摘要:

The authors present a method for differentiating between human mandibular premolars: P1 inf and P2 inf. The material with which the method was developed consisted of 260 stone casts. On these, both premolars were present and were intact on at least one side. The study models represented 131 girls and 129 boys, mean age 14.6 yr. In a comprehensive pilot project, a whole range of macromorphologic criteria was tested that, in various combinations, could be expected to be usable for differentiation between P1 inf and P2 inf. On the basis of the pilot study, the total variation was reduced to four criteria‐combinations, called types, which, in summary, can be characterized as the following: type 1: flattening of the mesiolingual part of the crown, no lingual lobe; type 2: at least one lingual lobe; type 3: lingual part of the crown symmetrically curved, no lingual lobe; type 4: other characteristics. After definition of the types, their occurrence on P1 inf and P2 inf was definitively registered. Observations were made with a stereomicroscope; 131 premolar pairs from the right side and 129 from the left were registered. Statistical tests showed that there was no significant difference in the distribution of types between variants from the right and left sides, or between girls and boys. These data were therefore pooled for P1 inf and P2 inf, respectively. A subsequent test revealed, as expected, a highly significant difference in the distribution of the four types among 1. and 2. premolar. For estimation of the degree of certainty when the types concerned were used for differentiation, 95% confidence limits were set up from the observed frequencies. Results of these statistical analyses can be described as follows: the probability that a mandibular premolar of type 1 was a 1. premolar was 0.96 (0.93–0.98), that a type 2 variant was a 2. premolar was 0.99 (0.96–1.00), that a type 3 variant was a 2. premolar was 0.79 (0.58–0.93), and that a type 4 variant was a 2. premolar was 0.92 (0.74–0.99). The target groups of this publication are clinical dentists, forensic odontologists, dental anthropologists, and dental morp

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01159.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The aims of this study were to determine the frequency of hypodontia of permanent teeth in twins discordant or concordant for clefts in each type of cleft, to determine the concordance of hypodontia in mono‐ and dizygotic twins, and to compare the findings with some earlier data. Thirty‐nine pairs of twins between 7 and 23 yr of age were investigated. Six of 13 monozygotic and 24/ 26 dizygotic pairs were discordant for clefts. Orthopantomograms of the dentition, treatment records, and anamnestic data were studied. Twenty‐three pairs of twins (59%) had at least one twin with hypodontia: 9/13 (69%) monozygotic and 14/26 (54%) dizygotic. The prevalence of hypodontia was 37% for monozygotic and 32.7% for dizygotic twins, 16.7% in the noncleft and cleft lip groups, 41.1% in the cleft palate group, and 64.3% in the cleft lip and palate group. All these were above the values observed earlier in the noncleft twins and in the Finnish normal and cleft group populations. Four of 13 pairs of monozygotic twins had no hypodontia, 8/9 pairs were discordant, and only 1/9 was concordant for hypodontia. The corresponding figures for the 26 dizygotic pairs were: 12/26, 11/14, and 3/14 pairs. Maxillary second premolars were the most frequently absent teeth, followed in order of frequency by the maxillary lateral incisors and the mandibular second premolars. Hence, for this sample of twins, the genetic component seems to be

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01160.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Patients with severely worn dentition were interviewed and clinically examined, and only those were included who had no or minimal subjective symptoms or clinical signs of craniomandibular disorder. During a 14‐month screening period, only 7 patients fulfilled the inclusion criteria; all were men. Maximal bite force was measured in the molar regions and in the incisal region. Facial morphology was evaluated from lateral cephalometric radiographs, and the form of dental arches from dental casts. Average maximal bite force in the molar region was 911 N and in the incisal region 569 N. The most characteristic findings concerning bite force were the high force levels in the incisal region and an incisal/molar bite‐force ratio of 63%. The facial morphology of the patients was rectangular, with an anteriorly rotated mandible, small anterior face height, and great interincisal angle. Moreover, the form of the maxillary dental arch was more rectangular than normal. The high bite forces of these patients, especially in the incisal area, can probably be explained by strong masticatory muscles and mechanically favorable skull morphology, which in its turn has been influenced by the surrounding musc

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01161.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The prevalence of salivary mutans streptococci and lactobacilli, salivary flow rate, and the type of dentition were studied in connection with a medical survey of 76‐, 81‐, and 86‐yr‐old inhabitants of Helsinki living at home. High bacterial counts were associated with low salivary flow rates. High counts of mutans streptococci (>106CFU/ml) were found in 68% of wearers of full dentures, as compared with 53% of subjects having natural teeth. High counts of lactobacilli (>106CFU/ml) were found in 44%) of subjects having removable partial dentures and in 39% of subjects having natural teeth. The bacterial counts correlated neither with medicines taken daily nor with diseases among this pop

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01162.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Ascorbic acid (AA) affects in vitro growth of bacteria and may also act in vivo to decrease caries activity. The aim of this study was to evaluate the possible association of AA level in plasma with number of caries lesions, relative numbers of some species of oral cariogenic flora, and rate of salivary secretion. The caries status and some bacteriologic variables of dentulous adult subjects with a low level of AA in the plasma (≤25 μmol/1;n=75) were compared with those of controls (plasma level ≥50 μmol/1;n=75) matched for age, sex, and number of teeth. For each subject, site‐specific recordings of the presence or absence of plaque, dental caries, fillings, and erosions were recorded clinically by the same dentist in a double‐blind system. The amounts of visible plaque and numbers of decayed tooth surfaces were significantly higher in the low AA group than in the controls. No between‐group differences were found in the number of fillings and the amount of oral bacterial growth. The frequencies of consumption of vegetables, berries, and other fruit were significantly lower in the low AA group than in t

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01163.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Chlorhexidine (CHX) is probably the most widely used and the most potent chemical plaque inhibitory agent, whereas fluoride (F−) is the only truly accepted anticaries agent available at present. As they have discrete mechanisms of action, a combination effect of these agents on human dental caries may exist. The inhibitory effect of CHX on the formation of, and acid production in, plaque may reduce a relatively extreme cariogenic challenge sufficiently for it to be overcome by the local F−concentrations achieved by brushing or rinses. The aim of this study was to evaluate the possible caries inhibitory effect of combining 2.2 mM CHX mouthrinses used twice daily with daily 11.9 mM NaF rinses in an in vivo human caries model using plaque‐retaining bands on premolars scheduled for extraction. Nine subjects (a total of 28 teeth) were fitted with the bands for 4 wk. Saliva and plaque samples were collected before and after the study period for bacterial cultures, and the tooth surfaces were analyzed by microradiography after careful tooth extractions. The combination of CHX and F−rinses resulted in enamel mineral loss only slightly higher than that observed in “sound” enamel and clearly less than with F−rinses alone. Both total plaque bacteria andStreptococcus mutanswere reduced by CHX rinses, confirming the discrete mechani

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01164.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The isolation frequency and serotype distribution of mutans streptococci andA. actinomycetemcomitans (A.a.) were investigated in a group of Finnish (n=16) and Vietnamese (n=16) children, matched by sex, age, and caries status. In the Vietnamese children, the isolation frequencies were higher than in the Finnish children: 100%/62% for mutans streptococci and 78%/13% forA.a. Isolates (n=3–8) from plaque and saliva were serotyped by immunodiffusion technique using serotype‐specific antisera against serotypesc, e, f, d, andgfor mutans streptococci anda, b, c, d, andeforA.a. The distribution of mutans streptococci serotypes in Finnish/Vietnamese children was:c100%/50%;e10%/31%;d0%/56%;g20%/38%. The frequency of plural serotypes was 30%/75%, respectively. In the Vietnamese group the serotype distribution ofA.a. was:a36%,b27%, andc63%; 45% of children carried two serotypes. One Finnish child harbored serotypeaand one serotypeb. The mean percentage of bleeding gingival sites was 7.4 in the Finnish and 15.1 in the Vietnamese group. Calculus and clinically deepened gingival pockets were more frequent findings in the Vietnamese children. The results indicate considerable differences in bacteriologic status and in clinical periodontal status between these Finnish and Vietnamese child

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01165.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Concentrations of salivary antimicrobial factors are well documented in children and young adults, but little information is available on such defense factors in healthy elderly persons. We determined the levels of total IgA, total IgG, lysozyme, lactoferrin, myeloperoxidase, salivary peroxidase, amylase, sialic acid, and total protein in a group of 71 subjects aged 76, 81, and 86 yr, as well as their correlations to paraffin‐wax‐stimulated salivary flow rate. Participants were either unmedicated (n=67) or using medicines with no oral significance (n=4). Statistically significant negative correlations existed between flow rate and total IgA, Iysozyme, lactoferrin, sialic acid, and total protein. Concentrations of sialic acid and salivary peroxidase were highest in the oldest age group. Total IgA concentration was higher in women than in men, although men showed higher concentrations of sialic acid and higher sialic acid/total protein ratios. Subjects with poor gingival health had higher concentrations of total protein than did those with no need for periodontal treatment. Edentulous subjects with complete dentures showed significantly lower concentrations of IgG, lactoferrin, and myeloperoxidase than did dentate subjects. Our results suggest that, when compared with data from previous studies, concentrations of salivary antimicrobial agents do not decline with age in unmedicated elderly people. However, defense factors which are derived also from gingival crevicular fluid are decreased in the absence of te

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01166.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The sensitization potential of two orthodontic bonding materials, one conventional premix product and one nonmix product, was evaluated by a modified guinea pig maximization test. The nonmix product, consisting of a liquid to be applied to the tooth surface and a paste which was placed on the bracket base, caused reaction in 50% of the tested animals. This material should be considered to be a possible cause of allergy in patients or professionals handling it.

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01167.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Human embryonic diploid lung fibroblasts (HEDL fibroblasts) and periodontal ligament fibroblasts (PDL fibroblasts) were cultured in media at fixed pH levels ranging between 7.2 and 8.4 and fixed calcium concentrations ranging between ≤100 μM and 20 mM in an attempt to mimic the effects of calcium hydroxide on vital cell functions such as attachment and growth. PDL fibroblasts appeared to be more susceptible to changes in pH and calcium concentration than HEDL fibroblasts. At pH levels above 7.8, both attachment and growth decreased significantly. Growth was influenced more by changes in pH and calcium concentration than was attachment. The results help explain why intracanal application of calcium hydroxide through its high pH may impair periodontal healing in areas on the root surface where the cementum has been damaged by either trauma or periodontal treatment, thus allowing the medicament access to the root surfa

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1994.tb01168.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY