Ethnic differences in the soft tissue profiles of Turkish and European-American young adults with normal occlusions and well-balanced faces.

The aim of this study was to evaluate soft tissue differences between Turkish and North American adults by comparing two sample populations with ideal occlusion and well-balanced faces. Lateral cephalometric radiographs of 117 Anatolian Turkish adults (65 female and 52 male, mean age: 23.9 ± 2.8 years) were compared with a sample of 116 adults of European-American ancestry (64 female and 52 male, mean age: 25.0 ± 6.8 years). The cephalometric analyses of Holdaway, Epker, and Legan and Burstone were performed using Dolphin Image Software 9.0. Thirty-two measurements (27 linear and 5 angular) were analysed. For statistical evaluation, independent samples t-tests were performed. Distinct differences were found between the two samples in facial convexity, upper lip position and length, lower lip position, chin prominence, and chin thickness. Vertical proportional findings were similar between groups. Ethnic differences were found between Turkish and North American adults in the soft tissue profile. It is appropriate to consider these differences during routine diagnosis and treatment planning of a Turkish patient or an American patient of European ancestry.

Effect of rapid maxillary expansion and transpalatal arch treatment associated with deciduous canine extraction on the eruption of palatally displaced canines: A 2-center prospective study.

INTRODUCTION: Our aim was to investigate the effect of rapid maxillary expansion and transpalatal arch therapy combined with deciduous canine extraction on the eruption rate of palatally displaced canines (PDCs) in patients in the late mixed dentition in a 2-center prospective study. METHODS: Seventy subjects were enrolled based on PDCs diagnosed on panoramic radiographs. The treatment group (TG, 40 subjects) underwent RME followed by TPA therapy and extraction of the deciduous canines. The control group (CG, 30 subjects) received no orthodontic treatment. At the start of the trial, panoramic radiographs and dental casts were compared between the TG and the CG with the Mann-Whitney U test (P <0.05). At the second observation (cervical vertebral maturation stage 5 or 6), all subjects were reevaluated, and the eruption of the maxillary permanent canines was assessed. The rates of success in the TG were compared with those in the CG by means of chi-square tests (P <0.05). The association of PDCs with other dental anomalies was reported. RESULTS: No statistically significant difference was found for any measurement at the start of the trial between the 2 groups. The prevalence rates of eruption of the maxillary canines were 80% for the TG and 28% in the CG, a statistically significant difference (chi-square =16.26, P <0.001). The prevalence rate at the start for the pubertal stages of cervical vertebral maturation (63%) was significantly greater in the unsuccessfully treated subjects than in the successfully treated ones (16%). In the CG, all successful subjects had PDCs that overlapped the corresponding deciduous canine or the distal aspect of the lateral incisor. Eruption of PDCs in both groups was associated significantly with an open root apex. CONCLUSIONS: Rapid maxillary expansion therapy followed by a transpalatal arch combined with extraction of the deciduous canine is effective in treating patients in the late mixed dentition with PDCs. Pretreatment variables indicating success of treatment on the eruption of PDCs were less severe sectors of displacement, prepubertal stages of skeletal maturity, and open root apices of PDCs. Several dental anomalies were associated significantly with PDCs, thus confirming the genetic etiology of this eruption disturbance.

An RCT on treatment of palatally displaced canines with RME and/or a transpalatal arch.

AIM: To investigate the effect of rapid maxillary expansion (RME) and/or transpalatal arch (TPA) therapy in combination with deciduous canine extraction on the eruption of palatally displaced canines (PDCs). SUBJECTS AND METHODS: Hundred and twenty subjects were enrolled in an RCT based on PDCs diagnosed on panoramic radiographs and they were randomly assigned to one of four study groups. Three treatment groups (TGs) (RME followed by TPA therapy plus extraction of deciduous canines, RME/TPA/EC group, 40 subjects; TPA therapy plus extraction of deciduous canines, TPA/EC group, 25 subjects; extraction of deciduous canines, EC group, 25 subjects) were analyzed. A control group (CG, 30 subjects) received no orthodontic treatment. Prevalence rates of eruption of PDCs in the three TGs were compared with the CG at T2. Predictive features at T1 for successful canine eruption were tested in the three TGs. RESULTS AND DISCUSSION: The prevalence of canine eruption was 80 per cent for the RME/TPA/EC group, 79 per cent for the TPA/EC group, 62.5 per cent for the EC group, versus 28 per cent in the CG, with statistically significant differences between all the groups, with the exception of the comparison between RME/TPA/EC and TPA/EC. Predictive pretreatment variables for the success of treatment were less severe sectors of canine displacement, prepubertal stages of skeletal maturity, and an open root apex of PDCs. CONCLUSIONS: The use of a TPA in absence of RME can be equally effective than the RME/TPA combination in PDC cases not requiring maxillary expansion, thus reducing the burden of treatment for the patient.

Comparison of craniofacial characteristics of typical Chinese and Caucasian young adults.

The purpose of this study was to determine the cephalometric norms of typical Chinese young adult subjects with normal occlusions and well-balanced faces and to compare these norms with those derived from a matched Caucasian sample. Lateral cephalograms of 65 untreated Chinese adults (25 males, mean age 19.3 ± 3.0 years and 40 females, mean age 20.3 ± 3.4 years) were compared with a sample of 90 untreated Caucasian adults (30 males, mean age 24.1 ± 5.7 years and 60 females, mean age 22.9 ± 5.2 years). Each lateral cephalogram was traced and digitized, and conventional cephalometric analyses were applied. Independent sample t-tests were used to compare the values between the two ethic samples. Smaller midfaces and shorter mandibles were observed in Chinese young adults compared with those of Caucasians. The average value of lower anterior face height (ANS-Me) was longer in the Chinese females than that in the Caucasian females (P < 0.001). A greater vertical dimension also was seen in Chinese males compared with Caucasian males when evaluated by analysis of the facial axis angle (P < 0.05). The upper and lower lips were more protrusive in the Chinese, and a more convex facial profile was seen compared with the Caucasian sample. Significant differences in hard and soft tissue characteristics were found between Chinese and Caucasian young adults with normal occlusions and well-balanced faces. Gender and racial/ethnic differences must be taken into consideration during orthodontic diagnosis and treatment planning for the individual patient.

Changes in occlusal relationships in mixed dentition patients treated with rapid maxillary expansion. A prospective clinical study.

OBJECTIVE: To prospectively measure occlusal changes in mixed dentition patients who underwent a standardized early expansion protocol. MATERIALS AND METHODS: The treatment sample consisted of 500 patients who were assigned to three groups according to molar relationship: Class I (n = 204), end-to-end (n = 166), and Class II (n = 130). All patients were treated with a bonded rapid maxillary expander (RME) followed by a removable maintenance plate and a transpalatal arch. Mean age at the start of treatment was 8.8 years (T(1)), with a pre-phase 2 treatment cephalogram (T(2)) taken 3.7 years later. The control sample consisted of the cephalometric records of 188 untreated subjects (Class 1, n = 79; end-to-end, n = 51; Class II, n = 58). RESULTS: The largest change in molar relationship was noted when the Class II treatment group (1.8 mm) was compared with the matched control group (0.3 mm). A positive change was seen in 81% of the Class II treatment group, with almost half of the group improving by > or = 2.0 mm. The end-to-end treatment group had a positive change of 1.4 mm, compared with a control value of 0.6 mm, and the Class I group of about 1 mm compared with controls, who remained unchanged (0.1 mm). Skeletal changes were not significant when any of the groups were compared with controls. CONCLUSION: The expansion protocol had a significantly favorable effect on the sagittal occlusal relationships of Class II, end-to-end, and Class I patients treated in the early mixed dentition.

The role of the posed smile in overall facial esthetics.

OBJECTIVE: To evaluate the role of the posed smile in overall facial esthetics, as determined by laypersons and orthodontists. MATERIALS AND METHODS: Twenty orthodontists and 20 lay evaluators were asked to perform six Q-sorts on different photographs of 48 white female subjects. The six Q-sorts consisted of three different photographs for each of two time points (pre- and posttreatment), as follows: (1) smile-only, (2) face without the smile, and (3) face with the smile. The evaluators determined a split-line for attractive and unattractive images at the end of each Q-sort. The proportions of attractive patients were compared across Q-sorts using a Wilcoxon signed-rank test for paired data. The evaluators also ranked nine facial/dental characteristics at the completion of the six Q-sorts. RESULTS: Evaluators found the pretreatment face without the smile to be significantly more attractive than the face with the smile or the smile-only photographs. Dissimilar results were seen posttreatment; there was not a significant difference between the three posttreatment photographs. The two panels agreed on the proportion of "attractive" subjects but differed on the attractiveness level of each individual subject. CONCLUSIONS: The presence of a malocclusion has a negative impact on facial attractiveness. Orthodontic correction of a malocclusion affects overall facial esthetics positively. Laypeople and orthodontists agree on what is attractive. Overall facial harmony is the most important characteristic used in deciding facial attractiveness.

A controlled study on diagnostic and prognostic measurements of palatally displaced canines on lateral cephalograms.

OBJECTIVES: The aim of this prospective controlled study was to determine the role that the lateral cephalogram can play in the detection of palatally displaced canines (PDCs). MATERIALS AND METHODS: The study was comprised of 85 subjects in the late mixed dentition. Thirty-five subjects had PDCs (either unilateral or bilateral) identified on the panoramic radiograph (PDC group), and 50 subjects presented with a normal pathway of upper permanent canine eruption as assessed on panoramic radiographs (No-PDC group). Linear and angular measurements on the lateral cephalograms concurrent with panoramic radiographs were compared between the PDC and No-PDC group statistically. RESULTS: All angular measurements that incorporated the main axis of the canine (to Frankfort horizontal, to the palatal plane, or to the axis of the central incisor) were significantly smaller in the PDC group (p<0.001). In terms of linear measurements, both the distance from the tip of the canine to the vertical axis of the central incisor parallel to Frankfort horizontal and the distance from the tip of the canine to the anterior alveolar ridge parallel to Frankfort horizontal showed significantly larger values in the PDC subjects than in normal controls. On the contrary, the vertical distance from the tip of the canine to the functional occlusal plane did not reveal any significant difference between the PDC and the No-PDC group. CONCLUSIONS: Early diagnosis of PDC is essential in order to avoid the occurrence of final canine impaction. If 3-D images of a displaced canine cannot be acquired, a lateral cephalogram can be a useful tool for the early detection of PDC in the late mixed dentition. The angle between the vertical axis of the canine and the palatal plane demonstrate diagnostic value when assessing PDCs. Values for this angle smaller than 102 degrees can indicate the presence of PDC.