- 學位論文
前牙贋復的美觀導引：牙齒型態與比例的研究
Esthetic guide for anterior teeth restoration : tooth morphology and proportion
摘要
研究目的：隨著病人對美觀的要求越來越高，在臨床上具有可靠且科學的美觀導引，將使製作前牙補綴物更加有效率。本研究的目的在探討臨床上供前牙贋復的美觀導引，在台灣年青族群的適用性，包括：Law of Hormony、Bolton’s Analysis以及黃金比例。 材料與方法：由高雄醫學大學牙醫系以及牙醫學研究所，依照牙齒排列整齊美觀、咬合穩定沒有不良干擾等要素篩選受測者。總共有學生62人完成研究，平均年齡22歲（分布由18到30歲），男性與女性比例相同。每ㄧ位受測者印製上下顎研究模型，並定位拍攝臉部外型與口內相片進行分析。應用1980年Mavroskoufis與2004年Wolfart的相片分析法，近ㄧ步直接以影像處理軟體研究上顎中門齒與臉部外觀之間是否存在相關性；運用上下顎模型分析Bolton’s analysis與黃金比例，是否適用於台灣年輕族群。將以上數據以Spearman correlation analysis、One-Way ANOVA、one sample t-test做統計分析。 結果： 臉部外型與上顎中門齒的關係： 上顎左右側中門齒的外型分類有顯著且高度相關性（p<0.01, r=0.717, Spearman rank correlation）；臉部外型分類與左右側中門齒外型分類都達到顯著但相關性並不高（p<0.01, r=0.49, Spearman rank correlation）；上顎左右側中門齒的長寬比則有顯著的高度相關性。（p<0.01, r=0.9024, Spearman rank correlation），「上顎臉部外型」長寬比與中門齒長寬比達到顯著但相關性並不高（p<0.01, r=0.368, Spearman rank correlation）。 Bolton’s analysis 在區段寬度方面除了上顎anterior segment之外，在上顎overall segmant以及posterior segment和下顎的anterior segment、overall segmant以及posterior segment區段寬度都是男性顯著的大於女性(p<0.05, One-way ANOVA)。 在區段比例方面，三個區段比例：anterior segment、overall segmant以及posterior segment，都沒有顯著的性別差異(p>0.05, One-way ANOVA)。本研究overall ratio與Bolton’s Ratios沒有顯著差異(p>0.05, one sample t-test)；anterior Ratio與Bolton的比例則有顯著差異(p<0.01, one sample t-test)，其中男性anterior ratio與Bolton的比例呈現顯著差異(p<0.01, one sample t-test)，女性則沒有顯著差異(p>0.05, one sample t-test)。 黃金比例 側門齒與正中門齒的比例為0.715±0.068，犬齒與側門齒的比率為0.822±0.131，犬齒牙阜尖與側門齒的比例為0.502±0.120，所有的區段寬度比例都與黃金比例呈顯著差異（p<0.01, one sample t-test）。 結論：在本研究中我們發現，確實不是所有前牙美觀導引都適用於本研究族群，在正中門齒與臉部外型分類、「上顎臉部外型」與正中門齒的長寬比方面雖達到顯著但相關性並不足夠；上下顎間牙齒寬度比例女性可以應用Bolton’s analysis，在男性則只能應用overall ratio；至於黃金比例，則少見於自然齒列的比例，本研究正中門齒、側門齒與犬齒的寬度比例約為： 1.389 : 1.0: 0.822。
並列摘要
OBJECTIVES : As the patients demand more and more esthetics today, dentists may make anterior restorations more efficiently with reliable anterior esthetic guide. The purposes of this study were to determine if it is possible to use all these esthetic guide, including “Law of Hormony”, Bolton’s analysis and golden proportion, in young age group of Taiwanese. Furthermore, we will evaluate the racial and gender correlation of them. MATERIAL&METHODS: The samples consisted of sixty-two students of Kaohsiung medical university. The inclusion criteria are esthetic natural dentition, stable occlusion and no visural interference. The mean age is twenty-two years (range 18-33 years) and the number of males equal to the number of females. Data collected contained study casts of both arch and photographs of face form and upper central incisors, taken under standardized orientation. We used the image analysis techniques of Mavroskoufis (1980) and Wolfart (2004) to evaluate the correlation between the Williams’ categorizations(1914) of upper central incisors and face form and the correlation between the length to width ratio of them by analyzing the digital image with software on a personal computer directly. To determine if the Bolton’s Analysis and golden proportion can be used in young age group of Taiwanese, we measure the study casts of both arch to confirm it. By the way, we evaluated gender differences in all these anterior esthetic guide then compared to other authors’ findings. The values were analyzed with Spearman correlation analysis, one-way ANOVA and one sample t-test. RESULTS: The correlation between face form and upper central incisors : The Williams’ categorizations of upper central incisors are significantly correlated(p<0.01, r=0.717, Spearman rank correlation). The Williams’ categorizations of face form is significant correlated to right(p<0.01, r=0.39, Spearman rank correlation) and left(p<0.01, r=0.49, Spearman rank correlation) upper central incisors. The length to width ratio of both incisors are significantly correlated(p<0.01, r=0.9024, Spearman rank correlation) and the length to width ratio of “Hairline to incisor edge face form” are significantly correlated to upper central incisors(p<0.01) Bolton’s analysis : Except the mean value of the upper anterior segment width, the mean values of other segment widths are bigger in male than in female (p>0.05, One-way ANOVA). The mean value of overall ratio is 90.89±1.66%, anterior ratio is 78.26±2.36% and posterior ratio is 102.94±2.3%. There is no gender differences in all of the ratios (p>0.05, One-way ANOVA). There is no significant differences between our overall ratio and Bolton’s(p>0.05, one sample t-test), but between our anterior ratio and Bolton’s(p<0.01, one sample t-test). There is significant differences between the male’s anterior ratio and Bolton’s(p<0.01, one sample t-test), but not between the female’s and Bolton’s(p>0.05, one sample t-test). Golden proportion The mean value of lateral-to-central incisor ratio is 0.715±0.068. The mean value of canine-to-lateral incisor ratios is 0.822±0.131. The mean value of canine tip-to-lateral incisor ratios is 0.502±0.120. All the ratios significantly differ from golden proportion(p<0.01, one sample t-test). Conclusion: In this study, we found not all esthetic guide suitable to young age group of Taiwanese. Although there is significant correlation between face form and central incisors, but the r value is low. We can use Bolton’s analysis in female group and the overall ratio in the male group. The golden proportion is not common in natual dentition. The width ratios of anterior teeth may be 1.389 : 1.0: 0.822 when central incisor : lateral incisor : canine.