ABSTRACT
This study aimed to investigate the correlation between the inclinations of the incisors and lips in mixed dentition aged 7 – 11 years. Lateral cephalometric radiographs of 353 children were analyzed to measure the upper incisor inclination, lower incisor inclination, lower-nasolabial angle, and mentolabial angle in relation to the skeletal malocclusion classification. The measurements were then assessed using the Kruskal-Wallis test, Pearson correlation, and multiple regression analysis.There were significant negative correlations between the inclination of the upper incisors and lower-nasolabial angle in all classes of skeletal malocclusion. There was a negative correlation between the inclination of the lower incisors and mentolabial angle; however, class Ⅱ malocclusion had a significant positive correlation.This study identified the factors that affect lip inclination and verified their associations.
Subject(s)
Child , Humans , Classification , Dentition, Mixed , Incisor , Lip , MalocclusionABSTRACT
BACKGROUND: This study is a quantitative evaluation of the influence of the mentolabial angle on perceived attractiveness and threshold values of desire for surgery. METHODS: The mentolabial angle of an idealized silhouette male Caucasian profile image was altered incrementally between 84° and 162°. Images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), lay people (n = 75) and clinicians (n = 35). RESULTS: A mentolabial angle of approximately 107° to 118° was deemed the most attractive, with a range of up to 140° deemed acceptable. Angles above or below this range were perceived as unattractive, and anything outside the range of below 98° or above 162° was deemed very unattractive. A deep mentolabial angle (84°) or an almost flat angle (162°) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups, a threshold value of ≥162° and ≤84° indicated a preference for surgery, although clinicians were least likely to suggest surgery. The clinician group was the most consistent, and for many of the images, there was some variation in agreement between clinicians and lay people as to whether surgery is required. There was even more variability in the assessments for the patient group. CONCLUSIONS: It is recommended that in orthognathic and genioplasty planning, the range of normal variability of the mentolabial angle, in terms of observer acceptance, is taken into account as well as threshold values of desire for surgery. The importance of using patients as observers in attractiveness research is stressed.
Subject(s)
Humans , Male , Esthetics , Evaluation Studies as Topic , GenioplastyABSTRACT
Introduction: While measurement of nasolabial angle and mentolabial angle is an important clinical examination in pre-orthognathic surgery assessment, data on non-western population is limited. This study was therefore conducted to determine the range of nasolabial angle and mentolabial angle in normal Malaysian adult with comparison of males and females. Materials and Methods: A total of 50 Class I males and 52 Class I females aged 19-30 years from three main ethnic groups were randomly selected from dental students, medical students and staffs in dental clinic of Hospital Universiti Sains Malaysia (HUSM). The photographic set-up consisted of a 50mm Nikon DAT camera held in position by a tripod. The photos taken in JPEG format were digitalized and analysed using ProVixwin software. Independent t-test was used to compare any possible gender difference in nasolabial and mentolabial angles. Results: The mean of nasolabial angle and mentolabial angle for male was 92.99? and 130.44? whereas for females it was 95.04? and 130.73? respectively. Gender differences were found to be insignificant for both nasolabial angle and mentolabial angle.Conclusion: Despite having great variation in our population, the nasolabial angle and mentolabial angle are gender independent.