2014 aao annual Session Oral Research Presentations



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2014 AAO Annual Session Oral Research Presentations
The Oral Research presentation will be held on Sunday, April 27 in Ernest N. Morial Convention Center Room 231-232 from 8:00am-3:00pm with a break from 11:45am to 12:30pm. Oral Research presentations are 10 minutes long with 5 minutes for questions from the audience.
*- Denotes financial interest or visual enhancement
Moderator: Dr. Flavio Uribe - 8:00am-10:00am
ASSESSING IMAGING MODALITIES
8:00am-8:15am

Clinical Use of a Direct Chairside Oral Scanner: An Assessment of Accuracy, Speed, and Patient Acceptance

Thorsten Gruenheid, et al.

Minneapolis, MN, USA


Objectives: To assess the relative accuracy, speed, and patient acceptance of a chairside oral scanner (COS) when used for full-arch scans. Methods: Fifteen consecutive patients had digital models made from Lava COS (3M ESPE, St. Paul, MN) scans and alginate impressions. The time required for each procedure was recorded and patient preference assessed using a questionnaire. Model pairs were digitally superimposed and differences computed and tested for statistical significance. Results: Differences between models made from scans and those made from alginate impressions were not statistically significant. The chair time required to perform scans (3027±186 s) was significantly longer than that required for impressions (455±26 s). The majority of patients (73.3%) preferred alginate impressions over the scan. Conclusion: Despite the high relative accuracy of the COS, alginate impressions are still the preferred model acquisition method with respect to chair time and patient acceptance.
8:15am-8:30am

Ultra-Low Dose CBCT in Orthodontics: Revisiting Actual and Effective Dose with Quantitative and Qualitative Assessments*

Budi Kusnoto, et al.

Chicago, IL, USA


The objective of the investigation was to implement and assess (quantitatively as well as qualitatively) an ultralow dose sparse view algorithm applied to an existing dental CBCT used for orthodontic diagnosis purposes. Sparse view algorithm was developed with multiple levels of view sparsity rendering 25-75% reduction of radiation as used in orthodontic diagnosis. Calibrated human dried skull phantoms were used to assess the actual doses produced by the CBCT machine as well as the quantitative and qualitative assessment of images. Quantitative assessment metrics included accuracy of 2D and 3D cephalometric landmarks identification, while qualitative assessment was based on visual analog scale data of different dental specialists looking at same radiographs generated at various levels of view sparsity. Parametric & non-parametric analyses (p=0.05) were conducted to assess differences. Conclusions: Sparse view algorithm produced no differences at 75% radiation reduction.
8:30am-8:45am

Accuracy and Reliability of CBCT Imaging for Assessing Adenoid Hypertrophy*

Carlos Flores-Mir, et al.

Edmonton, AB, Canada


Purpose: evaluate 1) reliability and accuracy of cone-beam computed tomography (CBCT) for assessing adenoid size compared to nasoendoscopy (NE), 2) Influence of clinical experience on CBCT diagnosis. Methods: Four blinded evaluators reviewed randomized CBCT images. Adenoid size was graded on a 4-point scale for CBCT and NE (by an pediatric otolaryngologist). Reliability was assessed with intra and inter-observer agreement. Accuracy was assessed with agreement between CBCT and NE, plus sensitivity/specificity analysis. Results: 39 consecutively assessed subjects (11.5 ± 2.8 years) were evaluated. CBCT demonstrated excellent sensitivity (88%) and specificity (93%), strong accuracy (ICC = 0.80, 95% CI ± 0.15), and very good reliability, both within observers (ICC = 0.85, 95% CI ± 0.08) and between observers (ICC = 0.84 ± 0.08). Clinical experience of the CBCT evaluators did not have an effect. Conclusions: CBCT is a reliable and accurate tool for identifying adenoid hypertrophy.
8:45am-9:00am

Reliability of Upper Airway Linear, Area and Volumetric Measurements in Cone Beam Computed Tomography

Eduardo Sant'Anna, et al.

Rio de Janeiro, Brazil


Objective: To assess reliability of upper airway linear, area and volumetric measurements in cone beam computed tomography (CBCT). Methods: An undergraduate student, an orthodontist and a dental radiologist measured 12 CBCT. ICC and Bland-Altman at 95% limits of agreement (LoA) were applied. Results: The ICC was > 0.9 for 93% of intra- and 73% of interexaminer assessments. Transversal width and the cross sectional area (CSA) at the level of the vallecula presented an ICC of 0.63, large 95% LoA and the greatest mean measurement errors. Linear anteroposterior measurements; CSA at the level of the palatal plane, soft palate and tongue; sagittal area and volume were reliable measurements, presenting a minimum ICC of 0.93, with more restrict LoA. Conclusion: Airway assessment presented reliable anteroposterior measurements, CSA at the level of the palatal plane, soft palate and tongue, sagittal area and volume; and unreliable width measurements and CSA at the level of the vallecula.
9:00am-9:15am

Reliability of Measurements Made on Digital Models Obtained from Intraoral Scanner

Mario Greco, et al.

Rome, Italy


To assess the reliability of dental measurements achieved by the iOC intraoral scanner (iTero) by means of comparison between intraoral scan, extraoral scan of stone casts, extraoral scan of impressions and traditional stone cast.Twenty five patients with full dentition were selected and subjected to intraoral scan and two set of PVS double impression. One set of PVS impression have been scanned by D700 (3Shape) extraoral scanner, while the other set have been used for stone casts realization. Different dental parameters have been measured: intercanine width, intermolar width, interpremolar width, mesio-distal width of anterior teeth for both arches.All measurements have been made by two experienced operators and stl file superimposed by rapidform software. The descriptive statistics showed no significant differences as well as stl superimposition. Dental linear measurements achieved from intraoral scan can be considered reliable and accurate for diagnostic or therapeutic purposes.
9:15am-9:30am

Evaluation of Three Dimensional Maxillary Arch Form Changes Related to Pharyngeal Airway Dimensions in Class II Division 1 Patients

Defne Kecik

Istanbul, Turkey


AIM: The purpose was to evaluate the 3D changes of maxillary arch and palatal form to inspect the correlation between pharyngeal airway dimension in Class II Division 1 cases treated with fixed orthodontic treatment by means of 4 premolar extractions, compared to Class II Division 1 untreated control subjects. METHODS: 3D graphic representations of maxillary dental casts from 40 Class II Division 1 extraction cases (17 females 23 males) with a mean initial age of 16 years 5 months before and after orthodontic treatment were correlated with pharyngeal airway dimensions and were compared to 40 Class II Division 1 untreated controls (25 females, 15 males) with a mean age 17,6 years. RESULTS: Palatal volume was reduced with treatment (p<0.001). The pharyhngeal area was reduced (p<0.001). There was a positive correlation was found between palatal form and pharyngeal changes. CONCLUSION: Extraction treatment in Class II Division 1 cases decreases palatal volume and pharyngeal dimensions.
ORTHODONTIC TREATMENT MECHANICS
9:30am-9:45am

Survival Analysis of Mini-Implants Placed in Infrazygomatic Region

Nandakumar Janakiraman, et al.

Farmington, CT, USA


Objective:The aim of the study was to evaluate patient, operator and mini-implant related factors associated with post-operative infrazygomatic (IZ) mini-implant related outcomes. Methods:The outcome factors include mini-implant failure and mobility. The independent variables included age, sex, implant type, diameter and length of mini-implant, magnitude of force placed on implant,oral hygiene and use of pilot hole prior to placement of mini-implant. Regression models were used to examine the association between the independent variables and outcomes. Results: A total of 30 patients (mean age 23 + 11.48 years) had 55 IZ mini-implants placed. The failure rate of mini-implants was 21.8% and mobile in 25.5% of patients. Female patients were associated with lower odds of having failed implant (OR=.16, p=.03) and mobile implant (OR=.16, p=.03). Conclusion: Success rate of mini-implants placed in IZ region was 78.2% and female patients experienced lower mini-implant mobility and failures.
9:45am-10:00am

Placement Angle Effect on the Insertion Torque of Mini-Implant in Human Alveolar Bone

Julio Gurgel, et al.

Sao Luis, Brazil


Objective: To evaluate the effect the vertical placement angle of mini-implants on primary stability by analyzing maximum insertion torque (MIT). Methods: We employed 60 self-drilling mini-implants; half were of the cylindrical type and half were of the conical type. The mini-implants were placed in human cadavers, and primary stability was assessed by measuring the MIT. The mini-implants were placed at either a 90° or 60° angle to the buccal surface of the first upper molar. The data were subjected to analysis of variance (ANOVA) and Newman-Keuls tests, and a significance level of 5% was adopted. Results: The MIT was higher for both mini-implant types when they were placed at a 90° angle (17.27 and 14.40 N cm) compared with those placed at a 60° angle (14.13 and 11.40 N cm). Conclusions: Mini-implants placed at a 90° angle provide higher MIT values than implants placed at a 60° angle, regardless of the mini-implant type.
Moderator: Dr. Frans Currier - 10:00am-11:45am
10:00am-10:15am

Early Treatment of Anterior Open Bite: A Prospective Randomized Clinical Trial

Paulo Rossato, et al.

Londrina, Brazil


The aim of this prospective randomized clinical trial was to investigate the dental changes produced by different protocols in early treatment of anterior open bite. One hundred patients with Angle Class I malocclusion and anterior open bite with initial mean age of 8,4 years and a mean open bite of -3,67mm were randomly divided in 4 treatment groups: bonded spurs, high pull chincup, fixed palatal crib and removable crib and followed for 12 months. Comparison of post-treatment changes between groups was accomplished with ANOVA test. The results showed increase in overbite in all four groups with significant difference between then. It may be conclude that fixed palatal crib were more efficient for the correction of the open bite, followed by removable crib, bonded spurs and chincup, respectively.
10:15am-10:30am

Quantifying Patient Adherence during Active Orthodontic Treatment with Removable Appliances during Microelectronic Wear-Time Documentation

Timm Schott, et al.

Tuebingen, Germany


a. To quantify the weartimes of removable appliances during active orthodontic treatment. b. The weartimes of 141 patients treated with removable appliances in different locations were documented over a period of 3 months using an incorporated microsensor. Sex, age, treatment location, health insurance status, and type of device were evaluated with respect to wear time. c. The median daily weartime was 9.7 h/d for the entire cohort, far less than the 15 h/d prescribed. Younger patients wore their appliances for longer than older patients (7-9 y 12.1 h/d, 10–12 y 9.8 h/d, and 13–15 y 8.5 h/d; p<0.0001). The median weartime for females (10.6 h/d) was 1.4h/d longer than males (9.3 h/d; p=0.017). Patients treated at different locations wore their devices with a difference of up to 5.0 h/d. d. The daily wear time of removable appliances can be routinely quantified using integrated sensors. The relationship between orthodontist and patient seems to play a key role in patient adherence.
10:30am-10:45am

Class II Treatment with Functional Appliances: A Meta Analysis of Treatment Effects

Nikhilesh Vaid, et al.

Mumbai, India


This meta-analysis aims to analyze current literature for evidence on effects of functional appliances (Removable FA & Fixed FA). Literature survey of articles was performed. A Meta analysis was attempted by using the Random Effect Model (REM); heterogenesis & sensitivity analysis were also done. Articles that met the inclusion criteria were 24 for RFA and 7 for FFA. The total subjects evaluated were 1469 (780 treated & 689 controls) for RFA and 353 (219 treated & 134 controls) for FFA. The results from a REM showed significant effects on Md skeletal (Co-Gn: 2.29 mm (p < .0005), SNB – 1.43º (p < .0005), N Perp Pg – 2.08 mm (p< .006) and dental changes (L incisor horizontal – 1.34 mm (p < .0005). Significant Mx dental changes (U Molar Horizontal – 2.84 mm (p < .0005) were only observed with FFAs. Sensitivity and chi square tests also confirmed these findings. The analysis of the effect of treatment by FFAs and RFAs versus untreated controls showed statistically significant changes.
ORAL HYGIENE/PERIODONTAL
10:45am-11:00am

Management of White Spot Lesions by Resin Infiltration (Icon, DMG): Long-term Durability of Esthetic Camouflage Effects In Vivo*

Michael Knösel, et al.

Göttingen, Germany


Purpose: To assess the long-term durability of the esthetic improvement of white-spot lesions (WSL) achieved by resin infiltration (Icon, DMG) in comparison to baseline and to untreated white spot lesions. Methods: Twenty subjects with WSL after multibracket treatment were recruited for lesion infiltration using a randomized split-mouth design. Spectrophotometric follow-up assessments of color and lightness (CIE-L*a*b*) data of WSL in comparison to surrounding sound enamel were carried out prior to infiltration (Baseline), after 1 day, 1 week, 4 weeks, 3 months, 6 months, 1 year, and 1.5 years. Effects of infiltration and time elapse on color differences were analysed by multi-factorial ANOVA and pairwise comparisons. Results: There was an assimilation of infiltrated WSL to the color of adjacent enamel that was found to be color stable over 1.5 years. Conclusion: Resin infiltration is a technique that is suitable for a long-term improvement of the esthetic appearance of WSL.
11:00am-11:15am

Enhancing Oral Hygiene in Patients with Fixed Appliances: A Randomized Controlled Trial

Li Mei, et al.

Dunedin, New Zealand

Educating patients as to the severe consequences of biofilm accumulation may enhance oral hygiene in patients wearing fixed appliances. This study was designed as a prospective, randomized controlled clinical trial. A total of 148 participants were randomly assigned to 4 interventions: A, shown images illustrating the severe consequences of biofilm formation; B, given biofilm disclosing tablets; C, a combination of A and B; D, control. Plaque index (PI) and gingival index (GI) scores were recorded during a 6-month follow-up. Groups A and C exhibited significantly lower PI and GI compared with control (p<0.001), whereas no significant difference was found between Group B and control, nor between Groups A and C (p>0.05). The adults had significantly lower PI and GI than did teenagers, and females had significantly higher GI than did males (p=0.039). The use of images showing severe consequences of biofilm enhanced the oral hygiene of patients wearing fixed orthodontic appliances.
11:15am-11:30am

Use of Genetic Test to Detect Periodontal Disease Risk before Orthodontic Treatment

Alessandra Lucchese, Enrico Gherlone

Milano, Italy


Orthodontic treatment (OT) requests are increasing in the last years,due to the functional and esthetical needs of the population, Presence of orthodontic appliances, poor oral hygiene, intrusive movements of the teeth can lead a progression from gingivitis to periodontal disease. PD is a multifactorial disease in which both environmental and genetic factors play a role. Cytokines, are key factors which mediate the inflammatory process during periodontal disease. We analyzed 6 specific polymorphisms of the IL-1A, IL-1B, IL-6, IL10 and VDR genes in order to test whether they act as a susceptibility factor of PD.412 individuals participated to the study; PD affected 183 while 230 constituted the control group,.A statistical significant association exists between common variant alleles, IL6 rs1800795-G and IL 10 rs1800872-A, and PD.These data could be important in implementing preventive oral hygiene protocols in patients with genetic susceptibility to PD.
11:30am-11:45am

Periodontal Health and Microbial Biofilm Mass in Teenagers Treated with the Invisalign® System and with Fixed Orthodontic Appliances

Federico Migliori, et al.

Varese, Italy


Objectives: Evaluation of periodontal health and microbial biofilm mass (MBM) in teenagers treated with Invisalign® and with fixed orthodontic appliances Methods: 50 teenagers were selected and randomly assigned to the two groups. Full Mouth Plaque Score (FMPS) and Bleeding Score (FMBS), Probing Depth (PD), Compliance to oral hygiene (COH) and subgingival microbial samples were evaluated before orthodontic treatment (T0), at 3 (T1), 6 (T2) and 12 (T3) months. Real time PCR was performed to detect periodontal pathogens and MBM Results: FMPS and FMBS at T3 were significantly lower in the Invisalign® group (p <0.001), in agreement with the increased COH (p <0.005). No significant changes were found on PD during treatment. MBM was greater in the fixed appliances group at both T2 and T3 (p <0.001) Conclusions: The use of removable aligners in teenagers showed a significantly higher COH, allowing to maintain a better periodontal health and lower MBM levels during the orthodontic treatment
Moderator: Dr. Nan Hatch - 12:30pm-1:45pm
BIOLOGY OF FACIAL GROWTH AND TOOTH MOVEMENT
12:30pm-12:45pm

Candidate Gene Analyses of 2D Dento-Facial Phenotypes in Patients with Malocclusion

Lina Moreno Uribe, et al.

Iowa City, IA, USA


Objectives: Dento-facial phenotypes present in moderate to severe malocclusion are the result of susceptibility genes, environmental factors and/or their interactions. This study evaluates genetic associations between craniofacial genes and 2D dento-facial phenotypes in patients with malocclusion. Methods: Lateral cephs of 254 Caucasian adults with Class I, Class II and Class III malocclusion were digitized with 29 landmarks. 2D coordinates were submitted to a Procrustes fit prior to a principal component (PC) analysis. Components explaining 60% of the total variation were regressed on 200 variants genotyped within 75 craniofacial genes adjusting by gender, age and image type. Results: Significant correlations (p<0.01) between vertical and anteroposterior malocclusion discrepancies were found for MYO1H, SNAI3, RUNX2, PAX5, NRIP2, 12q13.13, LEFTY1, IRX1 and TWIST1. Conclusion: Results replicated 12q13.13 and MYOH1 and suggested additional genetic pathways involved in malocclusion.
12:45pm-1:00pm

Candidate Gene Analyses of 3D Dental Phenotypes in Patients with Malocclusion

Cole Weaver, et al.

Iowa City, IA, USA


Objectives: About 2% of the US population suffers from severe malocclusion discrepancies that are beyond the limits of orthodontics alone. This study explores correlations between 3D malocclusion phenotypes and craniofacial development genes. Methods: CBCTs (124) or digital casts (161) of 285 subjects with skeletal Class I (n=60), II (n=143) and III (n=82) malocclusion were digitized with 48 dental landmarks. 3D coordinates were superimposed prior to Principal Component (PC) analyses to identify symmetric (sym) and asymmetric (asym) aspects of shape variation related to malocclusion. PCs explaining 51%-67% of total shape variation were regressed on 200 variants genotyped within 75 genes adjusting for race, gender, age and data source. Results: Significant correlations (p<0.01) were found for sym variation and BMP3, PITX2, SNAI3, ARHGAP29 and FGF8 and asym variation with PAX7, TBX1, LEFTY1, SATB2, SOX2 and TP63. Conclusion: Results suggest genetic pathways associated with malocclusion.
1:00pm-1:15pm

Mini Implant Facilitated Accelerated Tooth Movement in Rats: A Pilot Study

Tracy Cheung, et al.

Los Angeles, CA, USA


Objective: Accelerated tooth movement (TM) involves invasive procedures. We evaluated mini implant-facilitated corticotomy (CO) in rats to develop a non-surgical protocol for shortening orthodontic treatment. Methods: Six 350g Sprague-Dawley rats were administered split-mouth CO around left maxillary 1st molar. 25g close-coiled springs were secured to incisors and 1st molars and TM observed for 21 days. The diastema was measured on days 0 and 21. Samples analyzed by MicroCT, H&E and TRAP. Results: Greater TM demonstrated on the CO side. H&E showed more cellular activity and TRAP showed more osteoclastic activity on CO side. MicroCT showed similar BMDs between both sides. BV/TV was greater on CO side. BMD was similar between CO and control (CR) sides. Conclusions: TM occurred faster on CO side. Similar BMDs between CO and CR sides suggest that osteopenic effect of corticotomies was minimal. Greater BV/TV on CO side may be due to greater anabolic activity near decortication sites.
1:15pm-1:30pm

Biological Saturation Point during Orthodontic Tooth Movement

Bandar Alyami, et al.

New York, NY, USA


Application of orthodontic forces (OF) is accompanied by release of inflammatory markers (IM) but the relation between magnitude of OF and expression of IM is not clear. Objectives: to investigate the relation between expression of IM and magnitude of the OF. Methods: 80 rats were divided into sham and different experimental groups which received different forces on the upper first molar. At different time points IM were evaluated by RT-PCR or ELISA, tooth movement (TM) by µCT and Osteoclast activity by immuno-staining. Results: Increase in magnitude of OF increases the IM, osteoclasts numbers and TM until certain level after which no further increase in IM or TM is observed. Conclusion: There is a biological saturation point where increasing the OF does not increase IM or rate of TM, this point can be defined as optimal force.

1:30pm-1:45pm

Reduction of Orthodontically Induced Inflammatory Root Resorption following Increased Angiogenesis by bFGF

Massoud Seifi, et al.

Tehran, Iran
Aim: To determine the effect of increased angiogenesis by bFGF on OIIRR. Methods: Samples were randomly divided into 5 groups of 10 rats and received 10, 100, 1000 ng bFGF for groups A, B, and C respectively (plus Group D (positive control), group E (negative control)). Right maxillary first molar was protracted toward incisor. After 21 days, the rats were sacrificed and the distance between the first and second right molars was measured and angiogenesis was studied by histomorphometry(ANOVA and Tukey's HSD). Results: There was a significantly higher rate of tooth movement in the test groups (C=0.77,B=0.66,A=0.53 mm i.e. dose-dependent) compared to the control group (0.26 mm) (p<0.05). Number of blood vessels, osteoclast cells and Howship lacunas were significantly lower in group C relative to group Control Positive (p<0.05). Conclusion: Enhancement of bone remodeling, increased OTM, and significant reduction in OIIRR seems to be correlated to activity of bFGF.
Moderator: Dr. Sylvia Frazier-Bowers - 1:45pm-3:00pm
ORTHOPEDIC MODIFICATIONS
1:45pm-2:00pm

Preclinical Evaluation of Systematically Applied Bisphosphonate on Mid-Palatal Suture Expansion

Gowhar Iravani, et al.

Los Angeles, CA, USA


Objectives: Midpalatal suture expansion (MSE) is an effective method to treat transverse maxillary deficiencies, such as for cleft palate patients. This study evaluates the effects of Bisphosphonates (BP) on bone formation and relapse ratio after MSE in rats. Methods: 16 Sprague Dawley rats underwent 7 days of MSE using opening loops attached to central incisors. At the end of MSE, the control (n=6) and BP group (n=10) were given subcutaneous injection of saline and Zoledronate (0.1 mg/kg), respectively. After 14 days of retention, half the rats in each group were sacrificed and the remaining were sacrificed 7 days later. Results: There was a significant decrease in relapse ratio in BP group (12.8+/-3.82 %) compared to control group (25+/-1.73 %) (p<0.05). BP group also showed greater bone volume and density, greater number of osteoblasts, and decreased number of osteoclasts, in comparison to control group. Conclusion: Low dosage BP application after MSE may decrease the relapse ratio.
2:00pm-2:15pm

Three-Dimensional Evaluation of Pharyngeal Airway, Maxillary Sinuses, and Palate following Symmetrical and Asymmetrical Rapid Maxillary Expansion

Mehmet Akin, et al.

Konya, Turkey


AIM: To evaluate the 3D changes of pharyngeal airway, maxillary sinuses, palatal volume and area between symmetrical (RME) and asymmetrical (ARME) rapid maxillary expansion. METHODS: The CBCT and 3D model records of 60 patients treated with bonded RME and ARME were used in this study. CBCT and model records had been taken in pre- and 3 months post-expansion retention period. All the CBCT and 3D model records were analyzed using MIMICS 14.01 and Rapidform XOS. RESULTS: The upper and total pharyngeal airway volume in both groups increased significantly (P<.05). Volumes of maxillary sinus and palate and also area of palate were only increased in crossed sides in RME and ARME (P<.05). Volume of upper pharyngeal airway was increased in RME more than ARME and volume of maxillary sinus in crossed side was increased in ARME more than RME (P<.05). RME and ARME positively affected pharyngeal airway volume and quantitatively increased maxillary sinuses, palatal volumes and areas of crossed sides.
2:15pm-2:30pm

Evaluation and Comparison of Root Resorption between Tooth Borne (Hyrax) and Tooth Tissue Borne (Haas) Rapid Maxillary Expansion Appliances: A CBCT Study



Furkan Dindaroğlu, Servet Doğan

Izmir, Turkey


The aim of this study is to compare the amount of root resorption after RME between tooth borne and tissue borne appliances by CBCT and to evaluate repair after 6 months of fixed retention. MATERIAL AND METHOD: 33 subjects were randomly divided into 2 groups: Hyrax (n = 16), Haas (n = 17). CBCT scans were taken before and after RME and after 6 months of retention. Mimics 16.0 was used for segmentation of 198 tooth. Repeated measure Anova, Bonferroni and independent sample t tests were used for analysis. RESULTS: No significant differences were found in root resorption and repair after RME between all groups (p>0,05). Significant differences were found between pre- and post-expansion root volumes in all premolars and molars (p<0,001) but not in repair. There were no significant difference among the tooth on percentage of resorption. CONCLUSION: Root resorption was similar between appliances. Slight repair was observed after retention. Similar effects were occurred in unattached second premolars
2:30pm-2:45pm

Zygomatic Implant Gear to Control Vertical and Horizontal Maxillary Growth in Growing Class II Patients

Mostafa El-Dawlatly

Cairo, Egypt


The correction of some Angle Class II malocclusion requires distalization of the upper 1st molars with induced orthopedic effect. In the present study, the possibility of using mini-implant as a mean of a modified zygomatic anchorage system was tested. the study comprised 10 treated and 10 control Class II growing female subjects with an age range of 10-12 years. Orthodontic mini-implants were placed in the zygomatic buttress. The follow up period was 6 months, treatment changes were assessed by cone beam CT. The treatment group showed significant retrusion of point A, anti-clockwise rotation of the maxillary plane, a mean molar ditalization of 2.92 ± 0.69 mm with no extrusion, tipping or buccal rolling. There was a significant upper incisors intrusion (1.89± 0.84 mm). Conclusions: the use of the present technique allowed Class II correction with concomitant reduction of the gumminess of the treated subjects without the adverse effects experienced with other appliances.
2:45pm-3:00pm

Archwire-Borne Distractor to Reduce Unilateral Alveolar Clefts. Is It Effective? A 3D-CBCT Analysis

Fady Fahim, et al.

Cairo, Egypt


A new Archwire-Borne (not tooth-borne nor bone-borne) distraction device was used to close wide alveolar clefts in 10 patients (7 females and 3 males) with unilateral cleft lip/palate patients with age range 12-22 years with mean age of 16.9 y. Osteotomies were performed to include the maxillary canine and the first premolar in the transport segment. Three-dimensional control was achieved by sliding the transport segment on 0.019x x0.025 stainless steel arch wire. A new reference system was designed for 3D analysis after automatic superimposition of the pre- and post-distraction CBCTs. Teeth in the transport segment were assessed in the antero-posterior and mediolateral dimension. Also, the volume of the alveolar cleft pre- and post-distraction was automatically calculated in cubic mms and compared to each other by paired t-test. The alveolar cleft volumes were significantly decreased post-distraction at P=0.006, thus the distractor was efficient in closing alveolar clefts.


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