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1.
Congenitally missing lateral incisors are not a rarity in any dental practice, yet the treatment for this condition is usually a challenge. Various treatment possibilities and their indications, contraindications, and problems are discussed. A case report involving orthodontic treatment followed by placement of implants and single-tooth porcelain-fused-to-metal crowns.  相似文献   

2.
New developments are constantly introduced in the search for the optimal treatment modality to restore a single anterior tooth. The patient attention has shifted to aesthetics of the restoration, biocompatibility of the dental materials utilized, conservative preparation of the teeth to be restored, and the retention of intact adjacent dentition. The learning objective of this article is to review the methods currently utilized and to present a recently introduced treatment modality--the two-component bridge, which combines the strength and resiliency of composite resin with the aesthetic advantages of porcelain. The technology of the material is reviewed, the predominantly lingual tooth preparation procedures are outlined, and the bridge try-in is described. The advantages of the two-component bridge are presented along with the contraindications and suggestions of careful case selection. Three cases with congenitally missing maxillary lateral incisors in youthful patients are presented to supplement the theoretical outline and to describe and illustrate the clinical procedure.  相似文献   

3.
Malformations of the maxillary incisors, diagnosed as dental dysplasia, were observed as a spontaneous background lesion in 3% (females) to 9% (males) of CD-1 mice and 14.5% (females) to 10.5% (males) of CD (Sprague-Dawley) rats in a chronic inhalation study. Lesions were reported grossly as overgrown, maloccluded, or malformed incisors. Microscopic findings included tooth pulp and periodontal abscesses, fractured and necrotic teeth, periodontal cysts, malformations of the incisor roots, and expansile masses, including odontomas, of the incisor roots. Development of lesions followed a pattern of tooth pulp necrosis and/or traumatic disruption of the epithelial root sheath at the base of the tooth. Feeding a powdered ration, which reduced the normal wearing of the incisors, and repeated clipping of overgrown incisors were believed to contribute to the incidence of disease.  相似文献   

4.
470 injured teeth of 370 patients who consulted the Dental Clinic of Ege University, Izmir, Turkey for examination or treatment between 1981-1993 were evaluated. Information concerning sex, age of patients at the time of injury, cause of trauma, number of injured teeth, type of tooth and type of trauma were recorded. More boys suffered traumatic injuries (64.8%) than girls (35.2%). Patients aged 11-15 years old exhibited the highest number of injuries (34.4%) followed by the 6-10 years old group (24.5%). Most injuries involved one tooth (60%) and maxillary central incisors were the most often affected teeth (66.2%). The leading cause of injury was undefined falls (45.1%). At the initial examination, cases seen after a long posttraumatic period showed more complications than those presented within a short time period. Educational programs about the importance of dental trauma, the benefits of immediate attendance and conservation of avulsed and fractured teeth would be very helpful for patients. Additionally improving the knowledge of the dental practitioner about trauma would be another important point in solving the problem.  相似文献   

5.
Dental trauma occurs very often in children and its consequences vary from tiny fractures to the complete avulsion of the tooth. According to Andreasen, 86.5% of incidents of dental trauma suffered by preschool children cause injury to maxillary primary incisors, whereas only 0.5% cause injury to primary molars. This case report is of a male patient aged 7 years who had fallen down a month before, struck his chin against a step, and fractured the maxillary and mandibular left primary second molars (65 and 75) and the mandibular right primary second molar (85). The 65 required only smoothing of sharp edges, 75 received endodontic treatment and a stainless steel crown, and 85 was extracted and a space maintainer fitted. The early diagnosis of fractures of posterior teeth is very important; a thorough examination of all posterior teeth should be made, especially when child suffers trauma to the chin region.  相似文献   

6.
OBJECTIVES: Reattachment of the avulsed enamel-dentine coronal fragment to the remaining tooth structure has become an accepted clinical alternative to a resin composite build-up for the restoration of crown fractured teeth. Since little knowledge exists as to the pulpal response to this procedure, this study was designed to observe the condition of the pulp following experimentally induced crown fracture and restoration in monkeys. METHODS: Experiments were conducted in eight young green Vervet monkeys (Cercopithecus aethiops). In all, 64 fractured incisors were investigated. Light microscopic examination of pulp tissue specimens was carried out after 3 months of observation. RESULTS: The evaluation was restricted to specimens having a fracture plane within 2 mm of the pulp and no pulpal exposure. In general, pulp tissue was well preserved irrespective of the restorative procedure. Even if the restoration or the bonded tooth fragment had been lost during the follow-up period, the pulp generally remained in good condition. Inflammatory infiltrates where seen in only a few specimens and then as clusters of mononuclear leukocytes. Hard tissue repair was frequently observed and displayed various configurations from isolated hard tissue deposits to areas of extensive hard tissue repair in the coronal portion of the pulp. Pronounced hard tissue repair and occurrence of inflammatory cell infiltrates correlated with the presence of stainable bacteria on the fractured dentine surface. CONCLUSIONS: In the absence of direct exposure, reparative dentine is a frequent feature of the pulp's response to crown fracture and restoration with composite or reattachment of the crown fragment with dentine bonding. These restorative procedures appear to ensure continued function of the underlying pulp.  相似文献   

7.
We present the case of a 26-year-old man who at the age of 9 suffered severe trauma to both maxillary central incisors. The underlying malocclusion was skeletal and classified as dental Class II/1 with severe crowding. Both the maxillary central incisors and the two lower first premolars were extracted and the patient was treated with an edgewise appliance for 2 years. Acceptable occlusal relationships were achieved following orthodontic and adjunctive treatment which consisted of reshaping the maxillary lateral incisors with composite materials and grinding the canines to resemble lateral incisors. A critical evaluation of the esthetic and functional results at the age of 26 years is presented.  相似文献   

8.
Traditionally, the treatment of acid erosion lesions of the maxillary and mandibular dentition has been invasive, often utilizing full-coverage crown restorations. Intentional endodontic and post-and-core treatments have been used in the past to gain crown length for retention of cemented cast restorations. The learning objective of this article is to discuss the primary cause of acid erosion-bulimia nervosa-and present an alternative dental treatment modality. The alternative treatment uses conservative tooth preparation, dentin bonding technology, and pressed ceramic restorations, achieving aesthetic results. The indications and advantages are discussed, and a case report illustrates the clinical procedure. The importance of achieving the cessation of the purging habit as a prerequisite to dental treatment is emphasized.  相似文献   

9.
Information regarding orthodontic service provision by general dental practitioners in Australia is limited. The aim of this survey was to determine the amount and variety of orthodontic services provided by general dental practitioners in the Melbourne Statistical Division, Victoria, Australia. A random sample of 307 dentists drawn from the Victorian Dentists Register was surveyed by mailed questionnaire: 218 (71%) replied. Data were collected using a fortnight log. During this time 59 per cent of the dentists saw at least one orthodontic patient; one dentist saw 66 orthodontic patients. Removable orthodontic appliances were used by 35 per cent of the dentists and fixed orthodontic appliances by 18 per cent. Twenty-six per cent provided comprehensive orthodontic treatment, 22 per cent aligned incisors, and 21 per cent corrected anterior crossbites. The general dental practitioners surveyed provided a wide range of preventive and interceptive orthodontic services to generally a small percentage of their patients.  相似文献   

10.
A considerable body of evidence exists to suggest that genes play a dominant role in the etiology of the dental anomalies reviewed. It has been postulated that some kind of genetically controlled interrelationship may exist for some of these coincidental dental anomalies, as evidenced by their frequency of association. It has also been speculated that a "common genetic defect" may give rise to different phenotypic manifestations, including missing, malformed, and even ectopic and malpositioned teeth. The maxillary teeth that develop in the critical marginal areas of the dental lamina, namely the lateral incisors, canines and second premolars, seem most susceptible. Such dental anomalies may be symptoms of an inheritable developmental disturbance of tooth structures. Knowing that these dental anomalies can be inherited, a familial history and early clinical or radiographic detection of one anomaly, could alert parents and clinicians to the high likelihood of detection of other defects in the same individual and similar defects in other family members. Early diagnosis is important so that interceptive pediatric and orthodontic opportunities in relation to missing, malformed and ectopically erupting teeth are not overlooked. Further family studies are necessary to reveal the mode of inheritance of some of these dental anomalies and twin studies comparing monozygous and dizygous twins would enable an estimation of the extent of their inheritance.  相似文献   

11.
DF Murchison  RB Worthington 《Canadian Metallurgical Quarterly》1998,19(7):731-4, 736, 738 passim; quiz 744
Anterior crown fractures in children and adolescents are a common form of injury, affecting approximately 25% of that population. Common restorative treatments such as composite bonding, laminate veneers, or full-coverage restorations tend to sacrifice healthy tooth structure and challenge dentists to match the adjacent unrestored dentition. Incisal edge fragment reattachment, including the use of current bonding techniques, is a restorative treatment option that offers the advantages of simplicity, immediate esthetics, and conservatism in cases of dental trauma. This article presents a comprehensive literature review on this restorative technique. It also provides diagnostic and treatment algorithms to simplify and clarify the recommended diagnostic and clinical regimens.  相似文献   

12.
The purpose of this investigation was to evaluate the treatment effects of an intraoral appliance used for rapid distal movement of the maxillary molars. The appliance studied, the Jones jig, is designed to deliver a distalizing force to the maxillary molar against an intraoral anchorage unit thereby eliminating the need for patient compliance. A retrospective study was performed comparing before and after lateral cephalometric radiographs on 13 patients who were treated for an average of 26 weeks with the Jones jig. The cephalometric radiographs were evaluated to determine if there were significant differences between pretreatment and posttreatment variables that included skeletal, dental and soft tissue relationships. Differences between the pretreatment and posttreatment means were significant for mesial angulation of the premolar anchorage unit (P <.001), distal movement of the maxillary molars (P <.01), mesial movement of the premolar anchorage unit (P <. 01), mesial movement of the maxillary incisors (P <.001), and increased lower anterior facial height (P <.01). The anchorage loss, flared maxillary incisors, and increased facial height are negative treatment effects that should be expected when using this or similar appliance design.  相似文献   

13.
The prevalence of developmental enamel defects and dental caries was assessed in 344 Karen children aged 1-4 years who were chronically (70 per cent) and acutely malnourished (9.3 per cent) The teeth were cleaned with gauze to facilitate detection of hypoplastic lesions on labial surfaces of maxillary incisors. At least one tooth with defective enamel was seen in 31.9 per cent of children, while enamel hypoplasia was present in 22.7 per cent of children. Enamel defects were found in 21.2 per cent of teeth, with hypoplasia and opacities occurring in 14.6 and 6.6 per cent of teeth, respectively. Gender did not alter the prevalence of defects. The upper central incisors were affected more than lateral incisors. The prevalence of dental caries was 31.9 per cent with a mean dt of 1.1. The prevalence of caries associated with enamel hypoplasia was significantly greater than that associated with opacities and sound enamel (P < 0.0005).  相似文献   

14.
PURPOSE OF STUDY: To examine factors which may predispose to tooth fracture, and to assess the compressive strengths of foods and sweets which are associated with tooth fracture in vivo. POPULATION STUDIED: Consecutive dental patients presenting with one or more fractured posterior teeth at the surgeries of three general dental practitioners, over a four-month period. METHOD: A pro forma was designed to elicit information on the factors associated with tooth fracture and the nature and extent of such fractures. Three general dental practitioners were requested to complete a pro forma for each patient presenting with a fractured posterior tooth over a four-month period. Foods and sweets considered to be associated with tooth fracture were identified and their compressive strengths tested. FINDINGS: A total of 129 cases of fractured posterior teeth were recorded, of which 48% occurred in the mandibular arch and 52% in the maxillary arch. In the mandible, 75% of tooth fractures occurred in molars while in the maxillary arch 50% occurred in molars. In 57% of cases assessed, no identifiable causative item was noted. Forty-five per cent of fractures were in teeth which had been restored on three or more surfaces. Compressive forces of 0.16KN to 2.2KN were obtained for food items implicated in tooth fractures. CONCLUSION: As mesio-occlusodistal restorations were identified as a major predisposing factor to tooth fracture in this study, with mandibular first molar teeth particularly affected, placement of cuspal coverage restorations may be considered to be a justifiable preventative measure in teeth identified as being at risk.  相似文献   

15.
A prospective clinical trial was conducted to determine the skeletal and dental contributions to the correction of overjet and overbite in Class III patients. Thirty patients (12 males and 18 females with a mean age of 8.4 +/- 1.7 years) were treated consecutively with protraction headgear and fixed maxillary expansion appliances. For each patient, a lateral cephalogram was taken 6 months before treatment (T0); immediately before treatment (T1); and 6 months after treatment (T2). The time period (T1-T0) represented changes due to 6 months of growth without treatment; (T2-T1) represented 6 months of growth and treatment. Each patient served as his/her own control. Cephalometric analysis described by Bj?rk (1947) and Pancherz (1982a,b) was used. Sagittal and vertical measurements were made along the occlusal plane (OLs) and the occlusal plane perpendicular (OLp), and superimposed on the mid-sagittal cranial structure. The results revealed the following: with 6 months of treatment, all subjects were treated to Class I or overcorrected to Class I or Class II dental arch relationships. Overjet and sagittal molar relationships improved by an average of 6.2 and 4.5 mm, respectively. This was a result of 1.8 mm of forward maxillary growth, a 2.5-mm of backward movement of the mandible, a 1.7-mm of labial movement of maxillary incisors, a 0.2-mm of lingual movement of mandibular incisors, and a 0.2-mm of greater mesial movement of maxillary than mandibular molars. The mean overbite reduction was 2.6 mm. Maxillary and mandibular molars were erupted occlusally by 0.9 and 1.4 mm, respectively. The mandibular plane angle was increased by 1.5 degrees and the lower facial height by 2.9 mm. Individual variations in response to maxillary protraction was large for most of the parameters tested. Significant differences in treatment changes between male and female subjects were found only in the vertical eruption of mandibular incisors and maxillary and mandibular molars. These results demonstrate that significant overjet and overbite corrections can be obtained with 6 months of maxillary protraction in combination with a fixed expansion appliance.  相似文献   

16.
During endodontic treatment of any tooth, aesthetics must be considered in the same manner as during any other dental treatment. The most common aesthetic challenge associated with endodontics is the discoloration of natural tooth structure. The discoloration may be a result of pulp pathosis, especially pulpal hemorrhage prior to or during treatment, or it may be due to various endodontic and restorative materials placed in the pulp chamber. There are several simple measures that can be utilized during and following endodontic treatment to eliminate or reduce aesthetic deficiency. The learning objective of this article is to discuss internal bleaching of discolored pulpless teeth that have been endodontically treated. The discussion includes the chemical composition of bleaching agents and principles by which they function during the bleaching procedures.  相似文献   

17.
The prevalence and yearly incidence of traumatic tooth injury between 1 and 16 years of age were studied in a cohort of 16-year-olds, born in 1975, and residing in the County of V?sterbotten, northern Sweden. The study comprised 3007 dental records from the public dental health service. The general distribution was 50.3% girls and 49.7% boys. The records showed that 35% of the children on one or more occasions had sustained injury to their primary or permanent dentition. The frequency was nearly twice as high for boys (64%) as for girls (36%). Twenty-five percent of the 16-year-olds had met with tooth injury more than once and this group consisted predominantly of boys. The incidence of injury episodes to primary and permanent teeth was 28 per 1000 per year. The boys had sustained trauma to their teeth most frequently when they were 4 years of age and between the ages of 8 and 11. This was also true for girls at 4 and at 9 years of age, although less evidently so. In the primary dentition, the majority of dental injuries had affected the supporting tissue of the maxillary incisors. In the permanent dentition, 75% of the traumatised teeth were upper incisors. Fractures of varying severity constituted 60% of all registered diagnoses in this dentition, followed by subluxation (19%) and concussion (11%).  相似文献   

18.
The standard dental aesthetic index (DAI) is an orthodontic treatment need index based on perceptions of dental aesthetics in the United States. It is a regression equation that links perceptions of the social acceptability of dental aesthetics with the objective intraoral measurements of ten occlusal traits. For the index to be universally acceptable, the perceptions of dental aesthetics in other countries must be similar to those of the United States. This study was designed to determine whether the perceptions of dental aesthetics of Nigerian students are similar to those of different groups of the US population. The same 25 stimuli (photographs of dental configurations, a subset of the 200 stimuli used in deriving the standard DAI equation) were rated for dental aesthetics by Nigerian students. Their ratings were compared with ratings of the same 25 stimuli by US parents, students and orthodontists. Spearman rank-order correlations ranged from 0.75 to 0.84. These correlations were highly significant (P<0.0001), and showed that the perceptions of dental aesthetics of Nigerian students were very similar to those of the US groups. The study therefore concluded that standard DAI could be used as a screening tool and without modification in epidemiological surveys among Nigerians.  相似文献   

19.
The purpose of this article is to summarize the short-term and long-term results of the authors' clinical prospective study on the treatment of Class III malocclusion using the protraction facemask. An attempt is made to answer questions pertaining to this treatment modality. Twenty patients with skeletal Class III malocclusion were treated consecutively with maxillary expansion and a protraction facemask. A positive overjet was obtained in all cases after 6 to 9 months of treatment. These changes were contributed to by a forward movement of the maxilla, backward and downward rotation of the mandible, proclination of the maxillary incisors, and retroclination of the mandibular incisors. The molar relationship was overcorrected to Class I or Class II dental arch relationship. The overbite was reduced with a significant increase in lower facial height. The treatment was found to be stable 2 years after removal of the appliances. At the end of the 4-year observation period, 15 of the 20 patients maintained a positive overjet or an end-to-end incisal relationship. Patients who reverted back to a negative overjet were found to have excess horizontal mandibular growth that was not compensated by proclination of the maxillary incisors. A review of the literature showed that maxillary expansion in conjunction with protraction produced greater forward movement of the maxilla. Maxillary protraction with a 30 degrees forward and downward force applied at the canine region produced an acceptable clinical response. The reciprocal force from maxillary protraction transmitted to the temporomandibular joint did not increase masticatory muscle pain or activity. Significant soft tissue profile change can be expected with maxillary protraction including straightening of the facial profile and better lip competence and posture. However, one should anticipate individual variations in treatment response and subsequent growth changes. Treatment with the protraction facemask is most effective in Class III patients with a retrusive maxilla and a hypodivergent growth pattern. Treatment initiated at the time of initial eruption of the upper central incisors helps to maintain the anterior occlusion after treatment.  相似文献   

20.
The cause of mechanical failure of the fixture component of an osseointegrated dental implant was investigated. The surfaces of five clinical specimens that had fractured were compared to those of new specimens fractured in the laboratory under monotonic and cyclic loads. Scanning electron microscopy revealed striations on the fractured surfaces of the clinical specimens, similar to striations on the laboratory-fatigued specimens and in contrast to the dimpled surfaces on the overloaded specimens. The investigation demonstrated that fractures of the fixture component of this dental implant occurred by fatigue under physiologic loads, with marginal alveolar bone loss around the fixture.  相似文献   

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