A non-destructive dental method for age estimation

Dental radiographs have rarely been used in dental age estimation methods for adults and the aim of this investigation was to derive formulae for age calculation based on measurements of teeth and their radiographs. Age-related changes were studied in 452 extracted, unsectioned incisors, canines and premolars. The length of the apical translucent zone and extent of the periodontal retraction were measured on the teeth while the pulp length and width as well as root length and width were measured on the radiographs and the ratios between the root and pulp measurements calculated. For all types of teeth significant, negative Pearson's correlation coefficients were found between age and the ratios between the pulp and the root width. In this study also, the correlation between age and the length of the apical translucent zone was weaker than expected. The periodontal retraction was significantly correlated with age in maxillary premolars alone. Multiple regression analyses showed inclusion of the ratio between the measurements of the pulp and the root on the radiographs for all teeth; the length of the apical translucency in five types; and periodontal retraction in only three types of teeth. The correlation coefficients ranged from r = 0.48 to r = 0.90 between the chronological and the calculated age using the formulae from this multiple regression study. The strongest coefficients were for premolars. These formulae may be recommended for use in odontological age estimations in forensic and archaeological cases where teeth are loose or can be extracted and where it is important that the teeth are not sectioned.     

The use of tooth thickness in predicting intermaxillary tooth-size discrepancies

Intermaxillary tooth-size discrepancies can be assessed using a diagnostic setup or predicted using a mathematical formula, such as the Bolton analysis. However, variations in tooth thickness may produce inaccuracies in the Bolton analysis ratio. To date, no method for incorporating tooth thickness into discrepancy prediction has been proposed. The purpose of this study was to design and test a new method of predicting anterior tooth-size discrepancy that takes into account tooth thickness and width. Forty-four positioner setup models were set to ideal overbite (2.5 mm) and occlusion (Class I canine relationship). Interproximal gaps between the maxillary or mandibular central incisors were allowed in order to optimize tip and torque. The mesiodistal width of all anterior teeth and the labiolingual thickness of the maxillary incisors were measured on these idealized setups to the nearest 0.1 mm. Actual intermaxillary anterior ratios were then calculated. A new method of prediction was developed by assuming a linear relationship between tooth thickness and ideal intermaxillary ratio. Errors in Bolton's method were compared with the new method. The results showed wide variations in mesiodistal tooth widths, tooth thicknesses, and intermaxillary anterior ratios in orthodontically treated patients. The correlation coefficient between the intermaxillary ratio and tooth thickness was r = 0.68 when tooth thickness was < 2.75 mm, and r = 0.28 when tooth thickness was > or = 2.75 mm. The mean absolute errors in predicting the actual intermaxillary ideal ratio was 1.29 +/- 0.81 for Bolton's ratio and 0.84 +/- 0.46 for the new prediction formula. These new formulas were better than Bolton's ratio in predicting tooth-size discrepancies (p = 0.003). Tooth thickness combined with mesiodistal width may be useful in predicting intermaxillary tooth-size discrepancies.     

Examination of the degree of agreement among dental findings used for personal identification (report 5)--canonical correlation between dental findings on dental charts and those on radiographs

Findings obtained from dental charts and from radiograph taken one year later for the same individuals were examined and classified according to different criteria. Similarities between the two sources investigated by the canonical correlation method. The results obtained were as follows: 1. The correlation coefficient and the squared multiple correlations (R2) were calculated. Consequently, high similarities were seen between the two sources for the mandibular anterior teeth [sequence: see text], maxillary incisor teeth [sequence: see text], mandibular and maxillary first premolar teeth [sequence: see text], and the corresponding teeth of the same jaws. 2. Three roots showed high elucidative values by the canonical correlation method. The first root was understood to be the mandibular incisor factor, the second the maxillary incisor factor, and the third the first premolar factor. This seemed to indicate, that the similarities between the two sources in these regions were very high. 3. A study of the similarities between the two sources was done based on the individual scores of canonical variable loadings calculated in this analysis. High similarities were seen at [sequence: see text] in category 1 (intact & C1) for chart findings and category 1'(intact, C1-C3 & resin filling) for radiographic findings: at [sequence: see text] in category 2 (C2-C4, inlay & filling of repair) for chart findings and category 3'(stump of tooth) for radiographic findings; and at [sequence: see text] in category 3 (complete crown, jacket crown & post crown) for chart findings and category 3'(stump of tooth) for radiographic findings. 4. The present results suggest that if proper case in taken, one set of information can serve as a substitute for the other. In personal identification, higher efficiency may be achieved if this is borne in mind.     

Human leucocyte antigens in pregnant women with pre-eclampsia associated with intrauterine growth retardation and in normal controls

Prenatal exposure to anticonvulsant medication has been shown to cause craniofacial dysmorphology, prenatal growth retardation, hypoplastic nails and phalanges, and visceral abnormalities. In this study we examined maxillary and mandibular stone dental casts (45) and panoramic radiographs (39) from 45 individuals with ages 4.5 to 22.0 years for changes in mesiodistal crown size of deciduous and permanent teeth, and the presence of dental anomalies. These individuals had been exposed prenatally to antiepileptic drugs (AEDs). Mesiodistal crown diameters were measured from the dental casts and converted into standard scores (Z), using published normative data from the University of Michigan Longitudinal Craniofacial Growth Series. A significant increase in mesiodistal crown dimensions of the posterior maxillary teeth was observed, specifically in primary molars and their permanent premolar successors, as well as permanent molars. Changes in tooth size were more common in females than in males. Dental maturity, assessed using the panoramic radiographs, was equal to chronologic age. An increased frequency of hypodontia was the only notable dental anomaly.     

Some principles in the dental crown construction in permanent maxillary centrals of Slovenians

To increase the understanding of the incisors crown form, the lingual fossa depth, crown width and crown thickness between lingual marginal ridges of the permanent maxillary centrals were measured on 257 stone casts of Slovene children. The right-left, male-female differences, as well as the correlations between the variables themselves were analysed. Male centrals exhibited wider and thicker crown compared to female centrals, while the lingual fossa depth showed no sex differences. A positive correlation in terms of positive allometry between lingual fossa depth and crown width was established. A negative lingual fossa depth-crown thickness correlation was found with female left centrals. High right-left symmetry was established, except for the directional asymmetry of all three measured variables on female centrals. The results indicate that the positive correlation in terms of positive allometry between the thickness of the lingual marginal ridges and the crown width is one of the basic principles of the crown formation for the permanent maxillary centrals. Usually we have to work with absolute thickening of the lingual marginal ridges because relative thickening on the account of the crown thickness is less usual. The latter possibility is less favourable for the firmness of the dental crown.     

The cervical third of deciduous teeth. An ultrastructural study of the heard tissues by SEM

As information on amelocemental junction of deciduous teeth is limited, this topographical area was investigated by scanning electron microscopy (SEM) to verify differences from that of permanent teeth. Twenty-six carious and non-carious human maxillary and mandibular primary teeth were placed in a fixative immediately after extraction. Pulpal tissue was removed from the pulpal chambers and root. The primary teeth blocked onto stubs and all specimens were platinum coated and examined by SEM. In these specimens an overlapping of cementum onto to enamel and an edge to edge relationship was dominant. No gaps between enamel and cementum were observed. The amelocemental junction of deciduous teeth seem to differ to that described for permanent teeth.     

Dental caries in the deciduous teeth of the children from Gulbarga, Karnataka

A cross-sectional dental examination of 1,560 randomly selected unrelated children of Gulbarga, Karnataka has shown about 30% of the children with deciduous teeth suffering from one or more carious teeth. The proportion of male children with df teeth was larger than female ones; the difference between the two being statistically significant (chi 12 = 8.0387). Its incidence was higher in children of low income group. Muslims (36.2%) were found to be affected more than Hindus (29.6%) and Christians (27.8%). An increase in the frequency of carious children was observed with the increasing age excepting the children aged 12 years and above who have shown a decreasing trend. In both the sexes mandibular teeth were found more susceptible than maxillary ones. No side difference was found in either jaw. Lower second molars were affected more, followed by lower first and upper second molars. Toothwise prevalence of caries by age showed no consistent trend either in maxilla or mandible.     

A twin study of dental dimension. II. Independent genetic determinants

To demonstrate the presence of independent genetic determinants of multiple correlated tooth dimensions from twin data, a multivariate analysis was performed on the covariance matrices of monozygotic and dizygotic within-pair differences for mesiodistal and buccolingual dimensions of 28 teeth of the secondary dentition. The results provided strong evidences that the correlation among tooth dimensions is primarily genetic in origin, probably attributable to the pleiotropic action of either independent genes or groups of genes. Among the genetic factors that were identified, one appeared to affect the maxillary teeth in general while a second influenced primarily the anterior mandibular teeth. There was a striking tendency for homologous measurements on the right and left sides to be associated with the same genetic factor. In contrast, genetic determination of the maxillary and mandibular dentition seemed to be independent of each other, and a wider range of genetic factors were found to influence the mandibular than the maxillary teeth, suggesting that a differential degree of evolutionary stability may have been achieved in the teeth of the two jaws.     

Risk of renal cell carcinoma after kidney transplantation

Dental trauma occurs very often in children and its consequences vary from tiny fractures to the complete avulsion of the tooth. According to Andreasen, 86.5% of incidents of dental trauma suffered by preschool children cause injury to maxillary primary incisors, whereas only 0.5% cause injury to primary molars. This case report is of a male patient aged 7 years who had fallen down a month before, struck his chin against a step, and fractured the maxillary and mandibular left primary second molars (65 and 75) and the mandibular right primary second molar (85). The 65 required only smoothing of sharp edges, 75 received endodontic treatment and a stainless steel crown, and 85 was extracted and a space maintainer fitted. The early diagnosis of fractures of posterior teeth is very important; a thorough examination of all posterior teeth should be made, especially when child suffers trauma to the chin region.     

Caries prevalence in the deciduous dentition of a mediaeval population from the south-west of Scotland

The prevalence, distribution and location of dental caries were studied in the deciduous dentition of 185 skeletons aged between 6 months and 13 years from a large, mostly mediaeval, cemetery, where successive phases of use could be distinguished. The main phases dated from 1240 to 1440 AD. During this period, no consistent trend or pattern of caries was identified, but there was a significantly higher caries prevalence in the age band 6-12.9 years than in the age band 0.1-5.9 years. The caries prevalence in the juveniles from the earlier Northumbrian, or Anglo-Saxon, phase of the cemetery was higher than in any mediaeval phase group, with mostly approximal surfaces affected. In the mediaeval population, first deciduous molars generally showed lower caries prevalence than second deciduous molars, significantly lower for the older age band, and maxillary molars consistently showed lower levels than mandibular molars. The highest caries rate, shown by mandibular second molars in the older age band, was 7.9%. In deciduous molars, the occlusal surface was most frequently affected by caries, whereas in the permanent molars of the same population the approximal surfaces had shown the highest level of attack. The overall caries prevalence in deciduous teeth in the mediaeval population of Whithorn was 2.3% of the teeth present, lower than the levels found in previous Scottish and English population groups, including a small assemblage of children from the Scottish sites of Elcho, Southwick and Kirkhill.     

Interventional methods in breast diagnosis. Histological vs. cytological evaluation of core cut biopsies of the breast

The features of enamel hypoplasia in a small group of patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) are described. Using a recently developed method, the authors evaluated quantitatively the amount of defect in each tooth by measuring the width of the hypoplastic lesions and dividing the value by the crown height. They then assessed the degree of damage in each tooth type (from central incisors to second premolars) and patient. Canines were the most severely affected among maxillary and mandibular teeth, but all tooth types were involved. Analysing both the differences between patients and their age at the beginning of the defect, the authors observe that hypoparathyroidism is not responsible for the onset of enamel hypoplasia in APECED, although it may contribute to the damage.     

Removal of deciduous canine tooth buds in Kenyan rural Maasai

The removal of deciduous canine tooth buds in early childhood is a practice that has been documented in Kenya and in neighboring countries. This paper describes the occurrence, rationale and method of this practice amongst rural Kenyan Maasai. In a group of 95 children aged between six months and two years, who were examined in 1991/92, 87% were found to have undergone the removal of one or more deciduous canine tooth buds. In an older age group (3-7 years of age), 72% of the 111 children examined exhibited missing mandibular or maxillary deciduous canines. It was found that the actual removal of a deciduous tooth bud is often performed by middle-aged Maasai women who enucleate the developing tooth using a pointed pen-knife. There exists a strong belief among the Maasai that diarrhoea, vomiting and other febrile illnesses of early childhood are caused by the gingival swelling over the canine region, and which is thought to contain 'worms' or 'nylon' teeth. The immediate and long-term hazards of this practice include profuse bleeding, infection and damage to the developing permanent canines. A multi-disciplinary approach involving social anthropologists in addition to dental and medical personnel, is recommend in order to discourage this harmful operation that appears to be on the increase.     

Hypodontia of primary and permanent teeth in a sample of Saudi children

Hypodontia, congenitally missing teeth is more common in permanent than primary dentition. The present investigation reports the prevalence and pattern of hypodontia in the primary and permanent dentitions, excluding third molars in a sample of Saudi children. The sample consists of 1,300 children, aged 5 to 10 years of age. Clinical and radiographic examinations were performed. The prevalence of children with hypodontia was found to be 2.6 percent. The mandibular second premolar was the tooth most frequently absent and account for 45 percent of the total missing teeth. In primary dentition, the maxillary lateral incisor was the tooth most frequently absent (9%). A peg-shaped permanent maxillary lateral incisor was present in 0.7 percent of the sample. Congenitally missing teeth were almost equally distributed between maxillary (52%) and mandibular (48%) arches.     

Novel LQT-3 mutation affects Na+ channel activity through interactions between alpha- and beta1-subunits

This study describes mesial and distal enamel thickness of the permanent posterior mandibular dentition. The sample comprised 98 Caucasian adults (59 males, 39 females) 20 to 35 years old. Bitewing radiographs of the right permanent mandibular premolars and first and second molars were illuminated and transferred to a computer at a fixed magnification via a video camera. Enamel and dentin thicknesses were identified and digitized on the plane representing the maximum mesiodistal diameter of each tooth. The results showed that there were no significant sex differences in either mesial or distal enamel thickness. Enamel on the second molars was significantly thicker (0.3 to 0.4 mm) than enamel on the premolars. Distal enamel was significantly thicker than mesial enamel. There was approximately 10 mm of total enamel on the four teeth combined. Assuming 50% enamel reduction, the premolars and molars should provide 9.8 mm of additional space for realignment of mandibular teeth.     

A study of anterior guidance

PURPOSE: This study focuses on the curvature and inclination of the lingual surfaces of the maxillary anterior teeth from the transition point on the cingulum to the incisal edge. MATERIALS AND METHODS: On 32 sets of mounted casts, 768 measurements were made of the curvature of the lingual surfaces utilizing radius gauges. The inclination of the lingual surface relative to the occlusal plane was recorded. The relationship of the incisal edge of the mandibular teeth to the transition point on the cingulum of the maxillary teeth was determined. Centric occlusion contact was noted on each tooth. RESULTS: Significant differences were found between the measured areas of any one tooth and between the types of teeth. The average radius ranged from 20.5 mm on the mesial ridge of the canine to 5.3 mm in the fossa of the central. The average inclination of the lingual surfaces was 46 degrees. In centric occlusion, 97% of the canines and 59% of the centrals and laterals were in contact with the opposing teeth. These contacts occurred 2.8 mm incisal to the transition point. The centrals contracted two opposing teeth (45%), and canines contacted one opposing tooth (53%). CONCLUSIONS: The function and curvature of the incisor teeth vary considerably from those of the canines. Overcontouring the lingual surfaces of the maxillary incisors to gain contact is not normal and may be detrimental.     

Validation of the Chick Embryotoxicity Screening Test (CHEST). A comparative study

The purpose of the present study was to compare the effects of Gjessing's canine retraction arch with a sectional arch including a reverse closing loop, which are both used for canine retraction in extraction cases. Our study involved both the maxilla and the mandible independently. After upper first premolar extractions and levelling of the teeth with 0.018-inch slot standard Edgewise appliances on 12 subjects, with a mean age of 15 years, the right maxillary canines were retracted by 0.016 x 0.022-inch sectional arches including a reverse closing loop, for a mean period of 7.75 months whereas the left maxillary canines were retracted by 0.016 x 0.022-inch Gjessing retraction arches for a mean period of 6.25 months. Following lower first premolar extractions and levelling of the teeth in eight subjects with a mean age of 13 years 7 months, the right mandibular canines were retracted by 0.016 x 0.022-inch sectional arches with reverse closing loop for a mean period of 7.75 months and the left mandibular canines were retracted by 0.016 x 0.022-inch Gjessing arches for a mean period of 6 months. The present study was carried out on 40 lateral cephalometric films of 20 subjects taken prior to and at the end of canine retraction. The differences between the mean changes of the sectional arch including reverse closing loop and Gjessing retraction arch groups were found to be statistically significant for the amount of upper canine crown retraction, mesial movement of upper first molar crown and duration and rate of upper canine distal movement.(ABSTRACT TRUNCATED AT 250 WORDS)     

"The view" and the canine connection: an atlas of mandibular anterior tooth esthetics

Restoring splinted mandibular incisors and canines with full crown restorations has always presented a challenge in creating an esthetic illusion of reality of normal individual teeth. This treatise is designed to present the rules for mandibular anterior esthetics that have been distilled from almost 4 decades of clinical practice of restoring dentitions that have been severely compromised by the deformities of disease or accident. The resultant formula systematically creates the desired results with a high degree of predictability.     

Ketorolac (Toradol) as an analgesic in swine following transluminal coronary angioplasty

The arch forms of 38 cases (53 nonextraction and 23 extraction arches) in which expansion, while maintaining arch form, was the objective of the practitioner, were analyzed before treatment, after treatment, and an average of 6 to 8 years after retention. The cubic spline was used to fit a curve representing arch form. By superimposing the spline curves, changes in arch form were analyzed with the variables rebound change (RC), rebound index (RI), rebound number (RN), and stability number (SN). Traditional linear intraarch dimensions were also analyzed. Analysis of variance was used to determine differences between the maxillary and mandibular arches and between the extraction and nonextraction cases. Pearson correlation coefficients between spline variables and arch width variables were also computed. There was significantly more expansion in the maxillary arch than the mandibular arch during treatment, irrespective of extraction or nonextraction strategies. In the nonextraction cases, a greater amount of net expansion was achieved for all dimensions for the maxillary arch as compared with the mandibular arch. Overall, a relatively high stability in arch form was found. The findings suggest that stability may not be related to the amount of change produced during treatment. Significant expansion can be gained throughout the premolar regions and may be expected to be stable. The order of greatest net arch width gained was for the second premolars followed by first premolars, molars, and then the canines. The intercanine widths for both arches decreased toward pretreatment values, but were more stable in the maxillary arch in nonextraction cases. The cubic spline permits measurement of change in arch form both during treatment and retention periods.     

"Carious" and "noncarious" lesions of the hard dental tissues. Ultrastructural (SEM) and microanalytical (EDS) analyses of teeth from the 3rd century B.C

The study was carried out on 80 teeth (70 of permanent dentition and 10 of primary one) of mandibular and maxillary bones. The teeth owned to subjects lived in the III c.b.C. in Sicily, and they were found in Naxos necropolis. The teeth were examined as far as carious and non carious lesions, then they were prepared for instrumental analyses by Scanning Electron Microscopy (SEM) and Energy dispersed X ray spectrometry (EDS). To an objective examination of the sample no caries were detected in the teeth sample apart one tooth, on the other hand there was an extensive occlusal abrasion, from a macroscopic point of view there were no difference as far teeth morphology. SEM examination pointed out all around dentinal tubules a circle of sclerotic dentin as reaction to occlusal wear. The amelocemental junction showed from a ultramicroscopic point of view an overlap of cementum onto enamel. EDS analysis pointed out a higher P concentration on the crown versus the root in all the teeth of the sample.     

Calculation of mean skin temperature and changes in body heat content during paediatric anaesthesia

Mean skin temperature and changes in body heat content were calculated in several different ways from measurements made in five children during operation. Mean skin temperatures were calculated from 162 sets of measurements using 15, 12, eight, seven and four skin sites with various formulae modified according to age. The results of other formulae were compared with age-adjusted, area-weighted 15-site mean skin temperature which was used as a reference. Changes in body heat content were calculated from Burton's equation in different ways and errors from different variables in the formula were evaluated. Mean skin temperature from 12 skin sites was within 0.5 degrees C of the 15-point reference method, and that from four sites within 1 degree C. The core temperature selected and the weighting coefficients used in calculating mean body temperature were more important sources of error in the determination of change in body heat content than was mean skin temperature.