Three-dimensional evaluation of soft tissue changes in the orofacial region after tooth-borne and bone-borne surgically assisted rapid maxillary expansion

Objectives

This study seeks to three-dimensionally assess soft tissue changes in the orofacial region following tooth-borne and bone-borne surgically assisted rapid maxillary expansion (SARME).

Materials and methods

This prospective cohort study included 40 skeletally mature patients with transverse maxillary hypoplasia. A tooth-borne distractor (Hyrax) was used for expansion in 25 patients. In the remaining 15, a bone-borne distractor (transpalatal distractor, TPD) was used. Cone beam computed tomography (CBCT) scans were acquired before treatment (T0) and 22 months later (T1). 3D models were constructed from CBCT data and superimposed using voxel-based matching. Distance maps between the superimposed 3D models were computed to evaluate the degree of skeletal and soft tissue changes in the maxillary region.

Results

Distance maps showed negative distances (mean ?1.25 (±1.5) mm) in the middle of the upper lip, indicating posterior repositioning of this area. The cheek region showed positive changes (mean 1.66 (±1.1) mm), reflecting the underlying increase in maxillary width. There was no significant difference between the two groups in all measured distances (p?>?0.05). Retro-positioning of the upper lip accompanied skeletal remodeling in the anterior alveolar region at a mean ratio of 88 %, while the cheek region followed 32 % of the alveolar expansion.

Conclusion

Soft tissue changes following SARME include posterior repositioning of the upper lip and increased projection of the cheek area. These changes were comparable between bone-borne and tooth-borne appliances.

Clinical relevance

This study provides clinicians with more information over the expected orofacial soft tissue changes following SARME     

Morphologic evidence of muscle influence on dental arch width.

Tests on hypotheses to explain changes in arch width during correction of distoclusion with the activator appliance used in this study showed that statistically significant increases occurred in both maxillary and mandibular arch widths during treatment. The increase was substantially larger in the maxilla than in the mandible. The arch width showed no statistically significant decrease after completion of treatment. The activator designed for this study affected orofacial muscle balance. The findings suggest that there were changes in the influence of tongue and cheek muscles on the maxilla. Available experimental as well as clinical data support the assumption that the tongue had taken a higher and more anterior position in the palatal area and that the tension of the cheek muscles was reduced relative to the posterior part of the maxillary dental arch.     

鼻内窥镜微创手术治疗牙源性上颌窦炎的临床观察

目的探讨慢性牙源性上颌窦炎应用鼻内窥镜手术的治疗效果。方法回顾性分析41例慢性牙源性上颌窦炎患者的临床资料，其中采用柯-陆氏手术治疗24例，采用鼻内窥镜下联合进路中鼻道上颌窦造口术17例，比较两种方法的治疗效果。结果采用柯一陆氏术式者面颊肿胀、面颊麻木、上牙槽酸痛的发生率分别是100．0％、37．5％、33.3％，鼻内窥镜手术组未见上述表现；柯-陆氏术式第一次手术拔牙率37．5％(9／24)，5例再次手术者均拔除患牙，总拔牙率58．3％(14．／24)，鼻内窥镜手术组拔牙率35．3％(6／17)，11例经根管治疗的牙齿保存良好；柯-陆氏手术组3年内复发率为37．5％(9／24)，而鼻内窥镜手术组术后3～6个月鼻道窦口复合体完全恢复通畅，随访1～3年未见复发。结论鼻内窥镜微创手术能最大限度减少上颌窦粘膜及骨质的损伤，利于术后恢复，在保留鼻窦正常生理功能、保存牙齿及减少复发率等方面明显优于传统的柯一陆氏手术。     

骨性Ⅲ类错(牙合)正颌术后颊部宽度变化的三维研究

目的 探讨骨性Ⅲ类错(牙合)患者正颌术后颊部宽度变化的规律.方法 20例完成正颌手术的骨性Ⅲ类错(牙合)患者,男性9例,女性11例,平均年龄(25.06±5.33)岁,其中9例接受双侧下颌升支矢状劈开截骨(Bilateral sagittal split ramus osteotomy,BSSRO)后退术,11例接受Lefort-Ⅰ型截前移骨术和BSSRO后退术,分别在术前2周(T1)、术后6个月(T2)进行面部激光扫描检查,手术前后软组织面型的三维图像在同一坐标系中完成测量,分析颊部宽度的变化.结果 在经过外眦连线中点的冠状截面上,20例患者术后单侧颊部软组织宽度增加(3.58±2.21) mm,不同性别之间无显著性差异;下颌后退组单侧颊部增宽(1.74±0.76) mm,双颌手术组单侧颊部增宽(5.00±1.86) mm,两组之间存在显著性差异(P=0.001).结论 骨性Ⅲ类错(牙合)接受单纯下颌后退或者双颌手术后,颊部宽度均有增加的趋势.     

牙源性皮瘘病例报告及文献回顾

目的：通过病例分析,总结牙源性皮瘘的年龄分布及患牙位,为临床诊断、治疗及疗效评价提供依据。方法：展示6例牙源性皮肤瘘管的术前和术后面部和口内照片、X 线牙片,回顾以往报道的皮瘘病例60例,分析牙源性皮瘘的面部好发部位、及其对应的患牙位。结果：牙源性皮瘘主要好发在颊部、颏部、鼻旁和下颌下部4个部位,对应的患牙位分别是下颌第三磨牙、下颌切牙、上颌尖牙及下颌第一、第二磨牙,以下颌牙齿为主（71．2％）;相对于鼻旁和下颌下部皮肤瘘管好发于中老患者,颊部、颏部皮肤瘘管好发于年轻患者。对慢性牙周炎病灶牙进行根管治疗,拔除无需治疗的病灶牙,牙源性皮瘘均可痊愈。结论：对病灶牙的正确治疗是治疗牙源性皮瘘的主要方法。     

Inflammatory myofibroblastic tumor of the maxillary sinus related with pulp necrosis of maxillary teeth: case report

Inflammatory myofibroblastic tumor (IMT) is a benign lesion composed of myofibroblasts accompanied by varying numbers of inflammatory cells. Various pathogenetic factors have been proposed, but the etiology of most IMTs remains unknown. This article presents a case of IMT occurring in the left maxillary sinus. A 24-year-old man complained of throbbing pain in the maxillary left molars and swelling of the left cheek. His maxillary left second molar was diagnosed as pulp necrosis and root canal treatment performed. After that, his symptoms continued and he was referred to the Department of Otolaryngology. Computerized tomography disclosed compact soft tissue masses in the left maxillary sinus with obstruction of maxillary ostium. Under general anesthesia, the lesions were fully excised. Histopathologically, the lesions were composed of plump or spindled myofibroblasts. Cells were immunoreactive for smooth muscle actin and β-catenin, and were negative for ALK1, CD34, and EMA. The diagnosis was IMT of left maxillary sinus. Although it is very rare, IMT should be included as a differential diagnosis in patients with compact masses in maxillary sinus.     

Silent sinus syndrome: report of a case

Silent sinus syndrome (SSS) is a quite rare clinical entity characterized by unilateral enophthalmos and hypoglobus secondary to thinning and inward bowing of the maxillary sinus roof in the absence of signs or symptoms of intrinsic sinonasal inflammatory disease. We present a case of a 16-year-old female with a 10-month history of facial asymmetry due to swelling of the left cheek and ptosis of the left eye with no other symptoms. Computed tomography scans and Water's x-ray revealed an opacified left maxillary antrum with characteristic features of SSS. The patient underwent surgery and a thick maxillary sinus mucocele was found and enucleated successfully during the operation. Six-month and 2-year follow-ups after surgical treatment revealed satisfactory results and there was no need for reconstruction of the orbital floor. Although patients with SSS often initially present to ophthalmologists, oral and maxillofacial surgeons and radiologists should be familiar with this phenomenon since most of these patients will be referred to dental hospitals for further treatment.     

Three-dimensional primary reconstruction of anterior mouth floor and ventral tongue using the 'trilobed' buccinator myomucosal island flap

Three-dimensional reconstruction of the anterior mouth floor and ventral tongue after ablative surgery can be achieved using several techniques. The ideal reconstruction should be accomplished with the same or similar type of tissue, and cheek axial myomucosal flaps based on the branches of facial or internal maxillary arteries seem ideal for this purpose. From March 2005 to May 2007, 23 patients underwent cheek axial myomucosal flap reconstruction after oral cancer surgical ablation. Thanks to their thinness and pliability, these flaps were frequently shaped to obtain an accurate reconstruction. According to Whetzel's hypothesis, an intraoral flap designed to include the axial vessel of one area can safely carry the mucosa of a neighbouring vascular area. The authors describe a large buccinator myomucosal island flap based on the branches of the facial artery and formed in a trilobed shape in order to capture the adjacent buccal mucosal angiosome from the internal maxillary artery. The flap provided the correct anatomical oral reconstruction for the anterior mouth floor and ventral tongue. The function of the tongue, oral intake and mastication were not impaired. The trilobed buccinator myomucosal island flap is a suitable option for the three-dimensional reconstruction of the anterior mouth floor and ventral tongue.     

上唇系带附着异常及其治疗方法研究进展

上唇系带位于面部美学区,将唇、颊黏膜连接到牙槽黏膜、牙龈和骨膜,以便能够适应正常的唇活动。其附着异常与母乳喂养困难、菌斑堆积、儿童龋病、牙周疾病的发生和进展、上颌中切牙间隙等密切相关。因此,及时对异常附着的上唇系带进行治疗至关重要。文章对上唇系带的发育与解剖结构、上唇系带附着异常的临床诊断与分类方法、上唇系带附着异常与上颌中切牙间隙的关系以及上唇系带附着异常的治疗方法等几方面内容做一综述。     

Effect of setback Le Fort I osteotomy on midfacial soft-tissue changes as evaluated by cone-beam computed tomography superimposition for cases of skeletal Class III malocclusion

This study employed the cone-beam computed tomography (CBCT) superimposition method to evaluate postoperative midfacial soft-tissue changes in cases of skeletal Class III malocclusion after double-jaw surgery with setback and vertical reduction Le Fort I osteotomy. A retrospective study was carried out on 15 patients who had undergone maxillary setback Le Fort I osteotomy and mandibular setback sagittal split ramus osteotomy with alar cinch suturing and V-Y soft-tissue closure. Three dimensional CBCT volume scans were recorded preoperatively (T0) and 6 months postoperatively (T1) to measure soft-tissue changes of the upper lip and midface. Post-surgery, soft-tissue landmarks in the cheek and paranasal areas had moved forward; the soft-tissue thickness at the A-point had markedly increased (P < 0.05); there was no significant change in the subnasale, and the midline of the soft-tissue of the upper-lip area had moved backward. The extent of the mean soft-tissue change at the labrale superius was greater than that at the other soft-tissue landmarks of the upper lip. The results suggest that maxillary setback movement of the maxilla by alar cinch suturing has a beneficial effect on paranasal soft-tissue and lip contours for patients with protrusive lip and acute nasolabial angle.     

Detachable cheek plumpers with different attachments for improving esthetics in a conventional complete denture: A clinical report

Aging is associated with loss of teeth, resorption of the alveolar process, and reduced tonicity of the facial muscles, leading to sunken cheeks and an unesthetic appearance. Esthetics in patients in need of complete dentures can be improved with the help of cheek plumpers to support the cheeks. They are noninvasive and straightforward to fabricate. Despite the reported success with the sole use of maxillary cheek plumpers, in certain situations, maxillary cheek plumpers provide inadequate support to the cheeks, evident in the lower third of the face. This clinical report describes a technique for fabricating detachable mandibular and maxillary cheek plumpers with 2 different types of attachment mechanisms.     

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??The maxillary frenum locates in the facial aesthetic area?? which is a mucous membrane fold that attaches the lip and the cheek to the alveolar mucosa?? the gingiva?? and the underlying periosteum and adapt to the mobility of lip. Its abnormal adhesion is closely related to the breastfeeding difficulties?? plaque accumulation?? child caries??the development of periodontal disease and maxillary midline diastema.  Therefore??it is important to treat abnormal adhesion of maxillary labial frenum timely. This article reviews the development and anatomic structure of maxillary labial frenum??the clinical classification and diagnostic methods of the abnormal adhesion of maxillary libial frenum??the relationship between abnormal adhesion of the maxillary labial frenum and maxillary midline diastema and its therapies.     

异常吞咽与口周力相关性的研究

目的：定量分析异常吞咽口周力的分布特征。方法：用微力传感器和计算机辅助口周力测量系统对12名异常吞咽患者和12名正常吞咽错He患者上下颌中切牙、尖牙、第一磨牙颊、舌侧进行口周力的测量，对测量数据进行了统计学分析。结果：正常吞咽时男女之间各牙位的口周边值无显著性差异；异常吞咽时男性口周力大于女性，口周力与性别有相关性；异常吞咽组口周力大于正常吞咽组，其间差异有显著性。无论正常吞咽组还是异常吞咽组同侧上下颌同名牙位唇、颊侧与舌侧压力相比有显著性差异，下颌唇舌侧压力大于上颌唇舌侧压力。结论：异常吞咽时口周力与性别有相关性；异常吞咽组口周力大于正常吞咽组；舌的功能运动影响口周力，口周力会因吞咽方式的改变而发生适应性的变化。     

螺旋扩大器快速打开腭中缝后口颌系统横向变化的研究

目的 探讨支架半托式螺旋扩大器快速打开腭中缝后,口颌系统中牙齿、颌骨、肌肉的变化.方法 20例上颌骨发育不足伴上颌牙弓狭窄患者在快速打开腭中缝前后拍摄后前位头颅定位片,进行测量分析,同时测量颊肌压力变化.结果 上颌中切牙冠间距和根间距分别增大了（4.34±1.18） mm和（3.74±1.75） mm;上颌第一磨牙间距和上颌骨宽度分别增大了（7.83 ±1.49） mm和（5.07±1.07） mm;上颌尖牙间宽度增大了（6.79±1.82） mm;牙槽嵴间距、前鼻嵴间距和鼻腔宽度分别增大了（4.32±0.98） mm、（3.69±0.83） mm和（2.08±0.72） mm;双侧上颌第一磨牙处颊肌压力分别增大了（857.01±300.96） Pa和（772.06±296.93）Pa.结论 支架半托式螺旋扩大器可以快速打开腭中缝,牙齿、颌骨、颊肌压力均发生了显著变化.     

Instrumented indentation characterisation of mouth-guard materials.

OBJECTIVES: The aim of the study was to investigate the mechanical properties and energy absorption behavior of mouth-guard materials. Interpretation of indentation force-displacement data has been used to determine these properties. METHODS: An ultra micro-indentation system (UMIS) was used to determine near surface properties of mouth-guard materials with nanometer and micro-Newton displacement and force resolution. The measurement procedure was conducted with a small spherical steel indenter (R=500 microm), with impressions that were equally spaced (250 microm). Measurements of force-displacement response of surfaces at maximum forces of 10, 40 or 50 mN, 10 indentations were made at each of these forces. Tests were undertaken in two different modes to determine the mechanical properties, namely: (a) continuous load to the maximum force and then unload, (b) multiple loading and partially unloading sequence to the maximum load. RESULTS: The force-displacement results were analysed to determine the elastic modulus and contact pressure versus depth of penetration as well as the energy loss. Energy absorption for each material was determined from the ratio of the hysteresis energy loss to the total energy at maximum load and ranged from 10 to 24% among different mouth-guard materials. Energy absorption ratio, elastic modulus and contact pressure were significantly different between different materials with same thickness (FC, GC and C3) (p<0.01) and significantly different between materials with different thickness (C1 and C3) (p<0.01). SIGNIFICANCE: The present approach provides a simple and efficient method to readily measure the elastic-plastic (hysteretic) response of mouth-guard materials. The indentation technique lends itself to investigate the influence of ageing, heat treatment, sterilisation, moisture etc in a simple systematic manner.     

上颌第一磨牙近中颊根MB2根管研究

目的：观测上颌第一磨牙近中颊根MB2的存在率,根管口的位置及形态。方法：采用牙体硬组织切片机对拔除的上颌第一磨牙进行连续横断切片,并在显微镜下观测其近中颊根第二根管存在情况,根管口位置及根管形态。结果：220个上颌第一磨牙中有81个存在近中颊根第二根管,存在率为36．81％,近颊根第二根管口横切面形态为圆形或卵圆形,近颊第二根管口与近颊第一根管口,远颊根管口和腭根管口的位置关系呈斜四边形。结论：上颌第一磨牙近中颊根第二根管存在率较高,其开髓形状应为斜四边形。     

Cranial nerve injury after Le Fort I osteotomy

A Le Fort I osteotomy is widely used to correct dentofacial deformity because it is a safe and reliable surgical method. Although rare, various complications have been reported in relation to pterygomaxillary separation. Cranial nerve damage is one of the serious complications that can occur after Le Fort I osteotomy. In this report, a 19-year-old man with unilateral cleft lip and palate underwent surgery to correct maxillary hypoplasia, asymmetry and mandibular prognathism. After the Le Fort I maxillary osteotomy, the patient showed multiple cranial nerve damage; an impairment of outward movement of the eye (abducens nerve), decreased vision (optic nerve), and paraesthesia of the frontal and upper cheek area (ophthalmic and maxillary nerve). The damage to the cranial nerve was related to an unexpected sphenoid bone fracture and subsequent trauma in the cavernous sinus during the pterygomaxillary osteotomy.     

Variation and density of microplications in superficial cells of the normal oral lining mucosa in the monkey Macacus fascicularis

A scanning electron microscopic study on the oral surfaces of the buccal and labial mucosa of Macaca fascicularis was carried out to determine the variation and density of the microplication patterns expressed by the outer surface of superficial cells of non-keratinizing oral epithelium. Micrographs were recorded at two levels of magnification. A total of 76 micrograph pairs were used to estimate stereologically the visible cell surface area, the total microplication length and density per cell, as well as the frequency of occurrence of eight particular plication features. The visible surface area of cheek cells was slightly but insignificantly smaller than that of labial cells, with a proportional difference in the total microplication length. The basic microplical surface features were identical in cheek and lip cells but some, such as bifurcations and most types of free endings, occurred more frequently in lip than in cheek cells. The plication density ranged from 120 to 550 μm/100 μm² cell surface area. Independent of microplication density but based on the type of feature combination, four different microplication patterns could be distinguished, which occurred with equal frequency in both cheek and lip cells. The functional meaning of cell surface microplication is discussed in terms of several hypotheses: (1) intercellular interdigitation for the purpose of adhesion, (2) protection by way of reducing the surface area of cell contact, (3) channel formation for aiding laminar flow distribution of lubricating secretions, and (4) reserve surface area for cell stretching.     

台阶式垂直闭合曲内收上颌切牙的三维有限元分析

目的 研究台阶式垂直闭合曲在三维空间内对上颌切牙位置的控制作用.方法 选择一名正常 志愿者,对其上颌牙列和牙槽骨进行三维螺旋CT扫描,只对上颌右侧中、侧切牙及牙槽骨进行建模和数据计算,利用Ansys软件生成右侧弓丝-托槽-上颌切牙段及牙周支持组织的三维有限元模型,最后根据镜像对称原理建立弓丝-托槽-上颌切牙段及牙周支持组织的三维有限元模型.模拟台阶式垂直闭合曲在临床上的使用情况加力,分析上颌切牙的位移趋势以及牙周支持组织中的应力分布规律.结果 台阶式垂直闭合曲作用下,上颌中切牙舌向、唇向最大位移分别为5.29×10-2和0.71×10-2 mm;龈向、向最大位移分别为10.47×10-3和10.20×10-3 mm;近中、远中最大位移分别为10.26×10-3和1.63×10-3 mm;侧切牙舌向、唇向最大位移分别为3.31×10-2和0.41×10-2 mm;龈向、向最大位移分别为10.52×10-3 和5.10×10-3 mm;近中、远中最大位移分别为6.29×10-3 和4.64×10-3 mm;二者均表现为舌向、龈向的近似整体移动趋势.中切牙牙齿、牙周膜、牙槽骨的最大应力值分别为31.35、2.52、4.64 MPa;侧切牙牙齿、牙周膜、牙槽骨的最大应力值分别为19.59、1.28、4.12 MPa;二者的应力分布规律相似,牙周膜对应力起缓冲作用.结论 台阶式垂直闭合曲在上颌切牙内收阶段可控制其在三维方向上的位置,对抗"钟摆效应",对临床实践具有一定参考意义.

Abstract：

Objective To investigate the displacement and stress distribution of upper incisors in three-dimensional(3D) space controlled by step-shaped vertical closing loop. Methods The maxillary teeth and alveolar bone of a volunteer with normal occlusion were scanned with 3D spiral CT. Modeling and calculation were only carried out on right upper central incisor, lateral incisor and their alveolar bone in order to simplify the procedures. A 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was developed using Ansys finite element package. Finally, a 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was established based on mirror symmetry principle. The displacement of maxillary incisors and stress distribution in periodontal tissues were analyzed. ResultsWhen step-shaped vertical closing loop was simply drew back 1 mm, the maximum displacement of upper central incisor in labial and lingual direction were 5.29×10-2 and 0.71×10-2 mm; 10.47×10-3 and 10.20×10-3 mm in gingival and occlusal direction, 10.26×10-3 and 1.63×10-3 mm in medial and distal direction; the maximum displacement of upper lateral incisor in labial and lingual direction were 3.31×10-2 and 0.41×10-2 mm, 10.52×10-3 and 5.10×10-3 mm in gingival and occlusal direction, 6.29×10-3 and 4.64×10-3 mm in medial and distal direction, the displacement trend of them were moving lingually and gingivally similar to bodily movement. The stress peach of upper central incisor, periodontal ligament and alveolar bone were 31.35, 2.52 and 4.64 MPa, the stress peach of upper lateral incisor, periodontal ligament and alveolar bone were 19.59, 1.28 and 4.12 Mpa, the stress distribution of them were similar and the periodontal ligament buffered the stress imposed on the tooth. Conclusions The position of upper incisors in 3D space could be controlled by step-shaped vertical closing loop and the pendulum effect could be confronted.     

骨性Ⅲ类错牙合与额窦和上颌窦大小的相关性研究

目的　通过头颅侧位片测量额窦与上颌窦的面积，探讨骨性Ⅲ类错牙合与额窦和上颌窦大小的相关性。方法　选取2009年8月至2018年6月于中国医科大学附属口腔医院奉天门诊就诊的骨性Ⅲ类错牙合患者233例作为研究组，另选取同期收治的安氏Ⅰ类错牙合患者239例作为对照组。所有患者均拍摄头颅侧位片，使用Winceph 8.0软件定位头颅侧位片额窦和上颌窦边界，分别测量其面积。采用SPSS 21.0统计软件对所得数据进行分析。结果　研究组患者额窦和上颌窦面积均大于对照组，差异有统计学意义（t值分别为-9.298、-9.495，均P < 0.05）。研究组中男性患者额窦和上颌窦面积均大于女性患者，差异有统计学意义（t值分别为-6.684、-4.183，均P < 0.05）。对照组中男性患者额窦面积大于女性患者，差异有统计学意义（t = -4.426，P < 0.05）；而对照组不同性别患者的上颌窦面积比较，差异无统计学意义（P > 0.05）。结论　骨性Ⅲ类错牙合可能会影响额窦和上颌窦的大小，不同性别骨性Ⅲ类错牙合患者的额窦和上颌窦大小有差异。