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 4point 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, mesiodistal 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: Miniimplants 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 (CIEL*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, IL1B, 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 implantfacilitated 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.