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Biomedical subjects

L Alvesalo

Publications and source records attributed to L Alvesalo.

At least 37 records · Page 2Linked to original sources
PubMed1993

Palatal and alveolar arch dimensions in 47,XXY (Klinefelter syndrome) men.

Men with one extra X chromosome (47,XXY; Klinefelter syndrome) show a tendency to have a shallower but longer palate than normal (46,XY) men. The palate is also narrower than in 46,XY men. The mandible is clearly narrower but sagittally longer compared with the mandibles of 46,XY men. The present results indicate that the presence of one extra X chromosome in 47,XXY men is reflected in decreased growth of the maxilla transversely and vertically and of the mandible transversely. Increased length of the alveolar arches might be partly a compensation for the decreased width of the alveolar arch. This change might be associated with larger tooth sizes in 47,XXY men. Unbalanced appositional growth rather than disturbances in other orofacial growth mechanisms might be associated with the XXY sex chromosome pattern.

Adolescent↗
PubMed1992

Occlusion in 47,XXY (Klinefelter syndrome) men.

Occlusal morphology of permanent dentitions in 29 men with a 47,XXY chromosome complement (Klinefelter syndrome) was determined from dental casts. The results showed that a relatively frequent occlusal anomaly was mesial molar occlusion. Incisal open bite was also more common than in controls. Based on the present and previous observations of occlusal anomalies in various sex chromosome anomaly groups and normal controls, it is suggested that the presence of the Y chromosome in the genome is at least as important as the X chromosome for the development of harmonious occlusal morphology. The tendency towards sexual dimorphism in occlusal phenotype might result from a differential effect of the X and Y chromosomes on cellular activity which leads to different growth patterns.

Adolescent↗
PubMed1992

Dental morphology of 45,XO human females: molar cusp area, volume, shape and linear measurements.

A three-dimensional analysis of the maxillary first molars of five 45,XO females and comparison with normal females and males demonstrated a reduction of cusp areas and volumes in the 45,XO females. Mesiodistal and faciolingual dimensions were also reduced. The reductions in basal area and volume were greater in the later developing, distal cusps. In normal females the second X chromosome apparently does not exert an effect on the cusp height but increases the basal area. The results further indicate that the Y chromosome in normal males increases both cusp height and basal area. The steepest cusps were found in 45,XO females while the shallowest were in the control males. Both sex chromosomes thus seem to affect the shape of the cusp but the resulting phenotypes differ.

Female↗
PubMed1992

A study in 47,XYY men of the expression of sex-chromosome anomalies in dental occlusion.

Occlusal traits were determined for 47,XYY men and compared with previous determinations of occlusal morphology in other sex-chromosome anomalies and in normal women and men. The 47,XYY men, like 47,XXY men, tended to have a mesial molar occlusion and a mandibular overjet more often than did other groups, while 45,X women (Turner patients) clearly had the highest frequency of distal occlusion and large overjet. The 47,XXY men had the highest frequency of most occlusal anomalies. As a whole, these and earlier findings suggest that the number of X or Y chromosomes is associated negatively with distal occlusion and lateral crossbite, whereas a positive association was found with mesial molar occlusion and scissors bite.

Adolescent↗
PubMed1992

Maternal smoking and tooth formation in the foetus. I. Tooth crown size in the deciduous dentition.

Altogether 2159 pregnancies among black and white Americans in the Collaborative Perinatal Study and dental casts from the children at the age of 5-12 years were studied to find out the effect of maternal smoking on deciduous tooth crown growth. Minor crown size reduction (2-3%) in some dimensions was found in children whose mothers had smoked during pregnancy. The possible change in dimensions seems to be influenced by sex, race and smoking habit. The critical time periods of the gestational development (16th to 19th) weeks would possibly appear from these data to be targeted by the detrimental effect of maternal smoking. It is concluded that deciduous tooth sizes seem to be greatly unaffected when compared to reduction in birthweight.

Black People↗
PubMed1991

Tooth crown size in 46, X, i (Xq) human females.

Permanent tooth crown sizes of six Finnish females with a 46, X, i(Xq) chromosome constitution (isochromosome for the long arm of the X chromosome) were measured from dental casts and compared with those of normal women, first-degree female relatives and 45, X females. Crown diameters of the 46, X, i(Xq) females were not only smaller than in the normal women but even smaller than the 45, X females. These findings can be considered indirect evidence that X chromosome gene(s) for tooth crown growth are most probably located on the short arm.

Chromosome Aberrations↗
PubMed1991

Upper central incisor and canine tooth crown size in 47,XXY males.

Enamel and dentin thicknesses were measured in permanent tooth crowns of 47,XXY (Klinefelter syndrome) males. In 47,XXY males, enamel thickness in maxillary central incisors was significantly greater than that in control males or females, and dentin thickness in incisors and canines was significantly greater than that in control females, but smaller than that in normal males. These findings confirm the concept that human dental growth is affected by sex chromosomes. Amelogenesis is promoted by both X and Y chromosome genes, and sexual dimorphism in average tooth size is evidently determined by a promoting effect of the Y chromosome on dentin growth, probably through cell proliferation. This effect can also explain sex predilection for males in the numbers of supernumerary and ordinary teeth.

Amelogenesis↗
PubMed1991

Taurodontism and the presence of an extra Y chromosome: study of 47,XYY males and analytical review.

A sample of 47,XYY males was examined for taurodontism to provide further information on the effects of chromosome aneuploidies on the trait. The etiology of taurodontism is reviewed in light of recent findings. Two models have been put forward to explain the association of taurodontism with chromosome abnormalities: (1) Taurodontism results from a generalized disruption of developmental homeostasis, and (2) the development of taurodontism reflects a more specific action of the genes. The recent findings in 45,X females indicate that this chromosome aneuploidy does not have any effect on the development of taurodontism, in contrast to the findings of increased frequency of the trait in individuals with extra X chromosomes. The present results in 47,XYY males suggest that the presence of an extra Y chromosome does not cause an increase in the expression of taurodontism. It is concluded that the observed variation in the occurrence of taurodontism in individuals with sex chromosomes aneuploidies does not corroborate the hypothesis of disrupted homeostasis. Instead, the findings indicate that more specific action of gene(s) on the X chromosome is involved. We suggest that the effect of the Y chromosome on growth of both enamel and dentin, possibly in a regulative way, could be involved in the balanced growth of dental structures in 47,XYY males.

Adult↗
PubMed1990

Taurodontism in 45,X females.

Orthopantomograms of 87 45,X females, 61 first-degree female relatives of these females, and a population sample of 113 normal females and 44 normal males were examined for the occurrence of taurodontism in mandibular molars. In the sample of 45,X females, two showed taurodont lower molars. In one of them, a hypotaurodont second molar was detected, while hypotaurodont third molars were found in the other. Three of the females' relatives and four of the population control females showed taurodontism, three unilaterally and four bilaterally. In all cases, the affected teeth were hypotaurodont. The results suggest that taurodontism occurs in 45,X females with a frequency similar to that in normal females. This result is not in accordance with the hypothesis that low mitotic activity of the chromosomally abnormal cells is an etiological factor in the development of taurodontism. The present findings, together with earlier results, suggest that the gene content of the X chromosome, rather than the amount of heterochromatin, is the cause of taurodontism in individuals with chromosome aneuploidy.

Adult↗
PubMed1990

Caries occurrence in Klinefelter syndrome men (47,XXY males).

Men with the Klinefelter syndrome (47,XXY males) and their brothers were studied as regards their caries experiences as part of a comprehensive study on oral facial growth and health in individuals with sex chromosome anomalies. The results show that caries experience was greater among the 47,XXY men than among their normal brothers, and a greater proportion of the 47,XXY men's cumulative caries experience consisted of extractions.

Adult↗
PubMed1989

Occlusal anomalies in 45,X/46,XX- and 46,Xi(Xq)-women (Turner syndrome).

A total of 20 individuals with X-chromosome aberrations, 14 45,X/46,XX-women and six 46,Xi(Xq)-women, were examined for occlusal anomalies. The controls were first-degree woman relatives and population women. The results showed that the most common type of malocclusion in both study groups was lateral cross bite. Also distal molar occlusion, increased maxillary overjet and in 45,X/46,XX-women open bite was found. 45,X/46,XX-women's occlusion seems to be more affected than that of 46,Xi(Xq)-women. Compared to 45,X-women, the present study groups show milder expression of malocclusion. One might speculate that enamel genes of the X-chromosome are involved in occlusal development.

Adult↗
PubMed1989

Periodontal health in 47,XXY men (Klinefelter syndrome).

Periodontal health in 37 patients with a 47,XXY chromosome complement (Klinefelter Syndrome) and in 12 brothers of patients was studied. Mean age-adjusted Gingival, Gingival Bleeding and Calculus Indices were statistically significantly higher in 47,XXY men than in the controls. The mean percentage of tooth surfaces with pathologically deepened probing depths for all 47,XXY men was 8.5%, for the subgroup of 47,XXY men with brothers it was 7.1%, and for the brothers it was 7.5%. Tooth mobility was found in two 47,XXY men and in one control. The results indicate that gingival inflammation was increased in the 47,XXY men than in the controls.

Adolescent↗
PubMed1989

Shape of the craniofacial complex in 45,X females: cephalometric study.

The shape of the craniofacial complex was analysed cephalometrically in sixty-four adult 45,X females (Turner syndrome) using lateral skull radiographs, and the subjects were compared with first-degree female relatives and control females. The results showed that 45,X females have marked changes in relatively few craniofacial areas compared to the controls. Most of the changes are located in the cranial base, so that the face is retrognathic. The mandible is short, whereas the maxilla is of normal length. The results support the view that the morphology of the cranial base is markedly affected in 45,X females, whereas most other craniofacial changes could be considered secondary to the cranial base abnormality. It is suggested that retarded cartilage growth may be a factor leading to the present findings.

Adolescent↗
PubMed1989

Periodontal health in 45,X women (Turner's syndrome).

The overall periodontal states of 81 women with 45,X chromosome complement (Turner's Syndrome) and a sister of 31 of these women were studied. The ages of the subjects ranged from 13 to 35 years. Mean Gingival Index and Calculus Index values were lower in all 45,X women studied and in a subgroup of 45,X women whose sisters formed the control group than in the controls. When the effect of age was taken into account differences were similar. Pathologically deep probing depths of 4 mm or over were found in 9 (11.1%) of all 45,X women, in 3 (9.7%) of the subgroup of 45,X women whose sisters formed the control group and in 7 (22.6%) of the controls. The results indicate that periodontal health was better in the 45,X females than in the controls.

Adolescent↗
PubMed1989

Taurodontism in females with extra X chromosomes.

The association between taurodontism and extra X chromosomes was studied in four 47,XXX-females and in two 48,XXXX-females. Occurrence of the trait in the permanent mandibular molars was noted from orthopantomograms. Five first-degree relatives and a sample of 157 normal males and females were investigated as controls. Two of the 47,XXX-females and both 48,XXX-females each had at least one mandibular molar classified as taurodont. The two affected 47,XXX-females had hypotaurodont or mesotaurodont teeth, whereas both 48,XXXX-females showed hypertaurodontism. The manidubular molars of the other two 47,XXX females had normal root morphology. The only control relative with taurodont teeth was a sister to a 48,XXXX-female. In the population control group, four females had taurodont teeth. These results support the concept that a prevalence of taurodontism increases as the number of X chromosomes increases and also indicate that expression of the trait and the number of X chromosomes may be positively correlated. It is suggested that the X chromosome gene(s) influencing development of enamel may be involved in the development of taurodontism.

Female↗
PubMed1988

Tooth crown size in human females with 45,X/46,XX chromosomes.

Permanent tooth sizes in 15 Finnish females with a 45,X/46,XX chromosome constitution were measured and compared with those of normal females, first-degree female relatives and 45,X females. Mesiodistal crown diameters of the 45,X/46,XX mosaic females were smaller than those of normal females but similar to those of females with pure 45,X chromosome constitution. Labiolingual crown diameters of the 45,X/46,XX mosaics were near normal, being consistently larger than those of 45,X females. The mesiodistal crown sizes are consistent with a decrease in enamel thickness in 45,X/46,XX mosaic females. The difference in labiolingual dimension between teeth of 45,X/46,XX mosaic females and 45,X females may relate to a gradual normalization of growth when normal 46,XX cells are mixed with defective 45,X cells.

Chromosome Aberrations↗
PubMed1988

Taurodontism in 47,XXY males: an effect of the extra X chromosome on root development.

Effects of an extra X chromosome on root development were studied in males with a 47,XXY chromosome constitution. Occurrence of taurodontism in the permanent molars of the lower jaw was noted from orthopantomograms of 30 Finnish 47,XXY males, 16 of their first-degree relatives, and a sample of 157 normal males and females. Nine, or 30%, or the 47,XXY males had at least one mandibular molar which was classified as taurodont. Only hypotaurodont teeth were found, and the teeth affected were all either second or third molars. None of the control relatives showed taurodontism. In the population sample, four individuals, or 2.5%, had taurodont teeth. A change in the mitotic activity of the cells of the developing teeth is one possible factor that can affect root formation leading to the development of taurodontism.

Adolescent↗