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.     

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.     

Aging of the population: demographics for the Liege region

We present the case of a 26-year-old man who at the age of 9 suffered severe trauma to both maxillary central incisors. The underlying malocclusion was skeletal and classified as dental Class II/1 with severe crowding. Both the maxillary central incisors and the two lower first premolars were extracted and the patient was treated with an edgewise appliance for 2 years. Acceptable occlusal relationships were achieved following orthodontic and adjunctive treatment which consisted of reshaping the maxillary lateral incisors with composite materials and grinding the canines to resemble lateral incisors. A critical evaluation of the esthetic and functional results at the age of 26 years is presented.     

Parental awareness of dental caries in toddlers

Endodontic endosseous implants stabilize teeth that have crown-root ratios compromised by periodontal disease, trauma, or apical resorption. By increasing the crown-root ratio, the implant improves the prognosis of the tooth, thus increasing its longevity. The purpose of this study was to evaluate, in vivo, the healing response to a newly introduced titanium endodontic implant. Eight implants were placed in the maxillary incisors and mandibular premolars of two adult beagle dogs after completion of root canal and osseous preparation. Peri-implant tissues were examined radiographically and histologically at 6 months postinsertion. Radiographically, the periapical area and tissue surrounding the implants seemed normal. Histologically, fibrous connective tissue and healthy bone intimately surrounded the implant. Epithelium or chronic inflammatory cells were not observed along the length of the implant. These findings suggest that titanium is a biocompatible metal when used as an endodontic endosseous implant.     

Variation in maxillary and mandibular molar and incisor vertical dimension in 12-year-old subjects with excess, normal, and short lower anterior face height

Maxillary and mandibular molar and incisor vertical dimensions were evaluated in subjects who had excessive, normal, and short lower anterior face height in relation to upper face height. Sexual dimorphism was also investigated. The dentoalveolar heights were compared between Class I and Class II, dental and skeletal malocclusions. The sample was drawn from the Burlington Growth Centre sample and consisted of 188 male and 156 female subjects at age 12 years, for whom lateral head films were available. This sample was classified into excessive, normal, and short lower anterior face height, using the ratio upper anterior face height/lower anterior face height (UAFH/LAFH). The results showed that the dentoalveolar heights are significantly different between faces with excessive, normal, and short lower anterior face heights, except for the lower posterior dental height, which showed no difference between short and normal lower anterior face height subjects. All dentoalveolar heights are larger for male subjects except for the upper posterior dental height. Dentoalveolar heights are similar between Class I and Class II dental and skeletal malocclusions. The upper teeth present a higher correlation to the UAFH/LAFH ratio than the lower teeth. Stepwise regression analysis shows that 22% of the variation in the ratio is explained by the maxillary and mandibular molars and 41% is explained by the maxillary and mandibular incisors.     

Effect of zinc supplementation on cell-mediated immunity and lymphocyte subsets in preschool children

The pattern and distribution of periodontitis were investigated in 162 randomly selected dogs available for necropsy in veterinary practice. There were 82 males and 80 females of 50 different breeds (150 dogs were pure-bred and 12 were mongrels, aged between 7 months and 14 yr. Presence of periodontitis was determined by assessment of alveolar bone loss on radiographs of the skulls and jaws. Periodontitis occurred frequently with increasing age, although the prevalence varied markedly among and within different breeds. Of the breeds most represented in the sample, periodontitis was most frequently seen in poodles and dachshunds but was rarely recognized in German shepherd dogs. Regardless of age, the vast majority of the dogs displayed either one or both of two different radiographic patterns of alveolar bone loss. One pattern was characterized by slight, horizontal alveolar bone loss involving interradicular and interdental areas. The other pattern was one of predominantly crater-like, or narrow, vertical bone defects which, when advanced, often extended around a single root or tooth to surround the root apices. The two types of patterns did not seem to be breed-dependent. The posterior maxillary and mandibular premolars and molars were the most frequently affected teeth. Alveolar bone loss was most severe in the maxilla, while corresponding bone loss in the mandible was more often related to increasing age.     

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.     

Formation of replica of root canal morphology of maxillary first premolars. A technique

Various methods have been used to study the root canal morphology of human teeth. The purpose of this study was to develop a technique for the formation of a resin replica of the root canal morphology of maxillary first premolars. 30 recently extracted maxillary first premolars were used for the study. An occlusal access cavity was prepared and the teeth placed in 5% sodium hypochlorite solution to dissolve the pulp remnants. The teeth were then rinsed in water. A two-part resin system was then introduced into the root canal through the access cavity opening. Subsequent to curing the resin using a specific curing cycle the specimens were put in 20% hydrochloric acid. This facilitated the dissolution of the tooth and the retrieval of the resin replica of the root canal. The different types of root canal morphology observed are discussed. The relevance and utility of the resin models and further possibilities in this field are discussed.     

Decisions about prostate cancer screening in managed care

The primary object of this research project was to establish the amount of incisor retraction to be expected during full fixed mechanotherapy and to generate regression models that could provide more accurate prediction of each of the three most popular combinations of symmetrical premolar extractions, where extraoral anchorage would not be used. Pretreatment and posttreatment records of 73 cases that had their four first premolars extracted (group 44), 74 cases with four second premolar extractions (group 55), and 59 cases with upper first and lower second premolar extractions (group 45) were selected. All these cases were treated by one orthodontist, who used the same edgewise technique throughout. The results indicate that, on average, maxillary retraction in relation to the facial plane (N Po) differed only slightly between group 55 (mean 4.2 +/- 2.4 mm) and group 44 (mean 4.7 +/- 2.3 mm), with relatively more retraction for group 45 (mean 6.6 +/- 2.5 mm; p < 0.05). In contrast, the mandibular incisors were retracted slightly more in group 44 than in the other two groups (p < 0.05). The regression models that were developed could be useful as an additional tool to assist the practitioner in the selection of which teeth to extract for a particular case.     

Effects of chloroquine and its enantiomers on the development of rat embryos in vitro

Methods that have been proposed for mixed dentition analysis are reviewed. Prediction of the space required in the dental arch for unerupted permanent canines and premolars has been based either on the correlation between the mesio-distal widths of these teeth and of erupted mandibular incisors, or on measurements of the unerupted teeth on radiographs. Studies comparing the different methods have shown that the method of Hixon & Oldfather (1958), as refined by Staley & Kerber (1980), is the most accurate.     

Characterization of mechanisms of interleukin-6 gene repression by estrogen receptor

Some prior reports have suggested that guided tissue regeneration (GTR) procedures achieve only partial regeneration and induces the ankylosis rather than true attachment. Accordingly, others have developed an alternative procedure employing gelatine membrane compounded with bovine cementum particles (CGM) which has proven effective in stimulating a more physiologic form of attachment. This study was undertaken to perform a direct comparison of histological results when CGM and GTR membrane were used at comparable sites in the same monkey. Three monkeys with no periodontal disease were used. Following flap surgery, recession type defects were created on the buccal side of the maxillary lateral incisors and second premolars, and the cementum was removed from the root surface at an area corresponding to the bone crest. The right and left lateral incisors and second premolars were covered with CGM and GTR membrane, respectively. The GTR membranes were removed after 4 weeks. At 6 wks, the animals were sacrificed, and specimens were prepared for histological examination. More coronally placed true new attachment was observed following application of CGM to the planed root surfaces. Application of the GTR membrane resulted in formation of bone-like cementum and ankylosis, whereas CGM established true periodontal regeneration.     

Early lifestyle intervention in patients with non-insulin-dependent diabetes mellitus and impaired glucose tolerance

Some adult cleft palate patients show severe maxillary transverse contraction and posterior crossbite. This case report demonstrates successful surgical-orthodontic treatment of such a patient. Surgically assisted rapid maxillary expansion (SA-RME) was completed prior to comprehensive orthodontic treatment. The osteotomy was performed on both the buccal and lingual aspects of the posterior maxillary alveolus. A Hyrax-type maxillary-expansion appliance was used, and the screw (0.2 mm, one quarter turn) was turned two or three times per day. Comprehensive orthodontic treatment was initiated after extraction of the mandibular first premolars and four third molars. The maxillary lateral incisors were also extracted after active orthodontic treatment. The amount of expansion achieved using SA-RME was greater at the posterior than at the anterior maxilla. Midpalatal suture opening occurred. After orthodontic treatment, occlusal stability was satisfactory. This case demonstrates the effectiveness of SA-RME in adult cleft palate patients with severe posterior crossbite.     

Risk factors associated with incisor injury in elementary school children

This study examined risk factors associated with incisor injury in 3396 third and fourth grade school children in Alachua County, Florida. One of six orthodontists completed a standardized examination form for each child to assess severity of incisor injury, gender, age, race, skeletal relationships, morphologic malocclusion, incisor exposure, interlabial gap, TMJ sounds, chin trauma, and history of lower facial trauma. One in five (19.2%) exhibited some degree of incisor injury. This was limited to a single tooth in 73.1% of those with injury, while enamel injury predominated (89.4%). The majority of the injuries (75.4%) were localized in the maxillary arch, with central incisors the most frequently traumatized. Chi-square tests of association indicated that gender, race, school, orthodontist, history of lower facial trauma, chin trauma, profile, and maxillary and mandibular horizontal positions were associated with incisor injury (P < 0.05). Wilcoxon rank sum tests identified differences in age, overjet, time of screening, and interlabial gap between those with and without injury (P < 0.05). Results of logistic regression analyses indicated risk of incisor injury was greater for children who had a prognathic maxilla, a history of trauma, were older, were male, and had greater overjet and mandibular anterior spacing.     

New tongue protector to prevent decubital lingual ulcers caused by tongue thrust with myoclonus

We treated tongue ulcers in a twenty-two-month-old male child with Gaucher disease and several neuronopathic symptoms, including frequent convulsions. Because the patient was always thrusting his tongue and biting with his upper and lower primary incisors during the myoclonus and convulsions, traumatic decubital ulcers on the dorsum and ventral surface of the tongue were formed. During the convulsions, bleeding and pus discharges were observed. For the protection of the tongue from the teeth, a tongue protector was fabricated from a soft silicone relining material used for dentures. The protector covered the mandibular primary central incisors, the alveolar ridge, and the ventral surface, apex and dorsum of the tongue. The ulcer symptoms completely disappeared after two months of using the protector.     

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.     

Treatment response to maxillary expansion and protraction

A prospective clinical trial was conducted to determine the skeletal and dental contributions to the correction of overjet and overbite in Class III patients. Thirty patients (12 males and 18 females with a mean age of 8.4 +/- 1.7 years) were treated consecutively with protraction headgear and fixed maxillary expansion appliances. For each patient, a lateral cephalogram was taken 6 months before treatment (T0); immediately before treatment (T1); and 6 months after treatment (T2). The time period (T1-T0) represented changes due to 6 months of growth without treatment; (T2-T1) represented 6 months of growth and treatment. Each patient served as his/her own control. Cephalometric analysis described by Bj?rk (1947) and Pancherz (1982a,b) was used. Sagittal and vertical measurements were made along the occlusal plane (OLs) and the occlusal plane perpendicular (OLp), and superimposed on the mid-sagittal cranial structure. The results revealed the following: with 6 months of treatment, all subjects were treated to Class I or overcorrected to Class I or Class II dental arch relationships. Overjet and sagittal molar relationships improved by an average of 6.2 and 4.5 mm, respectively. This was a result of 1.8 mm of forward maxillary growth, a 2.5-mm of backward movement of the mandible, a 1.7-mm of labial movement of maxillary incisors, a 0.2-mm of lingual movement of mandibular incisors, and a 0.2-mm of greater mesial movement of maxillary than mandibular molars. The mean overbite reduction was 2.6 mm. Maxillary and mandibular molars were erupted occlusally by 0.9 and 1.4 mm, respectively. The mandibular plane angle was increased by 1.5 degrees and the lower facial height by 2.9 mm. Individual variations in response to maxillary protraction was large for most of the parameters tested. Significant differences in treatment changes between male and female subjects were found only in the vertical eruption of mandibular incisors and maxillary and mandibular molars. These results demonstrate that significant overjet and overbite corrections can be obtained with 6 months of maxillary protraction in combination with a fixed expansion appliance.     

Influence of the arterial blood pressure and nonhemodynamic factors on regional arterial wall properties in moderate essential hypertension

OBJECTIVES: The technique of resin-bonded bridgework is a well-accepted clinical technique to replace missing teeth. This study assesses the clinical performance of cantilevered resin-bonded bridgework provided in a university teaching hospital environment. METHODS: One-hundred and twelve patients who had a total of 142 cantilevered bridges were either examined or completed a questionnaire regarding their bridgework. The following data were recorded for each resin-bonded bridge: gender of patient, age at bridge cementation, date of initial cementation, tooth replaced, abutment(s) involved, and grade of clinician responsible for the provision of the bridge. Details of the incidence of debonding with date(s) and the subsequent treatment in relation to the debonded resin-bonded bridge were recorded. The subjects examined indicated their degree of satisfaction with their bridgework on a visual analogue scale. RESULTS: There were 112 patients with a total of 142 bridges, 116 (82%) maxillary and 26 (18%) mandibular. The mean length of clinical service was 36.2 months (s.d. 17.2 months). Only single pontics were included in the bridges, with almost half (49%) replacing a lateral incisor. Of the cantilever resin-bonded bridges studied, 88% remained bonded over the period of the study. A success rate of 94% is reported. CONCLUSION: This study confirms the clinical success of cantilever resin-bonded bridges particularly in the replacement of maxillary lateral incisors, maxillary premolar and permanent mandibular teeth.     

Occlusal stability in Class II, Division 1, deep bite cases followed up for many years after orthodontic treatment

This case report analyzes long-term occlusal stability that can be achieved in Class II, Division 1, deep bite cases with active treatment finished during the period of maxillomandibular growth. The analysis was designed to identify occlusal features common to two cases at the end of active treatment and to study how the occlusion changed with growth and jaw movement to achieve stability. The following occlusal features were shared by the two cases at the end of active treatment: (1) AB plane and axes of the maxillary and mandibular posterior teeth were perpendicular to functional occlusal plane; (2) the axis of the lower incisor was almost perpendicular to DC-L1i line; (3) the anterior occlusion was overcorrected to or near an edge-to-edge relationship. Items 1 and 2 remained unchanged throughout the follow-up periods, regardless of growth status, and the overjet and overbite increased during maxillomandibular growth after treatment. During the period of mandibular growth alone, after the end of retention, the axes of maxillary incisors tipped labially; as a result, F line became parallel to CDM line by the end of growth. The labial tipping of maxillary incisors brought the lower incisal edge into contact with or extremely near the inflection point (Bp).1 By the end of growth, the tangent of Bp became parallel to or coincident with DC-L1i line and perpendicular to the axis of the lower incisor, and the DC-L1i lines at various times posttreatment were almost parallel to each other in the two cases. Overjet increased as the maxillary incisors tipped labially, providing proper protrusive and retrusive paths for mandibular guidance. The angle between the functional occlusal plane and CDM line stayed almost the same as at the end of active treatment in the two cases, suggesting a possible change in the angle of eminence in harmony with the functional occlusal plane. These factors apparently contributed to the long-term occlusal stability in the two cases.     

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.