studies, retrospective studies, and studies with no well-defined control group were excluded. The quality of the available evidence and risk of bias within the studies were assessed. All disagreements were resolved via discussion.

Results: Seven animal studies were included in the systematic review. Five studies reported that ovariectomy increased that rate of OTM. Two studies reported that the administration of artificial female sex hormones decreased the rate of OTM.

Conclusion: There is an association between ovariectomies and OTM and between administration of artificial female sex hormones and OTM. The full extent of the association remains unclear due to the biases that are present and the length of time of orthodontic therapy.

Artificial Intelligence (Deep Learning) for cephalometric landmark identification

Dr. Katherine Chapman (Primary)1, Gaurav Sinha2, Maayan Eden Schmidt3, Madhur Upadhyay (Faculty Mentor)4

1. 3rd Yr, Orthodontic resident, University of Connecticut Health; 2. Computer Vision, Artificial Intelligence, and Software Development Alum UBC, Canada; 3. Third Year Dental student, University of Connecticut Health; 4. Director, Center for Orthodontics, Associate Professor, University of Connecticut Health

Objectives: 1) Develop an AI based image recognition model for automatic localization of landmarks on patient x-rays. 2) Analyze the performance of the AI algorithm to current standards of landmark identification. 3) Design a web application for clinicians to. access the technology.

Methods: Lateral cephalograms were collected from six centers across the world (6000 radiographs). All data and location of collection were deidentified. For computational power, graphic processing unit’s (GPU’s) were acquired & Amazon web services (AWS) were used. Digital ocean was used to provide the hosting service, COCO Annotator was used as a web-based annotation platform for the human experts (5 orthodontists with five or more years of experience) to complete landmark annotation on all cephalograms. 27 commonly used landmarks were annotated.

Results: Average error between experts was 0.73%, while between experts and AI it was 0.77%. Detailed results can be found at:
Data and statistics: The landmarks with the highest variability were O with 1.27%, PgS with 1.22%, and G with 1.19%. The landmarks with the lowest variability were Uc with 0.27%, Lc with 0.35%, and S with 0.38%.

Conclusions: 1) The directionality of errors suggest the model is performing consistent with the expectation of a human orthodontist. 2) The model has out-performed two leading models in two different clinical measures and a small sample of practicing orthodontists & residents, suggesting it’s clinical applicability and potential as a clinical, teaching and research adjunct. 3) Free access at (Username: grant, Password: neso2023)

Influence of Invisalign’s Precision Bite Ramps on Deep Bite Correction and Root Length in Adults

Husain F, Warunek S, Gurav A, Al-Jewair T

New York University at Buffalo, Buffalo, NY

Objectives: To assess the influence of precision bite ramp use on skeletal deep overbite correction and root length in adults treated with Invisalign.

Methods: This is a retrospective comparative study of 60 adults with skeletal deep overbites. Subjects were divided into 3 groups: full fixed appliances FFA (n=26), Invisalign without bite ramps INBR (n=22), and Invisalign with bite ramps IBR (n=12). Pre-treatment (T1) and post-treatment (T2) CBCT images were obtained and measured to compare difference in skeletal overbite using the overbite depth indicator (ODI) and root length and volume of maxillary anterior teeth.  

Results: The change in ODI from T1 to T2 was 2.65°, 1.5°, and 3.55° for the FFA, INBR, and IBR groups, respectively. However, between-group comparisons showed no statistically significant differences. The reduction in root length was significantly higher in the FFA group compared to the INBR and IBR groups (p<0.001). There was a statistically significant difference in root volume reduction between the two Invisalign groups, with the INBR group demonstrating a greater reduction, but no significant difference was found between the FFA group and both Invisalign groups. The treatment duration was significantly shorter in the IBR group compared to the FFA group (p=0.009). However, there was no significant difference in duration between the two Invisalign groups.

Conclusion: Deep overbite correction with Invisalign, with or without precision bite ramps, is comparable to fixed appliances. Invisalign demonstrated less reduction in root length compared to fixed appliances. When treating skeletal deep bite, Invisalign has shown to be more efficient than fixed appliances.

Analysis of Frictional Properties of Customizable 3D-Printed Ceramic Orthodontic Brackets and Tubes (Lightforce): An In-Vitro Study

Lukens E, Makowka S, Al-Jewair T, Gurav A

New York University at Buffalo, Buffalo, NY

Objectives: The objective of this in-vitro study is to analyze the frictional properties of LF 3D-printed polycrystalline alumina brackets compared to the contemporary bulk-manufactured metal and polycrystalline alumina brackets, as well as to analyze the frictional properties of 3D-printed polycrystalline alumina molar tubes compared to the metal tubes using stainless steel (SS) and nickel-titanium (NiTi) wires. We hypothesize that 3D-printed polycrystalline alumina orthodontic brackets and tubes will offer less frictional resistance when used with SS and NiTi wires compared to the conventionally produced ceramic brackets but not the metal brackets and molar tubes. This study will also attempt to characterize the surface topographic features of LF brackets and tubes to further understand the similarities or differences in their frictional behavior compared to conventional metal and polycrystalline ceramic brackets.

Materials: 3D-printed Lightforce (Burlington, MA) Maxillary canine brackets with 0° torque and 0.022”X0.028” slot will be used to analyze the frictional resistance compared to the Clarity Advanced and 3M Victory Series maxillary canine brackets (3M Maplewood, MN) with identical torques prescriptions and slot dimensions. Since LF molar tubes are one of the first commercially available 3D-printed ceramic tubes, their frictional properties will be compared against conventional metal buccal tubes (3M Victory Series) with a comparable torque prescription, offset
angle, and slot dimensions.

Methods: Frictional characteristics of all the brackets and molar tubes will be studied using a universal testing machine that will allow measurements of static and kinetic frictional resistance offered by the brackets/tubes while sliding 0.019”X0.025” dimension SS and NiTi wires through the slot at a rate of 10mm/min with a 100 N load cell and 150 g weight. To mimic intraoral conditions, test samples will be lubricated with artificial saliva while measurements are being recorded. A 3D-printed jig will be fabricated as a platform in order to standardize the orientation of bracket and molar tubes during the experimental procedures2. Archwires will be secured in the bracket slots using elastomeric ties (3M Alastik Elastomeric Ligatures). In addition, the surface topographic properties of the 3D-printed LF bracket slots will be studied and compared against 3M Clarity Advanced ceramic brackets using confocal microscopy and scanning electron microscopy3. Sample size: A priori sample size estimation with a error probability set to 0.05 and 80% power suggested each experimental group to contain at least 15 unique measurements to detect effect size of 0.4. In accordance with previous studies, we will replicate each experimental group with 20 observations2 for measurements of frictional resistance involving brackets and buccal tubes. Statistical analysis: Descriptive analysis will be conducted for all variables. An ANOVA test will be calculated to evaluate differences frictional resistance among the subgroups using SPSS at a significance 0.05. A regression analysis will also be performed to describe the effect of friction on the brackets and buccal tubes.

Evaluation of Dental Root Development Regarding Maxillary Canine Eruption Status after Secondary Alveolar Bone Grafting in Cleft Lip and Palate Patients

Kadriye Hargett, Melissa Ferguson

Harvard University, Cambridge, MA 

Research Question: Are there quantifiable differences in the pre-operative root development of the canines and premolars between successful versus non-successful maxillary canine eruption into the secondary alveolar bone graft?

Null Hypothesis: Following secondary alveolar bone grafting, we hypothesize there is no association between pre-operative dental root formation and successful maxillary canine eruption outcome in patients with cleft lip and palate. Aims: 1) To quantify and compare the developmental differences in root formation of the maxillary canines and premolars before and after secondary alveolar grafting between successful and non-successful canine eruption into the alveolar bone graft. 2) To create a three-dimensional visual map of root formation of investigated teeth pre- and post-operatively for successful and non-successful canine eruption into the alveolar bone graft.

Methodology: Records of nine hundred patients who received secondary alveolar bone grafting at Boston Children’s Hospital with pre- and post-operative cone-beam computed tomography (CBCTs) scans will be analyzed for inclusion in the study. Inclusion criteria includes an infant diagnosis of non-syndromic unilateral complete cleft of lip and palate, presence of unerupted cleft-side canine pre-graft, and patients that have CBCT data available pre- and post-secondary alveolar bone graft with the post-surgical CBCT not taken more than 2 years after the initial (pre-graft) CBCT. Using post-surgical data, the patients will be divided into two groups 1) cleft-side permanent maxillary canines that erupted within two years of the pre-surgical CBCT; or, 2) cleft side permanent maxillary canines which remained unerupted within 2 years of pre-surgical CBCT. Density values of different tissues, that is, teeth vs. bone, will be identified in Hounsfield units (HU) and will be used to segment the maxillary canines and premolars from both groups using the commercial software (Anatomage, San Jose, CA, USA). Upon the completion of the segmentation process, the root area will be sectioned from the crowns below the cemento-enamel junction (CEJ) to exclude the crowns. Then, linear and volumetric measurements of the roots will be performed on the resultant images. The pre- and post-operative root length and volume differences will be calculated for each group and compared statistically. In addition, a three-dimensional virtual morphometric superimposition of segmented roots will be performed to visually inspect the collective differences in both groups.