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PubMed2002

Dental caries in the primary dentition: assessing prevalence of cavitated and noncavitated lesions.

BACKGROUND: Dental caries in the primary dentition has received renewed attention in recent years because caries in the primary dentition is predictive of later caries experience, and because of efforts to address early childhood caries. More detailed caries diagnostic criteria have been developed and used for the permanent teeth; however, such criteria have not been widely adopted for caries diagnosis in the primary dentition. METHODS: As part of the Iowa Fluoride Study, caries diagnostic criteria were developed specifically for the primary teeth. The criteria included noncavitated (d1) lesions and cavitated (d2-3) lesions. Examinations were conducted on 698 children in the primary dentition by two trained examiners who did duplicate examinations on 11 percent (n = 67) of these children. RESULTS: Interexaminer agreement for any d1 and any d2-3 lesions at the person level was 100 percent. At the tooth level for d1d2-3f, there was 98.5 percent agreement and kappa was .91. For d1 at the tooth level, agreement was 97.0 percent agreement and kappa = .24. For d2-3 it was 99.4 percent agreement and kappa = .81. Prevalence of untreated d2-3 was 16.5 percent, while that of d1 was 24.1 percent. Nearly 73 percent had no d2-3 or filled surfaces, while over 63 percent had no d1, d2-3, or filled surfaces. Decay experience was most common on the primary second molars. About 56 percent of untreated d2-3 decay was located in the pits and fissures, while 58 percent of d1 decay was located on smooth surfaces. CONCLUSION: Despite some concern with reliability of diagnosing d1 lesions, it appears that the d1d2-3 criteria are informative and useful in assessing the primary dentition.

Child, Preschool↗
PubMed2003

[Cross-sectional study of the evolution of the primary dentition: shape of dental arches, overjet and overbite].

The aim of this study was to evaluate the characteristics (shape of dental arches, overjet and overbite) of the primary dentition of 6- to 39-month-old children from four nurseries of Rio de Janeiro, Brazil, and to associate them to gender and dentition phase. It was observed that 68.6% of the children presented round upper arch, while 31.4% had triangular upper arch; 92% of the children presented U-shaped lower arch and 8% had square-shaped lower arch. Moderate overjet was observed in 38.3% of the children, and slight overjet, in 30.3%. Severe (26.6%) and negative (25.5%) overbites were the most prevalent modalities of that condition. There was no association between gender and the studied characteristics. There was statistically significant association between the dentition phase and the shape of the arch, overjet and overbite (p < 0.001, chi-square test). It was possible to observe, in the present study, that early signs of malocclusions appeared when first primary molars erupted, as the posterior vertical dimension of occlusion increased. It was, thus, verified that early signs of malocclusions appear as the primary dentition develops. It is very important that the first dental visit occur during the first year of age, since it allows the pediatric dentist to prevent or carry out an early diagnosis of malocclusions in the primary dentition.

Brazil↗
PubMed1990

[Clinical study of evaluation on masticatory function in complete denture wearers. A comparison of masticatory movements between normal natural dentition and complete denture wearers].

The purpose of this study was to comparatively study and elucidate the characteristics of masticatory function of the subjects with complete denture and those with normal natural dentition. The study were carried out on 20 subjects with normal natural dentition and 30 subjects with complete denture having clinically good prognosis. Masticatory movements were analyzed by electromyograph (EMG) and sirognathograph (SGG) when the subjects were chewing peanuts and kamaboko (boiled fish paste). The results were as follows: 1. The duration of chewing cycle, closing phase, occluding phase, and EMGs burst duration (especially after tooth contact) were significantly longer in the subjects with complete denture. 2. The maximum opening distance was significantly shorter, the maximum opening and closing velocity were significantly slower, in the subjects with complete denture. Further, the standard deviation of the coordinates of the sample points in the occluding phase was indisordered in the subjects with complete denture, and standard deviation of the coordinates of sample points in occluding phase were varied in complete denture wearers. 3. The frontal masticatory pattern tended to unstable and typical tear drop shape pattern was found in about 60% of the subjects with complete denture. 4. Different reactions to the test foods were observed in the subjects with normal natural dentition, while such was not noted in the cases of the subjects with normal natural dentition. These results was suggest that the masticatory function in the subjects with complete denture were obviously differ from those of normal natural dentition due to the difference in the sensory-motor-system.

Arachis↗
PubMed1999

Evaluation of a bitemark using clear acrylic replicas of the suspect's dentition--a case report.

An assault occurred during which a bite was inflicted on the left ear of the victim, producing a laceration and severing a portion of tissue from the ear. During the course of their investigation police recovered a lacerated fragment of tissue thought to be of a person's left ear. Impressions of a suspect's dentition were made and cast in dental stone. Positive replicas of the occlusal surfaces of the suspect's dentition were subsequently made using acrylic resin. The ear fragment displayed a lacerated border and a surface which exhibited indentations. When compared with the details of the suspect's lower anterior teeth, correspondence was visible between the shape of the indentations and characteristics of the suspect's dentition. The use of transparent acrylic replicas of the suspect's dentition facilitated the interpretation and comparison between the marks retained in the ear fragment and the features of the suspect's dentition.

Acrylic Resins↗
PubMedDate not supplied

Dentition development and budding morphogenesis.

The development of functional teeth in the mouse has been widely used as a model to study general mechanisms of organogenesis. Compared with other mammals, in which three incisors, one canine, four premolars, and three molars may occur even in each dental quadrant, the mouse functional dentition is strongly reduced. It comprises only one incisor separated from three molars by a toothless gap diastema at the location of the missing teeth. However, mouse embryos also develop transient vestigial dental primordia between the incisor and molar germs in both the upper and lower jaws. These rudimental structures regress, and epithelial apoptosis is involved in this process. The existence of the vestigial dental structures allowed a better assessment of the periodicity in the mouse dentition, which extends opportunities for the interpretation of molecular data on tooth development. We compared the dentition development with tentative models of budding morphogenesis in other epithelial appendages lungs and feathers. We suggested how developmental control by signaling molecules, including bone morphogenetic protein (Bmp), sonic hedgehog (Shh), and fibroblast growth factor (Fgf), can be similarly involved during budding morphogenesis of dentition and other epithelial appendages. We propose that epithelial apoptosis plays an important role in achieving specific features of dentition, whose development involves both budding and its more complex variant branching. The failure of segregation of the originating buds supports the participation of the concrescence of several tooth primordia in the evolutionary differentiation of mammalian teeth.

Animals↗
PubMed2002

Diastemas in primary dentition and their relationships to sex, age and dental occlusion.

AIM: The prevalence of interincisive and primate spaces in the primary dentition, relating them to age and sex, was studied. An analysis was made as to what extent various occlusal aspects of the arches affect the existence of spacing. MATERIALS AND METHODS: A population of 267 children, 153 males and 114 females, aged 2.2-8.2 years, was evaluated. All were white Caucasian, apparently healthy and lacking any congenital malformations; they had complete primary dentition and no erupted permanent teeth, without existing dental malformation and not having undergone any type of orthodontic treatment. Cast models were fabricated from impressions taken of all the children. Tooth sizes and interdental spaces were measured on these models and the various occlusal aspects were noted. RESULTS: The prevalence of spacing was high in the primary dentition, being independent of the chronological age of each child. Spacing was more frequent in males than in females. The presence or absence of spacing was not directly related to occlusion except in cases of posterior cross-bite, where it was less frequently, and open-bites, in which spaces appeared more often than usual. CONCLUSION: Spaces in the primary dentition were very common among the population studied and more frequent in male children than in females. Primate spaces were more frequent at the earliest ages, but chronological age had no influence on the presence of interincisive spacing. The lack of the spaces in the maxillary arches, typical of the primary dentition, prevailed among individuals with posterior cross-bite, contrary to what normally happens in the rest of the population.

Journal Article↗
PubMed2001

[The distal active concept applied to the mixed dentition: a comparative study].

The "Distal Active Concept" (DAC) therapy used during the mixed dentition period shows a mandibular growth of 7.6 mm whereas the same treatment applied on the permanent dentition only shows a mandibular growth of 3.9 mm. This difference is highly significant. The DAC therapy is prescribed to a group of 30 nine years old patients with a mixed dentition for six months. The DAC therapy is prescribed to a group of 34 twelve years old patients with a permanent dentition for 24 months. As the mandibular answer to treatment seems to be more effective at the age of 9 than later, during the prepubertal period, the DAC therapy appears to be of interest and an alternative to activator treatments. Our results show the efficiency of a first stage treatment, for all the patients showing a significant class II malocclusion.

Cephalometry↗
PubMed2003

Tooth wear and the "design" of the human dentition: a perspective from evolutionary medicine.

Worn, flat occlusal surfaces and anterior edge-to-edge occlusion are ubiquitous among the dentitions of prehistoric humans. The concept of attritional occlusion was proposed in the 1950s as a hypothesis to explain these characteristics. The main aspects of this hypothesis are: 1) the dentitions of ancient populations in heavy-wear environments were continuously and dynamically changing owing to life-long attritional tooth reduction and compensatory tooth migration, 2) all contemporary humans inherit these compensatory mechanisms, and recent reduction in wear severity has resulted in failure to develop attritional occlusion, and 3) this failure leads to an increased frequency of various dental problems in modern societies. Because of the potential significance of this concept, we review and synthesize relevant works and discuss attritional occlusion in the light of current knowledge. Available evidence, on balance, supports the first and second points of the hypothesis. As noted by many workers, the human dentition is basically "designed" on the premise that extensive wear will occur, a conclusion that seems reasonable when one realizes that humans evolved in heavy-wear environments until relatively recently. Some dental problems in contemporary societies appear to reflect the disparity between the original design of our dentition and our present environment, in which extensive wear no longer occurs, but this possibility still needs further investigation.

Adaptation, Physiological↗
PubMed2002

Unique dentition of lungfish.

Lungfish are a group of ancient fish, represented almost continuously in the fossil record from their first appearance in the Devonian to the present time. They have numerous unique characters in the dentition, found only among lungfish, as well as some that are shared with other groups of fish and with higher vertebrates, such as a thin layer of true enamel, instead of the enameloid found in the dentition of most fish. Unique characters include the diversity of forms of dentine in the tooth plates, as well as the organisation of the dentines and the unusual mode of continuous growth of the dentition. Their enamel is based on amelogenin formed by the ameloblasts of the dental lamina, and is mineralised by long crystals of calcium hydroxyapatite deposited in layers over the developing tooth. The different forms of dentine, which show progressive evolutionary change within the group, are based on an extracellular matrix of collagen, mineralised with calcium hydroxapatite of variable crystalline form. Cells that line the oral cavity produce the ameloblasts that are endodermal in origin, and cells that form the dental papillae are, like the other cells that secrete skeletal tissues, derived from head mesoderm, as in other vertebrates. Unique to all dipnoans is the fusion of the dental tissues to the underlying bone and the way in which bone, included within the tooth plate, remodels to permit growth in the whole dentition.

Animals↗
PubMed2002

A study of children with unilateral posterior crossbite, treated and untreated, in the deciduous dentition--occlusal and skeletal characteristics of significance in predicting the long-term outcome.

BACKGROUND AND AIM: The generally recommended treatment in children with unilateral posterior crossbite is expansion of the maxillary dental arch. The reported treatment success rate varies between 50% and 96%. The aim of the present study was to analyse whether some occlusal and skeletal characteristics could be found in the deciduous dentition of children with treatment success (including self-correction) in contrast to those showing non-correction (including relapse) in the young permanent dentition. PATIENTS AND METHOD: Two groups of children with unilateral posterior crossbite were followed from the age of 5 years up to 13 years of age. The children in one of the groups (n = 32) were treated in the deciduous dentition, while the children in the other group (n = 32) were to be treated in the late mixed or early permanent dentition. Another 25 children (5 years old) with excellent occlusion were included as controls. Results of clinical examination and biometric and cephalometric analyses, performed at the first examination (at 5 years of age), are presented for the three groups ("treated" "untreated" and controls). RESULTS AND CONCLUSIONS: Compared to the controls, asymmetry was registered in both dental arches. The crossbite side, measured to the midline, was narrower than the non-crossbite side in the upper jaw but broader in the lower jaw. Differences between upper/lower widths (at intercanine and intermolar level) seem to be of importance for correction or non-correction, both for "untreated" and "treated" children. A narrow crossbite side in the upper arch together with a broad crossbite side in the lower arch was found in non-corrected children in both groups, even among those treated with maxillary expansion, where the SNB angle was larger and the ANB angle smaller than in controls as well as in those with correction (including self-correction). Possibilities and limitations of treatment planning are discussed.

Adolescent↗
PubMed2006

3-D imaging and quantitative comparison of human dentitions and simulated bite marks.

This study presents a technique developed for 3-D imaging and quantitative comparison of human dentitions and simulated bite marks. A sample of 42 study models and the corresponding bites, made by the same subjects in acrylic dental wax, were digitised by laser scanning. This technique allows image comparison of a 3-D dentition with a 3-D bite mark, eliminating distortion due to perspective as experienced in conventional photography. Cartesian co-ordinates of a series of landmarks were used to describe the dentitions and bite marks, and a matrix was created to compare all possible combinations of matches and non-matches using cross-validation techniques. An algorithm, which estimated the probability of a dentition matching its corresponding bite mark, was developed. A receiver operating characteristic graph illustrated the relationship between values for specificity and sensitivity. This graph also showed for this sample that 15% of non-matches could not be distinguished from the true match, translating to a 15% probability of falsely convicting an innocent person.

Australia↗
PubMed1975

Mesiodistal crown dimension of the permanent dentition of American Negroes.

A study of the mesiodistal crown dimension was conducted on the teeth of 162 American Negroes, equally divided between males and females. A total of 3,980 teeth were measured. Teeth were measured from the plaster casts by means of Boley gauges. The sample was drawn from a growth study, private practice, and a dental clinic. The mean width of the teeth of males and females was reported. The teeth of males were larger than those of females for each type of tooth in both arches, although they exhibited a similar pattern of tooth size. The maxillary first premolars were larger than the second premolars, while the mandibular second premolars were larger than the first premolars. The first molars were larger than the second molars in both the maxillary and mandibular arches in both sexes. The ratio of the mandibular dentition ot the maxillary dentition was 94 per cent in both sexes. The ratio of the sum of the widths of the canines and incisors of the mandibular dentition to those of the maxillary dentition was 77 per cent. Also, the ratio of the mandibular incisors to the maxillary incisors was 71 per cent in both sexes.

Black People↗
PubMed1989

The position of the dentition in the mandible and its possible relation to orthodontic abnormalities.

A method used to study human evolution has compared different positions of the lower dentition in relation to the position of the mandibular condyle in the sagittal plane. The method is modified here and, with data from the Burlington Growth Study, used to describe a normal range of positions for the human lower dentition in relation to the condyle from the ages of 4 to 20 years. Measurements of a randomly selected group of orthodontically treated patients showed that in about one half of them the lower dentition was outside the normal range before treatment. The effect of treatment was to move the dentition randomly toward or away from a normal position. It is concluded that the new cephalometric measurement described here could help in the diagnosis and treatment of orthodontic patients.

Adolescent↗
PubMed2004

Comparison of orthodontic and orthopedic effects of a modified maxillary protractor between deciduous and early mixed dentitions.

The purpose of this study was to investigate the effects of the maxillary protractor bow appliance (MPBA) on dentoalveolar structure and skeletal morphology in patients with Class III malocclusions in different dental stages. The sample consisted of 63 treated and 57 untreated Japanese patients who all had anterior crossbites. The former group was treated with MPBA and included 34 subjects with deciduous dentition (DT group) and 29 subjects with early mixed dentition (MT group). In the DT group, MPBA was used over a mean period of 5 months to obtain positive overjet, and, in the MT group, MPBA was used over a mean period of 10 months identically. Analysis of variance with 3 factors (appliance, treatment stage, sex) between treated and untreated subjects and unpaired t tests between DT and MT groups were performed from 2 lateral cephalograms before and after treatment to compare the dentofacial changes. The mechanisms of improving anterior crossbite were similar in both groups; however, the mean skeletal and dentoalveolar changes in the DT group were significantly greater than those in the MT group. The clinical effects of MPBA treatment were greater in the deciduous-dentition group than in the early-mixed-dentition group.

Analysis of Variance↗
PubMed1993

A longitudinal evaluation of the anterior border of the dentition.

Posttreatment changes of orthodontically treated dentitions are inherent to every orthodontic practice. Various studies have documented the ideal posttreatment dental and cephalometric norms that could pertain to stable long-term occlusal results. Clinically, changes in these parameters are often observed as mandibular incisor crowding. The purpose of this study was to evaluate the longitudinal changes in certain variables representing the anterior border of the dentition. Eighty-eight white subjects were assessed regarding stability of the dentition after edgewise orthodontic treatment. (44% nonextraction, 56% extraction) The following variables in proximity of the anterior limit of the dentition (overbite, overjet, mandibular arch length, upper and lower incisor position, Little irregularity index) were assessed and correlated with each other. The data were subjected to descriptive statistics, the Friedman test for significant changes and pairwise comparisons, and the Spearman correlation test. Mandibular intercanine width was not significantly altered during treatment, but although not significantly, p > 0.05 did decrease beyond the original measurement during posttreatment evaluation (mean 7 years after treatment). The other variables influenced by the orthodontic manipulation were all within normal ranges and remained stable. The arch length decreased significantly (p < 0.05) during the entire evaluation period and was the only variable not stable. It was concluded that: (1) sound treatment leads to attainment of ideal occlusal parameters, (2) mandibular intercanine expansion could lead to failure of results, (3) arch length change plays a major role in causing irregularity of mandibular incisors after treatment, and (4) patient education regarding posttreatment orthodontic changes is imperative.

Adolescent↗
PubMed1995

Mixed dentition case report.

Malocclusions can be successfully corrected by phase I mixed dentition therapy and significantly reduce the need for comprehensive orthodontic treatment in the permanent dentition. Phase I orthodontic treatment is designed to correct the skeletal and dental malocclusions at an early age with 12 to 18 months of treatment. After phase I treatment, there is a supervision phase of typically 18 to 30 months to hold the correction achieved and to supervise the eruption of the remaining permanent teeth. Good management during the supervision phase is key to maintaining the phase I result and to minimizing phase II treatment. If a second phase of orthodontic treatment is required, treatment time is usually limited to 6 to 18 months, depending on the malocclusion and growth pattern. In this case, full banded treatment and maxillary intrusion surgery was not recommended because of the excellent early treatment result. Reduction of vertical anterior maxillary excess can be successfully achieved with early mixed dentition treatment and remain stable during the supervision phase of treatment. At the University of the Pacific, mixed dentition treatment is an integral part of the graduate program in orthodontics. This patient had a severe skeletal ANB angle discrepancy of 8 degrees, a vertical growth pattern, and 8 mm of overjet. She was considered an excellent candidate for phase I treatment to reduce the severity of the problem. It is our philosophy to take advantage of the growth potential in a patient by initiating phase I treatment between the ages of 7 and 9 years, depending on the eruption of the permanent first molars and incisors and the severity of the malocclusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1998

Comprehensive mixed dentition treatment.

At the University of the Pacific, mixed dentition treatment is an integral part in the graduate program in orthodontics. One patient had a severe skeletal ANB discrepancy of 7 degrees, lower incisors crowding, and 12 mm of overjet. He was considered an excellent candidate for Phase I treatment to reduce the severity of the problem. It is our philosophy to take advantage of the growth potential in a patient by initiating Phase I treatment between the ages of 7 and 9 years, depending on the eruption of the permanent first molars and incisors and the severity of the malocclusion. We use leeway space to resolve crowding and to align lower incisors in the early mixed dentition. We find that these young patients are more compliant with orthodontic treatment than most adolescent patients. If treatment was postponed until eruption of the permanent dentition, we would have one chance for correction of the problem rather than a Phase I and Phase II (if needed) approach. We believe that the key to successful Phase I treatment is this comprehensive approach to early treatment. The entire malocclusion is addressed at an early age rather than only addressing one or two problems and postponing the majority of the orthodontic correction until the permanent dentition.

Cephalometry↗
PubMed2001

Prediction of the permanent dentition in deciduous anterior crossbite.

Early prospective evaluation for self-correction of deciduous anterior crossbite can enable identification of patients who require early treatment as well as those who do not. The purpose of the present study was to generate an algorithm that can be used to predict self-correction in the transitional dentition in 3-year-old subjects. The subjects were divided into 2 groups. One group comprised 22 subjects whose anterior crossbite self-corrected during the transitional stage (hereafter referred to as group N). The other group was comprised of 22 subjects whose anterior crossbite persisted during the transitional dentition (hereafter referred to as group R). All subjects were examined using lateral cephalometric radiography in order to evaluate differences in occlusion. Fifteen measurements were used for the evaluation. For each measurement, the variance ratio and the difference in the population mean between groups N and R were tested and t-values were derived. Based on the Student's t-test results, only measurements that had statistically significant differences (P < .05) were extracted. Predictor variables that had a partial F value of 5 or greater were selected for stepwise discriminant analysis, and the following equation was obtained: deciduous indicator (DI) = -0.58(cranial length anterior) + 1.31(posterior facial height) - 0.76(porion location) - 2.02(Wits appraisal) - 70.28. The lower the DI value (negative), the higher the probability that the crossbite will self-correct at the transitional dentition. On the other hand, a high (positive) discriminant score strongly suggests that the subject requires treatment in the primary dentition. The result of this analysis showed that the apparent error rate was 95.46% and the Maharanobis' generalized distance was 8.99.

Algorithms↗