Page 27 - MDJ Volume 47 Number 2 ( Jul-Dec 2024)

Fatima, et al.: Relationship of Cranial base growth with sagittal skeletal discrepancies
floor of the cranial vault is formed by the cranial base. 2021, at the Department of Orthodontics, Sindh Institute
Anteriorly, it extends to the foramen caecum. Posteriorly, of Oral Health Sciences, JSMU. Before enrolment of
it is limited to the basioccipital bone. The sella turcica is patients in the study, participants were briefed about the
the most central structure in the cranial base and it divides purpose and benefits of the study, and written consent
it into anterior and posterior limbs. This flexure formed was taken for the study.
at sella turcica between the anterior and posterior limb is By using the World Health Organization calculator, the
recorded as 130°–135°. [2]
sample size was calculated by taking mean ± standard
[2]
This angle at birth is 142°, at the age of 5 years it decreases deviation of 125.2 ±5.9, keeping the confidence interval
to 130°. It remains stable from 5 to 15 years. Different as 95% and absolute precision as 0.012, the sample size
theories have been proposed regarding cranial base flexure of the study was 93. The non-probability consecutive
and different types of malocclusion. Some reports showed sampling was used for sample collection.
a positive relationship between cranial base flexure and Patients of both genders with ages ranging from 13
malocclusion and others vice versa. [3-7]
to 30 years presented with malalignment of teeth and
The cranial base has an important role in the growth underwent orthodontic treatment having class I, class II
of the craniofacial complex. The fact that the maxilla and class III malocclusions. Patients previously treated
is connected to the anterior part of the cranial base and orthodontically, patients with syndromes like Treacher
the rotation of the mandible concerning it signifies that Collins syndrome, Down syndrome, Stickler syndrome,
a relationship exists between the growth of the cranial Cleidocranial syndrome, Apert syndrome, Van der Waude’s
base and sagittal position of the maxilla and mandible syndrome, Pierre Robin syndrome and cleft lip and palate
and the resulting malocclusion or skeletal sagittal were excluded from the study. Measurements of anterior
discrepancy. [8-10] cranial base length, posterior cranial base length, total
cranial base length and cranial base angles were taken.
The literature reports that there is an increased cranial Articulare, basion, nasion, sella, point A and point B were
base angle in class II malocclusion cases, which supports a the cephalometric landmarks used in the study.
more posterior position of the mandible in them, whereas
class III malocclusion presented with a smaller cranial base Measurements to classify sagittal malocclusions were
angle. It has been reported that the cranial base angle and made as: class I malocclusion if ANB 0–4, class II
length increase from class III to class I to class II division 1 malocclusion if ANB >4 and class III malocclusion if
malocclusion. Some researchers have found that the largest ANB <0.
cranial base angle is found in class II tendency cases. The mean Patients were selected by the primary investigator. For
cranial base angle SNAr and SNBa in the class II division the standard lateral cephalogram for each subject, each
2 group was found to be 126.71° ± 5.1° and 131.58° ± 4.6°, individual was asked to position in the cephalostat with
respectively. In the class III group, it was found to be SNAr the sagittal plane of the head vertical, the Frankfort plane
that is, 123.55° ± 6.97° and SNBa that is, 128.45°± 5.8°. horizontal teeth in centric relation with the headrest in
A study reported mean cranial base angles as SNAr that is, natural head position. On the obtained radiograph, linear
125.2° ± 5.9° and SNBa that is, 129.1 °± 5.4°, respectively. [2,3,7] measurements were recorded with a measuring scale, and
Another study reported mean total, anterior and posterior angular measurements were recorded with a protractor.
cranial base lengths as 103.87 ± 5.56, 68.47 ± 4.09 and Through cephalometric tracing anterior (NS), posterior
45.08 ± 3.29 mm, respectively, in class II individuals. [11] (SBa) and total cranial base lengths (NBa) were measured
along with the cranial base angles [<nasion–sella–
The study aimed to determine the relationship between articulare (NSAr) and <nasion–sella–basion (NSBa)]. For
cranial base morphology and different sagittal skeletal skeletal malocclusion type, SNA, SNB and ANB were also
discrepancies as different ethnicities cause different measured. Lateral cephalogram tracings were evaluated
morphological characteristics. Besides, understanding the twice by the same examiner with an interval of 1-week
cause of malocclusion can benefit in better diagnosis and difference. All the data were controlled anonymously
formulating appropriate treatment plans. Therefore, to and kept confidential according to international ethical
study any possible relation this study was carried out as guidelines. This study uses Statistical Package for Social
there are not many studies in this regard in our population. Sciences version 20.0 for Windows (SPSS Inc.; Chicago,
IL, USA) for data entry and analysis. Mean and standard
deviation were calculated for the quantitative variables
MaterIals and Methods such as anterior cranial base length (NS), posterior
This cross-sectional study was conducted after obtaining cranial base length (SBa), total cranial base length (NBa)
approval from the Institutional Review Board of Jinnah and cranial base angles (NSAr and NSBa). Analysis of
Sindh Medical University (JSMU), Karachi, Pakistan. The variance (ANOVA) test was used to compare the mean
study was carried out from June 1, 2021, to November 30, total, anterior and posterior cranial base lengths and

Malaysian Dental Journal ¦ Volume 47 ¦ Issue 2 ¦ July-December 2024 21