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目的    观察Bio-Oss骨粉或骨胶原植入较大根尖囊肿刮治术后骨腔的临床效果。方法    选择2008年2月至2009年2月在南阳市口腔医院牙周科就诊的直径超过2 cm的较大根尖囊肿患者43例（124颗患牙）,随机分为植骨组（22例,68颗患牙）和对照组（21例,56颗患牙）。囊肿刮治术后植骨组骨腔植入Bio-Oss骨粉或骨胶原,对照组不植骨,观察两组病例术后6个月和12个月的临床疗效。结果    植骨组术后6个月的成功率（81.8%）明显高于对照组（47.6%）,差异有统计学意义（χ2 = 5.53,P < 0.05）;两组术后12个月的成功率差异无统计学意义（χ2 = 2.20,P > 0.05）。结论    Bio-Oss骨粉或骨胶原能明显促进骨再生,缩短囊肿刮治术后骨腔的愈合时间。     

Traumatic bone cyst suggestive of a chronic periapical abscess: a case report

Traumatic bone cysts can mimic the signs and symptoms of an endodontic lesion. This case reports on a 19-year-old male patient who was referred for endodontic assessment of a symptomatic tooth with a gingival swelling and a draining sinus at the furcation of a mandibular second molar. Radiographically, a periradicular radiolucency is evident. A prior history of trauma as well as removal of the wisdom teeth was determined. After careful diagnosis unnecessary endodontic intervention was avoided. Surgical exploration, curettage and the generation of a blood clot resulted in healing at the 6 month review appointment. The tooth remained responsive to pulp sensibility testing at that time.     

Unicystic ameloblastoma: a possible pitfall in periapical diagnosis

AIM: To report a clinical case of unicystic ameloblastoma previously misdiagnosed as radicular cyst. SUMMARY: A 49-year-old white male was referred to a private practitioner complaining of an asymptomatic bony hard swelling of the left posterior mandible. The patient's dental history indicated that his left mandibular first molar had been extracted approximately 10 years previously. At that time, preoperative radiographic examination demonstrated a radiolucent area of 1.5 cm diameter with well-defined margins involving the distal root of tooth 36. The lesion was diagnosed as cystic and surgery for its removal was advised, but not performed. At presentation, radiography demonstrated a well-defined 3 cm diameter radiolucency extending from the second premolar to the second molar. The lesion was enucleated and histopathological examination confirmed a diagnosis of unicystic ameloblastoma. KEY LEARNING POINTS: *Despite a clinical diagnosis of periapical disease of endodontic origin, a nonendodontic lesion may be present. *Unicystic ameloblastoma located on the periapical area of a tooth can lead to a pulp-periapical misdiagnosis, and should be considered in differential diagnosis. *All tissue specimens recovered in apical surgery should be submitted to histopathological analysis.     

Bone scintigraphy in solitary (Simple) bone cyst of jaw

Six cases of solitary (simple) bone cyst with typical clinical, radiographical, and histological findings were examined by bone scintigraphy. Bone scintigraphy using^99mTc-HMDP was performed prior to operation. No uptake of^99mTc-HMDP in these solitary bone cysts was demonstrated. On the other hand, 2 cases of florid osseous dysplasia (Melrose et al. 1976) associated with bone cavities resembling solitary bone cyst showed remarkable uptake of^99mTc-HMDP.     

Simple bone cyst: A discrepancy between magnetic resonance imaging and surgical observations

OBJECTIVE: The purpose of this study was to compare magnetic resonance (MR) imaging and surgical observations of fluid in simple bone cysts. STUDY DESIGN: Findings during MR imaging of 7 simple bone cysts were compared with surgical observations 1 day or 1.8 months (mean) after MR imaging. RESULTS: All MR images showed cavities filled with fluid. In 2 patients operated on the day after the imaging, surgical observations were in accordance with the MR findings. At surgery 1.8 months after the MR examination, 4 cavities were found to be empty and 1 cavity contained only a minor amount of fluid. CONCLUSION: A discrepancy between MR imaging and surgical observations of fluid in simple bone cyst cavities was observed that might be dependent on the time between the observations, indicating that a fairly rapid absorption of fluid might occur or that the amount of fluid in a simple bone cyst can vary for unknown reasons.     

Simple bone cyst in the mandible--a rare occurrence in an elderly patient

Simple bone cyst (SBC) is an intra-osseous pseudocystic lesion lined by a thin fibrovascular membrane but lacks an epithelial lining. SBC is uncommon and comprises of approximately 1% of all jaw cysts. The lesion is usually discovered incidentally during the first two decades of life. Males are affected slightly more frequently than females. The most common sites of occurrence are the molar and premolar regions of the mandible; maxillary lesions are uncommon. The lesion is usually solitary, radiolucent, well demarcated, and non-expansile. Margins may be scalloped, between vital teeth, and root resorption is rare. A surgical approach to the lesion reveals an empty cavity with serosanguinous fluid. Histologically, the cavity lining consists of a loose connective tissue layer and hemosiderin-laden macrophages. Pathogenesis and etiology of SBC are still not clearly understood. It is assumed that the cyst forms following traumatic intra-osseous hemorrhage with subsequent lysis and resorption of the cellular content. Trauma, as the main cause of SBC, is not always conclusive and the origin of the lesion may be multifactorial. Treatment of SBC is by curettage. Intralesional hemorrhage due to either intentional curettage or during exploratory procedure may induce a reparative process. A rare occurrence of SBC in a 71 year old healthy male, referred to the Oral and Maxillofacial Outpatient Clinic, Sheba Medical Center by his dentist, because of a large radiolucent lesion in the left mandibular body is reported. The patient received a complete lower denture 3 months earlier. He returned to his dentist with a complaint of local pain and an ulcer under the denture. A panoramic radiograph revealed a large unilocular radiolucent lesion with demarcated borders in the left mandibular body and bone erosion in the upper alveolar border of the lesion Clinical examination showed a deep ulcer in the denture-bearing area of the left posterior alveolar ridge. There was no cortical expansion of the mandible. Incisinal biopsy revealed an empty cavity lined by fibrous connective tissue with no epithelial lining. According to the clinico-radiologic and histologic findings, a diagnosis of a simple bone cyst was made. The incidence of SBC is higher in younger age groups (second decade). Occurrence of the lesion in the elderly is rare with only a few reports in the literature. In the present case, the fact that SBC is asymptomatic, may be responsible for the late discovery of the lesion.     

Simple bone cyst: Evaluation of contents with conventional radiography and computed tomography

To evaluate whether gas is present in the cavity of simple bone cysts, the clinical and histologic findings of 53 patients with simple bone cysts were examined and compared with an experimental model. The model consisted of a dry mandible with the medullary bone removed and the resulting cavity injected with water. Although an air-liquid level was observed on all radiographs for the experimental model, none was observed in the clinical cases of simple bone cysts. When the experimental cavity was completely filled with water, the density in the cavity was similar to that of the surrounding water on computed tomography, but when it was filled with air, the density was lower than that of the surrounding water. In contrast, in simple bone cysts said to contain air at surgery, the cavity contents were not consistent with the density for gas on computed tomography. These results indicate that the operative finding of air in the cavity of simple bone cysts may have been in error at least in some cases.     

Odontogenic cyst induction by periapical infection in rats

The purpose of this study was to test the hypothesis that Odontogenic cysts can be induced by periapical infection. Pulp extirpation and reaming beyond the root apices were performed in 53 lower first molars in 27 Sprague-Dawley rats. The cavities were left open to allow continuous contamination by oral bacteria. Animals were killed at 6 and more than 8 months after operation. Odontogenic cysts were found in association with 8/53 teeth in 6 animals. Historically, cysts were observed around the lower incisors below the first molars. The cyst wall consisted of fibrous connective tissue with inflammation and was lined with keratinized squamous epithelium. The cyst cavity contained a mass of keratin and necrotic debris. These results support the hypothesis that inflammatory stimulation from the apices can cause cystic changes in the enamel epithelium of underlying teeth.     

11例颌骨单纯性骨囊肿回顾性研究

目的 探讨颌骨单纯性骨囊肿的临床、手术及放射学特点。方法 收集颌骨单纯性骨囊肿病例的资料,对其临床、影像学、手术及随访情况进行回顾性研究。结果 11例颌骨单纯性骨囊肿患者中,女性8例,男性3例。10例（90.9%）患者无症状,1例（9.1%）患者出现肿胀。所有的病例均发生于下颌骨且为孤立性病变,无外伤史。10例（90.9%）病变表现为单房,1例（9.1%）表现为多房。病变的形状可分为锥形、圆形、卵圆形、不规则形,分别有3、2、4、2例。10例行手术探查并搔刮骨壁治疗,其中7例（70%）术中发现病变骨腔为空腔,2例（20%）为浆液,1例（10%）为血性浆液。采取手术治疗的3例病变完全愈合,7例显示骨腔内有新骨形成。结论 颌骨单纯性骨囊肿通常无症状,下颌骨发病率较高,无明显外伤史,大多数病变骨腔为空腔。单纯行骨壁搔刮术是单纯性骨囊肿的一种有效的治疗方法。     

Leukotrienes: their possible role in pulpal and periapical diseases

Abstract Leukotrienes play an important role in inflammation and its sequelae such as pain, swelling, and bone resorption. This review covers, their history, structure, synthesis, metabolism, biological effects, inhibitors, antagonists, and their possible role in pathogenesis of pulpal and periapical disease.     

Plasmacytoma of anterior maxilla mimicking periapical cyst

Abstract An unusual case of plasmacytoma mimicking a large periapical cyst in the anterior maxilla is described. Of the involved teeth, 22 was discoloured and had an open, immature apex, a feature strongly suggestive of the lesion being of pulpal origin. The case was treated by a conservative endodontic approach, but failed to show any improvement. Apical surgery comprising complete enucleation of the cystic lesion and extraction of the involved tooth was carried out. The unexpected histopathological finding was a plasmacytoma.