Normative and subjective need for orthodontic treatment within different age groups in a population in Turkey.

OBJECTIVE: To evaluate and compare the normative and subjective need for orthodontic treatment within different age groups in Turkey. METHODS: One thousand and sixteen patients from seven different demographic regions of Turkey (Marmara, Black Sea, East Anatolia, Southeastern Anatolia, Mediterranean, Aegean, and Central Anatolia Region) (mean age ± SD: 12.80 ± 3.57 years) were randomly selected and divided into six age groups (7-8,9-10,11-12,13-14,15-16, and 17-18 year-olds) and categorized according to the dental health component (DHC) of the index for orthodontic treatment need (IOTN). Additionally, the patients were asked to indicate the photograph that was most similar to their own dentition from the 10-point scale of the aesthetic component of IOTN. RESULTS: The DHC of IOTN was not significantly different between the six age groups (P > 0.05). However, no/slight need (aesthetic component 1-4) for orthodontic treatment according to AC of IOTN was significantly higher in 13-14,15-16, and 17-18 age groups than 7-8, 9-10, and 11-12 age groups (P < 0.05). No sex differences were found in both DHC and aesthetic component of IOTN between age groups (P > 0.05). CONCLUSION: The normative need distribution was homogeneous within all the age groups according to DHC. However, the subjective need for orthodontic treatment was higher in the younger age groups.

Landmark errors on posteroanterior cephalograms.

INTRODUCTION: It is important to reduce the method errors when evaluating posteroanterior cephalograms to see either small deviations from normal or transverse changes caused by orthodontic treatment. The aim of this study was to determine horizontal and vertical intraexaminer and interexaminer agreement in localization of landmarks in posteroanterior cephalograms of adult patients. METHODS: The sample was gathered retrospectively from the archives of the Department of Orthodontics of Yeditepe University in Istanbul, Turkey. Radiographs of 39 patients diagnosed with skeletal asymmetries (20 women, 19 men) were drawn manually, and a coordinate system was established with software. The tracings were made by 2 operators, after a calibration session on 29 landmarks (22 bilateral, 7 midline). Intraclass correlation coefficients and the Bland-Altman test were used for detecting interexaminer and intraexaminer agreement for each cephalometric variable. RESULTS: The interexaminer agreement test showed that the most problematic landmark was crista galli, which showed moderate consistency between 2 examiners in the y coordinates at 2 time points. Condylar and zygomatic landmarks showed good agreement. The greater wing inferior and superior orbit, maxillary point, menton, anterior nasal spine, antegonial notch, mandibular and maxillary molar point, maxillary and mandibular incisor point, and maxillary and mandibular incisor edge landmarks had excellent agreement between the 2 examiners at the 2 time points in both the x and y coordinates. CONCLUSIONS: There are fewer errors in intraexaminer than in interexaminer correlations in landmark identifications on posteroanterior radiographs. All landmarks investigated except crista galli showed good agreement between measurements.

A report on the use of Er:YAG laser for pilot hole drilling prior to miniscrew insertion.

The aim of the present in vitro study was to investigate the required time period of the Er:YAG laser that is used for drilling through cortical bone when pilot hole drilling is needed before miniscrew insertion. Even though Er:YAG laser is used in various in vivo and in vitro studies, there is no accepted procedure of laser for depth control during drilling through cortical bone. The study sample consisted of 120 cortical bone segments having 1.5 and 2.0 mm of cortical bone thickness. An Er:YAG laser, with a spot size of 1.3 mm and an air-water spray of 40-50 ml/min, was used. The laser was held 2 mm away from and perpendicular to the bone surface with different laser settings. Twelve specimens were prepared for each subgroup. As the cortical bone thickness increased, the time needed to drill through the bone increased. Frequency increase directly caused a decrease in irradiation duration. When three different frequency, three different energy, and four different power values were tested for both the 1.5- and 2-mm cortical bone thicknesses, the shortest duration needed to drill through cortical bone was seen in the 3.6-W (300 mJ-12 Hz) setting. When pilot holes are drilled prior to miniscrew placement in 1.5 to 2 mm of cortical bone using Er:YAG laser, the most appropriate value is found with the 3.6-W (300 mJ-12 Hz) setting.

Cortical bone thickness of the adult alveolar process--a retrospective CBCT study.

OBJECTIVES: To investigate and compare cortical bone thickness of the posterior alveolar process in adult patients presenting with skeletal Class I, II and III malocclusions. METHODS: Cone beam computed tomographic (CBCT) images of 196 adult subjects, aged 20-45, were evaluated. Cortical bone thickness was measured 4 mm from the alveolar crest, as the shortest bucco-lingual dimension of the cortical bone at interdental sites from the distal of the maxillary canine to the mesial of the maxillary second molar. RESULTS: There were no differences between the malocclusion groups in mean age, gender, or vertical pattern (p > 0.05). At all sites measured, there were no statistically significant differences in the means of cortical bone thickness between the groups (p > 0.05). Maxillary palatal bone thickness was reduced in the Class I (p < 0.0001), and Class II (p < 0.001) groups; but mandibular buccal thickness increased significantly (p < 0.001) in all malocclusion groups from anterior to posterior. CONCLUSIONS: There was no difference in cortical bone plate thickness between Class I, II and III subjects when related to mini-implant placement sites. As the measurement site moved towards the posterior, maxillary palatal cortical thickness decreased except in Class III cases, while mandibular buccal bone thickness increased in all malocclusion groups.

Does facial growth pattern affect the perception of lower facial asymmetry?

OBJECTIVES: To investigate the influence of vertical facial type on esthetic perception of lower facial asymmetry as evaluated by orthodontists, dentists, and laypeople. MATERIALS AND METHODS: Three adult females were selected with normal growth patterns (NGP), vertical growth patterns (VGP), and horizontal growth patterns (HGP). Frontal photographs were made symmetric and digitally altered, rotating the lower facial third clockwise, ranging from 0° to 6° in 1° increments. A web-based survey was designed with 24 images (eight images for each model) in random order. Each image was rated using a scale ranging from 0 (unattractive) to 10 (the most attractive) by 75 orthodontists, 73 dentists, and 78 laypeople. Kruskal-Wallis test was used to determine whether differences among groups were significant. Pairwise comparisons were made with Mann-Whitney U test. The significance level was set at P = .05. RESULTS: In NGP, orthodontists and dentists could recognize slighter deviations (2°), while deviations in VGP and HGP under 3° were not recognized by all groups. Severe deviations (≥4°) were distinguished better in HGP by orthodontists and laypeople. In VGP and NGP, there was no significant difference over 4°. CONCLUSIONS: Growth pattern has a significant influence on perception of lower facial asymmetry. Less severe asymmetry can be detected better in NGP. In severe degrees, increments of asymmetry can be perceived more in HGP by orthodontists and laypeople.

Cortical bone thickness of the alveolar process measured with cone-beam computed tomography in patients with different facial types.

INTRODUCTION: The purpose of this study was to determine the cortical bone thickness of the alveolar process in the maxilla and the mandible on cone-beam computed tomographs of adults with low, normal, and increased facial heights. METHODS: This study was conducted on 155 images of adult patients (20-45 years old) who were assigned to the low-angle, normal, and high-angle groups. The thickness of the buccal cortical plates of the maxilla and the mandible, and the palatal cortical plates of the maxilla, were measured. RESULTS: There was no statistically significant difference between the groups regarding mean ages, sex, and sagittal facial types. High-angle patients had significantly lower values than did low-angle patients in all mini-implant insertion sites in both the maxillary and mandibular alveolar bones. The mandibular and maxillary buccal measurements showed a similar pattern; the lowest values were for the high-angle group, followed by the normal group; the highest values were measured in the low-angle patients. CONCLUSIONS: Clinicians should be aware of the probability of thin cortical bone plates and the risk of mini-implant failures at maxillary buccal alveolar mini-implant sites in high-angle patients, and at mandibular buccal alveolar mini-implant sites between the canine and the first premolar in normal and high-angle patients.

Orofacial Manifestations Associated with Muscular Dystrophies: A Review.

The aim of this review is to evaluate the developmental, functional, and morphological aspects of the craniofacial complex in patients with myotonic dystrophy type 1 (DM1), Facioscapulohumeral muscular dystrophy (FSHD), and Duchenne muscular dystrophy (DMD). The degree of disease onset and severity varied from patient to patient, and most parameters indicated a greater degree of deterioration in older patients. It was found that all the muscular dystrophies studied showed altered craniofacial morphology, with malocclusion as the most consistent clinical characteristic. Particularly DM1 patients, who are the most studied, showed significant vertical aberration and post-normal occlusion. DMD patients are reported mainly with altered dental arch dimensions which influence functional capacities. Data for FSHD patients are very limited, but facial asymmetry and muscular weakness appear to be the most prominent findings. Patients with muscular dystrophies present deviations in growth and development as well as in orofacial morphology. Increased prevalence of malocclusions, of both skeletal and dental origins, characterize patients with muscular dystrophies. Different dentofacial characteristics are reported among patients with different types of muscular dystrophies. Further research is needed to clarify the orofacial phenotypic expression of muscular dystrophies.

Influence of facial type on attractiveness of vertical canine position from the perspective of orthodontists and laypeople.

OBJECTIVES: To evaluate the attractiveness of changes in vertical position of maxillary canines in frontal smiles of different facial types, and to evaluate the esthetic perceptions of orthodontists and laypeople, and the influence of facial type on these perceptions. MATERIALS AND METHODS: Three adult female volunteers were selected as individuals with normal, vertical, and horizontal growth patterns. Frontal posed smile photographs were digitally altered by adjusting vertical positions of the maxillary canines above, below, or coincident with the incisal line in increments of 0.5 mm within a range of 1 mm of extrusion and intrusion. For assessment, a web-based survey was formed with 18 images (six images for each model). A scale was present underneath each image, graded from 0 to 10 (0: unattractive; 10: the most attractive). Images were rated by 233 participants (105 orthodontists; 128 laypeople). RESULTS: Orthodontists scored 0-mm images significantly as the highest in all groups. Laypeople scored significantly higher for -0.5 mm images regardless of facial type. The lowest scored images were -1 mm (except for horizontal pattern) and +1 mm images. Mean values of scores given by men were higher (P < .05). CONCLUSIONS: Orthodontists favored ideal dental alignment and preferred the incisal edges of central and canine teeth to be at the same level. Laypeople preferred a smoother smile arc than orthodontists and found harmony with the soft tissue more attractive. Facial type affected perceptions of the vertical changes of maxillary canines.

The Association of ACTN3 Rs1815739 Polymorphism with Various Malocclusion Phenotype.

OBJECTIVE: A functional polymorphism on the 16th exon of the alpha-actinin-3 gene has an effect on the protein structure and cellular signaling and therefore on muscle contraction. In this study, we aimed to analyze the alpha-actinin-3 rs1815739 polymorphism in 3-dimensional malocclusions and different craniofacial skeletal patterns. METHODS: Forty-nine volunteering subjects enrolled for the study. Genotyping of alpha-actinin-3 rs1815739 polymorphism was per- formed using real-time polymerase chain reaction. Pre-orthodontic cephalometric radiographs were traced using NemoTech ceph- alometric tracing software. IBM SPSS Statistics for Windows was utilized to carry out statistical analysis. P < .05 was considered to be statistically significant. RESULTS: The respective numbers and the percentages of alpha-actinin-3 rs1815739 polymorphisms for RR, RX, and XX genotypes were 39 (79.6%), 4 (8.2%), and 6 (12.2%), respectively. Twenty-one patients had low angle vertical patterns and 17 patients had Class I and the same number of the patients had Class III facial patterns. But none of these had statistically significant difference in terms of alpha-actinin-3 rs1815739 polymorphism and in vertical or sagittal facial patterns, and mandibular incisor inclination. When we examined the maxillary anteroposterior position, we found a significant difference between rs1815739 polymorphisms (P < .05). Also, we detected a significant difference between rs1815739 polymorphism and maxillary incisor inclination (P < .05). CONCLUSION: Maxillary incisor inclination and maxillary anteroposterior position are associated with alpha-actinin-3 rs1815739 poly- morphism in a Turkish cohort.

In-house Aligners: Why We Should Fabricate Aligners in Our Clinics?

As digital dentistry is evolving, contemporary orthodontics is embracing clear aligners as a tool more than ever before. On the other hand, aligners are being marketed to patients by aligner companies in every way that is possible. The demand of the end user and the pursuit of the orthodontist toward less chair time has made aligners popular in the last decade. As the price for having all machinery needed to fabricate aligners has decreased, orthodontists may choose to fabricate aligners in-house. In-house fabrication will bring advantages in the price, delivery time, and doctor's time if it is done correctly.

Temporomandibular Disorders: Fundamental Questions and Answers.

This review aimed to present the current evidence-based answers to a questionnaire which was developed to evaluate the beliefs and knowledge of dental professionals concerning temporomandibular disorder (TMD). A literature review was conducted using the PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane, Google Scholar, and Scopus search engines from January 1980 to June 2020 corresponding to TMD diagnosis, causes, management, and consequences. A total of 50 articles were considered relevant and selected for full review. The etiology of TMD is multifactorial and complicated and involves several direct and indirect factors. Orthodontic treatment does not appear to either prevent or relieve TMD to a great degree. Nevertheless, condylar and occlusal stability reduces the risk of TMD development. As a result, an assessment of the function of masticatory system prior to beginning orthodontic therapy is fundamental. If signs and symptoms of TMD are significantly present, they should be managed before any orthodontic intervention. Moreover, psychological disorders are strongly associated with joint and facial pain. Thus, professionals who work with chronic TMD patients need to be aware of the psychological aspects of chronic pain and refer the patient for psychological evaluation when warranted. Future research elucidating a cause-effect relationship and neurobehavioral processes underlining chronic pain should be performed.

Enamel colour changes at debonding and after finishing procedures using five different adhesives.

The purpose of this study was to evaluate enamel colour alteration of five different orthodontic bonding adhesives by means of digital measurements after exposure to photoageing in order to simulate discolouration of adhesives in vivo. Seventy-five non-carious premolars were randomly divided into five equal groups. The brackets were bonded with five different adhesives (Transbond XT, Eagle Bond, Light Bond, Blugloo, Unite) and subjected to artificial accelerated photoageing for 24 hours. The enamel surfaces were colourimetrically evaluated before bonding, following debonding and cleaning with a tungsten carbide bur, after polishing with Stainbuster, and after photoageing of the debonded enamel surface. The Commission Internationale de l'Eclairage(CIE) colour parameters (L*a*b*) were recorded and colour differences (DeltaE) were calculated. The results were statistically analyzed using the Kruskall-Wallis test. Further investigation among subgroups was performed using Dunn's multiple correlation test (P < 0.05). The clinical detection threshold for DeltaE value was set at 3.7 units. DeltaE values between the first and second measurements showed an increase in the Transbond XT, Eagle Bond, and Light Bond groups. The highest DeltaE value was 1.51 +/- 1.15 in the Transbond XT group. No clinically significant DeltaE value was observed. Colour changes of orthodontic bonding systems induced by photoageing cannot be clinically observed. Polishing with Stainbuster eliminates enamel surface roughness, which may improve light reflection.

Shear bond strength of brackets bonded to amalgam with different intermediate resins and adhesives.

The aims of this study were to compare, in vitro, the shear bond strength (SBS) of stainless steel orthodontic brackets bonded to silver amalgam with the use of three different intermediate resins and two different adhesives, and to evaluate bond failure mode. Forty-five amalgam specimens were divided into three equal groups. In groups 1 and 2, the brackets were bonded with Unite (3M Unitek) using Reliance Metal Primer (RMP; Reliance Orthodontic Products) and Power Bond OLC (PB OLC; Ortho Organizers Inc.) as intermediate resins, respectively. In group 3, Resinomer and One-Step Plus (OS+; Bisco Inc.) were used. Thirty bovine teeth served as the controls to test bracket bonding to acid-etched enamel with Unite and Resinomer-OS+. After thermocycling from 10 to 50 degrees C 1000 times, all samples were tested for SBS. Bond failure sites were classified using a modified adhesive remnant index (ARI) system. Data were analyzed with one-way analysis of variance, post hoc Tukey multiple comparison and chi-square tests. The results showed that the mean SBS to amalgam surfaces were significantly lower than those to etched bovine enamel (P<0.001). There were no statistically significant differences in mean SBS between the amalgam bonding groups (P>0.05). For the ARI, significant differences were found between the amalgam- and enamel-bonding groups (P<0.001). The mean SBS of stainless steel orthodontic brackets bonded to amalgam surfaces with RMP, PB OLC, OS+ intermediate resins and Unite and Resinomer adhesives was significantly lower than to etched bovine enamel. Bond failure occurred at the amalgam-adhesive interface regardless of the adhesive system and without damage to the amalgam restoration.

Reduction of salivary mutans streptococci in orthodontic patients during daily consumption of yoghurt containing probiotic bacteria.

Previous studies have suggested that probiotic supplements in dairy products may affect the oral microbial ecology, but the effect in orthodontic patients has not previously been reported. The aim of the present study was to examine whether short-term consumption of fruit yogurt containing probiotic bifidobacteria would affect the levels of salivary mutans streptococci and lactobacilli in patients with fixed orthodontic appliances. A double-blind, randomized crossover study was performed and 24 healthy adolescents (12-16 years) undergoing orthodontic treatment were followed over four periods. During periods 2 and 4 (2 weeks each), the subjects ingested 200 g fruit yogurt containing Bifidobacterium animalis subsp. lactis DN-173010 (2 x 10(8) colony forming units/g) once daily or a control yogurt without viable bacteria. Periods 1 and 3 were run-in and wash-out periods of 1 and 6 weeks, respectively. Salivary mutans streptococci and lactobacilli were enumerated with chair-side kits before and after the yogurt consumption periods. Pre- and post-treatment values within each regimen were compared with a two-tailed marginal homogeneity test for categorical data. A statistically significant reduction of salivary mutans streptococci was recorded after probiotic yogurt consumption (P < 0.05), which was in contrast to the control yogurt. No significant alterations of the salivary lactobacilli counts were observed. Short-term daily consumption of fruit yogurt containing Bifidobacterium animalis subsp. lactis DN-173010 may reduce the levels of mutans streptococci in saliva during orthodontic treatment with fixed appliances.

Impact of Discipline-Based vs. Interdisciplinary Orthodontic Courses on Dental Students' Performance.

The aim of this longitudinal study was to assess the effect on dental students' grades of participating in a third-year course taught in orthodontics alone versus an interdisciplinary course taught with orthodontics and pediatric dentistry combined. In the five-year dental curriculum at Yeditepe University in Istabul, Turkey, the third-year orthodontic course was taught as a single discipline until 2010, when the course was redesigned as an interdisciplinary course in orthodontics and pediatric dentistry. This retrospective study analyzed all 540 students' grades in orthodontic courses in the third, fourth, and fifth years from 2003-04 to 2014-15 to determine the impact of the third-year course design on students' performance. Students were divided into two cohorts: group A (which experienced the single discipline course, 2003-04 to 2009-10; 181 female, 117 male) and group B (which experienced the combined course, 2010-11 to 2014-15; 152 female, 90 male). In both groups, significant differences were found for the third-, fourth-, and fifth-year orthodontic grades (p<0.05). The grades of the third-year and fifth-year students in 2014-15 were significantly higher than in 2010-11 (p<0.05) in group B. Intergroup comparison showed that the third- and fifth-year grades were significantly higher in group B than in group A (p<0.05). These results suggest that the interdisciplinary delivery of basic knowledge in the third year had facilitated the learning process and deep learning in the more advanced orthodontic courses in the fifth year.

Evaluation of the Impact of Interdisciplinary Case-Based Courses in Dental Education on Smile Evaluation Skills of Undergraduate Students.

OBJECTIVE: The purpose of the present study was to compare the perception of smile aesthetic between 3rd-, 4th-, and 5th-year dental students to identify if interdisciplinary courses have an impact on the attitudes of students. METHODS: A total of 118 dental students (3rd-, 4th-, and 5th-year; N=43, 43, and 32, respectively) assessed the aesthetic attractiveness of four smile photographs (normal, high, low, and asymmetric smile lines). To enhance the crown, length-to-width ratio and color Digital Smile Design (DSD) were applied to all photographs, and then scoring was performed by using the Visual Analog Scale (VAS). RESULTS: The VAS scores were all <60 regardless of the year of the student. The lowest scores were given for asymmetric smile line. Comparison of the scores of the different years showed statistically insignificant scores between 3rd- and 4th-year dental students (p>0.05), whereas statistical differences between 4th- and 5th-year dental students were found (Cases 1, 2, and 3: p<0.05 and Case 4: p<0.01). CONCLUSION: All students were critical in the evaluation of smiles. Hence, the motivation for critical thinking based on multidisciplinary courses until 3rd year, the skepticism, and also the perception of the students were increased. The difference between 4th- and 5th-year student aesthetic perceptions showed the impact of interdisciplinary course on enhanced judgment competency of the students.

Effect of orthognathic surgery on masticatory performance and muscle activity in skeletal Class III patients.

OBJECTIVE: To evaluate the effect of double jaw orthognathic surgery (OGS) on masticatory performance and electromyographic activity of the masseter and anterior temporal muscles in skeletal Class III patients. METHODS: Individuals were instructed to chew standardized round tablets of silicone impression material. The cumulative weight percentage was calculated using sieve analysis. The bilateral surface electromyographic activity of the muscles was evaluated. Following the orthodontic treatment, a stabilization splint was fabricated. Patients were instructed to wear it full-time until the surgical procedure occurred. Recordings were performed before the splint application (T0), after the splint application (T1), 1 month after the OGS (T2), and 6-8 months after the OGS (T3). RESULTS: Median particle size of the chewed silicone material did not differ from T0 to T1 with the use of an occlusal splint (p > 0.05). However, it decreased from 9.46 to 6.92 cm from T2 to T3. From T0 to T3, a statistically significant decrease was found, following the surgical intervention (p < 0.01). A significant decrease in masticatory muscle activity was also observed during the relaxation test from T0 to T3, at which time it reached the control group value. DISCUSSION: OGS enhanced masticatory function by improving occlusion in individuals with a dentofacial deformity.

Evaluation of buccolingual molar inclinations among different vertical facial types.

OBJECTIVE: The aim of this study was to compare the buccolingual inclination of maxillary and mandibular molars in adults with different vertical facial types. METHODS: Cone-beam computed tomography images of 135 adult patients (age, 20-45 years) with skeletal Class I maxillomandibular relationships were assigned to normodivergent (n = 46), hypodivergent (n = 49), and hyperdivergent groups (n = 40) according to linear and angular sella-nasion/gonion-menton measurements. The normodivergent group consisted of 24 females and 22 males, hypodivergent group of 26 females and 23 males, and hyperdivergent group of 24 females and 16 males. Buccolingual inclination of the maxillary and mandibular first and second molars was measured relative to the occlusal plane. One-way analysis of variance was used for intergroup comparison. Gender differences were evaluated using independent t-tests. RESULTS: Buccolingual molar inclinations did not differ significantly between females and males (p > 0.05). There were no statistically significant differences among the buccolingual inclinations of the first and second maxillary and mandibular molars of the groups (p > 0.05). CONCLUSIONS: Buccolingual inclinations of maxillary and mandibular molars are similar in normodivergent, hyperdivergent, and hypodivergent adults with Class I sagittal relationships.

The Effect of Awareness of American Board of Orthodontics Criteria on Treatment Outcomes in a Postgraduate Dental Clinic.

The aims of this study were to evaluate the posttreatment outcomes in a postgraduate orthodontic clinic following a course on American Board of Orthodontics Cast and Radiograph Evaluation (ABO-CRE); to compare the outcomes of postgraduate students who took the course before and after finishing treatment of their cases; and to assess if the need for orthodontic treatment as determined by the Index of Orthodontic Treatment Need (IOTN) at the beginning of treatment affected students' final scores. A course on ABO-CRE was given to second- (group A), third- (group B), and fourth- (group C) year postgraduate students at Yeditepe University, Istanbul, Turkey, in 2012. Pre- and posttreatment plaster models of 253 cases (group A) were treated by students in 2011-12. An additional 251 (group B, 2012-13) and 341 (group C, 2013-14) cases were evaluated in the first and second years after the course, respectively. The models were graded retrospectively using the ABO-CRE and IOTN. The results showed that the total mean scores on the posttreatment plaster models were significantly higher in the pre-course group than the first- and second-year post-course group (p<0.05 and p<0.01, respectively). The borderline cases (grade 3) received a lower score on the ABO-CRE than the cases with need (grade 4) (p<0.01) and severe need (grade 5) (p<0.01) for orthodontic treatment. Increasing awareness by giving information about the ABO-CRE significantly improved the posttreatment success of these postgraduate students. After the course, treatment outcomes in the following year were better than two years later, suggesting it may be useful to teach the course annually to refresh students' knowledge.

Maxillary buccal cortical plate inclination at mini-screw insertion sites.

OBJECTIVE: To evaluate whether buccal cortical bone inclination varies for the maxillary alveolar processes of adult patients with decreased, normal, and increased facial heights. MATERIALS AND METHODS: Cone-beam computed tomography images of 135 adult patients, including 49 hypodivergent subjects (26 women, 23 men), 40 hyperdivergent subjects (24 women, 16 men), and 46 normodivergent (25 women, 21 men) were analyzed. Cortical bone inclination measurements were made relative to the occlusal plane. Cross-sectional slices of the maxilla were taken at interdental sites from the distal aspect of maxillary canine to the mesial aspect of maxillary second molar. RESULTS: Analysis of variance indicated significant differences (P < .05) between the angles formed by the line tangent to the cortical bone and the occlusal plane among the vertical facial types for the regions between canine and first premolar and between second premolar and first molar at miniscrew insertion sites. CONCLUSION: The results of this study indicate that vertical facial pattern should be taken into consideration when adjusting the insertion angle of miniscrews at the maxillary buccal region.