双期和单期矫治Ⅱ类错(牙合)儿童临床随机对照试验的系统评价

目的对于Ⅱ类错(牙合)儿童,采用双期或者单期矫治仍然存在争议,有必要对比较这两种治疗方案疗效的临床随机对照试验进行系统评价.资料来源我们搜索了MEDLINE和Cochrane中心注册资料库所收录发表的临床随机对照试验,不设发表语言限制,并且检索了所有相关文章的参考文献.评价方法本文最终收录了两篇临床随机对照试验,包括451个患者.对其方法学质量进行了评价,用头影测量、PAR指数、拔牙率和外科手术率指标衡量结果.由于资料不充分,没有做Meta分析,对结果进行描述总结.结果对于Ⅱ类错(牙合)的青春期儿童,两个临床随机对照试验都没有显示双期矫治优于单期矫治的疗效.结论尚缺乏比较儿童Ⅱ类错(牙合)双期和单期治疗并全面报告其相关临床结果的随机对照试验研究.现有的证据表明双期矫治相比较于单期矫治疗效没有差异.需要更多的临床随机对照试验来指导临床决策.     

Timing the early treatment of Class II,division 1 malocclusion — Clinical and research considerations

The aim of this study was to evaluate the correlation between timing of emergence of the permanent teeth and sagittal occlusal changes in children enrolled in a prospective clinical trial of Class II, division 1 treatment. The children, ages 7.2–13.3 years, met strict inclusion criteria and were assigned at random to treatment with either a headgear or a Fränkel functional appliance. Relationships between maxillary and mandibular first molars and canines, as well as overjet, were measured with digital calipers on casts made every 2 months and mounted on a SAM II articulator. The emergence of a permanent tooth was scored on a scale from 1 to 3, depending on the eruptive level of the tooth from cutting through the gingiva (1) to reaching the occlusal table (3). Specifically, emergence of the second premolars (PM2) and permanent second molars (M2), the most adjacent teeth to the first molars, was evaluated as it interacted with the development of the sagittal occlusion. Treatment of the distocclusion was as effective in late childhood as in mid-childhood. Within each appliance group, the emergence of PM2 and M2 did not affect the amount of progress toward Class I significantly (p> 0.05), indicating that improvement from distocclusion to neutrocclusion with each appliance is not influenced by the timing of emergence of these teeth. Although these findings support a one-phase treatment starting in the late mixed dentition, earlier intervention in mid-childhood may be required in the presence of several developmental conditions, or when the dental and skeletal development deviate significantly in the individual patient.     

A custom mandibular distraction device for the rat

In the last several years, the rat model has been used as a reliable means of studying distraction osteogenesis (DO). This model has several benefits, including lower cost, the availability of molecular reagents for the rat, and the ability to perform a large number of operations in a short time. We have recently developed an external device that is custom-made for the rat mandible and secured at the mandibular ramus. The device consists of a Leone (Florence, Italy) jackscrew distraction assembly (0.2 mm per one-quarter turn), 2 Luhr L-shaped 0.8-mm five-hole microplates, and four 0.8-mm x 3-mm microscrews (Stryker-Leibinger Corp., Kalamazoo, MI) for fixation. Additionally, there is a methylmethacrylate block that is placed on the lingual surface of the angle of the mandible to support the posterior screws. Sterile surgical technique was used, and the same two surgeons performed all operations. To date, we have operated on 153 Sprague-Dawley rats. The procedure has been well tolerated by the animals. We had 17 postoperative deaths (11% mortality), largely as a result of anesthetic complications. There were no wound infections or dehiscence. A mandible fracture was noted in 6 rats (4%), which occurred at the time of device placement. There were no device dislodgments. Postmortem examination showed the device to be well positioned in all rats, with good callous formation at the distraction site. The rats surpassed their preoperative weight after an average of 9.2 days. These results compare favorably with those of other models currently in use. We have developed a device that is currently being used in the study of DO in the rat mandible. Our device is small in size, does not require wide undermining for its placement, and has had a low incidence of device dislodgment or infection. This model has shown great reproducibility and thus should be effective in its application for the histologic and biochemical investigation of DO in the rat.     

Severe proliferative congenital temporomandibular joint ankylosis: a proposed treatment protocol utilizing distraction osteogenesis

The classical treatment for temporomandibular joint (TMJ) ankylosis in children: 1) joint release; 2) arthroplasty; 3) reconstruction; and 4) postoperative physical therapy (PT), is often unsuccessful. Postoperative physical therapy is difficult in the young patient due to poor cooperation. Moreover, there is a subgroup of patients who have a refractory congenital proliferative bony process that is the cause of their disease. In these patients, a role for distraction osteogenesis (DO) has been defined. We present a series of young patients with congenital proliferative TMJ ankylosis. Some have failed classic treatment. In such cases, DO is used to expand the mandibular size and soft tissue matrix. This creates a static open bite, facilitates mid-facial growth, and avoids compromise of the airway, speech, nutrition, and oral hygiene. To maintain these objectives, mandibular DO may be repeated as the child matures. Once skeletal maturity is reached, DO is used to normalize occlusion and further expand the soft tissue envelope prior to definitive reconstruction and aggressive post-op PT. In seven patients, this protocol has been used. Five patients are currently in the active phase of growth and undergoing interim treatment with mandibular DO. Two patients have reached skeletal maturity and have completed the protocol of DO with definitive arthroplasty and reconstruction. DO is a valuable aid in the treatment of the problematic child with congenital proliferative TMJ ankylosis. Interim DO, prior to definitive arthroplasty and reconstruction, can provide a static open bite that prevents progressive deformity and its associated functional disturbances.     

Squamous cell carcinoma of the gingiva presenting as localized periodontal disease.

Gingival squamous cell carcinoma represents less than 10% of diagnosed intraoral carcinoma. Many unique features of gingival squamous cell carcinoma clearly delineate it from oral squamous cell carcinoma arising in other sites. This article presents the clinicopathologic findings of a case. An 81-year-old woman presented for evaluation of multiple oral lesions primarily limited to the maxillary gingiva; the lesions had been present for about 2 years. Differential diagnosis included epithelial dysplasia, benign mucous membrane pemphigoid, inflammatory lesion of endodontic/periodontic origin, lichen planus, and squamous cell carcinoma. Clinical examination revealed extensive erythematous and ulcerative lesions of maxillary buccal and palatal gingiva extending into the maxillary buccal vestibule; the lesions did not respond to antibiotic therapy. Radiographic evaluation demonstrated advanced alveolar bone loss as well as displacement of the maxillary right first molar. Subsequent histology confirmed diagnosis of moderately differentiated squamous cell carcinoma. Gingival squamous cell carcinoma can mimic a multitude of oral lesions, especially those of inflammatory origin. In addition, predisposing and presenting factors are different from those of other oral squamous cell carcinomas. Careful examinations as well as routine biopsy are crucial for accurate diagnosis.     

Clinical complications with implants and implant prostheses

The purpose of this article is to identify the types of complications that have been reported in conjunction with endosseous root form implants and associated implant prostheses. A Medline and an extensive hand search were performed on English-language publications beginning in 1981. The searches focused on publications that contained clinical data regarding success/failure/complications. The complications were divided into the following 6 categories: surgical, implant loss, bone loss, peri-implant soft tissue, mechanical, and esthetic/phonetic. The raw data were combined from multiple studies and means calculated to identify trends noted in the incidences of complications. The most common implant complications (those with a greater than a 15% incidence) were loosening of the overdenture retentive mechanism (33%), implant loss in irradiated maxillae (25%), hemorrhage-related complications (24%), resin veneer fracture with fixed partial dentures (22%), implant loss with maxillary overdentures (21%), overdentures needing to be relined (19%), implant loss in type IV bone (16%), and overdenture clip/attachment fracture (16%). It was not possible to calculate an overall complications incidence for implant prostheses because there were not multiple clinical studies that simultaneously evaluated all or most of the categories of complications. Although the implant data had to be obtained from different studies, they do indicate a trend toward a greater incidence of complications with implant prostheses than single crowns, fixed partial dentures, all-ceramic crowns, resin-bonded prostheses, and posts and cores.     

Lichen planus evoked by periodontal surgery

A case of Lichen Planus (LP) following periodontal surgery in a patient previously free of the disease is described. Genetic predisposition and lymphokine secretion stimulated by local trauma are suggested as a possible mechanism of the phenomenon. It is recommended that LP patients, especially those suffering from the erosive type, should be treated as conservatively as possible, minimizing the possibility of trauma to the oral tissues where local immunity may have been altered by a pathological process.     

MB2 in maxillary second molar.

Occurrence of the second mesiobuccal canal (MB2) is a frequent finding. Literary reports have shown it to be found more in the cases of the maxillary first molar. However the maxillary second molars have also been found with this variation in a number of canals. This paper presents a case report on the occurrence of a second mesiobuccal canal or the MB2 in the maxillary second molar.     

Prevalence of dental caries and quality of restorations among new immigrants to Israel

The purpose of the present investigation was to gather information on the prevalence of dental caries and the quality of restorations of new immigrants to Israel, and to compare those two categories among immigrants from different regions of origin. New immigrants, residents of four absorption centers in Israel, were included in the study. Altogether, 1,031 immigrants (417 Eastern European, 338 Western European/North American and 276 South American) were examined. The results indicate that new immigrants to Israel from Eastern Europe are affected with more carious teeth (D), are missing more teeth (M), and have received quantitatively less treatment (F) than immigrants from Western Europe/North American and South America. The South America are an intermediate group. A similar distribution was found between the groups by their respective ages. The quality of dental restoration was found to be statistically higher among immigrants from Western European/North American and South American origins with the latter group exhibiting an intermediate level of quality of dental restorations.