Facial profile study using 3-dimensional photographs to assess esthetic preferences of Hong Kong Chinese orthognathic patients and laypersons.

INTRODUCTION: This study was conducted to investigate and compare esthetic perceptions of different facial profiles among Hong Kong Chinese laypersons and patients scheduled for orthognathic treatment. METHODS: Two sets of 3-dimensional facial photographs (1 male and 1 female) each comprised 7 images that showed different dentoskeletal relations (ie, Class I, bimaxillary protrusion, bimaxillary retrusion, maxillary protrusion, maxillary retrusion, mandibular protrusion, and mandibular retrusion). The sets of photographs were shown to 101 laypersons (age, 28.87 ± 6.22 years) and 60 patients seeking orthognathic treatment (age, 27.12 ± 6.07 years). They rated their esthetic perceptions of the photographs on the basis of a 100 mm visual analog scale (VAS) from 0 (very unattractive) to 100 (very attractive). RESULTS: The dentoskeletal Class I facial profile was ranked as the most attractive profile. Female orthognathic judges selected the retrusive maxilla while male orthognathic judges and male and female laypersons ranked the mandibular protrusion profile as the least attractive profile for both females and males. A bimaxillary protrusive female profile was viewed as more attractive by the orthognathic male (P = 0.006) and female (P = 0.006) judges, compared with female layperson judges. After adjustment for age, no statistically significant interaction between sex and judges (P >0.10) for all VAS scores were detected. For the female bimaxillary protrusive profile, orthognathic patient judges assigned a mean VAS score of 9.174 points higher than layperson judges (95% confidence interval, 3.11-15.24; P = 0.003). CONCLUSION: Dentoskeletal Class I facial profile was generally considered the most attractive profile in both sexes; male and female orthognathic patients preferred a bimaxillary protrusive female profile. A concave facial profile was perceived as least attractive in both sexes.

Three-Dimensional Pharyngeal Airway Changes After 2-Jaw Orthognathic Surgery With Segmentation in Dento-Skeletal Class III Patients.

PURPOSE: To investigate short- and long-term three-dimensional changes of pharyngeal airway morphology and hyoid bone position in dento-skeletal class III deformity patients after 2-jaw orthognathic surgery with segmentation. METHODS: A retrospective analysis has been performed on patients with dento-skeletal class III deformity who had undergone orthognathic 2-jaw surgery with segmentations, presenting both pre- and post-surgical cone-beam computed tomographys. Three-dimensional skeletal movements, pharyngeal airway changes and hyoid bone position were measured and correlated. RESULTS: The mean short term postsurgical review period for all included 47 patients was 5.8 ±â€Š2.2 months. Thirteen patients among them provided a mean long term period of 26.4 ±â€Š3.4 months. The mean postsurgical maxillary movement was 2.29 ±â€Š2.49 mm in vertical, 2.02 ±â€Š3.45 mm in horizontal direction, respectively, while the mandibular movement was 6.49 ±â€Š4.58 mm in vertical, and -5.85 ±â€Š6.13 mm in horizontal direction. In short-term, the vertical length of nasopharynx was found to be reduced (P = 0.005) but increased for the oropharynx (P < 0.001). Furthermore, the oropharyngeal minimum cross-sectional area has decreased significantly (P = 0.013). The hyoid bone moved posterosuperiorly, however, with only its horizontal movement found to be significant (P = 0.043). No significant result was detected in long-term analyses, neither in postsurgical pharyngeal airway changes nor the hyoid bone movement. There were no significant differences in pharyngeal airway measurements (P > 0.05) detected between patients with and without genioplasty advancement. CONCLUSION: Two-jaw orthognathic surgery in dento-skeletal class III patients led to a statistically non-significant reduction of the post-surgical airway volume in both short- and long-term. Although the post-surgical oropharyneal minimum cross-sectional area was decreased significantly in the short term, this finding did not persist in the long term.

Acid etching of human enamel in clinical applications: a systematic review.

STATEMENT OF PROBLEM: The laboratory-based enamel acid-etching doctrine with 30% to 50% phosphoric acid for 60 seconds to generate the maximum amount of Type 1 and/or Type 2 etch pattern has been established for more than 30 years. However, this recommendation may not be clinically relevant. PURPOSE: The purpose of this systematic review was to compare clinically accepted protocols of enamel acid etching with the laboratory protocol. MATERIAL AND METHODS: Studies were identified by searching 4 electronic databases: Medline, CINAHL Plus, Embase, and Cochrane Library. The final search was run on November 8, 2012. All clinical studies published in English that investigated enamel acid pretreatment methods on human permanent teeth were included. Additional publications were obtained from the reference lists of the included studies. The clinical evidence of all included studies was tabulated. RESULTS: Initially, 4543 publications were retrieved from the databases. A total of 4508 articles were excluded, including 2285 duplicates, 1805 publications according to exclusion criteria by their titles and abstracts, 368 laboratory articles, 49 reviews, and 1 pilot study. Only 1 study was added from reference lists of the included studies. Finally, 36 clinical publications were included. The included clinical studies provided different levels of clinical evidence on the efficacy of acid-etching protocols to enable successful enamel adhesion. CONCLUSIONS: Clinical protocols of enamel acid etching differ from the laboratory-generated doctrine, which may imply that maximization of the Type 1 and/or Type 2 etch pattern is not important in the clinical acid etching of human enamel.

Lingual retainers bonded without liquid resin: a 5-year follow-up study.

INTRODUCTION: The aim of this in-vivo study study was to evaluate the effect of excluding the liquid resin component of a composite bonding product that is based on bisphenol A diglycidylmethacrylate when bonding lingual retainers. METHODS: The material comprised 40 metal multistrand lingual retainers bonded onto the lingual surfaces of maxillary and mandibular anterior teeth. Transbond LR composite paste and liquid resin (3M Unitek, Monrovia, Calif) were used to bond retainers in the control group (20 retainers). The same bonding material was used in the test group (20 retainers), but the liquid resin component was excluded. The durations (in months) of retainer survival were analyzed by using the Kaplan-Meier product limit method and the log rank test. RESULTS: Fifty percent of the retainers in the control group and 60% of those in the test group had no bond failures during the 5-year observation period; the difference was not statistically significant. Bond failures were recorded in 13.6% of the bonded tooth surfaces in the control group and in 14.9% in the test group; the difference was not statistically significant. On average, the retainers stayed intact in the control and test groups for 36 and 32 months, respectively. The median survival times of the control and test groups were 43 months and more than 47 months, respectively. Neither the survival analysis nor the 95% confidence intervals (24-49 months in the control group, 24-40 months in the test group) suggested any statistically significant difference between the groups. CONCLUSIONS: Metal lingual retainers can be successfully bonded without liquid resin and serve the patient equally as well clinically as retainers bonded with the conventional bonding technique.

Does 3-dimensional facial attractiveness relate to golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles?

BACKGROUND: The established recommendations and guidelines regarding ideal measurements for an attractive face are mostly based on data gathered among Caucasian population. The aim of this study was to examine the relationship between perception of 3-dimensional facial attractiveness and golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles in Hong Kong Chinese. METHODS: Thirty 3-D photographs (15 males and 15 females) were shown to 101 laypersons and 60 patients seeking orthognathic treatment. The photographs were rated based on a 100 mm visual analogue scale (VAS) from 0 (very unattractive) to 100 (very attractive). RESULTS: More than half of the measurements (42/77) in females and thirty-two measurements in males were found to be significantly different from the ideal target value (p < 0.05) upon the comparison of the attractive faces with golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles. Meanwhile, correlation tests between VAS scores and the parameters detected significant results (p < 0.05) in only six ratios, eight angles, one neoclassical canon and one proportion. CONCLUSIONS: Despite several renowned 'ideal' parameters of attractive faces that have been recommended in the literature, only a few of them were found to be significantly correlated with attractive faces in Hong Kong Chinese.

Patient's satisfaction with facial appearance and psycho-social wellness after orthognathic surgery among Hong Kong Chinese using the FACE-Q.

PURPOSE: To assess and compare the changes in satisfaction with facial appearance and psycho-social well-being in dento-skeletal class II and III patients after orthognathic surgery with the FACE-Q among Hong Kong Chinese. METHODS: The questionnaires for thirteen orthognathic-relevant FACE-Q scales, translated into Cantonese and validated, were administered to Hong Kong Chinese patients before and after orthognathic surgery in the short- and long-term, respectively. The assessed scales were categorized into four main domains: satisfaction with facial appearance, quality of life, patient's experience of care, and adverse effects. RESULTS: Generally, highly significant (p < 0.001) improved FACE-Q scores were found in the long-term in the scales investigating the satisfaction with overall facial appearance, lower face and jawline, and chin. Although dento-skeletal class III patients demonstrated significantly improved satisfaction with their post-surgical nostril appearance (p = 0.003), this was not evident in dento-skeletal class II patients (p = 0.231). Nonetheless, both class II and class III subjects have also revealed significantly improved psychological well-being (0.003; <0.001) and social function (0.001; <0.001) in the long-term. Age was not found to be correlated with all scales for satisfaction of facial appearance. CONCLUSION: Previously validated Face-Q scales are valuable instruments to measure clinical outcomes, psychological well-being and social function in Cantonese speaking patients. Both Class II and Class III patients showed significantly improved satisfaction with facial appearance, psychological well-being and social function after orthognathic surgery regardless of skeletal pattern and gender, confirming findings in other ethnicities.