engleski

Premolars root morphology in gonadal dysgenesis

Premolar root forms were investigated in 40 females with Turner syndrome and 39 males with Klinefelter syndrome. Healthy females and males, 80 in each group, served as controls. The aim was to investigate the role of the X chromosome in dental root development. The presence of various root forms of upper and lower premolars was noted from the orthopantomograms. For the Turner sample standard intraoral radiographs were also analysed. Premolars were classified according to the method proposed by Midtbo (1), partially modified for the lower premolars. There were three types of the maxillary premolars: 1) one-rooted ; 2) two-rooted (separated buccal and palatal roots) ; 3) three-rooted (two buccal and one palatal root). The mandibular premolars were classified into five groups: 1A) one-rooted with one root canal ; 1B) one-rooted with two separate root canals ; 2A) two-rooted with separate buccal and lingual root components ; 2B) two-rooted with separate mesial and distal root components ; 3) three-rooted with two buccal and one lingual root. The maxillary and mandibular premolars with two or three root components were found significantly more often in the Turner group than in all other investigated groups (p<0, 000001). In maxilla there was 2, 9% one-rooted, 88, 2% two-rooted and 8, 8% three-rooted P1 and 28, 6% one-rooted, 65, 3% two-rooted and 6, 1% three-rooted P2. In mandible there was 21, 6% one-rooted and 78, 4% two-rooted P1 and 51, 4% one-rooted, 47, 3% two-rooted and 1, 4% three-rooted P2. In the lower two-rooted premolars type 2A was 2-4 times more frequent than type 2B. An asymmetry in the root number was significantly more frequent only for the lower premolars (p<0, 0005). There was no difference between the Klinefelter group and male controls, or between female and male controls. The findings indicate that the premolar root formation is influenced by the X chromosome deficiency. On the contrary, we didn&#8217; t find any evidence of the influence of the supernumerary X chromosome on premolar root morphology. Literature: 1) Midtbo M et al., Acta Odontol Scand 1994 ; 52: 303. 2) Varrela J. Archs Oral Biol 1990 ; 35: 109. 3) Kaić Z. 7th International Congress of Human Genetics 1986, Abs No C I.49.

Premolars; Root morphology; X chromosome

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