The maxillary sinus: evolution and function in aging

The maxillary sinus, or Highmore's antrum, is located in the maxillary bone. The maxillary, above the buccal cavity, below the orbital cavity and outside the nasal fossa, is going to take a part in the formation of the three cavities which surround it. Although voluminous, it is consists of a light bone. This distinctive feature is essentially due to the fact that the maxillary has a cavity. The maxillary sinus occupies the upper 2/3s of this maxillary bone. It is the largest of the facial structure's cavities. Its volume is very variable, depending on the individual, the condition of their edentulousness and their age. We find small, average or large sinuses. This sinus communicates with the corresponding nasal fossa by a canal. It opens at the level of the nasofrontalis duct by a meatic ostium, an ostium located at the top of the meatus nasi medius, i.e. under the floor of the sinus. This highly positioned drainage location easily explains the problems that sinus pathologies can come up against. The sinus is lined with a mucous membrane and we can point out that in the normal condition this mucous membrane adheres weakly to the bone. It is more or less thick as a function of the pathologies to which the sinus has been subjected, or even as a function of the geographical location where the individual lives. The imaging of this sinus as a function of age is not obvious due to the fact that it is invisible throughout embryonic and foetal development, and that it only becomes visible to X-rays relatively late, at about 6 years old. Its role is important at the level of the growth of the facial structure because it is always easier to have growth around cavities. It also has a mechanical role concerning the transmission of shockwaves during traumas. In old individuals, due to the condition of the edentulousness, the volume of the sinus is larger; in fact one can note the resorption of the alveolar bone. The maxillary sinus is a cavity which plays a very important role throughout an individual's existence because of the previously mentioned reasons, and which could be used during surgical reconstructions, by the partial filling of this space, to increase the quantity of usable bone (grafts...).     

藏酋猴上颌窦的应用解剖

目的 通过对藏酋猴上颌窦的应用解剖,为上颌窦的临床应用提供形态学依据。方法 对6只藏酋猴的12侧上颌窦进行大体解剖,从整体和局部对上颌窦的位置、形态,窦腔与眶、鼻腔和口腔的结构进行观察和测量。结果 藏酋猴的上颌窦位于上颌骨体内,由前、后窦构成。后窦位于前窦的后方,窦腔较小。前窦和人的上颌窦类似,位于第1前臼齿至第2臼齿及相应骨腭的上方,毗邻眶、鼻腔、口腔,窦腔较大且形态无异常;窦腔与眶间骨质较薄,有鼻泪管连通,其管径为(4.31±0.10)mm、长度为(15.89±0.31)mm;窦腔底与鼻腔间有大且恒定的上颌窦裂孔,自然状态下裂孔长度(12.59±0.46)mm、高度(1.01±0.12)mm;向上牵拉海绵状血管球可使裂孔高度增大到(11.14±1.44)mm;窦腔与口腔间骨质最厚处位于第1前臼齿根尖的上方,厚度为(6.20±0.20)mm,最薄处位于第2臼齿根尖的上方,厚度为(1.57±0.23)mm,窦底最低处位于第1、2臼齿间。同一个体双侧对比,差异无统计学意义。结论 藏酋猴上颌窦的形态结构特点,适合于作为动物模型,应用于人类上颌窦病变、上颌窦提升及种植牙的相关研究;其上颌窦裂孔是上颌窦底非开窗手术入路的最佳部位。     

Maxillary Sinus Anatomy: A Cadaveric Study With Clinical Implications

This study measured maxillary sinus volume, evaluated the location of the semilunar hiatus in correlation to the nasal floor, and the incidence, location, and height of antral septa and discusses their clinical implications. Maxillary sinus volume was quantified in 65 cadavers (130 sinuses) by water application through the semilunar hiatus and measuring the used amount. The location of the semilunar hiatus was identified as distance from the nasal floor. The septa were counted, evaluated, and the size measured from the antral floor. The medium maxillary sinus volume was 12.5 mL (range, 5–22 mL). The medium location of the semilunar hiatus was 25.6 mm above the nasal floor (range, 18–35 mm). Thirty‐five septa were counted in 130 maxillary sinuses. This equals an incidence of 27%. The medium height of the septa was 5.4 mm (2.5–11 mm). The main location of the septa was the region of the first molar (29%), the second molar (23%), and the second premolar (23%). The height, location, and number of septa as well as the height of the semilunar hiatus and volume of the maxillary sinus have to be taken into consideration to correctly plan the procedure and amount of grafting material in maxillary sinus floor elevation operations. Anat Rec, 292:352–354, 2009. © 2009 Wiley‐Liss, Inc.     

Long-term outcome of cryopreserved bone-derived osteoblasts for bone regeneration in vivo

Cryopreserved bone-derived osteoblasts (CBOs) have been considered as a promising cell source for bone regeneration. Previous studies have demonstrated that CBOs had good proliferation and osteogenicity. However, the long-term outcome of CBOs in vivo still remains unknown. In this experiment, we applied CBOs combined with calcium phosphate cement (CPC) to augment maxillary sinus in canine, computer tomography, polychrome labeling, biomechanical tests, fluorescent immunohistochemistry staining and histological analysis were used to analyze the property and mineralization process of the tissue-engineered bone preclinical application. Our results showed that CBOs combined with CPC could promote bone regeneration, dramatically maintain the height, volume and biomechanical property of augmented maxillary sinus. Furthermore, the tissue-engineered bone was more mature than scaffold alone or autogenous bone, and bone formation and remodeling were still apparent 20 months postoperatively. Additionally, 4 months after surgery might be the suitable time point for implants placement in the regenerated bone. These results also indicate that cryopreserved bone may be a potential source of osteoblasts for maxillary sinus augmentation.     

Understanding the formation of maxillary sinus in Japanese human foetuses using cone beam CT

The formation of the maxillary sinus (MS) is tied to the maturation of the craniofacial bones during development. The MS and surrounding bone matrices in Japanese foetal specimens were inspected using cone beam computed tomography relative to the nasal cavity (NC) and the surrounding bones, including the palatine bone, maxillary process, inferior nasal concha and lacrimal bone. The human foetuses analysed were 223.2 ± 25.9 mm in crown-rump length (CRL) and ranged in estimated age from 20 to 30 weeks of gestation. The amount of bone in the maxilla surrounding the MS increased gradually between 20 and 30 weeks of gestation. Various calcified structures that formed the bone matrix were found in the cortical bone of the maxilla, and these calcified structures specifically surrounded the deciduous tooth germs. By 30 weeks of gestation, the uncinate process of the ethmoid bone formed a border with the maxilla. The distance from the midline to the maximum lateral surface border of the MS combined with the width from the midline to the maximum lateral surface border of the inferior nasal concha showed a high positive correlation with CRL in Japanese foetuses. There appears to be a complex correlation between the MS and NC formation during development in the Japanese foetus. Examination of the surrounding bone indicated that MS formation influences maturation of the maxilla and the uncinate process of the ethmoid bone during craniofacial bone development.     

Engineering of bone using porous calcium phosphate cement and bone marrow stromal cells for maxillary sinus augmentation with simultaneous implant placement in goats

The aim of this study was to explore the effects of maxillary sinus floor elevation and simultaneous dental implantation with a tissue-engineered bone complex of calcium phosphate cement (CPC) scaffolds combined with bone marrow stromal cells (BMSCs). A large animal goat model is used with the tissue engineering method. Eighteen bilateral maxillary sinus of nine goats were randomly allocated into three groups; the CPC/BMSC complex (n=6) was used to elevate maxillary sinus floor with a simultaneous implant placement; the effects were compared with those treated with CPC alone (n=6) or autogenous bone (n=6). After a healing period of 3 months, sequential triad-color fluorescence labeling, micro-CT, as well as histological and histomorphometric analyses indicated that the tissue-engineered BMSC/CPC complex could promote earlier bone formation and mineralization, and maximally maintain the volume and height of the augmented maxillary sinus. By comparison, CPC-alone or autogenous bone achieved less bone formation and later mineralization. Besides, the average bone-implant contact value reflecting the osseointegration was 35.63%±9.42% in the BMSCs/CPC group, significantly higher than 22.47%±4.28% in the CPC-alone group or 28.26%±8.03% in the autogenous bone group. In conclusion, CPC serves as a potential substrate for BMSCs for the maxillary sinus floor augmentation and simultaneous implantation. The tissue-engineered bone might enhance the stability of implants and thus be of great significance to achieve improved quality to restore the oral function in clinic.     

比格犬上颌窦的应用解剖

目的探讨比格犬上颌窦正常解剖,为与上颌窦有关的动物实验提供解剖学依据。方法收集16个比格犬上颌窦,利用锥形束投照计算机重组断层影像(CBCT)扫描,并完成局部解剖,详细观察上颌窦形态、位置、容积、自然窦口位置及与周围组织的毗邻关系。另购买2只健康成年比格犬,利用CBCT确定上颌窦窦底,经腭侧开窗,显露软组织,夹取该位点黏膜行组织学检查,光学显微镜下验证所夹取黏膜是否为上颌窦黏膜。结果比格犬上颌窦形状略似锥形,前部较窄,后部宽大,位于上颌第3前磨牙与第1磨牙之间的腭侧,四周均有骨壁包绕。于第4前磨牙远中牙尖腭侧,距腭中缝约17~18mm处可见上颌窦最低点。同一个体双侧对比,差异无统计学意义。结论比格犬双侧上颌窦无明显差异,有利于上颌窦相关研究进行随机分组;窦腔内无明显骨嵴或分隔,降低窦黏膜穿孔的危险;行上颌窦外提升时,结合CBCT于上颌窦最低点经腭侧骨板开窗是最佳的术式。     

Observation of maxillary sinus septa and bony bridges using dry skulls between Hellman's dental age of IA and IIIC

Maxillary sinus septa and bony bridges were observed using dry skulls in childhood, classified based on Hellman's dental age, to clarify maxillary sinus septum formation. Eighty-eight maxillary sinuses of 44 dry skulls and a cone-beam computed tomography (CBCT) unit were used. The locations of the septum, defined as a pointed bony structure originating from the inferior wall, and bony bridge, defined as a bony structure between the maxillary sinus wall and dental germ, were antero-posteriorly recorded, and the superoinferior distance, distance from the bony palate, and angle to the median palatine suture were measured. The rate of septum presence in the maxillary sinus was high (41.7%) in IIIC, and the septa were located in the deciduous molars, premolars, and molars. Also, all bony bridges were related to the median maxillary sinus wall, and the rate of the maxillary sinus showing a bony bridge was high in IIA and IIIA. Septum presence in the maxillary sinus was observed in IIA, IIC, IIIA, IIIB, and IIIC of Hellman's dental age. Also, bony bridges were observed in IC, IIA, IIC, IIIA, IIIB, and IIIC of Hellman's dental age.     

在口腔种植上颌窦提升中植骨材料与影像学和器械应用的研究进展

背景：近年,上颌窦提升中是否使用及如何使用骨替代材料问题存在争议,器械及影像学的发展极大的推动了上颌窦提升的临床应用及术式的改良,新术式的不断报道也促进了上颌窦提升的成熟与发展。 目的：总结上颌窦提升在材料研究库、牙颌面专用锥形束CT及超声骨刀在临床中的应用等方面的新进展。 方法：由第一作者检索2000/2010 PubMed数据、SCI数据库、维普数据库及万方数据库有关上颌窦提升植骨材料、影像学应用及器械的应用、术式改良等方面的文献。 结果与结论：上颌窦提升在材料学、影像学及设备学上的发展将为口腔种植在术前诊断测量、手术设计、预后分析等方面提供更为科学的服务。目前的不足及有待解决的问题有：在上颌窦提升中植骨材料的选择及应用方面,由于植骨后观察时间不足还未能得出较有效和有力的比较;不使用植骨材料的观点和效果需更多研究及实验的验证;牙颌面专用锥形束CT只是硬组织的三维成像,不能得到黏膜等软组织的状态及观察测量信息,还有待研究发展;超声骨刀的出现较新,今后在器械工作头的选择及操作技巧方面还有待做进一步的探讨改进和临床实践。     

上颌窦内外提升不植骨替代材料同期种植牙：随访周围骨量及稳定性的变化

背景：研究已经证实,上颌窦黏膜具有促进成骨的能力,上颌窦内膜与种植体之间的空间随着时间的延长会有新生骨的形成。 目的：通过对两种上颌窦提升术不植骨同期种植牙的研究,明确不植骨对两种上颌窦提升后种植体成活状态的影响。 方法：将上颌后牙区骨量不足的50例患者随机分成上颌窦外提升和上颌窦内提升两组,分别在不植入骨替代材料的情况下同期进行种植体的植入,共植入种植体60个,外提升组25个植体,内提升组35个植体。 结果与结论：在不植骨的情况下,60个种植体经过12个月的观察,59个植体正常行使功能,1例外提升的种植体术后松动,治疗失败。内提升组手术时间和出血量均显著少于外提升组(P < 0.05)。两组患者的近期稳定性(术后12个月)比较差异无显著性意义(P > 0.05)。术后12个月外提升组种植体周围的骨量增加显著少于内提升组(P < 0.05)。结果说明不植骨在上颌窦的两种提升术中是可行的,而且能简化手术过程,减少治疗费用,但对种植体长期稳定性的影响有待进一步观察。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

脱基质小牛骨粉复合骨髓基质干细胞的成骨作用

背景：利用骨组织工程技术在上颌窦提升中的成骨研究是目前口腔种植学到研究热点。 目的：探讨骨组织工程在上颌窦底提升同期牙种植中的成骨效果。 方法：体外分离培养犬骨髓基质干细胞,将细胞与脱基质小牛骨粉复合培养并向成骨细胞定向诱导分化。健康成年犬12只行双侧上颌窦底提升同期牙种植,一侧植入复合物,另一侧植入脱基质小牛骨粉做对照。 结果与结论：种植体稳固无松动,上颌窦黏膜完整。实验侧可见新生骨形成较早、骨量较多;对照侧新生骨形成较慢。X射线显示实验侧新生骨质致密,与种植体结合紧密。随时间的增加,牵出力增大,12,24周时两侧差异有显著性意义(P < 0.05)。组织形态学检测显示新生骨面积逐渐增加,12,24周时差异有显著性意义(P < 0.05)。提示组织工程化骨在上颌窦提升同期牙种植中可获得良好的成骨效果。     

窦口鼻道复合体的应用解剖

目的：确定窦口鼻道复合体的境界，为临床在内窥镜下施行上颌窦手术提供解剖学依据。方法：在６０例成人鼻腔外侧壁的标本上，测量半月裂、钩突、筛泡、额鼻管和筛漏斗的有关数据。并观察了它们相互间的关系以及上颌窦的自然开口。结果：半月裂、钩突、筛泡、额鼻管的长度分别为１５．０ｍｍ，１８．３ｍｍ，１６．２ｍｍ和５．９ｍｍ；钩突与筛泡的高度分别为６．９ｍｍ和５．８ｍｍ；筛漏斗宽３．９ｍｍ、深３．７ｍｍ。上颌窦自然开口９８％在半月裂内，其中６０％位于半月裂后部、３３％位于中部、５％位于前部、１例变异。结论：窦口鼻道复合体的形态和病变与鼻窦炎的发病有直接联系     

Clinical anatomy of the posterior maxilla pertaining to Le Fort I osteotomy in Thais

This article studies the anatomy of the posterior maxilla pertaining to bone-cut design of Le Fort I osteotomy to avoid the injury to the descending palatine artery in Thais. Fifty-five skulls (38 males, 17 females) were assessed for the anatomical landmarks by a combination of direct inspection, computerized imaging, and computed tomography scan analysis. The results showed that 27.28% of the pterygomaxillary junction (PMJ) became synostosis. The mean heights of the PMJ, posterior maxilla, and maxillary tuberosity were 15.14 +/- 2.46 mm, 22.51 +/- 3.50 mm, and 7.45 +/- 2.76 mm, respectively. The mean length of the medial sinus wall measuring from the piriform rim to the descending palatine canal at the Le Fort I level was 34.40 +/- 2.96 mm. The mean widths of the posterior incision of Le Fort I osteotomy at the maxillary tuberosity and PMJ were 20.38 +/- 2.82 mm and 11.60 +/- 1.57 mm. The mean length of the posterior maxilla was 27.18 +/- 2.49 mm. Distances from the greater palatine foramen to the maxillary tuberosity incision and PMJ incision were 1.76 +/- 1.12 mm and 3.59 +/- 1.40 mm. The mean angle between the descending palatine canal and the hard palate was 57.33 +/- 4.54 degrees . There were no significant differences in any measurements between sides and genders, except the pterygoid process width and posterior maxilla length of males were longer than those of females (P < 0.05). This study could provide better understanding of the posterior maxillary anatomy that is important for the bone-cut design of Le Fort I osteotomy to avoid excessive intraoperative and postoperative hemorrhage including ischemia of the mobilized maxilla.     

Variations of the prominences of the bony palate and their relationship to complete dentures in Korean skulls.

The osteological and morphological variations of the prominences in the bony palate of 160 Korean skulls were studied. The frequency of the occurrence of the posterior palatine crest, located on the posterior border of the greater palatine foramen, was 13.8%. Palatal ridges were observed commonly in the skulls; however, the smooth type, which has no palatal ridges in the palate, was shown in 14.7% of cases, and palatal spines were observed in 33.8%. The prevalence of palatal tubercles was 11.6%, and all were found in the molar region. The palatine torus was found in 18.8% of cases and the most common type was along the median palatine suture from the incisive foramen to the posterior border of the palatine bone (63.3%). No significant differences between sexes or sides were found in the posterior palatine crest, palatal ridges, and palatal tubercle. However, the sex distribution of the palatine torus was significantly different (P < 0.05). These results would be helpful clinically in fabricating maxillary complete dentures for edentulous patients.     

Decellularized human Schneiderian membrane: Electron microscopic study as a bioscaffold and preliminary cell seeding

BackgroundPerforation of maxillary sinus mucous membrane is one of the most prevalent complications during open sinus lift surgery. Moreover, such complication can usually be managed by an absorbable membrane. As far as absorbable membranes are concerned, decellularized maxillary sinus mucous membrane, which is an extracellular matrix, can be used as a biologic scaffold and an insulating membrane in sinus lifting surgery.Materials and methodsThe decellularization process of the maxillary sinus membrane was performed by means of physical and chemical procedures (liquid nitrogen and sodium dodecyl sulfate). Then this membrane was used as a bioscaffold for culturing with adult mesenchymal stem cells, which were derived from adipose tissue.ResultsHistologic evaluation of the decellularized scaffold revealed that cells of the Schneiderian membrane were compatibly removed via SDS 1%. Moreover, the scan with electron microscope (S6N – Leo vp1450, Germany) of the scaffold indicated that the collagen fibers of the decellularized maxillary sinus membrane were intact. Furthermore, the culture studies carried out showed that this scaffold supported cell seeding.ConclusionThe decellularized human maxillary Schneiderian membrane has a 3D structure similar to that of the extracellular matrix of human normal tissues. As a matter of fact, it can be used as a bioscaffold to support cell seeding.     

上颌窦底骨分隔对内提升术后成骨效果的影响

目的　上颌窦骨分隔被认为是上颌窦内提术的相对禁忌症,文中旨在探讨上颌窦底骨分隔对内提升术后成骨效果的影响。 方法　收集上颌窦底骨分隔需内提升进行种植的患者7例（有分隔组）,另随机选取上颌窦无分隔需进行内提升的患者8例（无分隔组）,共15例,利用CBCT(Cone Beam Computed Tomography)和Simplant软件对植体周围骨高度及骨密度进行测量,采用SPSS19.0软件对数据进行统计分析。 结果　有分隔组及无分隔组的提升高度,植体根尖高度差,颊侧高度差,根尖区骨密度,颊侧骨密度的对比,P值均大于0.05,两组结果差异无统计学意义。 结论　上颌窦底骨分隔内提升术后的成骨效果无明显影响。     

翼腭神经节的解剖研究及其临床意义

目的　研究翼腭神经节及毗邻结构的显微外科解剖关系,为临床手术治疗相关疾病提供解剖学依据。 方法　成人尸头标本15例（30侧）,采用手术显微镜及鼻内镜观察翼腭神经节及毗邻结构。 结果　翼腭神经节为翼腭窝内副交感神经节,为翼管神经、上颌神经、腭神经三者交汇处,位于内上方为翼管神经,位于外下方为上颌神经,位于下方为腭神经,腭神经起始于腭骨垂直板与上颌骨后壁的夹角处,腭神经起始处外径为（1.23±0.32）mm,向前内走行,并于腭降动脉的后内侧逐渐紧贴腭骨垂直板下降进入翼腭管。 结论　翼腭神经节与腭神经及翼管神经相邻,先通过腭神经寻找到翼腭神经节,再通过翼腭神经节可定位翼管神经,因此可作为翼管神经切除术中的重要解剖标志。     

Comparative histomorphometric and tomographic analysis of maxillary sinus floor augmentation in rabbits using autografts and xenografts

Our goal was to evaluate bone neoformation promoted by a bovine xenograft composite (XC) compared with autogenous graft for maxillary sinus augmentation in a rabbit model. The left maxillary sinus of 18 male rabbits was filled with 200 mg of cortical and cancellous autogenous bone and the right sinus was filled with 200 mg of a composite comprised organic and inorganic bovine matrices, pool of bBMPs and collagen. Postoperative implant intervals of 2, 4, and 8 weeks were analyzed. Differences in the bone optical density among the groups and experimental periods were evaluated by computed tomography analysis. The tissue response was evaluated by histomorphometric analysis of the newly formed bone, connective tissue and/or granulation tissue, residual material, and bone marrow. The tomographic analyses showed a maximum optical density in the 4-week period for both groups. Histologically, an inflammatory infiltrate was observed at 2 weeks in the XC group but exclusively around the organic particles of the biomaterial. Regarding to the amount of newly formed bone, no statistical differences (p > 0.05) were observed among the two treatments throughout the implant intervals. However, by the end of the 8 weeks, the quantity of bone marrow was two times greater (p < 0.05) in the control group than in the XC group. In conclusion, the xenograft composite promotes formation of new bone in a similar fashion to autogenous bone and could therefore be considered a biomaterial with potential applications as a bone substitute in maxillary sinus floor augmentation.     

鼻腔外侧壁相关结构的解剖研究及其临床意义

目的　研究鼻腔外侧壁重要解剖结构的显微外科解剖关系,为临床手术治疗相关疾病提供解剖学依据。 方法 成人尸头标本15例（30侧）,采用手术显微镜及鼻内镜观察鼻腔外侧壁相关解剖结构。 结果 蝶腭动脉是供应鼻腔外侧壁的主要动脉,经过蝶腭孔时分为鼻后外侧动脉及鼻中隔后动脉两支。80%（24侧）鼻后外侧动脉从蝶腭动脉下方发出,20%（6侧）从蝶腭动脉上方发出,分出处位于筛骨嵴后方。鼻中隔后动脉有86.7%（26侧）在蝶窦前下壁分为上、下两支,13.3%（4侧）在进入鼻中隔后分为上、下2支。上颌窦开口位于中鼻道半月裂孔内,66.7%（20侧）开口位于半月裂孔中1/3段,30%（9侧）位于半月裂孔后1/3段,3.3%（1侧）开口于上鼻道,86.7%（26侧）上颌窦内口高于眶底水平。鼻囟门平均大小为（14.81±4.28）mm（前后径）×（9.71±1.43）mm（上下径）。 结论 蝶腭动脉及其分支和鼻囟门是鼻腔外侧壁手术中重要的解剖标志,熟悉其解剖关系有助于有效安全地开展鼻内镜手术。     

Quantitative and qualitative bone analysis in the maxillary lateral region

Purposes

The present study was conducted to assess the amount of bone present between root apices and the maxillary sinus floor in the maxillary lateral region, to compare the evaluations on cone beam computed tomography (CBCT) and orthopantomography (OPG), and to evaluate the bone density of the same region using three-dimensional images on CBCT.

Methods

Fifty-one dental patients were recruited for the study. All subjects were partially edentulous. The distances from the maxillary premolars and molars apices to the maxillary sinus floor were assessed using CBCT and OPG. Color codes were assigned to the bone density of edentulous loci. Parametric and non-parametric tests were used for statistical analyses. A p value <0.05 was considered statistically significant.

Results

The maxillary first and second molars recorded the shortest mean distances to the sinus floor, in contrast to the maxillary first premolar. The bone density of the maxillary lateral area increased from the maxillary first premolar to the second molar. No statistical significant differences were found between the evaluated sites.

Conclusions

Our results provide estimates of the minimal and maximal distances between teeth and sinus, as well as the average bone density in the maxillary lateral region. It is important that evaluation of a specific patient be performed during the preoperative planning of implants.