The single maxillary central primary incisor: report of case

The presented case is a single anomaly not associated with other conditions. In rare cases of the solitary maxillary incisor, the tooth is symmetrical and is always present in the midline, but the crown and root of the tooth are the size of a normal central incisor.

An enigmatic hypoplastic defect of the deciduous canine

A roughly circular hypoplastic defect restricted to the labial enamel surface of the deciduous canine is described. This pathology is quite common in available samples of Upper Paleolithic and Neolithic children and a cadaver sample of recent Calcuttans, affecting 44% to 70% of individuals. It is rare in a Neanderthal sample and in children from a clinical practice in Vancouver. The lesion occurs twice as commonly in the lower jaw. The defect appears to commence at or after birth owing to localized pressure on thin or nonexistent alveolar bone overlying the bulging crypt of the deciduous canine. Population differences in the incidence of the pathology probably reflect innate and acquired variation in hard and soft tissue thicknesses in this region.

Primary talon cusp

Talon cusps are seen most frequently on maxillary incisors. Only recently have reports of talon cusps on primary teeth appeared. This was a case involving a primary maxillary lateral incisor.

Hereditary agenesis of ten maxillary posterior teeth: a family history

A family is described, where the mother and her two sons had similar bilateral congenital absences of the following maxillary teeth: the second premolars, the first, second and possibly the third molars, as well as, in the sons, the second primary molars. The size, shape and formation of the remaining teeth were within normal limits. The near relatives of the parents had no history of hypodontia. The family members were otherwise healthy except that the mother and one of the sons had a slight nasality of speech. Moreover, the mother and both sons had adhesive otitis.

Hyperdontia in children below four years of age: a radiographic study

Sixty-six children (forty-one boys and twenty-five girls) were evaluated for differences in characteristics of premaxillary hyperdontia between the primary and permanent dentitions. The study population had forty-five supernumerary teeth in their primary dentitions and fifty supernumerary teeth in their permanent dentitions. Eighty percent of the primary supernumerary teeth were located in the lateral incisor regions, in proper alignment within the dental arch. Sixty-two percent of the supernumerary teeth in the permanent dentitions were situated in the central incisor regions; 90 percent were outside the dental arch, mostly palatal; and 42 percent were inverted. Seventy-three percent of the supernumerary teeth in the primary dentitions had erupted. Twin tooth formation occurred in twenty-eight patients, the majority in the primary dentition; but in eleven children, both dentitions were involved. Interference with the normal dentition occurred most often in the permanent dentition. Children with primary supernumeraries exhibit a greater chance of hyperdontia in the permanent dentition than do others.

Treatment of triple tooth: report of case

A case of a young girl with a triple primary tooth that retarded normal development of the maxillary left lateral incisor is described. The primary tooth was extracted to encourage normal development of the permanent tooth. Subsequent examination of the extracted triple tooth suggests that it was composed of the primary left lateral incisor fused either to a geminated central incisor or to a fused central incisor and supernumerary tooth.

An unusual lateral incisor

The conditions of hypodontia, hyperodontia and connation (fusion or gemination) have been outlined. A case has been reported in which there has been failure of development of a normal maxillary lateral incisor on one side, with an unerupted tooth in this region which exhibited characteristics of a supernumerary tooth; a diagnosis of hypo-hyperodontia is suggested. This has occurred in a patient in whom the deciduous incisors in the same quadrant were connate.

Hypodontia, hyperodontia, and double formation of primary teeth in Iceland. An epidemiological study

The aim of this study was to determine the prevalence of hypodontia, hyperodontia, and double formation of primary teeth in Icelandic children in the dental stage DS 02 (primary dentition complete). The study group comprised 927 children (498 boys and 429 girls). This was about 9% of all children aged 0-83 months in Reykjavik at the time of the registration of these anomalies, during the winter of 1978-1979. The children included those presenting for regular examinations in two health centers, children from three kindergartens, and seven pre-school classes from two schools in Reykjavik. Of these children 61.9% were selected for this study as they proved to be in dental stage DS 02 (primary teeth fully erupted). The prevalences were hypodontia, 0.5%; hyperodontia, 0.5%; and double formation, 0.7%. Comparison was made with earlier results from Iceland and with results from several other nations.

An analysis of the Carabelli trait in the mixed deciduous and permanent human dentition

Permanent first and deciduous second maxillary molars were examined on dental casts of 240 persons. A high degree of equivalence of Carabelli-trait expression between deciduous and permanent molars was demonstrated using the Wilcoxon matched-pairs signed-rank test and chi-square tests. Kolmogorov-Smirnov two-sample tests confirmed a lack of sex dimorphism of trait incidence and expression in permanent and deciduous molars. It is hypothesized that the high degree of within-individual equivalence suggests a low epigenetic and high genetic influence on Carabelli-trait expression and that the findings support the clonal rather than the field theory of tooth morphogenesis.