Introduction: Class II Division 1 malocclusions are characterized by a retrusive mandible and prominent upper incisors. Despite Class II malocclusions being one of the most frequently treated cases in orthodontists' office, there is no uniform consensus in the orthodontic community on the best treatment modality and biomechanical approach to use in treating patients with Class II malocclusions. Purpose: This paper examines the end-of-treatment outcomes of severe Class II Division I malocclusion patients treated with surgical versus non-surgical approaches. Study Design: This is a retrospective study of consecutively treated severe Class II Division I patients at the University of Iowa. Initial and deband lateral cephalometric radiographs were compared between 45 non-surgical and 21 surgical patients. All patients that were debanded between the ages of 13 to 19 years were included. Multivariable regression analyses were used to examine differences in outcomes between treatment groups. Results: Following adjustment for patient level confounders (age, gender, and race), those treated surgically had better end of treatment cephalometric outcomes. Those treated surgically had a more balanced skeletal profile, greater reduction in overjet, and improvement in ANB angle (p Conclusion: Orthodontic treatment in conjunction with orthognathic surgery is a more ideal treatment for patients with severe Class II Division I malocclusion. When treated surgically, a greater amount of overjet can be reduced while keeping lower incisors in a more stable position in bone.

Introduction: Skeletal expansion has been a treatment modality in orthodontics and orthopedics to correct skeletal transverse discrepancies with maxillary constriction. The utilization of microimplants in conjunction with these palatal expanders offers a higher degree of pure skeletal expansion and minimizes the dental side effects. The purpose of this study is to evaluate the changes of the hard and soft tissues of the face after skeletal expansion for orthodontics. Methods: 36 patients who had received successful expansion with a microimplant assisted rapid palatal expander were compared to their pre-expansion records. All patients received CBCTs from which a 3-D analysis configuration was created to trace hard and soft tissue landmarks of the midface and nasal cavity regions. 3 judges analyzed each set of records and the average was used to calculate the amount of expansion experienced at each anatomical region. A paired T-test and Wilcoxon signed-rank test were used for statistical comparison between time points. Results: Expansion can affect all of the midfacial hard tissues that support the overlying soft tissues. Increases in skeletal width from the Frontozygomatic suture down to the maxillary alveolar bone were all significant. The nasal cavity increased in width in all locations measured. Soft tissue changes were significant at the base of the ala suggesting a widening of the nose with expansion therapy. Conclusion: Maxillary expansion with microimplant assisted expanders can have skeletal changes throughout the entire midface and may affect the width of the nasal cavity. Soft tissue changes were less pronounced, and though a widening of the base of the nose may be expected this may not be noticed by the patient.

Introduction: The purpose of the study was to evaluate the effects of maxillomandibular advancement (MMA) surgery with counterclockwise rotation on soft tissue oral and nasal structures. Materials and Methods: This retrospective study included 34 subjects diagnosed with OSA who underwent MMA at the Stanford Sleep Clinic. Initial (T1) and Final (T2) CBCTs were evaluated and compared for 10 hard tissue and 15 soft tissue measurements. Additionally, the external nasal valve surface area was measured and compared between the two time points. A 3D superimposition was performed and used to evaluate the relative hard and soft tissue movements. Results: There was a linear correlation in the advancement of the maxilla to the sagittal movement of the upper lip of 75%, while the mandibular soft tissue moved 91-93% of the mandibular sagittal position. The interalar width and mouth width increased significantly following surgery while the lower vermillion border length decreased significantly. There was a clinically significant increase in the average surface area of the external nasal valve by 28%. No correlations were found between maxillary impaction and soft tissue oral or nasal measurements. Conclusion: MMA with CCW results in significant changes to the soft tissue nose and oral region. Soft tissue planning must be considered to maintain desirable esthetics following surgery.

December 2011. A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Introduction: The purpose of this study is to compare the shear bond strengths (SBSs) of two new commercial adhesive systems to a conventional multistep bonding system incorporating a 35% phosphoric acid gel. In addition, the amount of adhesive remaining on each tooth following debonding will be analyzed and compared using the adhesive remnant index (ARI). Methods: 88 human premolar teeth chosen from the Nova Southeastern tooth databank were randomly divided into four groups. Group I (control group): Transbond XT primer and adhesive (35% phosphoric acid), Group II: iBond Total Etch system with iBond 35 gel (35% phosphoric acid), Group III: iBond Total Etch system with iBond 20 gel (20% phosphoric acid). Group IV: iBond Self Etch. A scanning electron microscope (SEM) was utilized to qualitatively examine the enamel surface of one randomly selected tooth per group immediately after etching, leaving 21 teeth per group available for the debonding procedure (n=21). Following bonding of the stainless steel brackets (3M Unitek, Monrovia, CA), the teeth were stored in water at 37°C ± 2°C for forty-eight hours. A universal testing machine (Instron, Canton, MA) was then used to determine the shear bond strength of each bracket. Additionally, the amount of adhesive remaining on each tooth following debonding was recorded using 10x light microscopy. Results: A 1-way ANOVA revealed that no statistical differences in bond strength were found between the four groups. SBS values of groups I (11.7 ± 3.9), II (11.6 ± 4.6), III (10.3 ± 4.1), and IV (10.8 ± 3.9) demonstrated mean SBSs considered adequate. The iBond Total Etch (20%) and iBond Total Etch (35%) groups were more likely to have an ARI score of 2-3 than the control group (Transbond XT). No significant differences were found between iBond Self Etch and the control group. Conclusion: The SBS's of all three groups, as compared to the control group, were adequate. The iBond Total Etch system, whether used with iBond 20 gel or iBond 35 gel, had more adhesive remaining on the tooth surface after debonding. Standardization amongst shear bond strength studies is significantly needed in the near future in order to accurately compare findings.

December 2011. A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Introduction: This study aimed to investigate the influence of anteroposterior lip position on male and female facial profile attractiveness rankings among three groups of judges (orthodontists, general dentists, lay people) and to determine if these rankings might be influenced by demographic variables such as race, gender, and profession. Methods: Two serial sets of digitally constructed male and female profile images were employed to assess the rank order of preference in profile attractiveness as a function of anteroposterior lip position. A defined image area of the composite profiles, including superior and inferior lips, was "morphed" to produce a "base-line" image defined according to Ricketts esthetic ideal with the lower lip 2mm posterior to the E-plane. The area of the lips were "morphed" in 1mm increments from the "base line" image, six increments anteriorly and six increments posteriorly resulting in a total of thirteen images for both the male and female. The images were then segregated into two sets of 7 for both the male and female. Each set included the base-line image plus 3 images morphed anterior and 3 images morphed posterior relative to the base line image. The Set 1 images were morphed in 1 mm increments, and the Set 2 images were morphed in 2mm increments. Utilizing an online survey, three-hundred and forty-eight adult judges (116 orthodontists, 126 dentists and 106 laypeople) were asked to sort and then rank order the seven images in each set from most attractive to least attractive profile appearance. Results: Relative to the historical norms of the lower lip positioned 2mm posterior to the E-plane, for male profile preference, a more concave profile was most preferred in Set 1 by orthodontists and general dentists while a more convex was preferred by lay people. A more convex profile was preferred in Set 2 by all groups of judges. For female profile preference, the opposite was found, as a slightly convex profile was preferred in Set 1, while a more concave profile was preferred in Set 2 by all groups of judges. Conclusion: Preference for facial profile attractiveness can be significantly influenced by the anteroposterior lip position, and that while orthodontists, general dentists, and lay people were shown to be in general agreement in their profile preferences, there was considerable variability in their esthetic preference between male and female images and across morphs.

December 2011. A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Introduction: The nasoalveolar molding appliance is used pre-surgically in cleft lip and palate patients as a method of bringing together the lip and alveolus by applying force to direct desired growth.1 It is used in the infant to reduce the pre-surgical severity of the initial cleft and to improve alignment of the base of the nose and lip segments.1 The purpose of this study was to examine the long-term effect of nasoalveolar molding on facial growth and nasolabial esthetics in complete unilateral cleft lip and palate patients. Methods: Sixteen (N=16) post-surgical cleft lip and palate patients who had undergone nasoalveolar molding as infants and twelve (N=12) control patients, treated surgically without nasoalveolar molding, were recalled for a clinical examination including impressions, photographs, and a lateral cephalogram. Dental models were analyzed using the Goslon Yardstick, developed by Mars et al. in 1987.2¬ Photographs were analyzed using the Asher-McDade method for rating the nasolabial appearance in patients with cleft lip and palate.3 Finally, lateral cephalograms were digitized and analyzed using Dolphin Imaging software. Results: Separate ordinal logistic regression models indicated no significant difference between the molding and non-molding groups in Goslon score, nasal form, nose symmetry, vermilion border or nasolabial profile assessments. Generalized linear models revealed one cephalometric variable to be statistically significant between the two groups. The ANB angle was decreased by 2.34 degrees on average in the group who underwent nasoalveolar molding prior to cheiloplasty. Intra-rater and inter-rater weighted kappa statistics were calculated for each variable. Conclusion: Short-term benefits of nasoalveolar molding have been documented in the literature. However, more long-term studies are needed in order to demonstrate the longitudinal effects of the appliance on esthetics and midfacial growth. Due to the limitations of cleft lip and palate studies, it is often difficult to accurately assess treatment effects. Through inter-center studies such as the Eurocleft and Americleft projects, some limitations and biases can be overcome in order to compare various protocols and outcomes.4 In the future, it is the desire of the investigators to include the current sample of nasoalveolar molding patients in the future efforts and expansion of the Americleft study.

December 2011. A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Background: Temporary anchorage devices (TADs) provide a versatile means by which orthodontic anchorage can be established without the need for patient compliance and complex force systems. Their use is predicated on their ability to remain stable throughout the course of treatment in which they are needed. This has been shown to be the result of "primary stability" which is achieved through mechanical interlocking of the screw threads with the surrounding bone immediately upon placement. Therefore, evaluating the factors that can either enhance or detract from the primary stability of TADs can serve to improve the predictability of their success. Objectives: The objectives of this study were to describe how variations in synthetic cortical bone thickness and the angle of force applied in relation to the long axis of TADs affects their stability in terms of pull-out strength, and to ascertain the perspectives of practicing orthodontists in the state of Florida on their experiences with temporary anchorage devices with regards to success and failure. Methods: For the bench top study, 90 1.5x8mm long neck Orthotechnology Spider Screws were randomly allocated to 9 groups of 10 TADs each. The 9 groups were established based on both the thickness of synthetic cortical bone (1.0, 1.5, and 2.0mm) and the angle of force vector applied relative to the long axis of the TADs (45, 90, and 1800). Pull-out testing was carried out by applying a force to the TADs via a universal testing machine (Instron, Canton, MA) at a rate of 2.0mm/minute. Real-time graphical and digital readings were recorded, with the forces being recorded in Newtons (N). Each miniscrew was subjected to the pull force until peak force values were obtained. For the 450 and 1800 tests, the force registered at the time-point of pull-out, or screw head movement of 1.5mm within the synthetic bone blocks. The determination of 1.5mm of movement was made due the dramatically erratic deflection observed by the digital and graphical readouts at precisely this point. For the survey portion of this study, A customized survey was developed for this study. The survey was composed of 12 questions, some of which were obtained from a questionnaire that was created by Buschang et al.54 The additional questions were devised by the members of this research project, with the aim of answering questions regarding the clinical experiences that practicing orthodontists experienced with TADs. Results: For the bench top study: Implants placed in 2.0mm of synthetic cortical bone and pulled at an angle of 1800 had the highest pull-out strength among all groups (258.38N), while those placed in 1.0mm of synthetic cortical bone and pulled at an angle of 900 exhibited the lowest (67.11N). When evaluated separately, a cortical bone thickness of 2.0 mm displayed the highest pull-out forces for the three angles of force application, and 1800 angle of force displayed the highest-pull-out forces for the three cortical bone thicknesses. Conversely, 1.0mm of cortical bone thickness displayed the lowest pull-out forces for the three angles of force application, and 900 angle of force displayed the highest-pull-out forces for the three cortical bone thicknesses. For the survey: The most important factor associated with TAD failure was cited as placement location by 45.7% (n=16) of respondents, while root proximity was cited as the least important factor by 35.3% (n=12) of respondents. For the site from which practitioners indicated that they experience the greatest success, 81.8% cited the palate, while 51.9% responded that they experience the highest failure rates for the posterior maxilla (distal to the cuspids). Conclusions: A synthetic cortical bone thickness of 2mm and pull forces applied parallel to the long axis of TADs resulted in the greatest resistance to pull-out.

A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Objectives: To determine the amount of initial fluoride release from four orthodontic bonding systems over a period of four weeks, and then to subject these materials to an external source of fluoride for recharge in order to measure the amount of fluoride re-release over another four-week interval. Additionally the surface morphology of these materials was analyzed under the scanning electron microscope in order to identify microscopic changes in the materials that may have occurred during the experiment. Methods: Four orthodontic adhesives: Fuji Ortho LC (GC America, Alsip, IL), Transbond XT (3M Unitek, Monrovia, CA), Illuminate Light Cure (Ortho Organizers, Carlsbad, CA), and Opal Seal with Opal Bond MV (Ultradent, South Jordan, UT), n=120 (30/material) were tested for fluoride release at 1 hour, 24 hours, 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks. Samples (10/subgroup/material) were then recharged with an external source of fluoride (toothpaste, foam, or varnish), and retested for fluoride re-release at 1 hour, 24 hours, 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks. The scanning electron microscope was utilized in order to assess each material's surface morphology before testing and after completion of the experiment (n=16). Descriptive statistics, means and standard deviations were calculated for all four materials and their subgroups at each time interval. A mixed model two-way ANOVA was run, using a level of significance of 0.05. Bonferroni multiple comparison tests were conducted using if groups were found to be statistically significantly different. To determine significant differences between fluoride release and re-release for each recharge subgroup within each material group, paired t-tests were performed for the time intervals of 24 hours, 2 weeks, and 4 weeks. For the paired t-tests, the level of significance used was 0.02 to allow for Bonferroni correction. Results: During the initial 24 hours the fluoride measurements (in mg/L or ppm) were as follows: Fuji 9.78±0.65, Illuminate 7.83±1.49, Opal 0.05±0.02, and Transbond 0.01±0.0. At the initial four weeks time point, the readings were as follows: Fuji 6.68±0.79, Illuminate 3.82±1.84, Opal 0.06±0.01, and Transbond 0.01±0.01. The greatest fluoride release came from the varnish subgroups from each of the materials at 2 weeks post re-charge: Fuji 9.16±1.53, Illuminate 7.5±3.1 (tied with foam subgroup 7.5±4.4), Opal 5.3±2.45, and Transbond 3.75±1.67. The greatest fluoride measurement for each material at the final week post-recharge was: Fuji varnish subgroup 8.3±3.58, Illuminate foam subgroup 6.5±3.5, Opal varnish subgroup 2.50±1.1, and Transbond varnish subgroup 1.72±1.82. SEM results showed an observable difference between the materials pre-experiment and post-experiment at a magnification of 50X and 500X. The Fuji foam and paste subgroups displayed surface crackling patterns at both magnifications when compared to the control and varnish samples. The Illuminate control, foam, and paste specimens all had a roughened grainy appearance, while the varnish specimen seemed to be smoothed over by the varnish material. The Transbond samples appeared to have observable differences in surface morphology at 50X, but not at 500X. The Opal paste and foam specimens appeared to have a smoother surface than both the control and the varnish samples. Conclusions: There were significant differences in release and re-release of fluoride among all four adhesives at different time intervals over a period of eight weeks. Significant increase in fluoride re-release was seen for all three of the recharge subgroups for both Opal and Transbond at each time interval. A significant increase in fluoride re-release for the Illuminate group was mainly observed at the end of second and fourth week. Though no significant increase in fluoride re-release was observed, Fuji released highest amount of fluoride during release and re-release, at all different time intervals. Fluoride varnish was the superior recharge material, as it provided the greatest fluoride measurements, followed by foam and toothpaste. There were observable changes in the surface morphology of the materials pre-experiment and post-experiment at a magnification of 50X and 500X, which may have an affect on the fluoride releasing capabilities of the materials.

A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Objective: This study was conducted to examine the changes in the inclination of mandibular incisors and their alveolar bone dimensions between pre- and post- non-extraction orthodontic treatment, measured using cone beam computed tomography (CBCT) images. The study measured the association of the pre- and post- labial and lingual bone measurements with the pre- and post- treatment incisor inclination by comparing the incisor-mandibular plane angle (IMPA). Background: Teeth move through bone by extensive osseous adaptation within the alveolar process. It is a common belief in orthodontics that alveolar bone follows tooth movement. As a tooth moves, bone will remodel around the alveolar socket usually in a 1:1 ratio of bone resorption to bone apposition. However, conflicting evidence in the orthodontic literature questions whether the anterior alveolar bone is able to remodel and follow the direction and quantity of tooth movement. Many studies have shown that the width of the alveolar bone and the lingual and labial cortical plates set limitations on how much anterior tooth movement can be accomplished without negative effects such as periodontal problems, root resorption or fenestrations. Methods: Pre- and post- non-extraction orthodontic treatment CBCT scans of twenty Class I molar patients with mild to moderate crowding were used to observe the buccal and lingual width and incisor inclination of each of the patient's four mandibular incisors. The labial and lingual alveolar bone dimensions were measured pre-treatment and post-treatment at 6 mm apical to the CEJ and at the apex of each tooth. The inclination of the incisors (using IMPA) of both time points was also documented. Results: A Fisher's exact test and a Cramer's V test were performed. The results showed statistical significance between the change in bone of the incisors and the change in their inclination at the buccal 6mm, buccal apex, lingual 6mm and lingual apex. There was also statistical significance found between the change in bone between the buccal apex and lingual apex of the LR1, LR2, LL1, and LL2. Conclusion: Our results showed that the change in bone of the lower incisors is correlated to the change in their inclination. This suggests that incisors were tipped within the confines of the mandibular anterior alveolar process, or the alveolar process bent and remodeled around the incisors in the same direction of tooth movement or a combination of the two.

A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. ABSTRACT The significance of this research was to identify the optimal techniques to remove ceramic orthodontic appliances in order to prevent tooth-enamel fracture, pain, and esthetic complications. Discomfort and pain are common occurrences during orthodontic appliance removal. In debonding (bracket removal) appointments, less force, measured as reduced shear bond strength (SBS) is preferable because greater force creates more discomfort and pain. In a previous study, 24.3% of patients reported pain when metallic brackets were removed using a ligature-cutting plier, compared to 12.8% of patients reporting pain when a lift-off instrument was employed. These previous findings demonstrate the need to investigate new debonding removal methods which have less SBS to help reduce the pain experienced by orthodontic patients. Some recent studies have reported that orthodontic bracket debonding causes inevitable damage to the enamel surface. The debonding of ceramic orthodontic brackets can increase the risk of enamel damage. The application of heat to help debond a bracket can increase the temperature of the pulp chamber; this could injure pulp cells and threaten the long term vitality of the affected tooth. The purpose of this in-vitro study was to evaluate the safety and effectiveness of using a diode laser for the debonding of ceramic brackets in relation to the amount of debonding force required, the risk of direct force impact on enamel, and the risk of causing an adverse temperature increase inside the pulp chamber. The central hypothesis I investigated was that using a diode laser would facilitate the debonding of ceramic brackets by decreasing the SBS, increase the adhesive remnant index (ARI), and avoid causing an adverse temperature increase in the pulp chamber. I investigated these parameters with the goal of establishing an effective and safe protocol for debonding ceramic brackets. At present no guidelines exist, I recognized that guidelines are needed for using a diode laser to debond brackets in relation to the power level and duration of lasing. This study tested two types of ceramic brackets; a monocrystalline bracket called Radiance and polycrystalline ceramic bracket called Clarity. These brackets were selected because they are widely available and in common use. The experimental brackets were monocrystalline and polycrystalline: the laser power settings and lasing times were; negative control (not lased), lased at 2.5 watts for 3 and 6 seconds, and lased at 5.0 watts for 3 and 6 seconds. The diode laser treatments had little effect on the debonding SBSs for the removal of the Radiance monocrystalline brackets. Alternatively, the debonding of the Clarity polycrystalline brackets with laser treatment using 2.5 watts for 6 seconds, 5.0 watts for either 3 seconds or 6 seconds reduced the SBS. The debonding of the Radiance monocrystalline brackets with laser treatment using 2.5 watts for 3 seconds, and 5.0 watts for 6 seconds increased the ARI. The debonding of the Clarity polycrystalline brackets with laser treatment using 2.5 watts for 6 seconds, 5.0 watts for 3 seconds and 6 seconds increased the ARI. The increase in pulp chamber temperature likely to cause thermal injury to the pulp cells was measured against Zack and Cohen¡¯s in vivo standards (2.2¢ªC and, 5.5¢ªC).30 When compared to the 2.2¢ªC standard; the debonding of Radiance monocrystalline brackets with laser treatment using 2.5 watts for 3 seconds were within the standard, and the debonding of Clarity polycrystalline brackets using 2.5 watts for 3 seconds was cooler. When compared to the 5.5¢ªC standard, the debonding of Clarity polycrystalline brackets using 2.5 watts for 6 seconds was cooler. The research results showed that using a diode laser for debonding at 2.5 watts for 6 seconds decreased the SBS for Clarity polycrystalline brackets (reduced the force needed for debonding), increased ARI for Clarity polycrystalline brackets (increased adhesive on enamel), and did not increase the pulp chamber temperature by an injurious amount. The difference in the debonding SBS, ARI and pulp chamber temperatures of the two bracket types probably arose because of the difference in the designs of the two bracket pads. My research results demonstrate the long-term need to design brackets with pads which can be removed easily with a diode laser, leave more adhesive on enamel, and that do not cause injurious temperature increases within the pulp chamber. My research results also demonstrate why guidelines for bracket debonding using diode lasers are needed, which limit the power setting and lasing times. The debonding of brackets using diode lasers could benefit orthodontic patients and become more common if it can reduce the risk of tooth fracture, lower the sensation of pain, reduce the amount of enamel damage, and maintain the vitality of teeth in future studies.