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Biomedical subjects

R Ranta

Publications and source records attributed to R Ranta.

At least 19 recordsLinked to original sources
PubMed1992

Sizes of dental arches and general body growth up to 6 years of age in children with isolated cleft palate.

Development of the dental arches and height and weight at the ages of 3 yr and 6 yr were studied longitudinally in 60 children with isolated cleft palate (CP) and in 50 noncleft (NONC) children. Retrospective comparisons were also made in the CP group with arch size at the age of 0.2 yr and 1.8 yr. Anterior width at 0.2 yr of age was associated with canine width at the age of 3 yr (r = 0.70) and 6 yr (r = 0.60). Change in maxillary posterior width from 3 yr to 6 yr of age was related to the extension of the cleft, so that in the group with total cleft this dimension diminished. Measured in standard deviation scores (SDS), the means of maxillary width at canines and primary second molars in CP children varied from -1.0 to -2.0 and mandibular dimensions from -0.6 to -1.4. Discrepancy in arch depth diminished with age. Body size differed less from normal than the size of the dental arches. At 3 yr of age the height was -0.4 SDS in CP boys and -0.5 SDS in CP girls, but at 6 yr of age only -0.1 SDS in both boys and girls. Correlations between body size and the size of the dental arches were generally low (r less than 0.20) both in CP and NONC children. The small size of the dental arches in CP children does not seem to be merely a reflection of the overall smaller size of CP children.

Body Constitution↗
PubMed1991

Hypernasality and the nasopharyngeal space. A cephalometric study.

In the present study cephalometric measurements reflecting the nasopharyngeal space were traced on lateral cephalometric X-rays in 59 young adults with an isolated cleft palate. The distribution of the measurements AD1-PNS, AD2-PNS, AD1-BA, AD2-SO and PNS-BA and the magnitude of the hypernasality were analyzed with the ANOVA procedure and Duncan's multiple range test. The degree of hypernasality was assessed in terms of the hypernasality index. The results showed that AD1-PNS and AD2-PNS measurements were significantly related to the hypernasality index at the risk level of 0.03 and 0.05 per cent, respectively. The patients with the shortest sagittal depth of the nasopharynx had normal resonance in their speech, while the patients with the longest measurements demonstrated hypernasality. The thickness of the posterior pharyngeal wall in terms of AD2-SO was not clearly significant for speech, although the patients with the longest measurements tended to speak without hypernasal resonance. The other cephalometric measurements, i.e. AD1-BA and PNS-BA were not significantly related to the occurrence of hypernasality. It was concluded that the cephalometric measurements reflecting nasopharyngeal space are correlated with the occurrence of hypernasality, but the relationship is by no means simple and linear, and therefore it requires further study.

Adolescent↗
PubMed1991

Cephalometric analysis of the obstructive sleep apnea syndrome.

The cephalometric measurements of 33 Finnish OSAS patients showed a fairly normal relationship between the base of the skull and the maxilla (SNA 82.3), whereas the mandible was slightly smaller than average (SNB 78.0). In 58% of the patients the mandible was significantly retrognathic and/or small in relation to the maxilla, even if dental occlusion was satisfactory. The sagittal lengths of the anterior cranial base and the maxilla were fairly normal. The hyoid bone was constantly situated more inferiorly and posteriorly than on average (MP-H 32.6). UPPP, genioplasty and advancement of the floor of the mouth and hyoid suspension were found to be effective in severe OSAS. The changes caused by the operation could best be verified cephalometrically by a more anterior position of the hyoid bone (average change of 11.1 mm).

Adult↗
PubMed1990

Mandibular distraction. An experimental study on sheep.

In a series of 17 growing sheep (aged 13.5-19 weeks) the recently developed external fixation frame permitting gradual distraction, was tested. The frame gives good stability during distraction. Mandibular osteotomy was performed transversely in the middle of the ramus, under general anaesthesia, with an oscillating saw. Using distraction by approximately 1 mm per day, lengthening of the mandibular ramus was achieved. X-ray analysis showed all the distracted osteotomies to have healed in 25 days, showing new bone formation in the distraction gap. The pattern of radiological healing was graded according to the phase of consolidation. With this method it appears to be possible to lengthen the mandible without transplantation of additional bone.

Animals↗
PubMed1990

Effect of timing and method of cleft palate repair on dental arches at the age of three years.

The purpose of this study was to compare the influence of two different ages at the time of palatal closure and two surgical methods on the size of the dental arches at the age of 3 years in children, with CP, UCLP, and BCLP. In 88 children the one-stage palatal closure had been performed at the age of 1.8 years and in 92 children at the age of 1.1 years. In both groups palatal surgery had been performed with a V to Y push back procedure (Veau-Wardill-Killner) or with the Cronin modification. Dimensions of the maxillary arch in both groups at age 3 were smaller than in noncleft children, but the timing of palatal closure did not affect arch dimensions in children with CP, UCLP, or BCLP. Arch dimensions at 3 years of age were not related to the method used in palatal closure.

Age Factors↗
PubMed1989

Forward traction of the maxilla with cleft lip and palate in mixed and permanent dentitions.

The effect of forward maxillary protraction with the Delaire type facial mask was studied in fourteen patients with cleft lip and palate. Traction on the maxilla was initiated between 9 and 15 years of age and the duration ranged from 5 go 36 months, averaging 19 months. The average magnitude of the traction forces was 300-400 gm. Parallel or downward direction of the forces in relation to the occlusal plane were used from the first molars and the precanine loops of the arch wire. Forward movement of the maxilla was observed in five 9-11-year-old patients. No movement was observed in nine patients over 11-years of age. In spite of the poor results of forward movement of the maxilla in the older patients, the facial mask therapy proved to be successful in correction of the anterior crossbite, spacing of the dental arch, and as an anchor in widening the upper dental arch.

Adolescent↗
PubMed1989

Orthodontic treatment in adults with cleft lip and palate.

A conventional orthodontic treatment method for typical malocclusions of adult patients will be described. Over 100 patients have undergone this treatment during the last decade in our cleft centre. The method involves four stages: I) orthodontics, expansion of the upper dental arch with modified quad-helix and edge-wise appliances and alignment of the teeth; II) bone grafting and closure of the oronasal fistula; III) prosthodontics, bridgework in the upper dental arch; IV) soft tissue correction of the lip and nose. The method is easy, cheap, safe and rapid enough if the forces of the quad-helix appliance are modified individually. The orthodontic, surgical and prosthodontic treatment result in a permanently balanced dental occlusion.

Adult↗
PubMed1989

Sizes of dental arches and interdental space in 3-year-old children with and without cleft lip/palate.

The development of the dental arches in children with oral clefts differs from that in a normal population, due to the type and extension of the cleft, surgical procedure and timing, and decreased growth potential. The size of the maxillary and mandibular dental arches and the amount of interdental space in 3-year-old, cleft-affected and non-cleft children was investigated. Fifty non-cleft (NONC) and 104 cleft-affected subjects including different cleft groups were compared. On average, cleft lip was corrected at the age of 0.6 years and cleft palate at 1.8 years of age. The mean of all width and depth dimensions in the cleft lip group were close to the NONC controls, whereas the dimensions of the cleft palate group were 8-9 per cent smaller in the maxilla and 5-7 per cent smaller in the mandible than were those in the NONC group. In the unilateral complete cleft group, the maxillary dimensions were 11-19 per cent smaller, but in the mandible only 0-4 per cent smaller than in the NONC group. In the bilateral complete cleft group, the maxillary arch was only 6 per cent shorter but 30 per cent narrower at the canines than in the NONC group. In the mandible the corresponding differences were 2 per cent and 6 per cent. Forty per cent of the cleft palate subjects had a crowded maxillary arch compared with 6 per cent of the NONC controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalometry↗
PubMed1989

Tooth development in children with cleft lip and palate: a longitudinal study from birth to adolescence.

Dental maturity was assessed in 131 children with cleft lip with or without cleft palate in two age groups from panoramic X-rays using the method of Demirjian. The subjects showed a mean delay of 6 months in the age group of 3-9 years (x = 6.4 years), which decreased to 2 months in the age group of 8-14 years (x = 11.0 years). Involvement of the palate made the delay longer than in children with cleft lip only. Geographical differences between parts of Finland were also found. To study tooth development longitudinally, the timing of the beginning of calcification of one maxillary central incisor was assessed from occlusal X-rays taken between the ages of 2 and 18 months in 107 of the above mentioned 131 subjects. Using rank-order correlations, the beginning of the calcification of the maxillary central incisor weakly predicted the subjects' tooth developmental status. The correlation of dental maturity between the ages of 6 and 11 years was, however, high.

Adolescent↗
PubMed1989

Periosteal flaps and grafts in primary cleft repair: a follow-up study.

A long-term follow-up study of maxillary clefts operated on primarily with the maxillary periosteal flap (67 patients) and the free tibial periosteal graft (23 patients) showed a definite bone bridge in 64 versus 85 percent of the patients. Still, secondary bone grafting was indicated in both in over 70 percent. Lateral crossbite was observed in all and anterior crossbite (mostly dental) was seen in over 80 percent of both groups. There were no statistically significant differences in the cephalometric angular measurements between the groups. Inside the maxillary periosteal flap group the maxillary growth was more retarded in unilateral and especially bilateral complete clefts than in alveolar clefts only. The maxillary growth seemed to be on average better than in primarily bone-grafted materials. The primary use of periosteum had been abandoned in our unit already in 1974, because it did not fulfill the expectations of prevention of maxillary collapse, lesser need for secondary bone grafting, and better midfacial growth.

Adolescent↗
PubMed1989

Reliability in estimating taurodontism of permanent molars from orthopantomograms.

Taurodontism is a morphologic dental trait showing continuous expressivity, and criteria of the degree of pulp chamber elongation vary in different investigations. The aim of this investigation was to test a simple method of assessing taurodontism in the developing dentition from orthopantomograms in order to determine its reliability for later use in epidemiologic investigations. The method was also compared with other methods. Forty-three children 10-16.9 yr of age with one or more taurodontic permanent first or second molars were selected for the study. A subgroup of 16 children with two longitudinally obtained radiographs was used in a follow-up study of the same tooth in two different formational stages. The follow-up time averaged 2.2 yr. The distance between the baseline connecting the mesial and distal points of the cementoenamel junction and the highest point of the floor of the pulp chamber was measured (Measure 3). A tooth was classified as taurodontic when Measure 3 reached or exceeded 3.5 mm. This distance remained unchanged during the course of tooth development. Intraexaminer reliability of two examiners in reproducing the same classification was, on average, 96.2%, and the interexaminer reliability was 93.2%. The reliability was greater for the first than for the second molars. Results obtained by this method agreed well with those obtained by other methods. Measure 3 proved to be reliable in assessing taurodontism in the developing dentition from orthopantomograms in epidemiologic investigations.

Adolescent↗
PubMed1988

Minimal cleft lip. Comparison of associated abnormalities.

The literature relevant to minimal forms of cleft lip (CL(M)) has been reviewed. CL(M) has been defined as a cleft which does not extend past the vermilion. 20 patients with CL(M) (18 unilateral, 2 bilateral) were studied. Clinical and roentgenological findings from the lip, nose, alveolar ridge, teeth and palate were compared. All patients had some degree of nasal deformity; 13 of 15 patients had dental and 6 of 20 alveolar ridge deformities. Among 20 patients, there was 1 bifid uvula, 2 submucous cleft palate, and 1 cleft of the soft palate. 3 patients had several other abnormalities. A positive family history of clefts in relatives was noted in 2 cases. The severity of the dento-alveolar deformity did not seem to correlate with the severity of the nasal or the lip deformity, but the nasal deformity directly correlated with the lip deformity. Thus, the present CL(M) patients can be regarded as having actual clefts, although some may be normal variations.

Adolescent↗
PubMed1988

Oblique lateral oro-ocular facial cleft. Case report.

2 patients are presented, and the oblique lateral oro-ocular clefts discussed with emphasis on classification, dentition and microforms. A review of the literature revealed 10 patients with oblique lateral oro-ocular facial cleft (no. 5 in Tessier's classification), 3 bilateral and 7 unilateral. 5 unilateral cases had a median oblique facial cleft (no. 4) on the other side. 3 cases had a cleft lip and palate. The site of the alveolar cleft was in the region of the first and second premolar in 2 and slightly posterior to the canine tooth in 3 of 5 reliably documented cases. The dentition was documented only in 1 child with a lateral and median oblique facial cleft, resulting in full permanent dentition. The author's 2 cases had a bilateral oblique lateral oro-ocular facial cleft with the alveolar defect in the region of the first and second premolar. An isolated cleft (no. 6 in Tessier's classification) has to our knowledge not been reported at all. Furthermore, there are transitional forms between Tessier's clefts 5-8. Based upon our observations, it is also evident that variations inside one type occur as well. More attention should be paid to the exact location of the cleft and especially to the skeletal deformity, alveolar site and dentition. This would facilitate both classification and diagnosis of microforms.

Alveolar Process↗
PubMed1988

Comparisons of dental maturity between the rural community of Kuhmo in northeastern Finland and the city of Helsinki.

The aim of the study was to check whether dental maturity charts made in southern Finland can be used without modifications in other parts of the country. For this reason the dental maturity of 90 children living in the sparsely populated areas of Kuhmo in northeastern Finland was compared with that of a larger sample of Helsinki children. Most of the Kuhmo children were 7.0-8.5 and 10.5-12.5 yr of age. The method of Demirjian and associates was used to estimate dental maturity. The means of dental maturity scores were greater in Kuhmo in most half-year groups in both sexes. The median dental maturity scores of Kuhmo children were between the 50th and 84th percentile curves of Helsinki children. A referent of the same age and sex was chosen for each Kuhmo child from the Helsinki children. The paired t-test was based on the difference in dental age. The dental age of the Kuhmo children was higher (P less than 0.05). These findings suggest differences in dental maturity within a fairly homogeneous population, which should be considered when national charts are used.

Adolescent↗
PubMed1988

Symmetry and combinations of hypodontia in non-cleft and cleft palate children.

Symmetry and combinations of hypodontia was studied and compared in non-cleft (NONC) and cleft palate (CP) groups with different prevalences of hypodontia. The NONC group included 300 children with one or more congenitally absent permanent teeth, excluding the third molars, and 79 children with isolated cleft palate without accessory anomalies. There were no significant differences between the groups in distribution of children with agenesis of 1 to 11 teeth. Bilateral agenesis increased with increasing number of absent teeth per child, and it was more frequent in the maxillary teeth of the NONC group and in the mandibular teeth of the CP group. Concomitant agenesis was observed in one to four different dental fields per child, and the distribution of the subjects was similar in both groups. We conclude that the symmetry of agenesis may be dependent on the population frequency of hypodontia and on the number of absent teeth per child. The agenesis in the CP group may have a common genetic basis, but the substantially higher incidence of hypodontia in the maxilla is likely caused by factors similar to those causing the cleft itself.

Anodontia↗
PubMed1988

Dental age and asymmetry in the formation of mandibular teeth in twins concordant or discordant for oral clefts.

The aims of this investigation were: 1) to study the effects of zygosity and the type of cleft on dental age in pairs of twins concordant or discordant for oral clefts, 2) to compare dental age in the twins with that in a population of normal Finnish children, and 3) to study asymmetry in the formation of mandibular teeth with regard to zygosity and the type of cleft. Twenty-two pairs of twins (8 mono- and 14 dizygotic) and one set of monozygotic triplets concordant or discordant for cleft lip (CL), cleft palate (CP), or both (CLP) were investigated. Four of eight mono- and 12 of 14 dizygotic pairs were discordant for clefts. An orthopantomogram of both twins was taken on the same day. In 7 of the 8 monozygotic (88%) and in 4 of the 14 dizygotic (29%) pairs, the dental age was the same in both twins. Of the 12 pairs discordant for clefts, the dental age of the twin with cleft was delayed in 5, advanced in 3, and the same in 4 compared with that of the twin without a cleft. The means of chronologic age and dental age were counted separately for the cleft subgroups and the non-cleft (NONC) group. The dental age was advanced in the CL twins and in the NONC twins, and was the same as chronologic age in the CP twins, but it was delayed in the CLP twins. Asymmetric formation of the 14 mandibular teeth (mostly the second premolars) was encountered in 3 of 8 CLP, in 3 of 18 CP, in 1 of 16 NONC, and in none of 5 CL children. The great similarity in tooth formation among the monozygotic twins indicates strong genetic control of dental maturation in twins concordant and also discordant for cleft.

Adolescent↗