Cephalometric investigation of first cervical vertebrae morphology and hyoid position in young adults with different sagittal skeletal patterns.

The aim of this retrospective study was to examine hyoid bone position and C1 (atlas) morphology in males and females and analyze these parameters with respect to different sagittal skeletal patterns via cephalometry, with the goal of identifying cephalometric norms. Lateral cephalometric radiographs from 120 individuals (average age: 21.1 ± 2.9 years) were classified according to their ANB angle (Class I, II, or III) and used to assess 14 parameters. Class I and II patients showed significant differences in Hy-NSL, Hy-PD, Hy-CVT, Lum, and a-p measurements. These parameters were consistently larger in males than in females. Intergroup comparisons among males showed significant differences in the SNA, ANB, Hy-CVT, X, and Z measurements. The hyoid was positioned more inferiorly and anteriorly and was more prominent in males than in females in all groups. Among participants exhibiting a Class I skeletal pattern, C1 was also larger in the anterior-posterior direction in males than in females. In the sagittal plane, the hyoid was positioned similarly in males with either Class I or III skeletal patterns but was positioned posteriorly in males with a Class II skeletal pattern. In addition, the vertical position of C1 varied with sagittal skeletal pattern in males.

Surface roughness of the restored enamel after orthodontic treatment.

INTRODUCTION: After fixed appliance treatment, one concern is to restore the enamel surface as closely to its original state as possible. A variety of cleanup processes are available, but all are time-consuming and carry some risk of enamel damage. The purpose of this study was to examine tooth surfaces restored with different cleanup protocols. METHODS: Ninety-nine premolars extracted for orthodontic purposes were used. The 2 materials tested were Sof-Lex disks (3 M ESPE AG, Seefeld, Germany) and fiberglass burs (Stain Buster, Carbotech, Ganges, France). These were used alone and in combination with high- and low-speed handpieces, with which they were also compared. Eight groups were ultimately tested. All groups were compared with intact enamel, which served as the control group. From each group, 10 samples were examined with profilometry and 1 with scanning electron microscopy. Adhesive remnant index scores were recorded to ensure equal distributions for the groups. The time required for the cleanup processes and profilometry test results were also recorded. RESULTS: The fastest procedure was performed with high-speed handpieces, followed by low-speed handpieces. Sof-Lex disks and fiberglass burs required more time than carbide burs but did not result in significantly longer times for the cleanup procedure when combined with tungsten carbide-driven low- or high-speed handpieces or when used alone with low-speed handpieces. Although Sof-Lex disks were the most successful for restoring the enamel, it was not necessary to restore the enamel to its original surface condition. Generally, all enamel surface-roughness parameters were increased when compared with the values of intact enamel. The average roughness and maximum roughness depth measurements with Sof-Lex disks were statistically similar to measurements of intact enamel. CONCLUSIONS: No cleanup procedure used in this study restored the enamel to its original roughness. The most successful was Sof-Lex disks, which restored the enamel closer to its original roughness.

Mixed-dentition analysis in a Turkish population.

OBJECTIVE: To study the reliability of the Tanaka-Johnston mixed-dentition analysis in Turkish individuals and develop a new population-adjusted regression equation for predicting the size of unerupted canines and premolars. The new regression equations were tested to establish their validity in Turkish children. METHODS: The mesiodistal dimensions of teeth on study casts of 12- to 14-year-old Turkish children were measured. The actual tooth measurements were then compared with predicted values using the Tanaka-Johnston equation. Subsequently, the new regression equations were tested in a group of 50 individuals to determine their validity. RESULTS: The Tanaka-Johnston regression equations overestimated the actual mesiodistal widths of permanent canines and premolars. With the new regression equations, no statistically significant differences were observed between actual and predicted widths. CONCLUSION: The Tanaka-Johnston prediction method is not accurate when applied to a Turkish population. The new equations are reliable for predicting the width of unerupted canines and premolars in Turkish individuals.

Effects on the sagittal pharyngeal dimensions of protraction and rapid palatal expansion in Class III malocclusion subjects.

This study examined the effects of rapid palatal expansion (RPE) and maxillary protraction headgear therapy in 18 patients with a skeletal Class III malocclusion (11 girls and seven boys; mean age 10.9 years) on upper airway dimensions compared with an untreated control group (nine girls and eight boys; mean age 10.9 years). Pre- and post-treatment cephalometric radiographs were traced and analysed at similar time intervals. The average treatment time was 6.94 +/- 0.56 months. Wilcoxon's test was used for intragroup comparisons and the Mann-Whitney U-test for intergroup comparisons. A significant increase occurred in the maxillary forward position. Mandibular forward movement and downward and backward rotation were inhibited. In addition, the upper incisors were proclined (P < 0.001), and the lower incisors were significantly retroclined (P < 0.05). When the treatment and control groups were compared, the upper airway linear measurements (pns-ad1, pns-ad2, APW-PPW, APW'-PPW') and the nasopharyngeal area had increased in the treatment group. These results demonstrated that maxillary expansion together with protraction of the maxilla improved naso- and oropharyngeal airway dimensions in the short term.

Comparison of facial proportions and anthropometric norms among Turkish young adults with different face types.

BACKGROUND: This study aimed to determine the prevalence of three different face types among Turkish young adults based on facial indices, to assess and compare the vertical and horizontal dimensions for each type, and to establish anthropometric norms for Turkish adults. METHODS: A total of 173 healthy young adults (83 females and 90 males) 17 to 25 years of age were examined. Using anthropometric landmarks, 8 horizontal and 10 vertical direct measurements were made with a millimetric compass. RESULTS: Using facial indices, 59 of the 173 subjects were classified as euryprosopic, 49 as mesoprosopic, and 65 as leptoproposic. In the total evaluation of both groups, all the parameters were higher in the males except forehead heights 1 and 2. A comparison of face types in females and males separately showed no significant differences between the parameters. CONCLUSIONS: The data presented in this study may help plastic surgeons and orthodontists objectively determine the relationships between facial structures for different face types. Additionally, the facial anthropometric norms derived from this study may be useful in the treatment of Turkish patients.

A practical method for determining pubertal growth spurt.

INTRODUCTION: It is important to evaluate skeletal maturation in orthodontic treatment. Hand-wrist and cervical maturation stages have been shown to be correlated with skeletal growth changes during puberty. The cervical vertebrae have 6 maturation phases, whereas the medial phalange of the third finger has 5 stages; a modified version has 6 stages. The purpose of this study was to determine the correlation of the cervical vertebrae maturation index with the modified medial phalange index. METHODS: Lateral cephalometric and left-hand medial phalange radiographs of 150 males between the ages of 9 and 19 who were referred for orthodontic treatment were examined. RESULTS: The 6 modified medial phalange stages were found to correlate with the 6 cervical vertebral maturation stages. CONCLUSIONS: Because cervical vertebrae stage is a reliable maturation indicator, the medial phalange of the third finger can be used instead to assess a subject's skeletal maturation.

Orthodontic and orthopaedic changes associated with treatment in subjects with Class III malocclusions.

The aim of this study was to determine the cephalometric changes in subjects with Class III malocclusions after rapid palatal expansion (RPE) and facemask treatment. The 30 subjects presented with developing Class III malocclusions. The treatment group comprised 15 patients (eight girls and seven boys, mean age 11 years 6 months) who had undergone RPE and facemask therapy. The control group consisted of nine girls and six boys with a mean age of 11 years 8 months. Radiographs were take at the same time intervals for both groups, and the average treatment time was 15 months. A Wilcoxon test was used to determine significant differences before and after treatment, and a Mann-Whitney U-test to analyse differences between the treatment and control groups. In the sagittal plane, significant changes were observed in both groups. In the treatment group, the following dimensions increased significantly: A perpendicular to FHp (P < 0.001), ANS-PNS (P < 0.01), 6 perpendicular to FHp (P < 0.05); in the control group Go-Gn (P < 0.05) increased significantly. In the treatment group, SN/Go-Gn and SN/ANS-PNS had higher values and this finding was significant (P < 0.05). Managing developing Class III malocclusions with RPE and maxillary protraction presents favourable results, such as vertical and sagittal displacement of point A.