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PubMed1989

Social and biological correlates of localized enamel hypoplasia of the human deciduous canine tooth.

Recent studies of teeth from prehistoric children have reported a localized, roughly circular patch of deficient enamel on the labial aspect of the primary canine, which reaches its highest prevalence in the Upper Paleolithic of Europe. This study reports social and biological correlates of 33 affected kindergarten-aged children from Vancouver, Canada (2.4% of 1,350 examined). Affected children can be characterized as coming from low-income families often of East Asian or Chinese origin in which there is a degree of milk avoidance and reduced breastfeeding. The defect appears to be due to minor physical trauma to the face approximately 6 months after birth occasioned by normal motor development, involving handling and mouthing objects, which damages the developing tooth crown through deficient cortical bone over the canine crypt. Reduced cortical bone in the face of the infant is attributed to nutritional factors, involving calcium deficiency, of the mother and/or developing infant.

British Columbia↗
PubMed1995

Accidental swallowing of a gold cast crown during orthodontic tooth separation.

Accidental swallowing of a gold cast crown that became loose after separation with brass wire for orthodontic band placement, is reported. The intervention to remove the ingested crown subsequent to its location in the GI tract on immediate radiographic examination of chest and abdomen included endoscopic examination. Since the crown had past distal to the duodenum it was decided to keep a watch on its movement by daily radiographic examination. The crown passed with excreta on the 5th day uneventfully. Literature on ingestion of foreign bodies of dental origin is reviewed. Possible emergencies and their management is discussed.

Adolescent↗
PubMed1980

Morphometric affinities of gigantopithecus.

Multivariate analyses, supplemented by univariate statistical methods, of measurements from mandibular tooth crown dimensions and the mandible of Gigantopithecus blacki, G. bilaspurensis, Plio-Plelstocene hominids, Homo erectus, and seven Neogene ape species from the genera Proconsul, Sivapithecus, Ouranopithecus, and Dryopithecus were used to assess the morphometric affinities of Gigantopithecus. The results show that Gigantopithecus displays affinities to Ouranopithecus and to the hominids, particularly the Plio-Plelstocene hominids, rather than to the apes. Ouranopithecus demonstrated dental resemblances to G. bilaspurensis and the Plio-Pleistocene hominids but mandibular similarities to the apes. Results of analyses of tooth and mandibular shape indices, combined with multivariate distance and temporal relationships, suggest that Ouranopithecus is a more likely candidate for Gigantopithecus ancestry than is Silvapithecus indicus. Shape and allometric differences between G. bilaspurensis and the robust australopithecines weaken the argument for an ancestral-descendant relationship between these groups. The results support the hypothesis that Gigantopithecus is an extinct side branch of the Hominidae.

Animals↗
PubMed1981

Tooth sizes in two males with deletions of the long arm of the Y-chromosome.

Permanent and deciduous tooth crown sizes in two males with deletions of the long arm of the Y chromosome and their first-degree relatives were examined. The first proband with a deletion in the proximal part of Yq11 showed definitely smaller teeth than his father or population control males. The second proband with a deletion in the distal part of Yq11 showed large or normal sized teeth compared to his brother or population control males. These data support the results of earlier studies indicating a promoting effect of the Y chromosome on tooth growth, and suggest that the location of the growth-promoting gene(s) is in Yq11. It is postulated that statural growth is affected by the same gene(s).

Adult↗
PubMed2006

Separate whitening effects on enamel and dentin after fourteen days.

The purpose of this study was to investigate the mechanism of action of a bleaching agent, as it relates to enamel and dentin. Twenty-six extracted human molar teeth were sectioned at the cemento-enamel junction and were randomly assigned to two groups. L*a*b* readings were taken with a spectrophotometer: on buccal surfaces of the crown, at enamel and dentin. The teeth were exposed to carbamide peroxide or placebo gel and L*a*b* scores were again recorded to determine color changes. Treatments were compared using ancova test with baseline color as the covariate. Relative to placebo, buccal surfaces exhibited the greatest Deltab* and DeltaL* color change. On buccal surfaces, the adjusted mean (SE) treatment differences were -7.8 (1.00) for Deltab* and 5.7 (0.97) for DeltaL, with groups differing significantly (p < 0.0001). On enamel surfaces, treatment differences were -3.6 (0.61) for Deltab* and 4.6 (0.80) for DeltaL* (p < 0.0001). Dentin exhibited the least color improvement. Adjusted mean (SE) treatment differences were -1.9 (0.87) for Deltab* and 2.4 (1.10) for DeltaL*, with groups differing significantly (p < 0.02) on dentin color change. The majority of color change seen on the buccal surface of tooth crowns exposed to carbamide peroxide 15% was because of the color change in enamel. As compared to enamel, dentin was less affected after 14 days.

Analysis of Variance↗
PubMed1989

Morphological and metrical comparison of San and Central Sotho dentitions from southern Africa.

Comparative morphological and metrical study of San and Central Sotho dentitions indicates that the teeth of the two samples are significantly different from one another. The San dental complex contains traits that add mass to the occlusal surface of microdontic dentitions: moderate low-grade UI1 (13.5%) and UI2 shoveling (24.7%), high Bushman canine (43.1%), fairly low UM2 hypocone reduction (23.3%), high UM2 cusp 5 (55.6%), high LM1 cusp 7 (35.2%), LM1 distal trigonid crest (7.1%), and LM2 deflecting wrinkle (5.3%), lack of reduction of LM1 and LM2 cusp number, in the presence of very low UM1 Carabelli's trait (6.7%) and high LM2 Y-groove (86.3%). Culturally, males occasionally exhibit filed UI1 and females are missing LI1. Conversely, mesodontic Central Sotho dentitions display a more simplified morphology, with the exception of moderately high incidence of UM1 Carabelli's trait (41.0%) and very high LM1 cusp 7 (71.3%). Discriminant analysis of mesiodistal and buccolingual diameters and tooth crown surface area data for the left maxillary teeth supports classification of San dentitions as microdont and Central Sotho dentitions as mesodont. Additionally, metrical analysis indicates that San teeth are more sexually dimorphic than are those of Central Sotho.

Adolescent↗
PubMed2006

Complications of mandibular brachygnathism in a North African leopard.

A 9-year-old, male North African leopard (Panhtera pardus) presented with mandibular brachygnathism and lingually displaced mandibular canine teeth causing a large left oronasal fistula, rhinitis and nasal discharge, and a right orocutaneous fistula. Surgical closure of the left oronasal defect, bilateral mandibular canine tooth crown reduction, and root canal therapy resulted in a positive clinical outcome. A small recurrent left oronasal fistula and the right orocutaneous fistula healed spontaneously after alleviating the occlusal contact with the mandibular canine teeth. At 12-months postoperatively, clinical signs of oral and dental disease had resolved.

Animals↗
PubMed1999

Interproximal contact hypoplasia in primary teeth: A new enamel defect with anthropological and clinical relevance.

This study reports the prevalence, distribution, and expression of enamel defects in a sample of primary teeth (n = 225) from a prehistoric site in western India (1400-700 BC). Five enamel surfaces of individual, isolated primary teeth were observed for surface defects using a binocular stereomicroscope with variable power of magnification (8-20x). Standards for evaluating dental enamel defects (DDE) recommended by the Fédération Dentaire International (FDI) were employed. Details of defect expression were also recorded, including size, shape, and surface of tooth crown affected. Hypoplastic enamel defects were observed in 28% of teeth, but the distribution and expression of defects was not random. More than 50% of canine teeth had hypoplastic defects (HD); incisors and molar teeth exhibited far fewer HD. The buccal surface of canines was the most commonly affected crown surface. Areas of missing enamel were also common on the mesial and distal surfaces of canines and incisors and on the mesial surface of molar teeth. The high frequency of enamel defects found on interproximal crown surfaces warrants a label, and the name interproximal contact hypoplasia (IPCH) is proposed. Linear enamel hypoplasia (LEH) was absent from this primary dental sample. IPCH is more frequent in mandibular than in maxillary teeth, but no side preference was detected. In canine teeth, buccal hypoplasias (localized hypoplasia of primary canines; LHPC) were not positively correlated with interproximal hypoplastic defects. The etiology of IPCH may involve mesial compaction of developing teeth due to slow longitudinal growth of the jaws. Episodic bone remodeling results in ephemeral fenestrae in the mesial and distal walls of the dental crypt permitting tooth-tooth contact and disruption of amelogenesis. IPCH prevalence decreases across the subsistence transition from sedentary Early Jorwe agriculturalists to seminomadic Late Jorwe hunters and foragers, but the difference is not statistically significant. This may be due to underrepresentation of mandibular teeth in the sample. Am. J. Hum. Biol. 11:718-734, 1999. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗
PubMed2001

Regenerative therapy of furcation defect.

Furcation defects of multiple-root teeth are complications of progressive periodontal diseases. The recommended technique of regenerative therapy in furcation defects of the lower molars is implantation of hydroxylapatite or demineralized freeze-dried bone. A case of a completely absent interradicular bone of 46 tooth in a 35-year-old woman with generalized periodontitis is presented. After endodontic treatment and recovery of the tooth crown we undertook surgical treatment of the bone defect: open curettage, using the technique of Ramfjord and bony reconstruction with aloplastic material bioplant HTR (septodont). The preoperative preparation included clinical prophylaxis and chemical plaque inhibition; postoperatively, rinsing the mouth twice a day with 0.5% metronidazole. The patient was followed up clinically and radiographically up to the 6th month after treatment when the bone structure regenerated.

Humans↗
PubMed1998

Use of computed tomography to investigate cheek tooth abnormalities in chinchillas (Chinchilla laniger)

Computerised tomographic scanning was used to investigate tooth structure in chinchillas (Chinchilla laniger), both cheek tooth crown and root abnormalities being common in this species. This paper describes a common form of dental disease affecting species with continuously growing teeth, with particular reference to the chinchilla, and confirms the potential role of computed tomography (CT) in its early diagnosis. CT imaging is compared with previously available methods of investigation which frequently fail to detect early pathological changes.

Animals↗
PubMed2003

[Establishment of normal value of posterior arch length of adolescence in Chengdu].

OBJECTIVE: To investigate the development of third molar embryo and establish the normal value of posterior arch length of adolescence in Chengdu. METHODS: The samples consisted of 40 males and 41 females with Class 1 dentitions, normal second molar occlusion, no history of orthodontic treatment, and good facial balance. Cephalometry and statistic analysis were conducted for all the subject. RESULTS: The normal value of posterior arch length of maxilla in male was(16.52 +/- 2.35) mm and in female was(16.42 +/- 2.55) mm. The normal length of mandible was(13.00 +/- 2.44) mm in male and(12.43 +/- 2.18) mm in female. But statistic analysis showed no gender difference. Most of the third molar embryo had been formed and their tooth crowns had been calcified, the occurrence ratio was 84.0% in maxilla and 85.2% in mandible. Most of them located in the middle and inclined mesially. CONCLUSION: The data obtained in this study will be valuable for our clinical practice and be helpful for the study concerning dento-facial growth and development.

Adolescent↗
PubMed1976

Interim overdentures.

The construction of an interim overdenture using existing removable partial dentures with natural tooth crowns and artificial teeth can be a simple and economical method of providing patients with dentures while tissues heal and teeth are prepared and restored. A more definite prognosis for both the patient and his remaining dentition can be established before the final overdenture is completed. The procedures necessary to provide three types of interim overdentures have been outlined. Patients tolerate this method of changing their dentitions extremely well.

Denture Design↗
PubMed1997

Epidemiology of dental trauma treated in an urban pediatric emergency department.

STUDY OBJECTIVE: To describe the epidemiology of traumatic dental injuries to children treated in an urban pediatric emergency department (ED). DESIGN: A descriptive study of a consecutive series of patients. SETTING: The ED of a large, academic children's hospital. PARTICIPANTS: Children presenting to the ED with dental trauma from December 1992 to November 1993. RESULTS: Of 1459 children treated for dental emergencies, 541 had dental trauma (37%) and were enrolled in this study. Patients ranged in age from five months to 18 years. Fifty-nine percent of patients were less than seven years of age, and 59% of patients were male. Falls caused 63% of injuries, followed by being struck (17%), and motor vehicle crashes (2%). Injuries to the soft tissues included lacerations (32%), swelling (8%), abrasions (7%), and contusions (6%). Injuries to hard dental structures included tooth fractures (33%), luxations (18%), concussions (12%), avulsions (8%), and jaw fractures (1%). Tooth luxation and concussion were more common among children less than seven years of age, and fractures to the tooth crown with dentin exposure (Ellis class II) were seen most often among children with permanent dentition (chi 2 = 41.4, P < 0.005). The central incisors were the teeth most frequently traumatized. CONCLUSION: Findings of this large consecutive series provide a useful description of the epidemiology of this common type of pediatric trauma for pediatric emergency care providers.

Accidental Falls↗
PubMed1987

Ceramics: their place in dentistry.

A transfer molded ceramic coping material, Cerestore, and a castable ceramic, Dicor, are commercially available for fabrication of all-ceramic crowns. The manufacturers indicate their use should be in single unit anterior or posterior crowns. Tooth preparations are similar and should have rounded lines angles to avoid sharp points which may cause stress concentration. The amounts of tooth reduction are also similar and range from 1.0 to 2.0 mm depending on the location of surfaces. There are variations in fabricating procedures but both involve heat treatment and special equipment. Cerestore requires eventual veneer build-up and shading. Dicor requires surface shading. Both are evaluated and classified by the Council on Dental Materials, Instruments and Equipment of the American Dental Association. At least three other ceramic systems are being developed but are not yet commercially available.

Aluminum Oxide↗
PubMed2001

[Chronic radiation effects on dental hard tissue (radiation caries). Classification and therapeutic strategies].

OBJECTIVES: Since the first description of rapid destruction of dental hard tissues following head and neck radiotherapy 80 years ago, "radiation caries" is an established clinical finding. The internationally accepted clinical evaluation score RTOG/EORTC however is lacking a classification of this frequent radiogenic alteration. MATERIAL AND METHODS: Medical records, data and images of radiation effects on the teeth of more than 1,500 patients, who underwent periradiotherapeutic care, were analyzed. Macroscopic alterations regarding the grade of late lesions of tooth crowns were used for a classification into 4 grades according to the RTOG/EORTC guidelines. RESULTS: No early radiation effects were found by macroscopic inspection. In the first 90 days following radiotherapy 1/3 of the patients complained of reversible hypersensitivity, which may be related to a temporary hyperemia of the pulp. It was possible to classify radiation caries as a late radiation effect on a graded scale as known from RTOG/EORTC for other organ systems. This is a prerequisite for the integration of radiation caries into the international nomenclature of the RTOG/EORTC classification. CONCLUSIONS: The documentation of early radiation effects on dental hard tissues seems to be neglectable. On the other hand the documentation of Late radiation effects has a high clinical impact. The identification of an initial lesion at the high-risk areas of the neck and incisal part of the tooth can lead to a successful therapy as a major prerequisite for orofacial rehabilitation. An internationally standardized documentation is a basis for the evaluation of the side effects of radiooncotic therapy as well as the effectiveness of protective and supportive procedures.

Adult↗
PubMed1992

Thickness of cementum/dentin in mesial roots of mandibular first molars.

The mesial roots of 15 human first lower molars, along with the corresponding half of the tooth crown, were studied to determine the thickness of dentin-cementum. A device was developed whereby these could be embedded in resin with a precisely known orientation in space. The roots were radiographed in mesiodistal and vestibular-lingual projections, then sectioned perpendicular to the canal axis in the coronal third. Thickness of dentin-cementum was compared on sections and radiograms; results showed that the amount of hard tissue is effectively about one fifth less than that appearing on the radiogram.

Densitometry↗
PubMedDate not supplied

Characteristic dental arches and occlusion in patients with aspartylglucosaminuria.

Aspartylglucosaminuria (AGU) is a lysosomal storage disorder with progressive mental retardation as a presenting manifestation. The disorder is caused by a single nucleotide change in the gene encoding aspartylglucosaminidase (AGA). This rare disease is relatively common in Finland: we were able to examine 81 Finnish AGU-patients for dental and oral changes. Tooth crown size and crown shape were normal, but dental malocclusions were common, and prevalences of spacing, large overjet, anterior open bite, and lateral crossbite exceeded Finnish population prevalences (P < 0.0001). Dental arches were already large in childhood, and in adult patients, when compared to Finnish population standards, the lower dental arch was larger in all dimensions (P < 0.001). Almost all patients had abnormally large tongues, which we assumed to be the reason for the structural abnormalities observed.

Adolescent↗
PubMed2001

The effect of short-term tooth intrusion on human pulpal blood flow measured by laser Doppler flowmetry.

The purpose was to examine the effect of brief intrusive forces on human pulpal blood flow (PBF). Laser Doppler flowmetric measurements were made from 17 vital upper left central incisors of 17 participants who had clinically healthy tooth crowns and periodontal tissues. Brief intrusive forces (0.5,1,5 N; duration 20 s) were applied to the incisal edges of the examined teeth, and apical displacement of the teeth and the PBF were measured simultaneously. Recordings were made with and without an opaque rubber dam applied to the examined teeth. Intrusive force significantly reduced PBF flux both with and without the dam (P<0.05, Friedman analysis). The results indicate that transient apical displacement can reduce PBF.

Adult↗