离体牙上釉珠的观测与临床意义

本文从12379枚离体牙上观测了釉珠的发生率、发生部位、形态、直径大小。结果釉珠的发生率为2.49％,以上颌第三磨牙发生率最高,下颌第一磨牙次之。最常发生的部位是在冠颈部的根分叉处,上颌磨牙的釉珠多呈园形,下颌磨牙釉珠多呈梭形。釉珠最大直径为3.2mm,最小为0.5mm,平均为1.56mm。结合文献认为釉珠是一种牙齿形态发育异常,它对牙周病的发生、发展、治疗与预后有重要影响,口腔科医师对这种牙齿形态变异应予以重视。     

口外弓配合唇档远移磨牙的临床研究

目的:研究口外弓配合唇档远移磨牙的临床应用及其疗效。方法:选择15例恒牙早期上颌轻度牙性前突或轻、中度拥挤的安氏II类患者,应用口外弓配合唇档,通过X线头影测量观察其上颌磨牙及前牙治疗前后变化情况。结果:应用口外弓配合唇档推磨牙向远中3～6个月后,II类咬合关系恢复至安氏I类关系。上颌第一磨牙向远中平均移动4.14mm,上颌中切牙向唇侧移动0.66mm。结论:只要病例选择合适,方法运用得当,口外弓配合唇档就能获得较满意的远移磨牙的疗效。     

Fusion or gemination? An unusual mandibular second molar

Fusion and gemination is not an uncommon finding and affected most primary dentition and the permanent maxillary incisors. These changes can develop a series of complication. A 11-year-old male presented radiography finding: an unusual mandibular second molar. A well-documented case brings a challenge for radiologists classify between fusion and gemination. In conclusion, this alteration although common in other regions, there are no case in the literature involving “second and third” molar.     

Clinical applications of miniscrews that broaden the scope of non-surgical orthodontic treatment

Previously, in the case of malocclusion owing to skeletal discrepancy in adults, the amount of tooth movement was limited since there was no reliable skeletal anchorage device. The only way to treat this case was by repositioning the maxilla and mandible via orthognathic surgery, but most patients are reluctant to undergo surgery owing to the risk and expenses incurred. However, with the current introduction and use of miniscrews as temporary anchorage devices, the entire dental arch can be relocated to a target position without surgery, thus broadening the scope of non-surgical orthodontic treatment compared to the past. For a non-surgical approach to improve skeletal discrepancy, anteroposterior, vertical and transverse displacements of the dental arch are necessary. In this case, the localization of the centre of resistance of the whole arch must precede the appliance design with an appropriate biomechanical design. Especially, in the transverse dimension, the envelope of discrepancy is reportedly narrow, and the tooth movement must accompany the orthopaedic correction involving the midpalatal suture expansion. Recently, in adults with transverse maxillomandibular discrepancy, miniscrew-assisted rapid palatal expansion (MARPE) can be performed. Moreover, compared to surgically assisted rapid palatal expansion, MARPE reduces the cost to the patient and achieves clinically acceptable stable maxillary expansion. In this article, we will discuss the role of total arch movement and MARPE in widening the scope of non-surgical orthodontic treatment, despite the inherent limitations of miniscrews' mechanical aspects.     

Dentoskeletal changes following mini-implant molar intrusion in anterior open bite patients

Objective:To evaluate skeletal and dental changes after intrusion of the maxillary molars in subjects with anterior open bite.Materials and Methods:This retrospective cephalometric study evaluated skeletal and dental changes resulting from the use of maxillary orthodontic mini-implants in 31 consecutively treated patients. Radiographs were taken at the start and end of maxillary molar intrusion to evaluate the associated changes. Statistical analysis was performed using a one-sample t-test.Results:The mean treatment observation time was 1.31 years (SD  =  2.03). The maxillary first molars (P  =  0.0026) and second molars (P  =  0.039) were intruded. However, the mandibular first molars (P  =  0.0004) and second molars (P  =  0.003) erupted in adolescent patients. Both the maxillary and mandibular first molars inclined distally (P  =  0.025 and P  =  0.044, respectively). The mandibular plane angle decreased (P  =  0.036), lower facial height decreased (P  =  0.002), and the occlusal plane angle increased (P  =  0.009). The overbite increased (P < .0001). The ANB angle decreased (P < .0001). Mandibular dental and skeletal changes were more apparent in adolescents, while adults tended toward maxillary changes.Conclusions:Vertical traction from orthodontic mini-implants reduces the maxillary posterior dentoalveolar height, thereby assisting orthodontic closure of anterior open bite. However, simultaneous eruption or extrusion of the mandibular molars should be controlled. Adolescent patients tend to demonstrate more favorable effects of mandibular autorotation than do adults.     

Temporomandibular disorders with skeletal open bite treated with stabilization splint and zygomatic miniplate anchorage: A case report

This case report describes the treatment of a patient with temporomandibular disorder (TMD) and skeletal open bite. First, the patient was treated with a stabilization splint to stabilize the condyles in centric relation and to alleviate TMD signs and symptoms. After making a definitive diagnosis from postsplint records, orthodontic treatment was initiated. Titanium miniplates were placed at bilateral zygomatic buttresses and used as orthodontic anchorage for molar intrusion and distalization. The treatment was completed after 30 months. Satisfactory appearance and function were achieved for this patient.     

微种植体支抗联合自制式滑动杆单侧推磨牙向后的临床应用

目的：探讨运用微种植体支抗联合自制式滑动杆单侧推磨牙向后的应用要点。方法：选择安氏Ⅱ类亚类错牙合7例(男2例,女5例),年龄15～30岁,平均18.7岁。轻中度拥挤,拥挤度平均4～5mm,或伴上中线偏移,或侧貌较突者。采用单侧植入微种植体支抗钉联合自制式滑动杆推磨牙向后,恢复上下磨牙的中性关系,保持上颌磨牙两侧对称,推力250g。疗程3～5个月,平均4个月。通过临床评价和矫治前后的照片和模型分析其治疗的有效性。结果：7例患者有效地应用微种植体支抗联合自制式滑动杆单侧推磨牙向后,矫正了单侧磨牙Ⅱ类远中关系、轻中度拥挤、中线偏移或恢复上颌磨牙两侧对称,取得较好的临床疗效。远移侧上颌第一磨牙远中平均移动4.2mm,平均移动速度1.05mm/月。结论：微种植体支抗联合自制式滑动杆单侧推磨牙向后,发挥了绝对强支抗作用,有效地远中移动上颌磨牙,容易取得患者配合,取材容易制作简便,有临床推广价值。     

微种植体支抗远中移动下颌牙列的临床体会

目的利用微种植体支抗远中整体移动下颌牙列,并对其临床疗效及长期稳定性作一初步的探讨。方法选择9例需要远中移动下颌牙列的患者,在下颌第一磨牙和第二前磨牙间植入微种植体,利用微种植体远中移动下颌牙列。测量治疗前后的硬组织变化及下颌第一磨牙牙冠远中移动量,并作统计学分析。结果 9例患者均达到理想的治疗效果,达到正常的前牙覆牙合、覆盖及后牙咬合关系。∠SNA、∠SNB、PFH(mm)减小及∠FMA增加均没有显著性意义,∠IMPA、L1-NB(°)、L1-NB(mm)减小有显著性意义,下颌第一磨牙牙冠平均远中移动3.99 mm。结论运用微种植体支抗可以到达远中移动下颌牙列的目的,且临床效果稳定。     

Nonsurgical and nonprosthetic camouflage treatment of skeletal Class II open bite with bilaterally missing lower first molars

This report illustrates the successful nonsurgical and nonprosthetic camouflage treatment of a skeletal Class II open bite malocclusion combined with missing mandibular first molars bilaterally. In the mandible, the second and third molars were uprighted and protracted, substituting for the missing first molars. In the maxilla, anterior bodily retraction and full-arch intrusion were achieved following premolar and second molar extraction, which also induced autorotation of the mandible. The treatment outcome and prognosis were confirmed with three-dimensional superimposition techniques, along with long-term stability.