[Oral and maxillofacial manifestations of familial adenomatosis polyposis. Gardner's syndrome]

Patients suffering from familial adenomatosis polyposis develop multiple pre-malignant gastrointestinal polyps and are at high risk of developing colon cancer. In addition extra-intestinal manifestations are observed frequently. The combination of extra-intestinal manifestations and familial adenomatosis polyposis is named Gardner's syndrome. An early diagnosis of this disease is important because it could mean a better prognosis for the patient. This review describes the oral and maxillofacial symptoms of FAP, and its potential implications for dental treatment.

Epigenetic influences may explain dental differences in monozygotic twin pairs

BACKGROUND

Comparisons between monozygotic (MZ) co-twins have tended to focus on the similarities between their dentitions rather than differences. The aim of this study was to determine the prevalence of discordant expression for simple hypodontia and supernumerary teeth in MZ twin pairs and to explain how phenotypic differences might occur despite their similar genotypes.

METHODS

Records of 278 pairs of MZ twins, including dental casts and radiographs, were examined and the prevalences of discordant expression for missing upper lateral incisors (ULI) or second premolars (PM2), and of mesiodentes, were determined. Zygosities were confirmed by comparisons of blood markers and DNA.

RESULTS

There was evidence of at least one missing ULI or PM2 in 24 of the 278 MZ pairs (8.6 per cent), with 21 of these 24 pairs (87.5 per cent) showing discordant expression. Nine of the 278 MZ pairs (3.2 per cent) displayed evidence of mesiodentes, with eight of these nine pairs (88.9 per cent) being discordant.

CONCLUSION

Our findings show that differences in the expression of missing or extra teeth occur often between MZ co-twins whose genetic make-up predisposes them to simple hypodontia or mesiodentes. We postulate that minor variations in epigenetic events during odontogenesis may account for these distinct differences.

[Anomalies of the skull in cleidocranial dysplasia]

BACKGROUND

The description of the otorhinolaryngeal and craniofacial anomalies in patients with cleidocranial dysplasia.

METHODS

For this study, 26 patients with cleidocranial dysplasia were examined after their medical history had been recorded. The main focus was placed on otorhinolaryngological and orthodontic findings.

RESULTS

The portion of spontaneous mutations in our patient population was 46.1%. All patients exhibited otorhinolaryngological and craniofacial anomalies. While single ENT-anomalies were expressed in 76.9%-92.3% of the patients, the craniofacial findings were distributed over 84.6%-92.3%.

CONCLUSION

The expression of this rare disorder is variable and its symptomatology not always distinct. Otorhinolaryngological and craniofacial anomalies are often apparent. Appropriate treatment can significantly contribute to an improvement in the patient's quality of life. In cases of ambiguous findings, we recommend consultation with an experienced clinician as well as genetic counselling.

Five mandibular incisors: an autosomal recessive trait?

A fifth mandibular incisor is a eumorphic supernumerary tooth and has rarely been described in the medical literature. We report here a large Lebanese consanguineous family where four individuals displayed five incisors in the anterior mandible. Such familial observation has not been previously described. The possibility of an autosomal recessive inheritance for this nonsyndromic trait is discussed.

Supernumerary teeth "mesiodens". Case report

The supernumerary tooth is an anomaly of dental eruption that is not rare to find in the clinical practice. Among the supernumerary teeth the "mesiodens" is most frequent. The mesiodens is found in the region of the superior central incisors and it can be the cause of many complications. The aim of this work is the description of a rare symptomatic case of mesiodens and the diagnostic and therapeutic strategies to adopt when this dental anomaly occurs. In particular the authors suggest making radiographic examinations only in the family of patients with dental anomalies of number, thinking that the incidence of such anomalies is too low to justify mass radiographic examinations.

Familial occurence of mesiodens--a case report

Molariform supernumerary teeth in the maxillary central incisor area are uncommon. This article reports the presence of a molariform mesiodens in daughter and a conical mesiodens in father. Detailed investigation into family history of patients with mesiodens is needed. Though the etiology of this dental anomaly remains unclear, genetics as a key factor in the development of supernumerary teeth is highlighted.

Further studies of a model for the etiology of anomalies of tooth number and size in humans

A multifactorial model based on an underlying continuous distribution of tooth size, with thresholds determining hypodontia and supernumeraries, has been proposed [1]. Our aim is to investigate this model by comparing tooth morphology of affected patients and their first degree relatives with normal controls. An image analysis system [2] was used to measure teeth on study models of controls, patients with hypodontia of varying degrees and location, first-degree relatives of hypodontia index cases, and patients with supernumerary teeth in the maxillary incisor region. Mesio-distal crown size in hypodontia patients was smaller than controls, and this difference was significant for all tooth types. There was a general pattern: the more severe the hypodontia, the smaller the size of the tooth formed. Patients with supernumerary teeth had permanent maxillary central and lateral incisors and canines that were significantly larger in mesio-distal width than controls. The maxillary central incisors also differed in taper in supernumerary patients compared to controls. Hypodontia prevalence was higher in first-degree relatives (22%) of hypodontia index cases than in the general population (4.4%), and unaffected relatives had smaller teeth than controls. Thus, there were generalized and localized effects within the dentition, and these findings are compatible with the statistical expectations of the proposed multifactorial model.

Non-syndrome multiple supernumerary teeth in Nigerians

The present study was carried out to ascertain frequency of multiple supernumerary teeth not associated with syndrome in Nigerians. A total of 13 patients comprising of 10 males (76.92%) and 3 female (23.07%) representing 0.098% of the study population had multiple supernumerary teeth. Multiple supernumerary teeth without any associated systemic diseases or syndrome are rare as reported by BLUMENTHAL (3) RUHLMAN and NEELY (17), KANTOR et al. (10) is not the case in this study. The maxillary region has the highest frequency of occurrence with 12 times (66.67%) followed by the mandibular premolar region with 4 times (22.22%) while maxillary premolar and mandibular anterior region shared (5.55%) respectively. The conical and tuberculate types of supernumerary teeth were found in the midline region, while the supplemental supernumerary teeth were more in the mandibular premolar region with 12 (70.58%) follow by maxillary midline 4 (23.52%) and the lower incisor region 1 (5.88%) which is in consonant with WINTER and BROOK (2), STAFNE (19) NAZIF, FUTALO ZULLO (15). The role of genetics in the aetiology of multiple supernumerary teeth as found in this study, the occurrence of supernumerary teeth on two brothers and a daughter to one of the affected brothers, tends, to suggest an autosomal dominant mode of inheritance and the challenges to management by the orthodontists are discussed.

Fusion of the permanent maxillary right incisor to a supernumerary tooth in association with a gemination of permanent maxillary left central incisor: a dental, genetic and dermatoglyphic study

The relationship between fusion of the permanent maxillary right central incisor to a supernumerary tooth in association with gemination of permanent maxillary left central incisor and dermatoglyphics were investigated.

Congenital tooth anomalies and malocclusions: a genetic link?

The aim of the present study was to investigate putative relationships between different malocclusions such as Class III and Class II division 1, and congenital tooth anomalies. Two-hundred Class III and 215 Class II division 1 patients were examined for the presence of any of the following congenital tooth anomalies: maxillary incisor hypodontia, maxillary canine impaction, transpositions, supernumerary teeth, and tooth agenesis. Their occurrence rates were then calculated as a percentage of the total sample and were compared for statistical differences. The results revealed no statistical difference (P > 0.05) in the occurrence rates of upper lateral incisor agenesis, peg-shaped laterals, impacted canines, or supernumerary teeth between the Class III and the Class II division 1 malocclusions. When the occurrence rate of all congenital tooth anomalies was compared between the two malocclusions, Class III subjects showed significantly higher rates (P < 0.05). Comparison with published surveys on general populations showed similar occurrence rates. It can be concluded that subjects with Class III and Class II division 1 malocclusions show patterns of congenital tooth anomalies similar to those observed in the general population. Congenital tooth anomalies may represent another criterion for the study of malocclusion, with respect to their origin and development.

Similar locations of impacted and supernumerary teeth in monozygotic twins: a report of 2 cases

In this article, the cases of monozygotic twin brothers with similar developmental dental anomalies have been presented. Localization of impacted and supernumerary teeth and synchronous appearance of analogous ailments (leading to third tonsil removal and removal of supernumerary teeth from the anterior maxilla) are discussed. The boys' mother had also been treated for supernumerary teeth during childhood.

Retention of permanent incisors by mesiodens: a family affair

The term mesiodens refers to a supernumerary tooth that is present in the midline of the maxilla between the two central incisors. One or two mesiodentes may be present. We present a rare case of two sisters, in both of whom a pair of mesiodentes caused the retention of permanent incisors. They were referred to our hospital with asymptomatic delayed eruption of upper incisors. This article is written to point out genetic factors as the possible origin of supernumerary teeth.

Orthodontic, genetic, and periodontal considerations in the treatment of impacted maxillary central incisors: A study of twins

Treatment of twins each with one impacted maxillary central incisor and a mesiodens is described. Treatment included rapid expansion, extraction of the mesiodens, surgical exposure of the impacted central incisor, and its forced eruption. The impacted incisor was brought into functional position in one patient but was lost in the other because of insufficient root length and high mobility. Orthodontic, genetic, and periodontal considerations of these 2 cases are evaluated.

Inverted impaction of a mesiodens: a case report

Dental, radiological, dermatoglyphic and genetic findings of a patient showing inverted impaction of a mesiodens are presented. It is probable that the inversion of the mesiodens was caused by contact of the incisal edge of the crown of the mesiodens by the apex of the root of the erupting right maxillary central incisor tooth.

Taurodontism in association with supernumerary teeth

The dental, radiological, genetic and dermatoglyphic findings of an additional patient with taurodontism in association with supernumerary teeth were presented and the findings of the patient were compared with those in the literature.

A rare case of hereditary multiple impacted normal and supernumerary teeth

An eight-year-old girl residing in Bangalore presented with a complaint of retained primary maxillary and mandibular incisors. Radiographic examination of the case revealed multiple impacted permanent succedaneous teeth with deficient resorption of primary teeth and multiple impacted supernumerary teeth. Family history revealed that the mother also exhibited multiple impacted supernumerary teeth. Based on the clinical presentation, radiographic examination and histopathological studies, this paper discusses the differential diagnosis and management of such a case.

Multiple supernumerary teeth in two brothers: a case report

Supernumerary teeth (hyperdontia) are relatively common in the general population and occur more frequently in patients with a family history of such teeth. Supernumerary teeth have been reported in many genetic syndromes, but multiple supernumerary teeth occurring as an isolated non-syndromic trait are rare. This article describes a rare non-syndromic variety of multiple impacted supernumerary teeth in two brothers.

A controlled study of associated dental anomalies

The purpose of this study was to reveal patterns of association among seven types of dental anomalies (aplasia of second premolars, small size of maxillary lateral incisors, infraocclusion of primary molars, enamel hypoplasia, ectopic eruption of first molars, supernumerary teeth, and palatal displacement of maxillary canines) in an untreated orthodontic population, ages 7 to 14. The prevalence of associated tooth anomalies in seven groups of 100 subjects selected according to one primarily diagnosed dental anomaly was compared with the prevalence of the examined dental anomalies in a control group of 1,000 subjects. Significant reciprocal associations (p < 0.005) were found among five of the anomalies (aplasia of second premolars, small size of maxillary lateral incisors, infraocclusion of primary molars, enamel hypoplasia, and palatal displacement of maxillary canines), suggesting a common genetic origin for these conditions. Supernumerary teeth appeared to be a separate etiological entity with respect to all other examined tooth anomalies. The existence of associations between different tooth anomalies is clinically relevant, as the early diagnosis of one anomaly may indicate an increased risk for others.

Familial occurrence of mesiodentes with unusual findings: case reports

Supernumerary teeth are common and can occur throughout the oral cavity. Molariform supernumerary teeth in the maxillary central incisor area have rarely been reported. This article reports the presence of mesiodentes in two siblings, one of whom exhibited an unusual molariform mesiodens. The clinical and radiographic appearance of the anomalies and treatment modalities are discussed.

Supernumerary premolar teeth in siblings

The familial nature of supernumerary teeth is discussed in this paper and illustrated with a report showing the development of supernumeraries in siblings. The orthodontic treatment and possible sequelae to the development of supernumerary teeth in the premolar region is highlighted.

Genetic background effects on dental and other craniofacial abnormalities in homozygous small eye (Pax6Sey/Pax6Sey) mice

Small eye (Pax6Sey) is a semi-dominant mutation affecting development of the eyes, brain and nasal structures. The mutant phenotype arises from defects within the Pax6 gene and several mutant alleles have been identified. A previous study reported that Pax6Sey/Pax6Sey homozygotes, in a random-bred stock, had a median cartilaginous rod-like structure in the nasal region and 80% had supernumerary upper incisor teeth. In this study we show that supernumerary upper incisor teeth and a previously unreported nasal capsule-derived cartilaginous 'spur' occur in compound heterozygous Pax6Sey-Neu/Pax6Sey and homozygous Pax6Sey/Pax6Sey fetuses from several strains of mice. The frequencies of the abnormal phenotypes were not related to allele type but showed variable penetrance, which was dependent on genetic background. The median nasal cartilaginous rod-like structure was present in all homozygous small eye fetuses. The Pax6Sey/Pax6Sey homozygote may provide insight into the complex gene interactions involved in eye, nasal and craniofacial morphogenesis.

Mesiodentes: incidence, morphology, etiology

There are many publications in the literature focusing on clinical, radiological and surgical aspects of the treatment of mesiodentes. However, the etiology of this dental anomaly remains widely unclear. The purpose of this study was to evaluate etiologic factors for mesiodentes in a collective comprising 30 patients with a total of 45 mesiodentes. Thirty-one percent of the patients showed a familial disposition, pointing to inheritance as a key factor in the development of mesiodentes. Our results further support the hypothesis of related etiologic factors for several dental and craniofacial anomalies, such as hyperdontia, hypodontia and cleft lip and palate. Finally, we report the gemination of a deciduous incisor on the same side as a mesiodens. We also found differences in the mesiodistal width of central incisors depending on unilateral or bilateral occurrence of mesiodentes. Both these findings support the dichotomy theory of the split in the tooth bud inducing the development of mesiodentes, a theory we favor over that of local hyperactivity of the dental lamina.

Dental findings in parents of children with cleft lip and palate

The incidence of dental abnormalities in the cleft lip and palate population has been reported to be much higher than in the normal population. The role of genes in the production of a cleft lip and palate, and dental anomalies is thought to be complex, with autosomal dominant, recessive, and x-linked genes all playing a role. Noncleft parents can carry some of the cleft lip and palate genes, which produce clinically subtle manifestations in their facial skeleton. The purpose of this study was to look for evidence of increased dental anomalies in the non-cleft parents of cleft lip and palate children. The dentitions of the parents of 60 children with different types of cleft lip and palate were examined prospectively to see whether or not they exhibited features found more readily in the cleft lip and palate rather than did the normal population. Their dentitions were studied to record the following dental features: congenitally missing teeth, supernumerary teeth, or morphologic changes of the crowns of the permanent teeth. The number and position of any frenal attachments were also recorded. The results of this study did not show any differences in incidence of dental anomalies from the noncleft population. There was no evidence to support the hypothesis that congenital absence of lateral incisors is a microform of cleft lip and palate. Further, these results also failed to reveal any consistent pattern in the number and position of frenal attachments.

Severe dental aberrations in familial steroid dehydrogenase deficiency: a new association

Severe numerical dental aberrations are rare, and are most often seen as a part of certain syndromes. We here report on a Saudi Arabian family where first-cousin marriages have caused numerical and structural dental abnormalities linked to autosomal recessively inherited liver diseases. The two latest affected children in this family have had their liver defect successfully treated with fat-soluble vitamins and chenodeoxycholic acid, enabling us to study their dental development. One boy exhibits 11 supernumerary teeth, a general hypomineralisation and enamel hypoplasia, while an affected cousin successfully diagnosed at an early age, so far, only suffers from structural enamel defects. The children are otherwise healthy. There is no resemblance to any known syndromes. We suggest that the supernumerary teeth and the liver disease are caused by the same genetic defect, and represent a new association. The hypomineralisation, however, is most likely to result from vitamin deficiency secondary to malabsorption during the first years of life, before successful treatment was instituted.