|DENTAL SCIENCE - ORIGINAL ARTICLE
|Year : 2015 | Volume
| Issue : 6 | Page : 680-686
A study to evaluate cephalometric hard tissue profile of Tamil population for orthognathic surgery
S Nachiappan1, S Tharanikumar1, Ajay Chandran1, P Anusudha1, GD Nandini1, Murali Balasubramaniam2
1 Department of Oral and Maxillofacial Surgery, Sathyabama University Dental College and Hospital, Chennai, Tamil Nadu, India
2 Department of Oral Pathology, Sathyabama University Dental College and Hospital, Chennai, Tamil Nadu, India
|Date of Submission||28-Apr-2015|
|Date of Decision||28-Apr-2015|
|Date of Acceptance||22-May-2015|
|Date of Web Publication||1-Sep-2015|
Department of Oral and Maxillofacial Surgery, Sathyabama University Dental College and Hospital, Chennai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The primary aim of this study is to compare, the cephalometric hard tissue profile values and analysis between Tamil and Caucasian population. The study also aims to create a better understanding in the facial proportions of Tamil Nadu population and to have better diagnosis and treatment planning for orthognathic surgery for Tamil population in Tamil Nadu.
Keywords: Burstone, cephalometric analysis, Tamil Nadu population
|How to cite this article:|
Nachiappan S, Tharanikumar S, Chandran A, Anusudha P, Nandini G D, Balasubramaniam M. A study to evaluate cephalometric hard tissue profile of Tamil population for orthognathic surgery. J Pharm Bioall Sci 2015;7, Suppl S2:680-6
|How to cite this URL:|
Nachiappan S, Tharanikumar S, Chandran A, Anusudha P, Nandini G D, Balasubramaniam M. A study to evaluate cephalometric hard tissue profile of Tamil population for orthognathic surgery. J Pharm Bioall Sci [serial online] 2015 [cited 2019 Dec 9];7, Suppl S2:680-6. Available from: http://www.jpbsonline.org/text.asp?2015/7/6/680/163600
This study is a cross-sectional study which is a gateway to conclude upon the normal hard tissue values of Tamil Nadu population. These values will give an edge in diagnosis and treatment planning for this prestigious population. The first step in the diagnosis of the orthognathic surgical patient is to determine the nature of the skeletal and dental defects using specialized cephalometric appraisal system called cephalometric analysis.
Various attempts have made to investigate the differences in facial features among ethnic groups including American  -blacks, Australian, Chinese, Japanese, Koreans, and Indians. Further studies have been done among Indians population. ,, From this review, it could be concluded that there are differences in dentofacial relationships of various ethnic and racial group.
The purpose of this study is to identify the normal values for the hard tissue profile.
It was difficult to differentiate Tamil population in Tamil Nadu as it had people from all over the Dravidian state like Andhra Pradesh, Karnataka, and Kerala. Hence, to be specific, we had to stick on to the communities specific to this particular ethnic population. The candidate or the volunteer should be native of Tamil Nadu for three generations belonging to the same communities for all three generations. This detail was confirmed by questionnaire set to the candidate.
A study was conducted to provide a description of the craniofacial morphology of Singaporean Chinese children and to compare gender differences. , The data provide useful reference cephalometric values for Singaporean Chinese children. 
| Materials and Methods|| |
Sample constituted 54 individuals which included 28 males and 26 females with age ranging from 18 to 35 years were enrolled for the study consecutively who met inclusion and exclusion criteria. They were selected on the basis of their class I molar occlusions and well balanced facial profile.  The adults of Tamil Nadu origin residing in Tamil Nadu were included in the study. Lateral cephalograms were taken for each subject included in the study with their consent. A pre-structured proforma was used to collect the relevant information and record cephalometric measurements for each subject.
- Person who were native of Tamil Nadu
- Class I molar occlusion with acceptable profile
- Full permanent teeth with proper intercuspation
- Normal limits of overjet and overbite
- Presence of negligible crowding, rotations, and spacings
- The candidate should be in Tamil Nadu and should be settled in Tamil Nadu for three generations who belongs to the communities of Tamil Nadu.
- Person with major dental and skeletal discrepancy like syndromic patients and gross class II and class III skeletal and dental patterns
- History of trauma, fracture in maxillofacial region
- History of previous orthodontic treatment, orthognathic or plastic surgery
- People belonging to other state communities from Andhra Pradesh, Kerala, Karnataka were excluded.
Lateral cephalometric radiographs were taken for 54 people who were native of Tamil Nadu and met the above-mentioned criteria. Radiographs were taken in natural head position with the teeth in maximum intercuspation and lips in repose.
After standardization of cephalometric technique, the analysis for orthognathic surgery for hard tissue given by Burstone is used.
- Sella (S), the center of the pituitary fossa
- Nasion (N), the most anterior point of the nasofrontal suture in the midsagittal plane
- Articulare (Ar), the intersection of basisphenoid and the posterior border of the condyle mandibularis
- Pterygomaxillary fissure (PTM), the most posterior point on the anterior contour of the maxillary tuberosity
- Subspinale (A), the deepest point in the midsagittal plane between the anterior nasal spine (ANS) and prosthion
- Pogonion (Pg), the most anterior point in the midsagittal plane of the contour of the chin
- Supramentale (B) the deepest point in the midsagittal plane between infradentale and Pg, usually anterior to and slightly below the apices of the mandibular incisors
- Anterior nasal spine, the most anterior point of the nasal floor; the tip of the premaxilla in the midsagittal plane
- Menton (Me), the lowest point of the contour of the mandibular symphysis
- Gnathion (Gn), the midpoint between Pg and Me, located by bisecting the facial line N-Pg and the mandibular plane (lower border)
- Posterior nasal spine (PNS) the most posterior point on the contour of the palate
- Mandibular plane (MP), a plane constructed from Me to the angle of the mandible (Go)
- Nasal floor (NF), a plane constructed from PNS to ANS
- Gonion (Go), located by bisecting the posterior ramal plane and the mandibular plane angle.
- Horizontal plane (HP) is a surrogate Frankfort plane constructed by line 7° from the line S to N
- S-N Plane: A line joining sella and nasion
- Nasal floor (NF): A line passing from ANS to PNS
- Mandibular plane (Go-Gn): A line passing from gonion to gnathion
- Functional occlusal plane (OP): A line extending from buccal groove of first molar to 1 mm above incisal edge of the central incisor
- Long axis of upper incisors (U 1)
- Long axis of lower incisors (L 1).
[Figure 1] illustrates the reference planes used in the study.
- Posterior cranial base: Measured parallel to HP from articulare to PTM fissure
- Anterior cranial base: Measured parallel to HP from PTM fissure to nasion.
This is illustrated in [Figure 2].
- Angle of facial convexity: It is the angle formed between nasion-point A and pogonion [Figure 3]
- Apical base of maxilla to nasion: Measured from nasion to point A parallel to HP
- Chin prominence: Measured parallel to HP from nasion to pogonion.
Vertical (skeletal, dental)
- Middle third facial height: Measured perpendicular to HP from nasion to ANS
- Lower third facial height: Measured perpendicular to HP from ANS to gnathion.
- Posterior vertical height: Measured perpendicular to HP from PNS to nasion
- Posterior facial diversions: It is the angle formed between mandibular planes (Go-Gn) to HP.
- Anterior maxillary dental height: Measured from a perpendicular line dropped from the incisal edge of upper central incisor to the nasal floor
- Anterior mandibular dental height: Measured from perpendicular line dropped from incisal edge of mandibular anterior teeth to the mandibular plane.
- Posterior maxillary dental height: Measured from the mesiobuccal cusp tip of the maxillary first molar to the nasal floor
- Posterior mandibular dental height: Measured from the mesiobuccal cusp tip of mandibular first molar to the mandibular plane.
Maxilla and mandible
- Maxillary length: Distance between ANS and PNS
- Mandibular ramal length: Measured from articulare to gonion
- Mandibular body length: Measured from gonion to pogonion
- Gonial angle: Angle formed between articularegonion and gnathion
- Chin position: Measured from point B to pogonion.
- Occlusal plane angle: Angle formed between OP and HP
- Relation of maxilla and mandible to OP: Measured from the distance point A to point B dropped perpendicularly to OP
- Upper incisor position: Determined by measuring the angle formed between the nasal floor and the long axis of upper central incisor
- Lower incisor position: Determined by the angle between the mandibular plane and the long axis of the lower central incisor.
Mean, standard deviation, and range values were determined for the total sample male and female groups. The mean and standard deviation of each group and the values originally obtained by Burstone were subjected to Student's t-test using Excel program (Microsoft Corporation, Redmond WA, USA) and the level significance was set at 0.05.
| Results|| |
In our study, 54 individuals (28 males and 26 females) with age ranging between 18 and 35 years were enrolled for the study consecutively. They were selected on the basis of their excellent occlusions angles class I molar relation and well balanced facial pattern. Sample constituted adults of Chennai origin residing in Tamil Nadu. Lateral cephalograms were taken for each subject.
Various angular and linear measurements for hard tissues in both males and females were obtained and were tabulated. All the reading thus obtained were subjected to statistical analysis. Mean, standard deviation, and range values were determined for the total sample, male and female groups. The mean and standard deviations of each group and the values originally obtained by Burstone and Legan were subjected to a Student's t-test using Minitab software and the level of significance was set at 0.05.
[Table 1] and [Table 2] show results of hard tissue measurements for males and females. [Table 3] and [Table 4] show a comparison of hard tissue norms between Tamil Nadu population and Caucasian population for males and females.
Cephalometric comparison of Caucasian men and Tamil men
Tamil men have increased anterior and posterior cranial base length.
Horizontal (skeletal) relationship
- Tamil men have reduced convex profile than Caucasian men
- No significant difference in the horizontal relationship between both the population.
Vertical (skeletal) relationship
- Posterior maxillary skeletal height is increased for Tamil men than the Caucasian men
- Mandibular plane angle is low in Tamil population when compared with Caucasian men.
[Figure 4] illustrates the vertical relationship.
Vertical (dental) relationship
- Posterior dental height in maxilla is reduced when compared with Caucasian men
- Posterior dental height in mandible is increased for Tamil men when compared with Caucasian men.
Maxillary mandibular relationship
- Maxillary body length is increased in Tamil men
- Ramus length is increased in Tamil men
- Chin is less prominent when compared with Caucasian men.
[Figure 5] illustrates the Maxilla Mandibular relationship.
Maxillary and mandibular incisal angulation is more in Tamil men [Figure 6].
Cephalometric comparison of Caucasian women and Tamil women
Anterior and posterior cranial base for Tamil women is more compared with Caucasian women.
Horizontal (skeletal) relationship
No significant difference found when compared with Caucasian women.
Vertical (skeletal) relationship
- Anterior maxillary height is increased in Tamil women than Caucasian women (or) increased anterior middle third facial height
- Increased lower third facial height in Tamil women than in the Caucasian women
- Increased posterior maxillary skeletal height in Tamil women than Caucasian women.
Vertical (dental) relationship
- Maxillary anterior dental height is increased in Tamil women
- Mandibular posterior dental height is increased in Tamil women than in Caucasian women.
Maxillary and mandibular relationship
- Maxillary body length is increased in Tamil women
- Mandibular ramus height is increased in Tamil women
- Mandibular body length is increased in Tamil women
- Chin prominence is reduced in Tamil women.
Mandibular incisal angulation is increased in Tamil women
| Discussions|| |
In this study, the inclusion criteria and methodology were oriented to identify formative values that can assist in the diagnosis and treatment planning of adults of Tamil Nadu seeking orthognathic surgery. We intended to obtain a representative sample of the normal Tamil population. Hence, we did not include patients who have received orthodontic or any kind of cranial or facial surgical treatment or people from other states. Due to the facial growth and development, cephalometric studies whose samples included predominantly or exclusively children may not be useful for prospective orthognathic surgery cases. Similarly, patients of advanced age may show changes due simply to the aging process such as loss of vertical dimension between the jaws caused by attrition and loss of teeth. Keeping this in mind in the present study, the sample was limited to young adults with a range of 18-35 years.
Our study showed that males of this Tamil population had increased the posterior cranial base length and increased anterior cranial base length was present in both the sexes. There is less convex profile in the males and more convex profile in the female and also, increased maxillary and mandibular incisor proclination were noticed. It was inferred from our study that a separate norms for normal ethnic Tamil adults contemplating orthognathic surgery was needed. [Table 5] shows hard tissue norms.
| Conclusions|| |
A cephalometric appraisal is only one step in diagnosis and planning of treatment. In the present study, surgically useful cephalometric norms for hard in the diagnosis and treatment planning of orthognathic surgery in adult Tamil population have been determined. There was a significant difference in the values of Tamil and Caucasian population. These differences should be considered when formulating the diagnosis and treatment plan for patients of Tamil Nadu contemplating surgery.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]