ABSTRACT
The purpose of this study was to evaluate the soft-tissue profile changes from 24 to 32 years of age in Korean adults. The subjects used in this study consisted of 17 males and 8 females. The data obtained from the lateral cephalograms taken at age 24 and 32, were analyzed statistically. The obtained results were as follows : 1. During the observation period, there were no significant changes in the hard-tissue measurements in both sexes (p>0.05). 2. In the anteroposterior measurements of soft-tissue, the males had significant increase in chin area (Pog', Gn'), and the females had significant decrease in lower lip (LI) (p<0.05). 3. In the vertical measurements of soft-tissue, both sexes showed the increased tendency in upper lip length(Sn-Sto) where the males showed significant increase (p<0.05). 4. In general, the females and males had the increased tendency in soft-tissue thickness, especially significant increase in chin area (Pog', Gn') (p<0.05).
Subject(s)
Adult , Female , Humans , Male , Chin , LipABSTRACT
We usually accept 1 : 1 ratio soft tissue change in mandibular set-back surgery. But we cannot sure whether we can use this ratio as a long term predictor after surgery. We investigated the change of hard tissue and its effects to soft tissue and examined the predictability of cephalometric analysis in short term and long term follow-up periods in mandibular set-back surgery. Subjects were 15 patients (5 male, 10 female) performed mandibular set-back procedure only by BSSRO with rigid fixation. Cephalometric data were obtained before orthodontic treatment, immediate before surgery and immediate after surgery, 6 months, and 18 months after surgery consecutively. Differences in soft and hard tissue changes among the time intervals were examined using analysis of variance (ANOVA) ; the association between immediate surgical change in chin landmarks and subsequent short and long term soft and hard tissue changes were examined using linear regression analysis 1. Soft tissue mandibular structures were positioned posteriorly and superiorly after surgery. Average mandibular set-back were 8.17mm at Pog. The horizontal and vertical hard tissue mandibular changes were stable for 18 months after surgery. Although there was a small degree of change, soft tissue and hard tissue remain relatively stable after surgery and there was no clinically discernable changes between 6 months and 18 months post-operatively. 2. Some part of upper lip (Ls & stms)and most part of mandibular soft tissue moves postero-superiorly after mandibular set-back. The ratio of horizontal changes of hard tissue to soft tissue at Inf. labial sulcus(B'), Pogonion(Pog') were 84.7%, 74.7% after 18 months. respectively. 3. Predictability of the soft tissue change is less certain than hard tissue and this predictability is decreased over time. These result suggests that we cannot predict the surgical outcomes exactly. It is recommendable that the oral surgeon should be careful in using the computerized surgical prediction software program as a predictor of long term soft tissue change.
Subject(s)
Humans , Male , Chin , Follow-Up Studies , Linear Models , LipABSTRACT
The purpose of the study is to estimate hard and soft tissue changes after orthognathic surgery for the correction of the mandibular prognathism and to describe interrelationship and ratios of soft and hard tissue changes. The presurgical and postsurgical lateral cephalograms of 31 treated patients(17 males and 14 females) was used ; these patients had received combined orthodontic-surgical treatment by means of a bilateral sagittal split ramus osteotomy. Their ages ranged from 16 to 31 years and mean age was 21.4 years. A computerized cephalometric appraisal was developed and used to analyse linear and angular changes of skeletal and soft tissue profile. The statistical elaboration of the data was made by means of SPSS/PC+. The results of the study were as follows: 1. The correlations of soft and hard tissue horizontal changes were significantly high and the ratios were 97% at LI, 107% at ILS, and 93% at Pog'. 2. The correlations of vertical changes at Stm, LI and horizontal changes at Pog were high (26 %) and at the other areas were not statistically high. 3. The correlations of soft ad hard tissue vertical changes were not significantly high in all areas except Gn' (30%) and Me' (56%). 4. The soft tissue thickness was significantly decreased in upper lip and increased in lower lip, and the amount of changes after surgery was reversely correlated with initial thickness. 5. The facial convexity was increased and relative protrusion of upper lip was increased and that of lower lip was decreased. 6. The upper to lower facial height(G1-Sn/Sn-Me') was increased and upper to lower jaw height(Sn-Stms/Stmi-Me') was increased.