Quantitative assessment of interradicular bone density in the maxilla and mandible: implications in clinical orthodontics

Background

Bone density at the interradicular area plays an important role during orthodontic treatment. In view of this fact, the study was designed to quantitatively evaluate the bone density at the interradicular areas of the alveolar and basal bones of maxilla and mandible by computed tomography.

Methods

One hundred and nine computed tomographic images were randomly selected, and bone density was measured in Hounsfield units (HU) with bone mineral density software (Siemens VA20A_SP3A). The sample consisted of 78 males (mean age 29.5 years, range 20 to 40 years) and 31 females (mean age 27.6 years, range 20 to 40 years). Cortical and cancellous bone density was measured at the interradicular areas at the alveolar and basal bone levels of the maxilla and mandible, and the data was subjected to statistical analysis for comparisons.

Results

The highest cortical bone density was observed between the second premolar and first molar at the alveolar bone level and between the first and second molars at the basal bone level in the maxilla. Maxillary tuberosity showed the least bone density. The density of the cortical bone was greater in the mandible than in the maxilla and showed a progressive increase from the incisor to the retromolar area. The basal bone showed a higher density thanthe alveolar bone.

Conclusion

Different qualities of the bone were found in the anatomic regions studied, which confirms the importance of knowledge of site-specific bone tissue density to correlate with various clinical findings.     

Usefulness of CT images for diagnosis of odontogenic maxillary sinusitis

To assess the usefulness of CT images for the diagnosis of suspected odontogenic maxillary sinusitis, 52 patients with maxillary sinusitis who had received CT examination were retrospectively analyzed. maxillary sinus ostium was established on coronal CT image in 20 out of 55 lesions in those 52 patients. However, a considerable number of patients who had inflammatory disease not only in the maxillary sinus but also in other paranasal sinuses (38/55) or in the nasal meatus (34/55) were included in those 52 patients. Concerning the opening of the ostium, the clinical diagnosis is frequently different from the diagnosis made using CT. The CT findings of the maxillary sinus ostium, nasal meatus and other paranasal sinuses were thus important in planning the treatment for patients with maxillary sinusitis in dentistry, as in otorhinolaryngology.     

口腔颌面部恶性黑色素瘤的CT表现

目的：评价口腔颌面部恶性黑色素瘤的CT表现。方法：回顾性分析了经CT检查的口腔颌面颈恶性黑色素瘤病例15例(23灶)。CT检查包括平扫(15例,23灶)和增强(12例,19灶)。所有病例均经病理检查证实。结果：22/23灶恶性黑色素瘤在CT检查中呈阳性表现．包括原发病变14灶和颈部淋巴结转移性病变8灶。病变呈软组织肿块者20灶,黏膜增厚者2灶(均为原发灶)。病变边缘不清者18灶,边缘清晰者4灶。增强CT显示：不均匀强化者9灶,均匀强化者5灶,无强化者5灶。病变压迫颈静脉变形3灶,侵犯上颌骨7灶,侵犯下颌骨2灶。结论：口腔颌面部恶性黑色素瘤的CT表现具有多样性。病变多以边界不清并有增强的软组织肿块为特点。     

上颈部淋巴结恶性肿瘤影响颈鞘的CT评价

目的：评价上颈部淋巴结恶性肿瘤影响颈鞘的CT表现。方法：收集经手术和活检病理证实的上颈部淋巴结恶性肿瘤病例77例(83例病变),并对其在CT上显示的影响颈鞘及其内部血管的形式进行分类和评价。结果：CT上,病变对颈鞘及其内部血管影响的表现主要有：①颈鞘内血管受压变形者52例病变(颈内动脉1例;颈内静脉51例);②颈鞘内血管受压“消失”者13例病变(均为颈内静脉);③颈鞘内血管受压移位者67例(颈内动脉22例,颈内静脉50例);④淋巴结恶性肿瘤围绕颈鞘血管者15例。结论：上颈部淋巴结恶性肿瘤对颈鞘内部血管的影响主要表现为推移和受压变形。判断病变是否侵犯颈鞘及其内部血管,应综合考虑其CT影像表现。     

不同垂直骨面型成人上下颌后牙区皮质骨密度测量研究

目的探讨不同垂直骨面型成人上下颌后牙区微螺钉种植体（MSI）常植入部位的皮质骨密度,为临床成功植入MSI提供参考。 方法采用整群抽样的方法从2015年1月至2018年12月广州市花都区妇幼保健院（胡忠医院）口腔正畸科就诊并拍摄锥形束CT（CBCT）的20 ~ 40岁成人患者中抽取57例患者,其中高角组患者20例、均角组患者22例和低角组患者15例。应用Ez3D-i软件重建上下颌骨三维模型,测量上下颌骨12个牙根间部位（距离牙槽嵴顶4 mm处）皮质骨密度（HU值）,运用单因素方差分析（ANOVA）比较3组各测量部位皮质骨密度均数的差异。 结果3组间上下颌后牙区颊侧多数测量部位皮质骨密度差异有统计学意义（P<0.001）,其中高角组最小。上颌腭侧多数测量部位差异无统计学意义。各组中相同牙位上颌后牙区颊侧、腭侧、以及下颌颊侧皮质骨密度差异有统计学意义（P<0.001）,其中上颌腭侧最小,下颌颊侧最大。 结论成人上下颌后牙区颊侧皮质骨密度受垂直骨面型影响,高角成人在上颌后牙区颊侧植入MSI需谨慎;上颌后牙区腭侧皮质骨密度几乎不受垂直骨面型影响,但骨密度低,植入MSI时也需谨慎。     

Chondroblastic osteosarcoma of maxilla: a case report and review of literature

Craniofacial osteosarcoma is a relatively rare entity comprising about 6.5–7% of all osteosarcomas, whereas it is reported to be one of the most common malignancies of long bones. We present a case of chondroblastic variant of osteosarcoma (COS) of the maxilla in an 18 year-old-girl. She was treated with a subtotal maxillectomy and later referred for adjuvant chemotherapy. The relevant review of literature with regard to clinical, radiographic findings, histopathological similarities to Chondrosarcoma (CS), role of Immunohistochemistry (IHC) and management modalities of Osteosarcoma of jaw bones (OSJ) in comparison with Osteosarcoma of the long bones (OSL) are being presented in this report.     

Radiographic outcome after maxillary sinus floor augmentation with allogeneic adipose tissue-derived stem cells seeded on deproteinized bovine bone mineral. A randomized controlled experimental study

The objective was to test the hypothesis of no difference in radiographic outcome after maxillary sinus floor augmentation (MSFA) with allogeneic adipose tissue-derived stem cells (ASCs) seeded on deproteinized bovine bone mineral (DBBM) (test) compared with excipient on DBBM (control). Eighteen minipigs were assigned into three groups of six animals and euthanised after one month (T1), two months (T2), and four months (T3), respectively. Each maxillary sinus was randomly allocated to either test or control with an equal volume of graft. Computed tomography scans (CTs) after MSFA (T0) were compared with CTs after euthanasia to evaluate graft volume (GV) changes and bone density (BD) using three-dimensional measurements and Hounsfield units. GV was larger in test compared with control at T1 (P = 0.046), whereas GV was larger in control compared with test at T3 (P = 0.01). BD increased from T0 to T1-T3 (P < 0.001) with both treatments. Higher BD was observed in control compared with test at T3 (P = 0.01), while no significant difference was observed at T1 and T2. Conclusively, the present study demonstrate that allogeneic ASCs seeded on DBBM in conjunction with MSFA seemed not to improve the radiographic outcome compared with excipient on DBBM. However, radiological outcomes need to be supplemented by bone histomorphometry before definitive conclusions can be provided about the beneficial use of allogeneic ASCs seeded on DBBM in conjunction with MSFA compared with DBBM alone.     

Plasma cell granuloma with severe cortical bone destruction of the mandible appearing as a malignant lesion—A case report

We experienced a case of plasma cell granuloma of the mandible appearing as a malignancy in a 22- year-old man. Plasma cell granuloma tends to be diagnosed as a potential malignancy as radiography reveals irregular bone destruction with an obscure margin. Therefore, plasma cell granuloma is classified as an inflammatory pseudotumor which may occur in any organ or soft tissue, including lung, vagina, bladder, and larynx. In the present case, the lesion was initially diagnosed as a malignant lesion on the basis of imaging analysis, but was later diagnosed histopathologically as a inflammatory lesion. This report reinforces the existence of inflammatory pseudotumors in the oral region, as well as the need for clarification of the unknown nature of inflammatory pseudotumors.     

上颌四眼圈簧扩弓后对上颌牙齿及上颌骨变化影响的 CBCT 研究

目的：使用锥体束 CT（CBCT）评估上颌四眼簧慢速扩弓后上颌牙齿及上颌骨宽度的变化。方法：选择13例需要综合性正畸治疗的患者（男5例,女8例）,平均年龄（14．4±2．2）岁,使用上颌四眼圈簧扩弓。对患者扩弓前（T1）后（T2）的变化进行 CBCT 扫描,测量扩弓前后两侧尖牙、第一前磨牙、第二前磨牙和第一磨牙之间的牙冠和根尖之间的宽度,第一磨牙的倾斜度,基骨弓和腭中缝宽度的变化。应用 SPSS 17．0软件对测量结果进行配对 t 检验。结果：四眼圈簧扩弓后牙弓变化明显。4对牙的牙间距分别增加了（2．47±1．05）mm、（2．97±1．90）mm、（2．79±1．21）mm、（3．15±1．15）mm,根尖距分别减小了（1．19±0．40）mm、（2．12±0．68）mm、（2．02±0．65）mm、（1．34±0．63）mm,左侧磨牙倾斜度减小了4．45°±2．86°,右侧磨牙倾斜度减小了4．02°±1．45°,基骨弓宽度增加了（2．37±0．96）mm,腭中缝宽度增加了（1．21±0．50）mm,差异均具有统计学意义（P ＜0．001）。结论：四眼圈簧扩弓器对上颌牙弓的扩弓主要通过牙齿倾斜移动完成,而非整体移动。     

腭侧错位的上颌侧切牙牙根位置锥形束CT测量分析

目的:通过锥形束CT(CBCT)测量分析上颌腭侧错位的侧切牙牙根位置分布规律,为正畸治疗中此类牙的移动设计提供参考依据.方法:选取符合入选标准伴上颌侧切牙腭侧错位的病例共200例,调取其CBCT,将腭侧错位的上颌侧切牙根长平分8等份,自根尖向牙槽嵴顶方向依次做标记点T1-T8,分别测量各位点的唇侧、腭侧牙槽骨厚度;测量...     

湖南地区5443例口腔颌面部恶性肿瘤临床分析

目的：调查湖南地区1989—2008年口腔颌面部恶性肿瘤患者发病情况及各类肿瘤的构成比。方法：对湖南地区12家大型三甲医院1989—2008年住院并经病理确诊的口腔颌面部恶性肿瘤患者的临床资料进行回顾分析。结果：患者平均年龄52.7岁,好发年龄段为41～70岁;男女性别比2.23∶1.00;口腔、唾液腺、颌骨分列口腔颌面部恶性肿瘤原发部位的前3位,口腔黏膜恶性肿瘤以舌、牙龈最多见。组织来源以上皮源性肿瘤最多,占94.9%;病理类型上,鳞癌3268例,占60.0%。唾液腺恶性肿瘤病理类型前4位依次为黏液表皮样癌、腺样囊性癌、腺癌、恶性多形性腺瘤;发病部位前3位依次为腮腺、下颌下腺、腭腺。2004—2008年口腔黏膜鳞癌患者中,有咀嚼槟榔习惯者平均年龄48.6岁,好发部位以舌、颊最为多见。结论：湖南地区口腔颌面部恶性肿瘤以41～70岁为好发年龄段,口腔黏膜恶性肿瘤好发部位以舌、牙龈最多,近10年来舌、颊部恶性肿瘤有明显升高趋势,而牙龈部则有下降趋势。     

Clinical evaluation of thermography in the diagnosis of malignant tumors in the oral and maxillo-facial region

Thermographic images of 48 cases of malignant tumors were analyzed and compared with those of other lesions: 93 cases of acute inflammation, 48 cases of chronic inflammation, 48 cases of benign tumors and 28 cases of cystic lesions. The majority of the cases with malignant tumors showed higher skin temperature over the affected area, but usually not so remarkable such as those of the cases with acute inflammation. The border of the thermal pattern of the tumors showed the tendency to be unclear. Both malignant tumors and acute inflammation appeared to cause an increase in skin temperature of the common carotid artery region on the affected side as compared with the opposite side. Malignant tumors showed the tendency that the temperature of the common carotid artery region of the affected side is equal or lower than the affected region in many cases. It is suggested that with further sophistication of the system suitable for the maxillofacial region, thermography may serve a role in the clinical diagnosis of malignant tumors.     

颌骨囊肿及肿瘤中三维螺旋CT容积再现和表面再现技术的对比研究

目的：观察和比较三维螺旋CT表面再现和容积再现技术显示颌面部囊肿及肿瘤的效果,探讨三维成像技术的临床应用价值。方法：对40例颌面部囊肿及肿瘤患者进行螺旋扫描后,在三维后处理工作站进行表面再现和容积再现重建并测量,结合术中所见比较二者在定位定界,显示病损所破坏,骨皮质膨胀等方面的效果。以既往二维CT为基础进行的颌骨手术为对照,比较三维螺旋CT在术中并发症、术后并发症及手术时间上的差别。结果：容积再现技术在定位、定界、显示骨膨胀和破坏方面均优于表面再现技术,测量值更接近术中测量（P〈0.05）。三维螺旋CT在手术中的指导意义优于二维CT,术中及术后并发症少（P〉0.05）;试验组患者术后12个月复发率（7.50%）低于对照组（15.11%）。结论：容积再现技术在定性及定量评估方面较表面再现技术更精确,所获信息更全面,更能反映病损的真实情况。三维螺旋CT,尤其是容积再现技术作为口腔颌面外科的重要诊断手段,对提高手术效果,防止复发有重要意义。     

Correlation of cone beam CT-derived bone density parameters with primary implant stability assessed by peak insertion torque and periotest in the maxilla

Purpose

Primary implant stability is crucial to osseointegration. The aim of this study was to assess correlation of preoperative radiologic parameters with intraoperatively obtained biomechanical tests in the maxilla.

融合CT和MRI数据构建颌面部3D数字化模型

目的 探索通过精确、高效配准CT和MRI数据,建立包含颌面部主要肌肉和骨骼组织的3D数字化模型.方法 对1名志愿者行颌面部螺旋CT及MRI扫描,数据分别导入Mimics 15.0中,在3个视窗,即横断面、矢状面、冠状面,分别调整两种数据至同一断层,以树脂球为配准点,至少5个点配准两组数据.再利用CT分割并重建颌骨和面部皮肤3D模型,利用MRI分割重建面部主要肌肉3D模型.结果 建立了包含3对咀嚼肌、12对表情肌、面部皮肤与颌骨组织的3D模型,配准模型具有较高的一致性和相对位置精度.结论实现了CT与MRI两种影像学数据的配准融合.     

早期植骨修复腭裂对上颌骨生长影响的实验研究

目的:探讨大白鼠人造腭裂行早期自体骨移植修复对上颌骨生长发育的影响。方法:选取40只4周龄的雄性Wistar大白鼠,随机分为4组,即正常对照组、人造腭裂组、人造腭裂两瓣法修复组、人造腭裂自体骨移植加两瓣法修复组;每组10只。术后10周观察上颌骨的生长发育指标,应用SPSS软件进行统计学处理,再行组间方差分析。结果:上颌骨宽度指标、最大上颌骨长度指标(A-D)、上颌骨高度指标值,植骨修复组均显著小于正常组与人造腭裂组,有统计学意义(P﹤0.01)。两侧硬腭后份宽度指标,植骨修复组显著大于两瓣修复组,有统计学意义(P﹤0.01);其余多项指标,植骨修复组与两瓣修复组均无显著性差异(P﹥0.05),但上颌骨高度的3项指标和长度指标(AD)均值,植骨修复组均小于两瓣修复组。结论:人造腭裂行自体骨移植修复对上颌骨的横向生长有积极意义,但对上颌前后向、垂直向的生长发育较两瓣修复法有进一步受限的倾向。     

Double mental foramina of the mandible on computed tomography images: a case report

Double mental foramina found with preoperative computed tomography (CT) prior to implant therapy are reported and discussed in reference to literature reports. A 52-year-old man visited us for implant therapy. Preoperative panoramic radiography and CT were conducted. A multisection reconstructed sagittal image showed two mental foramina leading to the mandibular canal on the right side of the mandible, which were diagnosed as double mental foramina. The incidence of double mental foramina reported in the literature is approximately 6.9% in dry Japanese skulls. Many reports have indicated that non-Caucasians have a higher incidence than Caucasians. The general incidence ranges from 2% to 10%. However, only one clinical case report is available.     

髁突骨软骨瘤与髁突增生患者的CT表现特点分析

目的:比较下颌骨髁突骨软骨瘤和单侧下颌骨髁突增生的CT表现特点。方法:对2005—2010年上海交通大学医学院附属第九人民医院口腔颌面外科收治的下颌骨髁突骨软骨瘤11例和单侧下颌骨髁突增生8例患者的CT影像学资料进行评价,评价指标包括病变髁突大小、病变范围以及病变周围软硬组织改变。结果:11例下颌骨髁突骨软骨瘤病例CT显示肿瘤与病变髁突无明显分界(8/11)或与患侧髁突有蒂相连(3/11);肿瘤骨皮质及骨髓腔均与患侧髁突相续,瘤体表面均有特征性薄层软骨帽覆盖,瘤体外周密度通常高于中心;瘤体周围均有薄层软组织包绕。患侧颞骨关节面表面均有明显矿化,且因受瘤体压迫改建而较对侧平坦,患侧关节上、下腔间隙较对侧明显变窄;肿瘤生长方向不尽相同。8例单侧下颌骨髁突增生病例CT显示髁突颈部和(或)下颌支延长,髁突形状改变;增生的髁突外周骨皮质均有不同程度的骨化,硬化层厚度较对侧大;骨髓腔密度较不均匀。结论:CT检查能有效提供病变髁突及其周围软硬组织情况,为鉴别诊断下颌骨髁突骨软骨瘤和单侧下颌骨髁突增生提供良好的依据。     

Computed tomography (CT) of cervical lymph nodes in patients with oral cancer: comparison of low-attenuation areas in lymph nodes on CT images with pathological findings

Objectives  To clarify the histopathological features of low-attenuation areas in computed tomography (CT) images of cervical metastatic and benign lymph nodes in patients with oral squamous cell carcinoma (SCC). Methods  CT images of 230 lymph nodes from 37 patients with oral SCC were classified into four categories and compared with histopathological findings. Metastatic lymph nodes were evaluated in terms of focal necrosis, keratinization, fibrous tissue, and the proportion of the lymph node showing focal necrosis. Benign lymph nodes were evaluated in terms of adipose tissue, follicular hyperplasia, sinus histiocytosis, hyperemia, focal hemorrhaging, and the amount of adipose tissue. Results  Histopathologically, all 13 metastatic lymph nodes with rim enhancement on CT images included focal necrosis. However, most of the lymph nodes showed no focal necrosis. In addition, tumor cells, keratinization, and fibrous tissue were observed in the lymph nodes. Of the 26 metastatic lymph nodes with a heterogeneous appearance on CT images, four did not show focal necrosis. These lymph nodes showed keratinization or accumulation of lymph fluid. Histopathologically, 20 of 24 benign lymph nodes with a heterogeneous appearance on CT images (83.3%) had accompanying adipose tissue. Conclusions  Focal necrosis was the most important factor contributing to low attenuation in metastatic lymph nodes. However, other factors, such as tumor cells, keratinization, fibrous tissue, and accumulation of lymph fluid, also contributed. In benign lymph nodes, the presence of adipose tissue was a contributing factor in low-attenuation areas, as was focal hemorrhaging.