|Year : 2019 | Volume
| Issue : 3 | Page : 112-115
Study of patterns of sella turcica with different malocclusions
Pranali Kadam, Aishwarya Sabharwal, Amol S Patil, Anand Sabane, Veera Bhosale
Department of Orthodontics, Bharati Vidyapeeth Dental College and Hospital, Pune, Maharashtra, India
|Date of Submission||09-Apr-2019|
|Date of Decision||16-May-2019|
|Date of Acceptance||16-May-2019|
|Date of Web Publication||23-Sep-2019|
Department of Orthodontics, Bharati Vidyapeeth Dental College and Hospital, Satara Road, Katraj, Dhankawadi, Pune - 411 043, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: In the field of orthodontics and dentofacial orthopedics, for treatment of malocclusion, diagnosis of facial skeletal type is one of the important aspects. Sometimes, cephalograms are not enough to determine the facial skeletal pattern. Hence, the relationship between sella turcica and other facial skeletal patterns can guide us to determine the proper facial skeletal type and can also help in treatment planning.
Aims: The aim of the study was to investigate the normalcy of the dimensions of sella turcica and comparison of the relationship of sella turcica with different skeletal malocclusions.
Materials and Methods: A total of 90 pretreatment digital lateral cephalograms were selected according to the criteria and grouped into 3 groups: Group 1: Class I (n = 30), Group 2: Class II (n = 30), and Group 3: Class III (n = 30). Lateral cephalograms were traced and studied on the basis of sella turcica. The following linear measurements were recorded: length, depth, and diameter of the sella.
Statistical Analysis Used: Data were subjected to descriptive analysis for mean and standard deviation of all variables and ranges. ANOVA and a post hoc test (Bonferroni and Sidak) were used for multiple comparisons. P <0.05 was considered as the level for statistically significant data.
Results: The linear measurements of length and diameter showed statistically significant differences in Class I, Class II, and Class III (P = 0.005). However, depth showed no statistically significant difference in the groups.
Conclusions: The importance of sella turcica is established and normalcy is set by statistical analysis, and the standard values are given for the dimensions of the sella turcica. This can be used for further analysis and reference standards for the Indian population. The length and diameter were statistically significant with different groups. The largest value was given in Class III.
Keywords: ANOVA test, lateral cephalograms, malocclusions, sella turcica, sella turcica dimensions
|How to cite this article:|
Kadam P, Sabharwal A, Patil AS, Sabane A, Bhosale V. Study of patterns of sella turcica with different malocclusions. Int J Orthod Rehabil 2019;10:112-5
| Introduction|| |
The sella turcica is a saddle-shaped depression in the body of the sphenoid bone of human skull and of the skulls of other hominids including chimpanzees, orangutans, and gorillas. The pituitary gland of hypophysis is located within the most inferior aspect of the sella turcica, the hypophyseal fossa.
It serves as a cephalometric landmark. The sella turcica is a structure which can be readily seen on lateral cephalometric radiographs, and sella point is routinely traced for various cephalometric analyses.,, The morphology is very important for the cephalometric position of the reference point sella, not only for evaluating craniofacial morphology but also when growth changes and orthodontic treatment results are to be evaluated. This makes it a good source of additional diagnostic information related to pathology of the pituitary gland, or to various syndromes that affect the craniofacial region.,,,,, Clinicians should be familiar with the normal radiographic anatomy and morphologic variability of this area, to recognize and investigate deviations that may reflect pathological situations, even before these become clinically apparent. Abnormal sella turcica causes various diseases such as intrasellar pituitary primary tumors, hypopituitarism, or syndromes like Williams or Sheehan's syndrome. Furthermore, keeping in mind the cephalocaudal gradient of growth, the size of the sella may be a key diagnosing factor of Class III and Class II patients, and early treatment can be planned. As the maturation of the sella will take place before the mandible and hence can help in diagnosis of a large or short jaw.
Therefore, the purpose of the study was to investigate the normalcy of the dimensions of sella turcica and comparison of the relationship of sella turcica with different skeletal malocclusion. In orthodontics, sella point which is located at the center of sella turcica is one of the most commonly used landmarks in cephalometrics.,,, Such landmarks located within the craniofacial region are used to measure the positions of maxilla and mandible in relation to the cranium and to themselves. The benefits gained from studying these structures range from assisting the orthodontist during diagnosis, as a tool to study growth in an individual through superimposition of structures on a longitudinal basis, and during evaluation of orthodontic treatment results. Since sella area is an important region, and morphology may vary from individual to individual, establishing normal standards will aid in the process of eliminating any abnormality in the size or shape of sella turcica.
| Materials and Methods|| |
Ninety pretreatment lateral cephalograms were selected on the basis mentioned below. The ethical approval was obtained from the institutional ethical committee. Being a retrospective study, the patients were informed that their lateral cephalograms will be used for further studies, and consent was obtained during that time. Criteria for selection of cephalograms were as follows:
- Individual with no previous orthodontic treatment
- Individual should be healthy with no systemic diseases
- Individual should be above 18 years
- All Class I malocclusion patients had an A point, nasion, B point (ANB) value 1°–3°
- All Class II malocclusion patients had an of ANB value >4°
- All Class III malocclusion patients had an ANB value <1°.
Cephalograms were divided into 3 groups: Class I malocclusion (n = 30), Class II malocclusion (n = 30), and Class III malocclusion (n = 30). They were traced by single researcher using 0.5 mm lead pencil and an orthodontic paper. Beside routine anatomical designs, the cephalometric points traced are given in [Table 1], and linear measurements taken are in [Table 2] (refer to [Figure 1]).
The data were statistically analyzed with SPSS 20 Software (IBM, Chicago, Illinois, USA). Data were subjected to descriptive analysis for mean and standard deviation (SD) of all variables and ranges. ANOVA and a post hoc test (Bonferroni and Sidak) were used for multiple comparisons [Table 3] and [Table 4]. P <0.05 was considered as the level for statistically significant data.
|Table 3: Comparison of size of sella turcica in different skeletal patterns using ANOVA test|
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| Results|| |
The linear measurements with the arithmetic mean and SDs are tabulated in [Table 3]. This sets the normalcy of the size of the sella turcica and can be used for further analysis and as a reference for further studies in the Indian population. The linear measurements of the length (a) was statistically significant in different groups: Class I, Class II, and Class III (P = 0.043). The effective length of the mandible was statistically significant and showed the length of the mandible in different classes (P = 0.002). This shows the variation in length in different classes.
Due to inconsistency of the reader or the small number of data, no statistical difference was found between Class I and Class II. Furthermore, the depth of the sella was not statistically significant in Class I, Class II, and Class III individuals and showed no correlation between the length of the mandible and the depth of the sella turcica (P ≥ 0.05). This further also states that the size of the sella turcica is largest in Class III individuals as compared to Class I and Class II individuals.
| Discussion|| |
From this study, it can be inferred that the length of sella turcica is directly correlated to the effective length of the mandible, i.e., the skeletal type. In some cases, the depth of sella may be correlated with the facial pattern. As we have seen that size of sella turcica is greater in Class III malocclusion, it can also mean that the size of pituitary gland may also be greater, which can also lead to considerably more release of growth hormone that can increase the growth of mandible leading it to Class III malocclusion.
,,,,,, The measurement and morphology of sella turcica are valuable in the assessment of pathology in the pituitary gland. Studies of sella turcica size on radiographs have been based on linear or various methods of area and volume measurements., Based on anteroposterior relation of maxilla with mandible, facial skeletal patterns are classified as Class I, Class II, and Class III. The orthodontic treatment for all three facial skeletal patterns is different. Before commencement of treatment, it is necessary to determine the relation between both the jaws. Sometimes, measurements done during lateral cephalometric analysis may provide a borderline finding which makes it difficult to differentiate between skeletal facial patterns., Hence, to determine a proper treatment plan, the shape and size of sella turcica can help in determining the facial skeletal type., In the present study, manual tracing was used for calculation of the length, depth, and diameter of the sella turcica. Although in some studies, the digital method was used to measure these factors, the manual technique has accuracy similar to that of digital technique in this regard. Thus, considering its affordability, the manual technique was used. It seems that further investigations in several centers with larger sample sizes can increase the accuracy of the obtained data and standards.
| Conclusions|| |
- In skeletal Class III or prognathic mandible, the anteroposterior dimensions of the sella turcica, that is, the length and the diameter are the largest as compared to Class I and Class II
- Depth of the sella turcica and the effective length of the mandible do not correlate with the three skeletal types.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]