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ORIGINAL ARTICLE |
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Year : 2016 | Volume
: 8
| Issue : 3 | Page : 124-130 |
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Soft tissue cephalometric analysis applied to Himachali ethnic population
Isha Aggarwal1, Anil Singla2
1 Department of Orthodontics and Dentofacial Orthopedics, Gian Sagar Dental College and Hospital, Patiala, Punjab, India 2 Department of Orthodontics and Dentofacial Orthopedics, Himachal Dental College and Hospital, Sunder Nagar, Himachal Pradesh, India
Date of Web Publication | 7-Oct-2016 |
Correspondence Address: Dr. Isha Aggarwal Department of Orthodontics and Dentofacial Orthopedics, Gian Sagar Dental College and Hospital, Patiala, Punjab India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0976-4003.191731
Introduction: The modern society considers facial attractiveness as an important physical attribute. The great variance in soft tissue drape of the human face complicates accurate assessment of the soft tissue profile, and it is a known fact that facial features of different ethnic groups differ significantly. This study was undertaken to establish norms for Himachali ethnic population. Materials and Methods: The sample comprised lateral cephalograms taken in natural head position of 100 normal individuals (50 males, 50 females). The cephalograms were analyzed by Arnett soft tissue cephalometric analysis for orthodontic diagnosis and treatment planning. Student's t-test was used to compare the means of the two groups. Results: Statistically significant differences were found between Himachali males and females in certain key parameters. Males have thicker soft tissue structures and a more acute nasolabial angle than females. Males have longer faces and females have greater interlabial gap and maxillary incisor exposure. Males have more deep-set facial structures than females. Conclusions: Statistically significant differences were found between Himachali males and females in certain key parameters. Differences were also noted between other ethnic groups and Himachali faces. Keywords: Himachali population, soft tissue, soft tissue cephalometric analysis, true vertical line
How to cite this article: Aggarwal I, Singla A. Soft tissue cephalometric analysis applied to Himachali ethnic population. Indian J Dent Sci 2016;8:124-30 |
How to cite this URL: Aggarwal I, Singla A. Soft tissue cephalometric analysis applied to Himachali ethnic population. Indian J Dent Sci [serial online] 2016 [cited 2023 May 28];8:124-30. Available from: http://www.ijds.in/text.asp?2016/8/3/124/191731 |
Introduction | |  |
Throughout recorded history and even earlier as evidenced by archaeological artifacts, human beings have been aware of and concerned about beauty and facial esthetics.[1] In 1982, Ricketts found numerous examples of divine proportion in the faces of commercial models, well-aligned dental arches, and in measurements of both frontal and lateral head cephalographs, suggesting that esthetics can indeed be analyzed scientifically.[2] According to Angle, “The mouth is a most potent factor in making or marrying the beauty and character of the face.” The modern society considers facial attractiveness as an important physical attribute.
Since the inception of orthodontics as a specialty, orthodontists have been interested with measurements. The greatest trust in this direction evolved with the introduction of cephalometry by Broadbent in 1931 and its application to clinical orthodontics.[3] Facial harmony and balance are determined by the facial skeleton and its overlying soft tissue structure. The methodology of cephalometric radiography led to the development of numerous cephalometric studies dealing with norms which provide useful guidelines in orthodontic diagnosis and treatment planning. Diagnosis by hard tissue cephalometric norms is unreliable.[4] These cephalometric analyses concentrate mainly on the measurement of hard tissue structures, which are not constantly related to the soft tissue of the face.
Another method of diagnosis emerged which was based on direct facial examination and diagnosis.[5],[6] This clinical examination is three-dimensional and it is more useful for showing shapes and contours. It is, however, subjective. The advantage of soft tissue cephalometrics is that it provides the ability to make objective measurements of important structures and relationships. In the past, a few soft tissue cephalometric analysis were developed to measure facial positions.[7],[8],[9] These early soft tissue analyses were not combined with clinical assessment, and none of them examined all the important facial components.
Dr. G. W. Arnett improved facial balance, beauty diagnosis, and treatment planning by means of a combination of clinical facial analysis and soft tissue cephalometrics.[10] It provides normal values, emphasizes soft tissue outcome, and lessens the emphasis of overjet as the sole indication of success.[11] It correlates various soft and hard tissue structures which determine balance and harmony as well as to a true vertical line (TVL) in both sagittal and vertical planes. The other important advantage of this analysis is that it is based on natural head position. The analysis has proved useful in planning strategies for both orthodontic and orthognathic surgery treatment.
The norms in the Arnett's analysis were given for the Caucasian population. It is a known fact that facial features of different ethnic groups differ significantly. Therefore, it is essential to rely on norms established for individual ethnic groups instead of relying on norms established for the Western population.[12],[13],[14],[15],[16] Hence, this study aimed to develop Arnett's soft tissue cephalometric norms for Himachali ethnic population.
Materials and Methods | |  |
The present study included a sample size of 100 participants (50 males and 50 females) selected from the Himachali ethnic population and were judged to have well-balanced facial profiles from a panel of orthodontists. All had natural Class I occlusions, no history of trauma, no history of orthodontic treatment, and full complement of teeth. The participants were first assessed clinically in natural head position, with seated condyles and passive lips. Metallic markers were placed on various soft tissue structures on the faces to study and relate them to the TVL as described by Arnett et al.[10] A lateral head film was obtained with the participant in natural head position, with seated condyle and passive lips. The natural head position was recorded based on the method proposed by Cooke and Wei.[17] All lateral cephalometric films were recorded by the same operator. They were then traced on a transparent cellulose acetate sheet. All reference points were first identified, located, and marked. The TVL was then established. This line was drawn through subnasale and was perpendicular to the natural horizontal head position. Structures to the right of the TVL were given a positive sign and those to the left were given a negative sign. The soft tissue cephalometric parameters were divided into five groups: dentoskeletal factors, soft tissue structures, facial lengths, projections to TVL, and harmony values [Figure 1]. | Figure 1: Lateral cephalograph with the tracing describing the 5 groups of soft tissue cephalometric parameters i.e., dentoskeletal parameters, soft tissue structures, facial lengths, projections to TVL and harmony values taken for the study.
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Results | |  |
The results were statistically analyzed to establish norms for the local population as well as to compare them with the findings of other studies. Normal values were calculated as mean, standard deviation (SD) for reference in the treatment procedure. Significance of the difference between the male and female samples was tested with Student's t-test. Statistical analysis showed that the sexes were similar in some but not in all measurements. In dentoskeletal factors [Table 1], only the maxillary central incisor to occlusal plane to TVL showed a significant higher value in the females. The remaining means were not statistically different between the sexes. Soft tissue measurements [Table 1] showed that males have greater soft tissue thickness than females and also more acute nasolabial angles (98.72°) than females. Facial length measurements [Table 1] showed that male faces were statistically longer (Nasion' to Menton', 132.36) than female faces (127.81). Females had greater interlabial gap and maxillary incisor exposure than males; these measurements were statistically significant. In the projections to TVL [Table 1], statistically significant differences were seen in the midface and the lower third structures of the face between the sexes. The measurements of cheekbone, orbital rim, subpupil, and alar base to TVL were higher in males. In addition, nasal projection was higher in males (15.17 mm) compared with females (13.43 mm). In the lower third of the face, males had more protrusive lips (upper lip anterior, 2.08 mm; lower lip anterior, 2.112 mm), whereas females had more proclined dentitions. The facial harmony values [Table 1] were statistically similar for all except for mandibular incisor to soft tissue pogonion, soft tissue B-point to soft tissue pogonion, orbital rim to soft tissue point A, and orbital rim to soft tissue pogonion, which were higher in males than in females.
Discussion | |  |
Diagnosis and treatment planning are necessary for the successful treatment of malocclusions. However, facial esthetics does not rely solely on hard tissues, as analysis of hard tissue alone might be inadequate or misleading. This inadequacy is because the soft tissue dimensions vary as a result of the variation in thickness of the soft tissue, the lip length, and the postural tone. As craniofacial morphology and thickness of soft tissue vary among different population groups, there is a need of establishing separate cephalometric norms for the different populations, races, or ethnic groups. Many authors also found that the Caucasian norms for different soft tissue cephalometric analyses were not applicable on the Turkish, Japanese-Brazilian, and Yemeni populations, so they established separate soft tissue cephalometric analysis norms for their population. Among the various soft tissue analyses, Arnett's analysis is a combination of hard tissue and soft tissue analysis; it evaluates the upper face, mid face and lower face structures, and has the advantage of gender consideration. This is the reason for establishing the Arnett's analysis norms for the Himachali population. In the dentoskeletal factor measurements, the mean maxillary occlusal plane to TVL for Himachali male and females was statistically significant. This might indicate that females have a steeper occlusal plane. This is in accordance with the study conducted by Lalitha and Gopa Kumar.[18] All the remaining parameters measured did not show statistically significant differences between the sexes.
In the soft tissue measurements, significant differences were found between the sexes with males having higher values for upper lip thickness, lower lip thickness, soft tissue Pogonion and Menton thickness when compared with females. This difference in male and female lip thickness will have to be considered while planning the amount of incisor retraction for improving esthetics. Similar results were seen in the study conducted by Kalha et al.[19] and Arnett et al.[10]
In the facial length measurements, the parameters measured showed statistically significant differences between the sexes. Facial height, lower lip length, lower third of the face, and mandibular height were greater in males than in females. Kalha et al.,[19] Arnett et al.,[10] Uysal et al., Kadhom and Al-Janabi, and Lalitha and Gopa Kumar [18] revealed that maxillary height increased in females as compared to males. This is in accordance with the study conducted by Scheideman et al.[20] who also reported increased lower facial height in males because of increased lower lip length (LLs-Me'). These significant differences in facial heights between males and females might be significant in treatment planning.
Females had a greater interlabial gap and maxillary incisor exposure than did the males. This is because of short upper and lower lip lengths in Himachali females than in males. This is in accordance with the study conducted by Kalha et al.,[19] Arnett et al.,[10] and Lalitha and Gopa Kumar.[18]
In the projections to TVL measurements, the mean values for the orbital rim, cheek bone, subpupil, alar base, maxillary incisor, and mandibular incisor to TVL showed statistically significant differences between males and females. The values for midfacial structures were more negative to TVL in males. This indicates that males had more retruded or deep-set midfacial structures. The nasal projection in males was higher as compared to females. This is in accordance to the study conducted by Scheideman et al.,[20] Kalha et al.,[19] Arnett et al.,[10] and Lalitha and Gopa Kumar.[18]
In the lower third of the face, females had more proclined maxillary and mandibular anterior teeth. This is because of thicker soft tissue structures in males. In a study of dentofacially normal participants, Scheideman et al.[20] reported that maxillary lips was slightly anterior, mandibular lips was just posterior, and chin was 4.5–4.2 mm posterior to TVL in male and female participants. The differences between the mean values of soft tissue B point and pogonion to TVL did not show statistically significant differences between the sexes. The nasolabial angle was more acute in males as compared to females; this is because of thicker soft tissue structures in males. This is in accordance with the study conducted by Kalha et al.[19] and Lalitha and Gopa Kumar.[18]
In facial harmony measurements, there was statistically significant increase in mean values for mandibular central incisor to soft tissue pogonion' and soft tissue B point' to soft tissue pogonion' in males. This indicated that mandibular incisors are more upright in males as compared to females. The values for orbital rim to soft tissue point A and orbital rim to soft tissue pogonion were found to be higher in males than females.
The mean facial angle of the males was higher than that of females, suggesting that females have more convex profiles. Although the result may not be clinically significant, the values are higher in males than females. These values are in accordance with the study conducted by Legan and Burnstone [9] and Scheideman et al.[20]
In the dentoskeletal factor measurements, the Himachali population had less proclination of mandibular and maxillary incisors when compared with Caucasian population [Table 2] and [Table 3], which may be due to ethnic variations. Maxillary occlusal planes in Caucasian males were steeper as compared with the Himachali males.
In the soft tissue thickness measurements, when Himachali population was compared with the Caucasian [Table 2] and [Table 3], the mean and SDs of upper lip thickness, lower lip thickness, and soft tissue thickness at chin for Himachali males and females were found to be greater. Although the results are not significant clinically, the values are higher in Himachali population. This suggests that Caucasian have thinner soft tissue drape.
The comparison of mean facial lengths of the Himachali population was done with the Caucasian population [Table 2] and [Table 3] which suggested shorter facial lengths in Himachali males and an increase in Himachali females. The difference in facial heights between males and females might be significant in treatment planning because these differences can be indications to increase or decrease facial height.
In the projections to the TVL, the mean values of orbital rim, cheekbone, subpupil, alar base, and glabella were found to be higher in Himachali males and females when compared with Caucasian [Table 2] and [Table 3]. It suggests more retruded and deep-set midfacial structures in Himachali males and females. The nasal projection values were higher in Caucasian females when compared with the Himachali females. These findings also suggest that maxillary and mandibular incisors in both the sexes of the Himachali population are more upright when compared with the Caucasian population.
In facial harmony measurements, the mean values of facial harmony in the intramandibular relationships of the mandibular central incisor to pogonion, B point' to pogonion' were found to be more in Himachali population when compared with the Caucasian [Table 2] and [Table 3]. This indicates that Caucasians population have more proclined teeth. The neck–throat length was found to be less in case of Himachali population in both the sexes when compared with the Caucasian. A comparison of mean interjaw relationship of facial harmony showed that all values for both the sexes were increased in the Himachali population when compared with the Caucasian. The mean facial angle for both the sexes in Himachali population is lower than that of the Caucasian, indicating that Himachali population has more convex profile compared with the Caucasian.
Conclusion | |  |
Based on the present study, it was concluded that statistically significant differences were found between the participants of Himachali ethnic population and Caucasian populations. Differences were also found between the Himachali males and females.
- Males have a flatter occlusal plane, thicker soft tissue structures, acute nasolabial angles, longer faces, and more deep-set facial structures, when compared with females, whereas females have greater interlabial gap and maxillary incisor exposure and convex profile than males
- The comparison between Himachali population and Caucasian population suggested that Himachali population had increased soft tissue thicknesses, decreased facial heights, midface deficiency, flatter occlusal plane, and more convex profile.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1]
[Table 1], [Table 2], [Table 3]
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