Exploring the association between PITX2, third molars agenesis and sella turcica morphology : PITX2, third molars agenesis and sella turcica morphology

Abstract

Objectives: PITX2 is required for mammalian development and single nucleotide polymorphisms (SNPs) in this gene could be involved in dental agenesis and sella turcica patterns. Thus, the present study evaluated the association between SNPs in PITX2, third molars agenesis and sella turcica phenotypes.

Materials and methods: The sample consisted of healthy orthodontic German patients with lateral cephalometric radiographs with clearly visualization of the sella turcica, and dental orthopantomograms. The morphological variations of the sella turcica were evaluated using the lateral cephalograms, while third molar agenesis was evaluated using orthopantomograms. DNA isolated from buccal cells was used for genotyping three SNPs in PITX2 (rs3796902, rs1947187, and rs2595110). The analyzes were performed using a significance of 5%. There was no association between third molar agenesis and sella turcica phenotypes (p > 0.05). SNPs in PITX2 were also not associated with third molars agenesis (p > 0.05).

Results: SNPs in PITX2 were associated with sella turcica phenotypes. The rs3796902 was associated with hypertrophic posterior clinoid process (p = 0.013). The rs1947187 and rs2595110 were associated with sella turcica bridge type A (p = 0.013 and p = 0.011, respectively for genotype distribution). Patients that carry the genotypes GG-CC-AG (rs3796902- rs1947187- rs2595110) had 7.2 higher chance to present sella turcica bridge type A (p = 0.002; Odds ratio = 7.2, Confidence interval 95% 2.04-27.04).

Conclusions: Third molar agenesis was not associated with SNPs in PITX2 and sella turcica phenotypes. SNPs in PITX2 may have an important role in sella turcica pattern.

Keywords: Gene; Sella turcica; Tooth agenesis.

Fig. 1

Sella turcica classifications Sella turcica calcification phenotypes (I- calcification; II- partially calcified; III- completely calcified). Sella turcica patterns (A- normal sella turcica; B- sella turcica bridge type B- extension of the clinoid process; C- sella turcica bridge type A- ribbon-like fusion; D- incomplete bridge; E- hypertrophic posterior clinoid process; F- hypotrophic posterior clinoid process; G- irregularity (notching) in the posterior part of the sella turcica; H- pyramidal shape of the dorsum sella; I- double contour of the floor; J- oblique anterior wall; K- oblique contour of the floor)

Fig. 2

Sella turcica landmarkers and linear measurements. a: length; b: depth; c: diameter; d: anterior height; e: posterior height; f: width SF means sella floor