X trisomy in an infertile bitch: cytogenetic, anatomic, and histologic studies.
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Three copies of the X chromosome were identified in a 5-year-old mixed breed infertile bitch. One year after the cytogenetic examination, the bitch died due to gastritis hemorrhagica, an inflammation of the mucus coat of the stomach. Dental studies showed congenital lack of some premolar and molar teeth. Ovaries were of normal shape and size. Also, histologic sections of the ovaries revealed their normal structure, with two corpora lutea and primary follicles. Phenotypic effects of X trisomy are discussed. (+info)
Persistence of deciduous molars in subjects with agenesis of the second premolars.
(2/197)
The purpose of the present study was to investigate persistent primary second molars in a group of young people in their late twenties with agenesis of one or two second premolars. In 1982-83 it was decided, in connection with the orthodontic evaluation of 25 patients, to allow 35 primary molars (one or two in each patient) to remain in situ. All patients had mixed dentitions and agenesis of one or two premolars. The primary teeth were generally in good condition, although root resorption and infra-occlusion (compensated by occlusal composite onlays) occurred. In 1997, 18 of the 25 patients with a total of 26 retained primary molars were reexamined, comprising a clinical examination for exfoliation, extraction, loosening, and ankylosis, and a radiographic examination for root resorption, tooth morphology (crown and root), and alveolar bone contour. The examination showed that the degree of root resorption was unaltered in 20 of the 26 primary molars. In the permanent dentitions, where these primary molars persisted, there were no morphological deviations. Three of the six remaining primary molars had been extracted and three showed extensive resorption. In three of the 26 primary molars the infra-occlusion had worsened. The present study shows that persistence of primary second molars in subjects with agenesis of one or two premolars, and normal morphology of the permanent dentition can be an acceptable, semi-permanent solution for the patient. Whether this could also be an acceptable long-term solution will be shown by follow-up studies. (+info)
The long-term survival of lower second primary molars in subjects with agenesis of the premolars.
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This study investigated 41 subjects, 13 male and 28 female, with agenesis of one or both lower second premolars, and with retained lower second primary molars. Intra-oral radiographs of 59 primary teeth were examined to judge the resorption of the mesial and distal roots, and were measured to record infra-occlusion of the primary teeth and tipping of the adjacent permanent teeth. The study commenced at 11-12 years of age. The mean age at the last measurement was 20 years 6 months (SD 3.62, range 13.6-31.8 years). During the observation period, only two of the 59 primary teeth were exfoliated. Five were extracted, two of which were replaced by upper third molar transplants. Beyond the age of 20 years no teeth were lost. Root resorption varied widely between individuals, but was slow. There was no typical pattern for development of infra-occlusion. Mean infra-occlusion was 0.47 mm (SD 1.13) at 11-12 years, increasing by less than 1.0 to 1.43 mm (SD 1.13) at age 17-18 years. At age 19-20 years, 55 per cent of teeth showed infra-occlusion between 0.5 and 4.5 mm, but 45 per cent showed no infra-occlusion. The space between the first molar and first premolar was a mean of 10.35 mm (SD 0.76) at age 10-12 years compared with the mean width of the second primary molar of 10.53 mm (SD 0.51). The space reduced by less than 0.5 mm to 9.95 mm (SD 1.50) at age 17-18 years. If primary molars are present at 20 years of age they appear to have a good prognosis for long-term survival. (+info)
An analysis of the skeletal relationships in a group of young people with hypodontia.
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The objective of this investigation was to examine the dentofacial features of a group of patients with hypodontia, in particular assessing whether cephalometric analysis confirmed the clinical assumption of a reduced lower face height, and to determine the relationship of these facial features with different numbers of missing teeth. It took the form of a cephalometric study, undertaken in a dedicated Dental Hospital clinic for patients with hypodontia. The study group comprised 59 patients seen on the Hypodontia Clinic: 32 females, 27 males, mean age 13.1+/-3.1 years (range 6-23 years). The average number of missing teeth was 7 (SD 5), ranging from 1 to 21. The mean SNA, SNB, and MMA angles were within normal limits, but there was a statistically significant reduction in the MMA when more than one tooth type was missing (P = 0.007) and the ANB angle decreased as the number of missing tooth types increased (P = 0.034). The mean values for the whole sample were within the normal range and did not demonstrate any feature specific to the group, but patients with more severe hypodontia showed tendencies to a Class III skeletal relationship and a reduced maxillary-mandibular planes angle. (+info)
Congenitally missing maxillary lateral incisors and orthodontic treatment considerations for the single-tooth implant.
(5/197)
Implant restorations have become a primary treatment option for the replacement of congenitally missing lateral incisors. The central incisor and canine often erupt in less than optimal positions adjacent to the edentulous lateral incisor space, and therefore preprosthetic orthodontic treatment is frequently required. Derotation of the central incisor and canine, space closure and correction of root proximities may be required to create appropriate space in which to place the implant and achieve an esthetic restoration. This paper discusses aspects of preprosthetic orthodontic diagnosis and treatment that need to be considered with implant restorations. (+info)
Survey of dental treatments for pediatric patients referred to the pediatric dental clinic of a dental school hospital.
(6/197)
This survey was conducted to clarify which dental treatments in children are regarded as difficult by general dentistry practitioners. The subjects were 615 children who first visited Tokyo Dental College Chiba Hospital from January 1995 to August 1999 with reference letters. There were 615 children in the study; 571 (92.8%) came from Chiba City where our hospital is located and the 11 regions surrounding Chiba City. The prime reasons for referral in the order of frequency were treatments of dental caries, malalignment/malocclusion, traumatized teeth, supernumerary teeth, retarded eruption/impacted teeth, abnormal direction of erupted teeth, congenitally missing teeth, prolonged retention of deciduous teeth, and abnormal frenulum. Patients with dental caries or traumatized teeth in the deciduous dentition period and those with malalignment/malocclusion, supernumerary teeth, or retarded eruption/impacted teeth in the mixed dentition period were often referred to medical organizations specializing in pediatric dentistry because of the difficulties in controlling the patients' behavior and in providing adequate treatment. The information about pediatric dental treatments considered difficult by general dentists revealed by this survey appears to be useful and needs to be incorporated in the programs for clinical training of undergraduate students and education of postgraduate students. (+info)
The congenitally missing upper lateral incisor. A retrospective study of orthodontic space closure versus restorative treatment.
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Orthodontic treatment for patients with uni- or bilateral congenitally missing lateral incisors is a challenge to effective treatment planning. The two major alternatives, orthodontic space closure or space opening for prosthetic replacements, can both compromise aesthetics, periodontal health, and function. The aim of this retrospective study was to examine treated patients who had congenitally missing lateral incisors and to compare their opinion of the aesthetic result with the dentists' opinions of occlusal function and periodontal health. In this sample, 50 patients were identified. Thirty had been treated with orthodontic space closure, and 20 by space opening and a prosthesis (porcelain bonded to gold and resin bonded bridges). The patient's opinion of the aesthetic result was evaluated using the Eastman Esthetic Index questionnaire and during a structured interview. The functional status, dental contact patterns, periodontal condition, and quality of the prosthetic replacement was evaluated. In general, subjects treated with orthodontic space closure were more satisfied with the appearance of their teeth than those who had a prosthesis. No significant differences in the prevalence of signs and symptoms of temporomandibular dysfunction (TMD) were found. However, patients with prosthetic replacements had impaired periodontal health with accumulation of plaque and gingivitis. The conclusion of this study is that orthodontic space closure produces results that are well accepted by patients, does not impair temporomandibular joint (TMJ) function, and encourages periodontal health in comparison with prosthetic replacements. (+info)
Face, palate, and craniofacial morphology in patients with a solitary median maxillary central incisor.
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The occurrence of a solitary median maxillary central incisor (SMMCI) is a very rare condition and might be a sign of a mild degree of holoprosencephaly. In this investigation, material from 10 patients, nine girls and one boy with a SMMCI (8-17 years of age) registered in orthodontic clinics was examined. The purpose was to evaluate the clinical characteristics and craniofacial morphology in this group of patients. Oral photographs, study casts, profile radiographs, and orthopantomograms were analysed. The study showed that this group of SMMCI patients were characterized by an indistinct philtrum, an arch-shaped upper lip, absence of the fraenulum of the upper lip, a complete or incomplete mid-palatal ridge, a SMMCI, and nasal obstruction or septum deviation. The craniofacial morphology of the nine girls, compared with normal standards for girls showed a short anterior cranial base, a short, retrognathic and posteriorly inclined maxilla, and a retrognathic and posteriorly inclined mandible. Furthermore, the sella turcica had a deviant morphology in five of the 10 subjects. The results indicate that the presence of a SMMCI should not be considered as a simple dental anomaly, since it may be associated with other clinical characteristics and more complex craniofacial malformations. It is therefore suggested that the SMMCI condition in future studies is classified according to clinical symptoms and craniofacial morphology. (+info)