Anodontia

The purpose of this study was to evaluate the dimensional changes of the alveolar ridge in patients with congenitally missing maxillary lateral incisors. The width and height of the alveolar ridge were compared before and after opening space for an endosseous dental implant between the central incisor and canine. Pre- and post-treatment dental stone models of 31 patients (8 males, 23 females; mean age 15.1 ± 7.9 years pre-treatment, 17.6 ± 8 years post-treatment) with unilaterally or bilaterally, congenitally missing maxillary lateral incisors were used in this study. Pre- and post-treatment measurements included: the space between the maxillary central incisor and canine, the depth of the labial concavity, and the width and height of the lateral incisor alveolar ridge. Two different techniques were used to measure the ridge width. Student's paired samples t-test was used to test for significance. The alveolar ridge underwent statistically significant width loss (Method 1: 4-8 per cent, Method 2: 13-15 per cent) during the course of orthodontic treatment. A 6-12 per cent loss in ridge height was also noted. The depth of the labial concavity between the maxillary central incisor and canine nearly doubled. There was a significant decrease in the width and height of the alveolar ridge in patients congenitally missing a maxillary lateral incisor who received orthodontic treatment to create space for an endosseous dental implant.

Certain discrete malpositions of the human canine tooth and agenesis of at least 1 tooth (hypodontia) are abnormalities known to occur together frequently. This study examines the specificity of tooth-agenesis sites associated with the occurrence of 3 unambiguous canine malpositions: palatally displaced canine (PDC; n = 58), mandibular lateral incisor-canine transposition (Mn.I2.C; n = 60), and maxillary canine-first premolar transposition (Mx.C.P1; n = 43). A fourth sample was formed from 4 cases of combined occurrence of PDC and Mn.I2.C, the only combination-phenotype noted among the 161 subjects. Oral panoramic radiographs were used to identify agenesis of at least 1 third molar (M3), mandibular second premolar (MnP2), and maxillary lateral incisor (MxI2)-the 3 most frequently absent tooth types among people of European descent. PDC and Mn.I2.C transposition appear to be associated with significantly increased M3 agenesis (P <.01), representing the posterior orofacial field, and Mx.C.P1 transposition appears to be associated with conspicuously elevated MxI2 agenesis (P <.001), representing the anterior orofacial field. MnP2 agenesis appears to represent an intermediate field, found in significantly elevated frequencies with all 3 canine positional anomalies. Coupling these new clinical findings with results from recent molecular studies, we suggest that transcription factors such as MSX1 and PAX9, which have been associated with agenesis of molars, might be involved in the genetic control of Mn.I2.C transposition and PDC, tooth malpositions connected here with the specific expression of posterior-field (M3) hypodontia.

The objective of this article is to describe the various clinical situations of prolonged retention of mandibular deciduous second molars. Indications for orthodontic space closure in the absence of permanent successors and treatment alternatives in space opening, including retaining the deciduous molars, are described. Periodic monitoring, composite buildups, and indications and timing of extraction of infraoccluded and ankylosed deciduous molars with and without permanent successors are reviewed.

To compare the biological, technical and aesthetic outcomes of single implant-supported all-ceramic versus metal-ceramic crowns. Thirty-six patients with premolar agenesis were randomly treated with 38 all-ceramic (AC) and 37 metal-ceramic (MC) implant-supported single-tooth restorations. A quasi-randomisation of consecutively included restorations in patients with one or more implants was used, i.e. a combination of parallel group (for 13 patients with one restoration) and split-mouth (for 23 patients with ≥2 restorations). All patients were recalled for baseline and 1-year followup examinations. Biological and technical outcomes, including complications, were clinically and radiographically registered. The Copenhagen Index Score and visual analogue scale (VAS) score were used to assess professional and patient-reported aesthetic outcomes, respectively, by blinded assessors. One-year after loading, no patient dropped out and no implant failed, though one MC restoration had to be re...

This clinical report describes the 5-year follow-up treatment of an 11-year-old boy with ectodermal dysplasia. The dentition was initially restored with a combination of maxillary anterior-bonded composite restorations and a mandibular complete denture. This individualized approach allowed successful management of the patient.

Prosthodontic treatment in patients with ectodermal dysplasia (ED) is difficult to manage because of the oral deficiencies typical in this disorder and because afflicted individuals are quite young when they are evaluated for treatment. This clinical report describes an 18-year-old patient with hypohidrotic ED treated with dental implants. Treatment included a maxillary implant overdenture and a mandibular hybrid prosthesis supported by osseointegrated implants. At the one-year follow-up, the patient presented significant improvements in oral function and psychosocial activities.

Concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition. The presence of this condition in the same area of dental arch and specifically in the mandibular anterior region is reported very infrequently. This case report presents a case of 20 years old male with congenitally missing permanent mandibular central incisors in conjunction with a mandibular midline supernumerary tooth. Only 3 cases have been documented in English literature till date. The article focuses on the review of mandibular mesiodens and the clarity regarding the usage of the terminology "mesiodens".

Down syndrome (DS) is an autosomal chromosomal anomaly which results from trisomy of all or part of chromosome 21. It is the single most common genetic cause of mental retardation affecting approximately 1 in 700 live births. Since its first description in 1866 by John Langdon Down, much research has focused on this condition. In the past two decades there has been a significant increase in information about its causes, diagnosis and medical and dental consequences. In this, the first of two articles, we pay tribute to the work of Harvey Brown, and we review the pathogenesis, general and cranio-dental features of Down Syndrome. The cause of DS is usually non-dysjunctive trisomy 21, with 91 percent of cases being maternally derived. Uncommon causes are mosaicism or translocation from other chromosomes. DS patients suffer from congenital cardiopathies, growth retardation, endocrinopathies, sleep apnoea, neoplasias and early-onset Alzheimer's disease. Typically, craniofacial featur...

The GAPO syndrome is an extremely rare autosomal recessive disease that presents as main characteristics evident growth retardation, alopecia, pseudoanodontia, progressive optic atrophy and a typical face. Until now, only 30 patients have been reported in the medical literature (nine of them from Brazil, including the three cases described in the present article). This study describes three siblings with GAPO syndrome, two female and one male, the children of consanguineous parents (first-degree cousins, inbreeding F = 1/16), who are older than the previously described patients, presenting the characteristic phenotype besides serious bone alterations in the lower limbs, which had not yet been observed. © 2008 Wiley-Liss, Inc.