Permanent Mandibular Lateral Incisors Research Articles

Sequence analysis of PAX9, MSX1 and AXIN2 genes in a Chinese oligodontia family

ObjectivesThe goal of our research was to look into the clinical traits and genetic mutations in nonsyndromic oligodontia in a Chinese family and to gain insight into the role of mutations of PAX9, MSX1 and AXIN2 in oligodontia phenotypes. Materials and methods6 subjects from a family underwent complete oral examination, including panoramic radiographs. Retrospective data were reviewed and blood samples were collected. PCR primers for PAX9, MSX1, and AXIN2 were designed through the Oligo Primer Analysis Software. PCR products were purified and sequenced using the BigDye Terminator Kit and analysed by the 3730 DNA Analyzer. ResultsThe proband missed 4 permanent canines, 2 permanent maxillary lateral incisors, 2 permanent mandibular lateral incisors, and 2 permanent mandibular central incisors, whilst his maternal grandfather lacked only 2 permanent mandibular central incisors. Moreover, the size of some permanent teeth appeared smaller than normal values of crown width of Chinese people. Oligodontia and abnormalities of teeth were not present in other family members. Radiographic examination showed that the proband and the rest of family members retained all germs of the third molars. There was one known mutation A240P (rs4904210) of PAX9 in the coding region in the proband and the maternal family members (II-2, II-3, and II-4), which possibly contributed to structural and functional changes of proteins. No mutations were identified in MSX1 and AXIN2. ConclusionsOur findings may imply that the PAX9 A240P mutation is a risk factor for oligodontia in the Chinese population. A240P is likely to be a genetic cause of oligodontia though previous literature suggested it as a polymorphism only.

Neoplastic potential of odontogenic cysts

Odontogenic cysts and tumors are distinct entities and quite a common occurrence in the jaw bones. The lining of odontogenic cysts shows a potential for neoplastic transformation to non odontogenic malignancies like squamous cell carcinoma and mucoepidermoid carcinoma, and odontogenic tumors like ameloblastoma and adenoamatoid odontogenic tumor (AOT). AOT is a benign, epithelial odontogenic tumor, common site being the anterior maxilla. Its origin from a dentigerous cyst and in the mandible is rare. A case of an AOT arising from a dentigerous cyst associated with an impacted permanent mandibular left lateral incisor is reported.

Early orthodontic treatment of unilateral mandibular left lateral incisor–canine transposition: A Case Report

Among dental anomalies, tooth transposition is considered the most difficult to manage clinically. Distal migration of permanent mandibular lateral incisor happens rarely. It can be discovered radiographically in the early mixed dentition & interceptive treatment is often appropriate. If left uncorrected it may erupt ectopically and the results are often unsatisfactory both esthetically and functionally. When transpositions are detected early the positions of the root apices are important in deciding where to move the transposed tooth. This article reports a case of early orthodontic treatment of a rare unilateral mandibular left lateral incisor - canine transposition.

Alignment of transposed mandibular lateral incisor and canine using removable appliances

The purpose of this paper was to present the management of a rarely encountered transposition anomaly involving the mandibular permanent lateral incisor and the canine. In the literature, the treatment of this type of anomaly involves fixed orthodontic appliances. The treatment of the present case, however, was performed with removable appliances. Transposition of the permanent mandibular right lateral incisor and the permanent mandibular right canine was detected in a 12 year old girl. The primary mandibular right canine was extracted to enable the distal movement of the permanent lateral incisor by the eruption force of the permanent canine. The transposed teeth were then aligned in the arch by using removable appliances. The forms of the teeth were changed with each other with composite restorations.

Bilateral fusion of permanent mandibular incisors with Talon′s cusp: A rare case report

Whenever nature diverts from the “normal or usual” it gives rise to something called “abnormal or unusual,” which we call “a Disorder”. Fusion of two teeth is a common developmental disorder that is seen by a clinician. However, bilateral fusion along with Talon's cusp is very rarely seen and reported in literature. This article describes a rare case of the bilateral fusion of permanent mandibular central and lateral incisors, along with presence of Talon's cusp on the left fused teeth.

Bilateral fusion of mandibular primary teeth

The aim of the report was to highlight the rarity of occurrence of bilaterally fused mandibular primary lateral incisors and canines by virtue of the number of such cases reported in literature; to identify congenital absence of successor teeth;and to evaluate their pulpal morphologies to understand the type of fusion. Clinical observation along with an orthopantomograph and periapical radiographs were used to arrive at a diagnosis. The pulpal morphologies varied in each of the fused teeth although both were fusions of the Complete type. There was congenital absence of the permanent mandibular lateral incisors, bilaterally. It was a case of bilateral fusion of mandibular primary lateral incisors and canines of the Complete type with congenitally absent mandibular permanent lateral incisors. Only 13 such cases have been previously reported in literature.

Kabuki make-up (Niikawa-Kuroki) syndrome: dental and craniofacial findings in a Brazilian child

This article reports the case of a Brazilian child diagnosed with Kabuki make-up syndrome (KMS), addressing the clinical features observed, with emphasis on the disease-specific oral and craniofacial manifestations. The patient had the distinctive KMS craniofacial appearance, mild delayed mental development, fingers with prominent fingertip pads and visual deficit. The dental findings included fusion of the left mandibular incisors (central and lateral), gemination of the right mandibular central incisor and congenital agenesis of the right mandibular lateral incisor, in the primary dentition, as well as absence of both permanent mandibular lateral incisors. Fusion and gemination have not been previously referred to as typical dental features in KMS. The detection of unique dental findings, such as missing teeth and dental anomalies of form in the primary dentition by means of clinical and radiographic examinations, might consist of a helpful diagnosis parameter in identifying children who may have milder forms of Kabuki syndrome.

Loss of permanent mandibular lateral incisor and canine tooth buds through extraoral sinus: Report of a case

Extraoral sinus tract may occur as a result of an inflammatory process associated with the necrotic pulp. Several non odontogenic disorders may also produce an extraoral sinus tract, the differential diagnosis of these clinical findings is of prime importance in providing appropriate clinical care. Presented here is a case report of 4 year old female child with extraoral sinus tract through which the tooth buds of mandibular permanent left lateral incisor and mandibular permanent left canine were lost. The extraoral sinus was due to mandibular left primary canine with class IX fracture (Ellis and Davey's classification).

The ectopically erupted mandibular lateral incisor

Seven cases of ectopically erupting permanent mandibular lateral incisors are reported and their orthodontic management is described. In severely crowded cases the ectopic lateral incisor was extracted. When complete transposition occurred, the teeth were aligned in their transposed positions. If malposition is detected early, orthodontic correction may prevent development of a transposition. Panoramic survey of the developing dentition at the age of 6 to 8 years is a very useful tool in the early detection of this as well as many other dental developmental anomalies.

Dental caries: Distribution, by age-group, between the mesial and distal surfaces of human permanent mandibular incisors

We describe the distribution of dental caries (decayed or filled—DF), by age-group, between the mesial and distal surfaces of permanent mandibular central and lateral incisors. In the central incisors, the distribution of attacks of caries (DF) between the mesial surfaces only, the mesial and distal surfaces of the same tooth, and the distal surfaces only, remains almost constant with age from 15 yr and upwards. Lateral incisors exhibit a very different anatomical distribution of caries with age. The percentage of attacks (DF) affecting mesial surfaces only, declines slightly with advancing age; the percentage affecting mesial and distal surfaces of the same tooth declines markedly with age; and that affecting distal surfaces only, increases markedly with age. It is inferred that these observations are inconsistent with the notion that acid determines the specific anatomical siting of attacks of caries. The autoaggressive theory of the aetiology and pathogenesis of dental caries provides a quantitative interpretation of these data.