Theses supervised by Prof. Dr. Derya Çakan
10 theses · Yeditepe University
Short term follow-up of nasolabial growth in patients with cleft lip and palate treated with nasoalveolar molding
The aim of this prospective study was to evaluate the short-term longitudinal nasolabial changes of patients with complete unilateral cleft lip and palate (CUCLP) treated with nasoalveolar molding (NAM) and primary cheilorhinoplasty and to compare the nasolabial characteristics with that of healthy individuals. The study group comprised 20 patients with CUCLP (mean age: 20.60 ± 9.00 months) whereas the control group included 12 children without UCLP (mean age: 20.83 ± 8.96 months). Three-dimensional (3D) stereophotogrammetric records of the study group were taken at the first visit after primary surgeries (T0) and approximately 1 year after the first record (T1). Same records were taken at a similar time interval in the control group. Nasolabial measurements were performed on 3D facial images and statistical tests were performed. At T0, on the cleft side, nostril width and perimeter, alar length and width were significantly greater whereas upper lip transversal length, philtrum and medial lip height were shorter in the UCLP group compared to the control group (p<0.05). Nasal tip protrusion and projection angle were higher in the UCLP group (p<0.001 and p<0.01, respectively). Cleft side nostril height and columella inclination did not differ between groups (p>0.05). Nasal base width, alar length, nostril width and height ratios showed significant asymmetry in the UCLP group (p<0.01). At T1, significant nasolabial growth changes occurred and the differences between groups observed at T0 were mostly maintained. No significant difference was seen in upper lip transvers length C and columella inclination between UCLP and control groups (p>0.05). From T0 to T1, comparable growth changes occurred in both groups. To conclude, children with UCLP had flatter facial profile and more asymmetry in the nasolabial region compared to healthy children. During 1 year of observation period following primary treatments, the nasolabial growth of the patients with UCLP was similar to normal growth, without any relapse.
Retrospective evaluation of cortical bone thickness in patients with unilateral cleft lip and palate
The purposes of this study were to evaluate the buccal and palatal cortical bone thickness in patients with complete unilateral cleft lip and palate (UCLP) and compare the cortical bone thicknesses at these specific locations between cleft and non-cleft sides and between subjects with and without UCLP. Fifty patients with UCLP (mean age of 14.76 ± 5.06 years) were selected for study group. The control group also contained 50 subjects (mean age of 16.54 ± 4.55 years) without any congenital deformity. Cortical bone thicknesses were evaluated using cone beam computed tomography images on 3dMD Vultus software program. Posterior buccal cortical bone thickness (BCBT) measurements were made on the cleft and non-cleft sides of UCLP patients, and on one side of the control group at maxillary interradicular areas between canine and 1st molar, at 4, 6 and 8 mm from the alveolar crest whereas palatal cortical bone thicknesses (PCBT) were also measured at 10 and 12 mm. Statistical analysis were made using NCSS software program. According to statistical evaluation, in patients with UCLP, the mean BCBT and PCBT at posterior maxilla ranged between 1.2 and 1.5 mm. There was no difference between BCBT and PCBT in UCLP group and furthermore they did not show any differences between cleft and non-cleft sides as well (p>0.05). On the other hand, BCBT and PCBT in UCLP group were significantly lower than that of the control group (p<0.001). BCBT and PCBT are generally prone to increase from anterior to posterior and from the alveolar crest to apex. In patients with UCLP, although most of the interradicular sites was found to be suitable for mini-implant insertion in terms of cortical bone thickness, less than 1 mm thicknesses may also be seen between canine and premolars, and closer to alveolar crest.
Effect of different PH level of drinks on the surface topography of orthodontic wires
The aim of this study was to evaluate and compare the changes in surface roughness of three different orthodontic wire types after their immersion in different soft drinks with dissimilar pH levels. A total of 90 samples, 30 stainless steel (SS), 30 nickel titanium (NiTi) and 30 titanium molibdenium alloy (TMA) wire sections were immersed in Coca Cola (pH:2.2), iced tea (pH:3.1), kefir (pH:4.3), coffee (pH:6.8) and artificial saliva (pH:7.1) as the control group. The duration of immersion was 60 minutes in each liquid. Then the samples were rinsed with deionized water and preserved in artificial saliva for 28 days at 37 °C. Surface roughness parameters before and after immersion were measured using atomic force microscopy (AFM) and data was statistically analyzed using one-way ANOVA and post-hoc testing at a confidence level of p < 0.05. There were significant differences in the changes of Ra, Rq and Rz of SS, NiTi and TMA wires among soft drink groups (p<0.05). △Ra and △Rq of the SS wire immersed in Coca Cola were significantly higher than that of the SS wires immersed in other soft drinks and the artificial saliva (p<0.001). △Ra of the NiTi wires immersed in Coca Cola were significantly higher than that of the NiTi wires immersed in other soft drinks and the artificial saliva (p<0.001). △Ra of the TMA wires immersed in Coca Cola were significantly higher than that of the TMA wires immersed in other soft drinks and the artificial saliva (p<0.01). Surface roughness changes of SS wires were significantly smaller than that of NiTi and TMA wires in all soft drinks (p<0.05). More acidic soft drinks caused more surface roughness changes on the archwires. In general, NiTi and TMA wires exhibited more increase in surface roughness compared to SS wires when immersed in soft drinks with different pH levels. Keywords: archwires; SS; NiTi, TMA; surface roughness; soft drinks
A comparison of oral health-related quality of life among children with and without cleft lip and palate
The aims of this prospective cross-sectional study were to evaluate the perceived oral health related quality of life (OHRQoL) of children with cleft lip and or palate (CLP), to compare their perceptions with that of their parents and children without CLP. The instrument adopted in the study is based on Paediatric oral health-related quality of life scale (POQL) with three main dimensions: physical & role function, social effect, and emotional effect. The scale was applied to 80 children with CLP (mean age: 11.66 ± 2.09 years) and their parents, as well as other 80 children without CLP (mean age: 11.26±1.52 years) as a control group. Statistical tests were performed to assess POQL scores between groups. The internal consistency measured by Cronbach alpha was satisfactory in children's sample (0.849) and parents' sample (0.882). When dimensions of POQL were evaluated, social effect scores of the children with CLP were significantly higher compared to that of control group (p<0.01). Comparison of POQL scores between the children with CLP and their parents' report on the child's oral condition revealed significant differences between groups (p<0.05). POQL scores of the parents were higher compared to that of their children (p<0.01). Pearson's correlation tests revealed that social and emotional domains had strong correlation with POQL of the children with CLP and the parents (Pearson rho 0.894-0.908, p<0.01). As a conclusion, children with CLP had lower oral health related quality of life in terms of social dimension compared with children without CLP. The parents of children with CLP showed more negative perception regarding their child's oral health
Assesment of changes in occlusal contact areas after orthodontic treatment in patients with different vertical growth pattern
The aim of this prospective study was to investigate the changes in posterior occlusal contact areas during the 1-year retention period in individuals with different vertical growth patterns. Within the scope of this study, 30 low angle and 30 high angle patients who received fixed orthodontic treatment without tooth extraction at Yeditepe University Faculty of Dentistry, Department of Orthodontics were enrolled in the study groups. The control group consisted of 30 individuals with normal growth pattern who did not receive orthodontic treatment. All the patients had maxillary and mandibular canine to canine bonded lingual retainers. After the treatment (T1), 6 months later (T2) and at the end of the 1-year retention period (T3), all patients were scanned with a three-dimensional intraoral laser scanner (Cerec, Omnicam). Occlusal contact areas were measured in mm2 using image analysis software (ImageJ) on digital models. Statistical analysis was performed. A statistically significant difference was observed between the initial mean occlusal contact area of the control, and low and high angle groups (p<0.001). The mean occlusal contact area of the control group at T1, T2, T3 was statistically significantly higher than the low angle and high angle groups (p<0.001). No statistically significant difference was observed between the mean occlusal contact area of the low angle and high angle groups at the time of T1 (p>0.05) whereas mean occlusal contact area of the low angle group was statistically significantly higher than the high angle group at T2 and T3 (p<0.001). The changes in the occlusal contact areas were significantly higher in low angle group compared to high angle group from T1 to T2 (p<0.001), with significantly greater changes in the first 6 months compared to the second 6 months of the retention period in both groups (p<0.001). As a conclusion, a significant occlusal settling occurred in the first year after orthodontic treatment but it differed between high and low angle patients. Low angle patients exhibited greater occlusal contact areas at each period and the increase in contact areas was higher compared to the high angle patients in the first 6 months.
Retrospective evaluation of tooth and arch dimensions in patients with different patterns of congenital tooth agenesis
Aim: This study aimed to evaluate tooth and arch sizes of patients with different patterns of congenital tooth agenesis and determine the effect of tooth agenesis severity on tooth sizes and arch sizes. Material and method: Study casts of 132 patients who have been diagnosed on panoramic radiographs with congenitally missing teeth were collected from the Yeditepe University Faculty of Dentistry Department of Orthodontics' archive. The study group was divided into 2 subgroups according to severity of the hypodontia as mild (2 or less tooth agenesis), moderate (more than 2 teeth agenesis). Control group included 90 patients consist of equally number of patients as Class I, Class II and Class III skeletal relationships. The dental casts were scanned by using 3 Shape E Scanner. The mesiodistal (MD), labiolingual (LL) and occlusogingival (OG) measurements of the tooth were performed digitally. Arch dimensions were measured including intercanine and intermolar widths. The study groups and control group were compared. Results: MD width of all the teeth in the mild and moderate agenesis group was statistically significantly smaller than that of control group except for first molars and mandibular left central incisor in the mild agenesis group and except for the mandibular incisors for the moderate agenesis group. LL widths of all the teeth in the mild and moderate agenesis group were statistically significantly smaller than the control group (p<0.05) except for mandibular premolars and first molars. In general, OG measurements were smaller in agenesis groups (p<0.05). MD width of maxillary central incisors, first and second premolars and molars, and mandibular first premolars, and LL width of maxillary premolars of the moderate agenesis group was statistically significantly smaller than that of mild agenesis group (p<0.05) whereas there was no difference in OG dimensions between groups (p>0.05). Maxillary and mandibular intercanine widths were smaller in agenesis groups compared to the control (p<0.05) with no difference between study groups. Conclusion: Individuals with tooth agenesis have smaller tooth dimesions compared to individuals without tooth agenesis. The tooth size reduction increases as the severity of tooth agenesis increases particularly for mesiodistal and labiolingual dimensions of maxillary premolars. Key words: Hypodontia, Severity, Tooth Sizes, Arch Dimension
Evaluation of patients' preferences of impression techniques among different age groups
The aim of this prospective study was to evaluate and compare chairside time, perception and preference of patients receiving conventional and digital impressions in different age groups. Within the scope of this study, 63 patients who applied for orthodontic treatment and met the inclusion criteria were enrolled in the study groups. The patients were grouped according to the age (Group 1: 8–12 years old, Group 2: 13–17 years old, Group 3: 18 years old and above). Each group consisted of 21 patients. Each patient's anxiety level was evaluated by state anxiety measurement test (STAI) prior to the intervention. After an anxiety test, patients' dental records were taken with alginate impression (Kromopan® Lascod, Florence, Italy) and intraoral scanning (iTero Element 2, Align Technologies, San Jose, Calif.) and the chairside time was recorded. Each patient filled out a perception and preference questionnaire. Statistical analysis were performed. The duration of digital impression was shorter than that of the conventional impression in all groups (p<0.001). The chairside time of digital impression method in the 8–12 age group was statistically shorter than that of the 13–17 age group and ≥18 age group (p<0.001). Chairside time of digital impression method in the 13–17 age group was statistically shorter than that of the ≥ 18 age group (p<0.05). For the conventional impression method, there was no statistically significant differences in perceptions of the patients in different age groups (p>0.05). For the digital method, the overall VAS scores of perception of the 13-17 age group was statistically lower compared to other groups (p<0.05). In each age group, digital impression method was mostly preferred over conventional impression method although there was no statistically significant difference among age groups in terms of impression method preferences (p>0.05). As a conclusion, intraoral scanning took less time in children aged 8–12 compared to older patients. All age groups perceived digital scanning more positively compared to the conventional method. The patient's perception of digital impressions differed between different age groups. 13–17-year-old patients had a more positive overall perception of the digital method. The majority of patients preferred digital impressions; however, the age of the patients did not play a role in their preference. Keywords: Conventional impression method, Digital impression method, Age groups
Evaluation of mandibular retromolar space of patients with different facial types and skeletal malocclusion with cone beam computed tomography
The study aimed to evaluate the mandibular retromolar space in adults with different sagittal skeletal relationships (Class I and Class III), vertical facial patterns (High-Angle, Normal, Low-Angle) and different genders using Cone Beam Computed Tomography (CBCT) . A total of 131 individuals (65 males, 66 females), aged 18 years or older, were retrospectively analyzed. Retromolar distance (RD), alveolar housing (AH) and root width (RW) were measured at 0, 2, 4, 6, and 8 mm apical levels from the crest. Molar inclination was also assessed. Statistical tests were performed.The results revealed that skeletal Class III patients exhibited significantly greater buccal and lingual RD than Class I individuals, particularly at coronal levels (p<0.05). In gender-based subgroups, lingual RD was significantly larger in female Class III patients compared to female Class I patients at all levels (p<0.05). Among vertical groups, Low Angle subjects presented higher buccal RD at level-2 and 4 mm compared to Normal and High Angle subjects (p<0.05),whereas. lingual RD did not differ significantly among the vertical facial pattern groups (p>0.05).Positive correlations were found between retromolar distance and both ramus height and corpus length, (r=0.231, p<0.05 and r=0.413, p<0.01, respectively). AH were found to be smaller in Class III patients, particularly at the 0 mm and 2 mm levels (p<0.05). Male subjects exhibited significantly larger retromolar spaces, greater root width, and increased alveolar housing dimensions than females. Molar inclination showed no significant differences across skeletal or gender groups (p<0.05).Class III and Low Angle patients, particularly males, may represent the most appropriate candidates for mandibular molar distalization As the ramus height and corpus length increase, retromolar distance also increases. Due to the variations in retromolar anatomy between males and females with particularly different vertical facial types, it is important to evalaute CBCT before mandibular molar distalization to ensure safe tooth movement within anatomical limits and to avoid undesirable outcomes such as root resorption or cortical perforation.
Three-dimensional evaluation of the nasolabial effects of nasoalveolar molding in unilateral cleft lip and palate patients
The aim of this prospective study was to evaluate three-dimensional nasolabial changes in infants with complete unilateral cleft lip and palate (CUCLP) treated by nasoalveolar molding (NAM) and compare to non-cleft controls. Thirty-nine CUCLP patients treated with NAM (mean age of 23.1±6.5 days) composed the study group. The control group comprised 10 healthy infants with a mean age of 23.7±6 days. Stereophotogrammetric records of the subjects in the study group were taken at pre-NAM (T0) and post-NAM (T1) whereas the control subjects' records were taken at a matching interval. Linear, angular and proportional measurements were carried on 3d stereophotogrammetric images using a software program. At T0, the cleft patients had significantly greater nostril and nasal widths, smaller nostril and columella heights, shorter philtrum on the cleft side, deviated columella and decreased nasal projection (p<0.001). Following NAM, on the cleft side, lip gap, nostril base width and diameter decreased (p<0.001), nostril height increased (p<0.001). Initially increased nostril height ratio significantly decreased with treatment (p<0.001). Inclination angle of the columella was steepened (p<0.001). Nasal projection angle significantly increased (p<0.01). Proportional measurements improved significantly in NAM group whereas in control group they remained the same. At T1, comparison of the study and control groups revealed that alar width, nasal base width and nostril diameter were greater (p<0.01, p<0.001 and p<0.001 respectively). Columella height was shorter on the cleft side compared to the controls (p<0.01). Nostril height and nasal projection angle did not differ between groups (p>0.05). The initial nasolabial cleft deformity of the CUCLP patients were significantly improved with NAM treatment. This improvement was mainly correlated with the severity of the initial deformity. Nasal projection and nostril height reached the normal values, whereas the transversal measurements were found to be larger despite the significant reduction. On the other hand, asymmetry of most of the nasolabial structures was improved following treatment. Key words: Complete unilateral cleft lip and palate, nasoalveolar molding, nasolabial changes, stereophotogrammetry, non-cleft control
The evaluation of the torque control parameters in upper incisors with finite element analysis during posterior expansion in clear aligner treatments
ÖGÜT ÖZUĞUR, E. (2024) The Evaluation of the Torque Control Parameters in Incisors with Finite Element Analysis During Posterior Expansion in Clear Aligner Treatments The aims of this study were first to evaluate the effect of the posterior expansion with clear aligner on both posterior and anterior teeth using Finite Element Method (FEM), and then to compare the effectiveness of the attachments or power ridges to prevent torque loss of the anterior teeth during posterior expansion by determining the stress distribution on the teeth and periodontal ligament, and the amount of displacement of the teeth. The study focused solely on dental expansion, utilising cone-beam computed tomography (CBCT) data from a 19-year-old female with median palatal suture fusion. Bone modelling was conducted using 3D Slicer software, including reverse engineering and 3D computer-aided design (CAD) activities. Solid models compatible with analysis environments were generated, and meshing was optimised using ANSYS Workbench software. The LS-DYNA solver was employed to solve finite element models. The aligner thickness was determined as 0.76 mm. Buccal expansion activation was 0.2 mm with 1.5° buccal root torque. In the first phase of the study, Model 1.1 was attachment free model whereas Model 1.2. included gingival beveled horizontal attachments (GBHA) on the posterior teeth. In the second phase of the study, additional 3 models were compared based on Model 1.2; Model 2.1 with labial and palatal power ridges on the central incisor, Model 2.2 with a labial horizontal attachment on the central incisor and Model 2.3 with a labial GBHA on the central incisor. Model 1.2 showed more parallel movement compared to the Model 1.1 attachment free model during posterior expansion with clear aligner. With Model 1.1, a greater expansion was obtained. In both models, incisors showed retroclination during posterior expansion. In Model 2.1, 2.2 and 2.3, adding attachments and power ridges to central incisor prevented retroclination of the incisors. In all the models, the von Mises stresses were higher at the central and lateral incisors compared to the posterior teeth. On the periodontal ligament, main stresses were found to be distributed on the premolars. As a conclusion, this FEM study demonstrated that the use of attachments on the posterior teeth during expansion with clear aligners is effective to prevent buccal tipping of the molars. Furthermore, adding horizontal attachments or double power ridges on the central incisor avoid retroclination of anterior teeth during expansion with aligners. Keywords: FEM Analysis, Torque Control, Expansion, Clear Aligner Treatment