下颌后牙区颌骨高度的曲面体层片测量研究

目的:为下颌后牙区牙槽嵴增高术提供临床测量方法及定量指标。方法:对90名50岁以上中老年患者的曲面体层片下颌后牙区不同部位颌骨高度进行了测量。结果:颏孔上缘至牙槽嵴顶高度,有牙侧15.91±1.85mm,无牙侧9.07±2.48mm,平均值相差6.84mm;颏孔区下颌体高度,有牙侧33.64±2.69mm,无牙侧23.65±4.28mm,平均值相差9.99mm;下颌后牙区下颌体高度,有牙侧30.68±2.76mm,无牙侧20.96±4.15mm,平均值相差9.72mm。结论:通过曲面体层片测量颏孔和颏孔后1.0cm颌骨高度,了解下颌后牙区骨量丧失情况,为牙槽嵴增高术提供定量数据,方法简单,位置较恒定。下颌后牙区颌骨垂直吸收7～10mm,可供该区牙槽嵴增高术参考。     

Relationship between size of denture foundation area and resorption of alveolar ridge in the edentulous mandible

summary The relationship between the size of the denture foundation area and the resorption of the alveolar ridge was investigated in 55 edentulous subjects. The denture foundation area was recorded using a modelling compound impression technique with border moulding. Both sides of each edentulous mandible were examined separately, making a total of 110 experimental sides in the study. On a stone cast made from each impression, the size of the superficial denture foundation area and of the projected denture foundation area on the tentative plane of occlusion of each anatomical zone were measured. The vertical height of the alveolar ridge at the lateral incisor and first molar region was also evaluated. The size of the superficial denture foundation area in the antero-lingual and postero-lingual zones showed no significant correlation with the degree of alveolar ridge resorption. The size of the projected denture foundation area on the tentative plane of occlusion in the anterior section showed negative significant correlation with the degree of alveolar ridge resorption. The size of the projected denture foundation area on the tentative plane of occlusion in the posterior section showed no significant correlation with the degree of alveolar ridge resorption.     

Prosthetic evaluation of the sagittal curve of the edentulous mandibular ridge

The literature lacks reports on measurement-based investigations of the sagittal curve of the mandibular ridge. The prosthetic significance of that curve is a debated issue even today. Our investigations have been carried out on functional samples of randomly selected edentulous patients (55 females and 17 males) treated at the Department of Prosthodontics of the Semmelweis University, Budapest. We made photographs using a Polaroid MACRO 5 SLR camera on a squared factory-made film, under standard circumstances, from both right and left directions. The photographs were then scanned with 600 dpi resolution and saved as non-compressed tif files (Tag Image File Format). The evaluation of the digitalized photographs has been carried out using a specifically developed computer program. On the four-times enlarged pictures, we made three measurements at each point; the arithmetical means of those sets of three figures served as a basis for statistical analysis. The data were analysed by gender and by side, using the SPSS program package (t-test). Our measurements showed that the sagittal curve is characteristic of the edentulous mandibular ridge as well. However, it does not exhibit significant differences by gender, individual, or side. The average value of the lowest point of the sagittal curve was 5.78 mm, s +/- 1.96 mm, minimum = 1.83 mm, maximum = 11.12 mm. It was concluded from our measurements and comparative anatomical data--clinical observations, as well as measurement-based investigations--that the Spee-curve of the healthy dentition and the sagittal curve of the edentulous mandibular ridge are formed by the same forces. If, in everyday practice, sagittal curves of the occlusion surfaces of complete lower dentures are set parallel with the mandibular edge, this is the most preferable solution with respect to both the stability of complete lower dentures and the optimal functioning of constrictor muscles.     

外斜线取骨自体骨移植及其他牙槽嵴骨增量法的研究进展

针对严重骨缺损且有种植修复意向的牙列缺损位点，自体骨移植是实现种植体三维方向充足骨量的“经典方案”，常用的口内供骨区有颏部和外斜线区域。相比颏部取骨，下颌骨外斜线取骨移植后神经并发症少，但跟其他牙槽嵴骨增量方式相比，术后骨吸收率大。本文重点讲述下颌骨外斜线块状取骨及其局限性，并阐述了其他临床应用广泛的牙槽骨增量方法，对比移植骨术后牙槽嵴宽度及高度变化、术后骨吸收率，为临床提供减小外斜线块状取骨局限性的其他骨增量方法。     

A technique for impressing the severely resorbed mandibular edentulous ridge

Patients presenting with severe resorption of the residual alveolar ridges are relatively common today in both private practices and teaching institutions. The severely resorbed mandibular ridge is more challenging to impress than is the maxillary ridge. Accurately capturing the denture-bearing surface in its entirety is crucial to providing the patient with a functionally successful prosthesis. This article presents a technique to overcome the difficulties encountered in impressing the severely resorbed mandibular ridge using elastomeric impression materials and a modified special custom tray.     

Alternative bone expansion technique for immediate placement of implants in the edentulous posterior mandibular ridge: a clinical report

PURPOSE: The aim of this study was to evaluate the effectiveness of a split-crest bone augmentation technique performed for immediate implant placement in thin edentulous posterior mandibular ridges. MATERIALS AND METHODS: In the present study, 125 implants were placed in posterior mandibular ridges of 30 patients. The mandibular buccal walls were split, expanded, and grafted with a combination of platelet-rich plasma and Cerasorb. The split segments were held in place by cortical bone screws. Before loading, periodontal status was checked, implant stability was evaluated with the Periotest, and panoramic radiographs and computerized tomography scans were obtained. Second-stage surgery (cover screw removal and healing abutment placement) was performed after 3 to 4 months. RESULTS: All implants osseointegrated successfully and underwent loading after 4 months. Optimal healing occurred 3 to 4 months earlier than the usual 6 to 9 months required, and no lip paresthesia was noted. DISCUSSION: Although onlay-inlay grafts, sandwich osteotomies, guided bone regeneration, piezoelectricity, and alveolar distraction have been indicated for augmentation in the posterior mandibular region, each of these techniques involves risks and complications. The crest-splitting bone expansion technique enables single-stage immediate implant placement and lateral ridge augmentation in thin crests and may prevent neurosensorial deficiencies. CONCLUSIONS: The split-crest surgical technique is a valid reconstructive procedure for sharp posterior mandibular ridges. If performed using platelet-rich plasma and Cerasorb, it can shorten the osseointegration period.     

Atypical cartilage in reactive osteocartilagenous metaplasia of the traumatized edentulous mandibular ridge

Eighteen cases of reactive osteocartilagenous metaplasia of the edentulous mandibular alveolar ridge forming clinical masses that mimic neoplasms are reported. Although most of these lesions appeared histologically benign, three exhibited atypical microscopic features suggestive of chondrosarcoma. Of those cases that were followed, none of the lesions recurred after simple surgical excision. Because many investigators consider all cartilagenous lesions of the jaws potentially malignant, the importance of recognizing this benign condition is stressed.     

Clinical results of alveolar ridge augmentation with mandibular block bone grafts in partially edentulous patients prior to implant placement

A group of 15 partially edentulous patients who needed alveolar ridge augmentation for implant placement, were consecutively treated using a two-stage technique in an outpatient environment. A total of 18 alveolar segments were grafted. During the first operation bone blocks harvested from the mandibular ramus or symphysis were placed as lateral or vertical onlay grafts and fixed with titanium osteosynthesis screws after exposure of the deficient alveolar ridge. After 6 months of healing the flap was re-opened, the screws were removed and the implants placed. Twelve months after the first operation implant-supported fixed bridges could be provided to the patients. Mean lateral augmentation obtained at the time of bone grafting was 6.5 +/- 0.33 mm, that reduced during healing because of graft resorption to a mean of 5.0 +/- 0.23 mm. Mean vertical augmentation obtained in the 9 sites where it was needed was 3.4 +/- 0.66 mm at bone grafting and 2.2 +/- 0.66 mm at implant placement. Mean lateral and vertical augmentation decreased by 23.5% and 42%, respectively, during bone graft healing (before implant insertion). Mandibular sites showed a larger amount of bone graft resorption than maxillary sites. All the 40 implants placed were integrated at the abutment connection and after prosthetic loading (mean follow-up was 12 months). No major complications were recorded at donor or recipient sites. Soft tissue healing was uneventful, and pain and swelling were comparable to usual dentoalveolar procedures. A visible ecchymosis was present for 4 to 7 days when the bone was harvested from the mandibular symphysis. From a clinical point of view this procedure appears to be simple, safe and effective for treating localised alveolar ridge defects in partially edentulous patients.     

一氧化氮合酶在兔下颌骨牵张成骨过程中的表达

目的：利用种植型牵张器增高兔下颌牙槽嵴，观察成骨过程中一氧化氮合酶（NOS）的表达。方法：日本大耳白兔20只，随机分为5组，分别为空白对照组，牵张后1d组、1周组、2周组和4周组，每组4只，随机选取一侧下颌骨行牵张成骨术。术后延迟4d开始牵张，每天牵张2次，共4d。处死各组兔子，游离下颌骨进行大体观察、X线观察、组织学观察和免疫组化观察，通过细胞图像分析仪测定阳性面积，利用SPSS13．0统计软件包分析诱导型NOS（iNOS）、内皮型NOS（eNOS）和神经型NOS（nNOS）的阳性表达。结果：X线及组织学检查显示，牵张间隙内新骨逐渐形成。免疫组化观察，正常骨组织NOS仅有少量的阳性表达；iNOS在间充质细胞、成骨细胞中有阳性染色，牵张后1d、1周、2周组的阳性面积显著高于正常组（P〈0．05）；eNOS在间充质细胞、增生血管内皮细胞中有阳性染色，牵张后1d、1周、2周组的阳性面积显著高于正常组（P〈0．05）；而nNOS在各实验组均无明显的阳性表达。结论：iNOS和eNOS在牵张成骨过程的不同时期具有不同的表达，提示可能对牵张成骨的新骨形成起一定的调节作用。     

Cell proliferation and expression of Cbfa-1 in a peripheral osteo-chondroma arising from the mandibular oral mucosa of an edentulous alveolar ridge

This report describes the proliferation and the expression of Cbfa-1 in a rare case of peripheral osteo-chondroma arising from the mandibular oral mucosa of an edentulous alveolar ridge. Histologically, the lesion consisted of mesenchymal cells with either bone or cartilage tissue in the center. Almost all the tumor cells were reactive for PCNA, however, only the cells around the bone and cartilage tissues were reactive for Cbfa-1. These results suggest that both the bone and the cartilage tissues in this case were produced by mesenchymal cells that originated from the peripheral periosteum of the alveolar ridge. Furthermore, we have shown that immunohistochemical staining for PCNA and Cbfa-1 can be used to investigate lesions with bone or cartilage formation and to distinguish between those produced by osteogenic cells from those that are just reactive and produced by dystrophic calcification.     

Primary reconstruction of the mandibular alveolar ridge following resection.

Standard techniques of mandibular reconstruction aim at the restoration of function. However, the height and shape of the alveolar ridge are often neglected and reconstruction often results in difficulty in subsequent denture wear. Immediate reconstruction of the alveolar process with particulate autologous iliac bone is described, a technique used in 10 patients since 1978.     

动态实时导航辅助下颌后牙区牙槽骨骨量不足种植

目的评价动态实时导航辅助下颌后牙区牙槽骨骨量不足种植手术中的精准度及临床效果。 方法回顾分析2021年1—12月因下颌后牙缺失就诊于中山大学附属第一医院口腔科,且采用动态实时导航辅助植入的23例患者。将术前规划种植体数据和术后实际植入种植体锥形束CT数据导入动态导航精度验证软件,对术前设计与术后植入种植体的三维轴向信息进行误差分析,计算并报告实际种植体顶部、根尖部、角度和深度偏差。使用SPSS 23.0统计学软件,对动态实时导航引导种植体植入术后的精度偏差和植入深度进行数据处理。本研究为符合正态分布的计量资料,采用 ±s描述。 结果本次计算机辅助动态导航系统指导下完成下颌后牙区25颗种植体植入,获得了良好的初期稳定性,术后CBCT示种植体精确植入规划位置,规避了下牙槽神经及邻近重要解剖结构,未发生相关手术并发症。25颗种植体的总体顶部偏差为（0.23 ± 0.11）mm,根尖部偏差为（0.45 ± 0.29）mm,深度偏差为（0.33 ± 0.32）mm,角度偏差为1.01° ± 0.65°。 结论动态实时导航辅助下颌后牙区骨量不足种植,可获得良好的植入精度和满意的临床效果。     

Enlarging soft tissue mass involving the mandibular left alveolar ridge

The central giant-cell granuloma is a benign, fairly uncommon lesion that can appear clinically and radiographically similar to many other lesions. When histopathological examination discloses a giant-cell lesion of bone, clinical, radiographic, and laboratory data must be obtained and carefully analyzed to rule out such conditions as hyperparathyroidism, Paget's disease, and cherubism, and to confirm the diagnosis of central giant-cell granuloma. Once the diagnosis is established, thorough curettage or surgical excision of the tumor is recommended to assure complete removal. Although recurrence is rare, periodic postoperative examination is also suggested.