Establishing Cephalometric Norms using Sagittal and Vertical Occlusal Cephalometric Analysis of Pancherz for Dakshina Kannada Children.

BACKGROUND: The purpose of this study was to establish norms for the sagittal occlusal (SO) and vertical occlusal (VO) cephalometric analyses of Pancherz for Dakshina Kannada children and to analyze and compare the difference between boys and girls of same age group (10-14 years).
MATERIALS AND METHODS: Two hundred and sixty-three (132 boys and 131 girls) children of Dakshina Kannada were included in this study. Lateral cephalometric radiographs of children belonging to the age group of 10-14 years were taken. Dental lateral cephalometric radiographs were obtained and these cephalometric radiographs were then manually traced. All the parameters considered in the Pancherz analysis were considered while establishing the norms for Dakshina Kannada children.
RESULTS: Statistically significant sex differences were found for 9 of 11 parameters in the sagittal occlusal analysis, and 10 of 10 in the Vertical occlusal analysis.
CONCLUSIONS: For the sagittal and Vertical occlusal analyses of Pancherz a separate sex-specific standards are needed for Dakshina Kannada children.

Introduction

Since the introduction of cephalometrics by Broadbent in 1931, its role has been vital in orthodontic diagnosis and treatment planning, and for monitoring treatment and growth changes.1 The diagnostic norm is a standard, which helps us to determine the extent of deviations from the “normal” or what is considered “healthy.” A shortcoming of various studies attempting to establish population standards (“norms”) is that a wide range of ages or only adults were considered. “Norms” should ideally be valid for children at the age when orthodontic treatment usually commences, i.e., close to 12 years.2-5 Patients most commonly undergo orthodontic treatment at around 10-14 years of age, and priority should be given to obtain solid norms for this age group.6-9 The Pancherz and pitchfork cephalometric analyses are commonly used for the evaluation of treatment changes. Pancherz and Wu and others had established norms for Whites and Chinese children.10 The Pancherz method has been used not only for evaluation of treatment but also for comparison of dentofacial morphology. The Pancherz cephalometric analysis comprises of 2 parts, the sagittal occlusal analysis (SO analysis), and vertical occlusal analysis (VO analysis), which make it possible to distinguish between sagittal and vertical dentofacial problems and changes.10-29 In orthodontic practices, a diagnosis is determined, in part, by comparing a patient's cephalometric measurements to standard norms. These norms may be however specific to an ethnic group and cannot always being applied to other ethnic types.

Material and Methods

Two hundred and sixty-three (132 boys and 131 girls) children of Dakshina Kannada were included in this study. Fresh lateral cephalometric radiographs of children belonging to the age group of 10-14 years were taken from various schools in Dakshina Kannada using PLANMECA - 9200 - Proline XC with Dimax 3 X-ray machine after taking their parents consent. Inclusion criteria: (1) All subjects are in the age group of 10-14 years. (2) All set of complement teeth was present for that age. Exclusion criteria: (1) No history of previous and current orthodontic treatment. (2) No history of obstructed nose breathing. (3) Craniofacial anomalies and any other syndromes. Figure 1 illustrates The land marks and planes used in pancherz Aanalysis

Figure 1

(a) Diagrammatic view of sagittal occlusal analysis. (b) Diagrammatic view of vertical occlusal analysis.

Land marks used in this study

Ii - Incision inferior: The incisal tip of the most prominent mandibular incisor.

Is - Incision superius: The incisal tip of the most prominent maxillary incisor.

Mi - Molar inferius: The mesial contact point of the mandibular first permanent molar by a tangent parallel to OLp.

Mic - The mesiobuccal cusp tip of the mandibular first molar.

Ms - Molar superius: The mesial contact point of the maxillary first permanent molar by a tangent parallel to OLp.

Msc - The mesiobuccal cusp tip of the maxillary first molar.

Pg - Pogonion: The most anterior part of the bony chin determined by a tangent parallel to OLp.

A - The deepest point on the anterior contours of the maxillary alveolar projection determined by a tangent parallel to OLp.

N - Nasion.

S - Sella.

ANS - Anterior Nasal Spine.

PNS - Posterior Nasal Spine.

Me - Menton.

Go - Gonion.

Planes used in this study

NL – Nasal line (Maxillary plane – ANS – PNS)

ML – Mandibular line (Mandibular plane – Me – Go)

NSL – Nasal Sella Line.

OLs – Maxillary Occlusal Plane.

OLi – Mandibular Occlusal Plane.

OLp – Occlusal Plane perpendicular-Reference line perpendicular to OLs through S.

Results

Student's unpaired t-test was used to analyze the variation between boys and girls of Dakshina Kannada. Statistically significant sex differences were found for 9 of 11 parameters in the SO analysis, and 10 of 10 in the VO analysis. The cephalometric norm of the SO for boys is summarized in Table 1. The cephalometric norm of the SO for girls is summarized in Table 2. The cephalometric norm of the VO for boys is summarized in Table 3. The cephalometric norm of the VO for girls is summarized in Table 4. The difference in the SO for boys and girls is summarized in Table 5. The difference in the VO for boys and girls is summarized in Table 6. There were large individual variations for all variables for both sexes.

Table 1

Sagittal measurements for males.

Table 2

Sagittal measurements for females.

Table 3

Vertical measurements for males.

Table 4

Vertical measurements for females.

Table 5

Difference in sagittal measurements between males and females.

Table 6

Difference in vertical measurements between males and females.

Discussion

This is the first study to provide cephalometric population norms for Dakshina Kannada children using Pancherz's SO and VO analyses. Originally, these 2 methods (SO and VO analysis) were intended to quantify dental and skeletal changes during orthodontic treatment of Class II malocclusions with various removable and fixed functional appliances. This study was based on cephalograms obtained from a sufficiently large randomized untreated sample of l0-14 years old Dakshina Kannada children. This sample can be considered representative of the dentofacial morphology for that age group. 263 (132 boys and 131 girls) children of Dakshina Kannada were included in this study. All subjects were in the age group of 10-14 years with no history of previous orthodontic treatment or craniofacial anomalies and any other syndromes. For Pancherz's SO analysis, Table 7, variables like, over jet, position of mandibular base, jaw relationship, maxillary and mandibular central incisor positions, mandibular central incisor relationship to pg, Position of maxillary and mandibular first permanent molar were greater in female subjects. Whereas molar relationship, the position of the maxillary base and maxillary central incisor relationship to A point is greater in male subjects. Furthermore, for Pancherz's VO analysis, Table 8, all variables except overbite and nasal plane angle were greater in the female subjects. Thus, 10-14 years old Dakshina Kannada children have greater over jet, less overbite, average lower face height, and steeper maxillary and mandibular plane angles with the prevalence of Class II molar relationships considerably higher in the Dakshina Kannada children compared to Chinese children.10 Out of 21 parameters which are used in Pancherz's analysis, there were a statistically significant sex differences found in 9 of 11 parameters in the SO analysis and 10 of 10 in the VO analysis.

Table 7

Difference in Sagittal measurements between males and females.

Table 8

Difference in Vertical measurements between males and females.

Conclusion

The results of this study suggest that separate norms for Pancherz's SO and VO analyses are justified for 10-14 years old Dakshina Kannada children. The results also suggest that separate norms are needed for both sexes in different age group. Over jet, position of mandibular base, jaw relationship, maxillary and mandibular central incisor positions, mandibular central incisor relationship to pg, position of maxillary and mandibular first permanent molar were greater in girls, whereas molar relationship, position of maxillary base and maxillary central incisor relationship to A point is greater in boys.