FACIAL ESTHETIC AND DEVINE PROPORTION: jc

JC ON FACIAL ESTHETIC IN CLASS II
JOURNAL CLUB
ORTHODONTICS

1. Deprtment Of Orthodontics & Dentofacial Ortopeidics Dr. Ritesh Kumar Presents, Journal Club Under the guidance Dr Rakesh Koul prof&HOD ) Dr K.L. Pradhan ( prof . Dr . Ram Autar ( prof ) Dr Shantanu Khatri ( Reader) Dr Madhvi ( Reader) Dr H uma ( Sn . Lect ) Dr Vijeyta ( Sn . Lect ) Dr Prachi ( Sn . lect )

2. Facial aesthetics and the divine proportion: a comparison of surgical and non-surgical Class II treatment Australian Orthodontic Journal Volume 20 Number 2, November 2004 Tracey L. Shell and Michael G. Woods The University of Melbourne, Australia

3. Introduction : This study was designed to compare selected divine or golden proportions in Class II division 1 patients treated either during the growth phase with an activator and fixed appliances or after the completion of growth with fixed appliances and orthognathic surgery; and to determine the associations between divine facial proportions and perceived facial attractiveness .

4. The divine relationships of the subjects were assessed on pre- and post-treatment lateral cephalometric radiographs, and on lateral and frontal facial photographs. In addition, the attractiveness of the subjects was scored by a panel of judges using a visual analogue scale. Facial aesthetic scores were then correlated with the presence of particular divine facial proportions

5. D ivine proportion The divine proportion, also commonly referred to as the golden proportion, the golden section, or phi, is defined as the place where a line is sectioned so that the ratio of the small to the large section is the same as that of the large section to the whole line The larger section being 1.618 times that of the shorter one .

6. The use of the divine proportion has been proposed which is based on proportional rather than absolute measures, and because it can be used to evaluate the harmony of both skeletal and soft tissue structures

7. Ghyka16 noted the repeated occurrence of the divine proportion in natural forms such as flowers , shells, and in particular, the human body

8. Objective 1. The presence or otherwise of divine proportional relationships , either before or after treatment, in the faces of subjects with Class II division 1 malocclusions undergoing either attempted growth modification or later surgical correction. 2. If there are any significant differences between two such treatment groups in divine proportion ratios either before or after treatment. 3. If there is any correlation between the aesthetic rating for each patient and the difference from the divine proportion for each ratio, either before or after treatment . 4. If there is any correlation between a change in aesthetic rating and the change in the difference from the divine proportion for each ratio.

9. Materials and method The records of 60 patients with Class II division 1 malocclusions were obtained from the of two experienced private practitioner orthodontists and from the Graduate Orthodontic Clinic at the University of Melbourne

10. Measured lateral cephalometric divine proportions.( proposed by Ricketts) 1. The corpus axis length (Xi- SPog , 1.618) : the condylar axis length (Xi-Co, 1.0) 2. The nasion to cranial centre length (N-CC) : the cranial centre to point articulare (CC- Ar ) 3. The maxillary depth (ANS-PNS) : the length from the posterior nasal spine to the posterior border of the mandible (PNS-PBM) 4. The length from point A to the anterior border of the mandible (Pt A-ABM) : the length of the anterior border of the mandible to the posterior pharyngeal wall (ABM-PPW) 5. The anterior length of Frankfort plane from pterygoid vertical to orbitale (Pt V-Or) : the length from pterygoid vertical to the glenoid fossa centre (Pt V-GFC) 6. The facial axis length (CC- Gn ) : the posterior facial height (CC-Go) 7. The lower facial axis from the crossing of the ANS-Xi line to gnathion (ANS/Xi- Gn ) : the upper facial axis from cranial centre to the crossing of the ANS-Xi line (CC-ANS/Xi) 8. The vertical height from point A to suprapogonion (Pt A- SPog ) : the length from point A to Frankfort horizontal (Pt A-FH) 9. The length from the superior palatal surface at the incisive canal to menton (SPS-Me) : the length from the superior palatal surface at the incisive canal to the canthus of the eye (SPS-LC) 10. The height of the lower incisor tip from suprapogonion (L1-SPog) : the length from the lower incisor tip to point A (L1-Pt A) 11. Sella to nasion length (S-N) : sella to basion length (S- Ba ) 12. Ramus height (R3 to R4) : ramus depth (R1 to R2)

11. Aesthetic rating The measurement of facial attractiveness was based on a method documented by Phillips et al ., utilising separate 100 mm visual analogue scales, each anchored on the left by the descriptor “very unattractive (0 )” and on the right by “very attractive (100)”. At any one time photographs of only one patient were visible to the judge. An additional pair of photographs of one subject not included in the sample was placed on the first page of the folder, so that the judges could first familiarise themselves with the rating procedure The whole aesthetic rating process was repeated , a minimum of four weeks later. The first and second ratings for each subject were averaged to give that subject’s final aesthetic rating.

12. Measured soft tissue divine proportions .( 1. The lateral canthus of the eye to menton (LC’-Me’, 1.618) : trichion to the lateral canthus of the eye (Tri-LC’, 1.0) 2. Trichion to the ala of the nose (Tri-Al) : ala of the nose to menton (Al-Me’) 3. The ala of the nose to menton (Al-Me’) : the lateral canthus of the eye to the ala of the nose (LC’-Al) 4. The angle of the mouth to the lateral canthus of the eye (Ch-LC’) : the angle of the mouth to menton (Ch-Me’) 5. The ala of the nose to the lateral canthus of the eye (Al-LC’) : the ala of the nose to the angle of the mouth (Al-Ch) 6. The angle of the mouth to menton (Ch-Me’) : the ala of the nose to the angle of the mouth (Al-Ch) 7. Lateral canthus of the eye to menton (LC’-Me’) : ala of the nose to menton (Al-Me’) 8. Trichion to lateral canthus of the eye (Tri-LC’) : lateral canthus of the eye to the ala of the nose (LC’-Al) 9. Lateral canthus of the eye to the angle of the mouth (LC-Ch) : lateral canthus of the eye to the ala of the nose (LC’-Al) 10. Ala of the nose to menton (Al-Me’) : angle of the mouth to menton (Ch-Me’) 11. Top of the head to menton (V-Me’) : width of the face (TS-TS) 12. Width of the face (TS-TS) : the distance between the lateral canthi (LC’-LC’) 13. The distance between the lateral canthi (LC’-LC’) : the width of the mouth (Ch-Ch) 14. The width of the mouth (Ch-Ch) : the width of the nose (LN-LN) 15. The distance from the base of the tragus of the ear to the lateral canthus along Frankfort Horizontal ( Tg - LC’): the distance from the tip of the nose to the lateral canthus along Frankfort horizontal (NT-LC’) 1Ratios 1–6 and 15 described by Ricketts,13,14 7–11 by Ghyka,16 and 12–14 by both Ricketts and Ghyka .

13. Results The ratios that were different between the treatment groups were all related to the vertical plane, although not all vertical ratios were significantly different from each other. There were no significant differences between the horizontal ratios for the two treatment groups Pretreatment ratios Post-treatment ratios Seven of the 12 mean ratios for the surgery group were significantly different from 1.618. Eight ratios were significantly different in the growth modification group. When comparing the two treatment groups, three of the mean ratios, all related to the mandible, were statistically different. These mean ratios were 1 . Corpus axis length : condyle axis length ( relatively longer mandibular body after surgery ). 2. Facial axis length : posterior facial height ( relatively longer facial axis after surgery). 3. Lower facial axis : upper facial axis ( relatively longer lower facial axis after surgery).

14. Ratios showing changes .All of these were related to the vertical dimension. At the same time neither treatment method seemed more likely to result in a greater number of divine proportions after treatment

15. Relationship with facial aesthetics the higher an individual’s pretreatment aesthetic score, the closer their overall pretreatment facial proportions were likely to be to the divine proportion. This relationship did not, however, carry through for the post-treatment aesthetic scores and facial proportions

16. Relationship of the divine proportion with facial aesthetics It has been claimed that, by using the divine proportion as a treatment planning tool, more aesthetically pleasing facial aesthetics can be achieved it was noted that the pretreatment and post treatment mean aesthetic scores for the two treatment groups were similar. The same was true for the numeric and percentage changes in aesthetic score An individual’s aesthetic score could improve or worsen with either form of Class II treatment. At the same time, their facial proportions might equally move toward or away from divine proportion . it is the individual aesthetic character of facial features, and not just facial proportions, which significantly influence the perception of facial beauty

17. Conclusions 1. Prior to treatment, individuals with skeletal Class II division 1 malocclusions are unlikely to have dentofacial ratios fitting the divine proportion. 2. The growth status of Class II patients may have an impact on their facial proportions . While cranially related facial proportions may be similar in growing and nongrowing subjects, more caudally-related proportions, in particular those related to mandible , may be quite different. 3. Despite the likelihood of improving occlusal and skeletal relationships with either surgery or attempted growth modification, a large proportion of the measured ratios is still unlikely to fit the divine proportion at the end of treatment. 4. At the end of treatment, proportions which differ between two such different treatment techniques are likely to be related to the mandible, a fact which could largely be attributed to the direct effects of surgery on mandibular size and proportion. 5. Neither surgery nor attempted growth modification of Class II division 1 malocclusions is more likely to result in larger numbers of divine facial proportions at the end of treatment. 6. There is likely to be considerable individual variation in the amount of change in proportions with treatment , regardless of the treatment method. Ratios in some patients will move toward the divine proportion , others will move away from it. 7. The use of the divine proportion seems to be subject to the same limitations as other methods of cephalometric and external facial analysis, in that the divine proportion is not an absolute determinant of facial attractiveness.

18. Critical analysis of study Aesthetics is racial dependent place dependent devine proportions can not be considered as diagnostic guide line