بررسي ارتباط برخي لندمارك هاي بافت سخت و نرم در افراد مونث 14 - 18 ساله داراي مال اكلوژن CI II/Div1

Correlation between selected soft and hard tissue landmarks in 14 to 18 years-old Iranian girls with ClassII/Div 1 malocclusion

Background and Aim: Esthetic is one of the major demand of orthodontic patients. Therefore, esthetics orthodontics with special attention to soft tissue is considered as a new philosophy and approach. The purpose of this study was to investigate the correlation between selected hard tissue structures and soft tissue profiles. Materials and Methods: The sample was composed of 36 pre-treatment lateral cephalograms from 14-18 year-Old Iranian girls with class II Div 1 malocclusion. They had all their permanent teeth in the dentition, with no apparent syndrome. The cephalograms were taken with the same machine, and similar magnification for all. Eleven cephalometric hard and ten soft tisuue landmarks were measured. Analysis of data was conducted using Pearson correlation and multiple regression procedures. Results: A significant correlation was observed between some of the dento-skeletal parameters and soft tissue structures. In the upper lip, the thickness in the base was related to the angle of ANB (P= 0.032) and upper incisors position (P= 0.032), whereas, the vermilion was affected by the position of the lower incisors (P= 0.032). The basal soft tissue thickness of the lower lip was related to the position of lower incisors (P= 0.015), while in the vermilion, was related to the position of upper incisors (P= 0.001). The upper lip height was associated with Wittʹs app (P= 0.003) and lower incisor position (P= 0.037), whereas, the lower lip height was affected by FMA (P= 0.019) and the lower incisor position. Mentolabial angle had the highest coefficient with hard tissue structures such as FMA, ANB, and position of the upper and lower incisors. No relationship was detected between chin height, nasolabial angle and hard tissue parameters. Conclusion: According to correlations between soft tissue and dentoskeletal structures that tend to compensate for hard tissue problems both factors should be considered when diagnosing or treating orthodontic patients. Key words: Soft tissue - Hard tissue - Correlation - Class II - Div1 malocclusion. Corresponding Author: Dr. Sodagar A., Assistant Professor, Orthodontics Department and member of Dental Research Center, Faculty of Dentistry, Tehran University / Medical Sciences. Tehran, Iran. e.mail: sodagara @ tums.ac.ir