Orofacial prosthesis design and fabrication using stereolithography

The use of stereolithography for the manufacture of implantable prostheses is relatively new. Until now, its use with regard to mandibular resection has been to produce pre-operative models that allow more sophisticated planning of the contour and better preparation of the metallic framework to be implanted. This framework rejoins the sections of the mandible, returning some function, but providing no soft tissue support. Hence, the aesthetic results are not optimal. The aim of this study was to investigate the accuracy with which a stereolithographic model could be made to completely reunite both surfaces of the resected mandible and restore full contour. The design and fabrication of a mandibular prosthesis utilizing CAD/CAM technology and stereolithography is still in the early stages, but initial results indicate that with further research and better tools this could provide a new approach to mandibular resections, providing better aesthetic results.     

Aesthetic smile evaluation--a non-invasive solution

Enhancement of the aesthetic zone is a common reason for patients to seek dental care. This article describes a protocol for the examination, assessment and treatment planning for a patient seeking a solution to an aesthetic concern. The technique of undertaking an intra-oral'mock-up' using resin composite as a diagnostic approach can be particularly helpful when planning for future prosthodontic rehabilitation. The latter can allow the operator and patient to visualize crudely what is aesthetically and functionally possible, given the constraints imposed by that patient. The patient has ultimately managed in a minimally invasive manner. CLINICAL RELEVANCE: It can be very tempting for a dental operator to impose his/her concepts of the'artistic ideal' when planning for care in the smile zone. Such ideals are largely based on established universal aesthetic principles of tooth colour, size, shape, form, position, symmetry and proportion. However, beauty is a very subjective matter. It is essential for the operator to listen attentively to his/her patient's concerns. Meticulous patient examination and assessment are absolutely critical factors in attempting to attain a successful outcome. The use of reversible, chairside intra-oral mock-up techniques can not only help with the transference of essential information to the dental technician when planning for restorative intervention in the smile zone, but can also allow the patient to gain an insight and indeed contribute his/her views to the possible restorative endpoint, respectively.     

微创和无创瓷贴面修复的适应范围

瓷贴面修复是经典的微创美学修复形式,但经典的瓷贴面修复仍需通过牙体预备获得主体厚度为0.7-0.8mm的修复空间.为获得更加微创的效果,学者们不断探索更加微创的修复手段,微创和无预备瓷贴面修复可满足临床医师和患者更加微创的要求,但其治疗效果有所局限、适应范围也更为有限.本文首先从外部空间的概念探讨了微创贴面所需的修复空间的获得形式,当具备一定的“外部修复空间”时,就有机会采用更为微创的治疗方案;之后探讨了微创瓷贴面的优势和局限性,只有当其局限性对修复效果的影响可控、可接受时,方可采取这种治疗形式;最后从颜色缺陷、形态排列缺陷、患者唇齿感受和功能等方面探讨了患者美学缺陷和需求评估的问题.     

Lasers in aesthetic dentistry

This article focuses on lasers and aesthetic dentistry and their unique parallel in history from their early development to their present day usage and application. The demand for aesthetic dentistry has had a major impact not only on treatment planning but also on the choice of materials, techniques, and equipment. It is this demand that has married the use of lasers with aesthetic dentistry. A short literature review on the five basic laser types precedes the basic premise of smile design and its critical importance in attaining the desirable aesthetic end result. A short review on biologic width and biologic zone reinforces their importance when manipulating gingival tissue. Four case reports highlight the use of diode, erbium, and carbon dioxide lasers. The end results show the power of proper treatment planning and the use of a smile design guide when using these instruments and confirm a conservative, aesthetic treatment without compromising the health and function of the patients.     

Treatment of congenital facial nevi

The treatment of congenital facial nevi is often difficult and challenging. Previous authors have reported their techniques, results, and complications when treating these lesions. Our objectives are to simplify the treatment planning by subdividing the lesions with a new classification and using this to formulate a surgical algorithm. One hundred and two patients with congenital facial nevi were reviewed. All of these patients have had surgical excision for the lesions. We have subgrouped the lesions into three groups, according to size, number of aesthetic units involved, and number of reconstructive stages required. Group I included lesions 1 to 3 cm in maximal diameter, within one aesthetic unit, and requiring one or two reconstructive stages. This group included 29 patients. Group II included lesions 3 to 12 cm in maximal diameter, covering one or two aesthetic units, and requiring not more than two stages of reconstruction. This group had 41 patients. Group III consisted of extensive lesions, over 12 cm in maximal diameter, covering several aesthetic units, and requiring several stages of reconstruction. In this group, we had 32 patients. On the basis of our experience in treating congenital facial nevi in this series, we have developed a surgical algorithm for reconstruction. We are optimistic that this will assist the surgeon in surgical planning and treating this complex patient population. The algorithm is arranged according to the new classification of congenital facial nevi that is presented.     

Operative tactics in floor of mouth and tongue cancer resection - the importance of imaging and planning

Complete tumour resection (R0 margin) is an axiom of surgical oncology. Oral cancer ablation is challenging, due to anatomical, functional, and aesthetic considerations. R0 margin is strongly linked to better survival outcomes with great variation in the R0 % across units. This is commonly attributed to disease biology. Without disputing the importance of biological characteristics, we contend that image-based anatomical surgical planning has an important role to play in achieving complete resection. Here, we present our approach utilising cross-sectional imaging, anatomical characteristics and spatial awareness in planning resections for floor of mouth (FOM) and oral tongue cancers. We highlight the challenge of controlling the deep tumour margin lingual to mandible due to anterior vector constraints and emphasise the importance of resecting the genial muscles in a planned fashion and that any rim resection should be obliquely sagittal. In resecting lateral FOM tumours, assessing extension to the parapharyngeal fat is crucial; and mandibular rim resection at a sagittal plane below the mylohyoid line is often required. Assessing the proximity of the contralateral neurovascular pedicle, pre-epiglottic space and hyoid bone are crucial parameters to determine the extent of tongue tumour resection. Our cohort included 173 patients with FOM SCC and 299 patients with tongue SCC. Six patients (3.5%) from the FOM group and eight patients (3%) from the tongue group had involved (R1) margins following surgery. This was associated with local relapse (p<0.05). In conclusion, we demonstrate that image-based planning can aid achieving R0 resections and reduce disease relapse.     

Three-dimensional osteotomy planning in maxillofacial surgery including soft tissue prediction

Preoperative planning of complex osteotomies in craniomaxillofacial surgery, in conjunction with a surgeon's expertise, is essential for achieving an optimal result. However, the soft tissue changes that accompany facial bone movements cannot yet be accurately predicted. Bony tissue, because of its greater density, can be better predicted, but it alone does not account for the final aesthetic result. A new approach using not only three-dimensional (3-D) surface models of the patient's anatomy, but also a corresponding volumetric model, is discussed. This 3-D planning software was used in the treatment of 15 patients and was found to provide a good correlation between simulation and postoperative outcome.     

Aesthetic crown lengthening: classification, biologic rationale, and treatment planning considerations.

The rationale for crown lengthening procedures has progressively become more aesthetic-driven due to the increasing popularity of smile enhancement therapy. Although the biologic requirements are similar to the functionally oriented exposure of sound tooth structure, aesthetic expectations require an increased emphasis on the appropriate diagnosis of the hard and soft tissue relationships, as well as the definitive restorative parameters to be achieved. The development of a clinically relevant aesthetic blueprint and attendant surgical guide is of paramount importance for the achievement of successful outcomes. LEARNING OBJECTIVES: This article provides a classification system that clinicians can use when treatment planning for aesthetic crown lengthening. Upon reading this article, the reader should have: A clear understanding of the involved biological structures. Didactic instruction on the classification and treatment planning for aesthetic crown lengthening procedures.     

Effect of presilanization filler decontamination on aesthetics and degradation resistance of resin composites

Filler-matrix coupling determines, to a large extent, the mechanical strength and clinical longevity of dental composites. The aim of this study was to examine how far a methodology to decontaminate filler prior to silanization may improve aesthetic performance in addition to physico-mechanical properties such as degradation resistance. It was reported that filler particles are surrounded and wrapped by a film that consists of multiple layers of silane molecules. X-ray photoelectron spectroscopy, however, revealed that silanization of filler particles largely depended upon siloxane bridge (Si-O-Si) formation between the silica surface and the silane molecule rather than on intermolecular bonding between adjacent silane molecules. In this study, we showed that filler decontamination resulted in a higher translucency, thereby providing a better aesthetic potential. In addition, experimental composites produced following presilanization decontamination of filler revealed a higher Vickers hardness value and a diametral tensile strength that was resistant to degradation by thermo-cycling.     

Correction of congenitally missing lateral incisors with porcelain veneers.

The ability of the dental professional to improve a patient's smile has become a benchmark in modern aesthetic dentistry. When one type of tooth is transformed into another through the restorative process, special care must be taken to ensure correct preparation and gingival contours to create the illusion that the teeth are in their correct position. With accurate digital photographic planning, active patient consultation, detailed tooth preparation, and a meticulous laboratory sequence, porcelain laminate veneers can be functional and can achieve the aesthetic expectations of the patient.     

Management of the peri-implant soft tissues

To provide a patient with an implant supported restoration that is functional and aesthetic requires effective diagnosis. Deficiencies in the bone and soft tissue can be dealt with in planning, and decisions can be made regarding what surgical corrections are indicated, and when these will be most effectively performed.     

美学牙冠延长术对于烤瓷修复前韵准备

目的：牙冠根向延长术属于是一种常见的牙周手术术式,其去除部分牙槽骨,可以降低龈缘的位置,重建生物学宽度,延长过短的临床牙冠,这样将有利于解决和修复前牙的美观问题。方法：将15例应用牙冠延长术对前牙进行美容修复治疗,均取得了良好的效果。结论：通过牙冠根向延长术保留临床上一定比例冠折牙,并解决临床过短牙冠的美观问题,使其获得较好的美学修复。     

口腔治疗中前牙区美学的考量因素

前牙区是口腔美学治疗的关键,前牙形态和位置的调整是系统性美学治疗的重要部分。临床诊疗中,口腔期望恢复天然牙形态使之与面型协调;关闭前牙间隙、调整中线位置使弓形美观、对称;通过垂直向和水平向控制使牙列与龈、颊组织关系协调,展现美丽微笑。完善的前牙美学治疗需要多学科联合、多种治疗方法介入,同时应考虑患者的文化背景和审美习惯,以实现最佳治疗效果。数字化诊疗技术为治疗前美学分析预测、治疗后美学评估提供了保障。该文结合国内外最新研究成果,从前牙位置、形态以及牙列与龈、颊等软组织关系等方面对口腔治疗中前牙美学考量因素作一综述,为美学区口腔治疗规划提供参考。     

Management strategies of the unsalvageable tooth

A tooth is deemed unsalvageable when it can no longer be preserved for use of function or aesthetic purposes. If proper treatment planning is done, tooth extraction can be performed with adjunctive procedures, to provide a more predictable restorative outcome for the patient.This review paper summarizes the possible treatment strategies available for the management of a tooth with a poor prognosis, so as to manage the patient better before the restorative treatment phase commences. Clinical Relevance: The management of an unsalvageable tooth using interdisciplinary approaches offers the clinician strategies for providing a more favourable restorative outcome.     

Simultaneous maxillomandibular distraction in unilateral mandibular hypoplasia

In craniomaxillofacial surgery we often deal with hypoplastic mandibles and mandibular asymmetries, the correction of which is critical to obtaining acceptable aesthetic results. In all of them we find common skeletal problems once growth has finished, such as an inclined occlusal plane and facial asymmetry with a stable dental occlusion. Simultaneous maxillomandibular distraction, which involves a Le Fort I osteotomy and a mandibular osteotomy with intermaxillary fixation during the period of active distraction, is an excellent technique to solve these problems. Virtual surgical planning, stereolithographic models, and surgical guides are supportive tools for obtaining excellent results. In this paper we present our experience with five cases of hypoplastic mandibles and mandibular asymmetries of different aetiologies. In all patients we achieved a considerable improvement in their physical appearance in the distance between the lateral canthus and oral commissure, the height of the mandibular ramus, the inclination of the occlusal plane, and the medial position of the chin. The benefits of virtual surgical planning in terms of choosing the optimal vector and the amount of distraction make it a promising technological tool to achieve excellent outcomes.     

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目的评价上颌前牙区种植义齿即刻修复的短期美学效果。方法选择中国医科大学附属口腔医院种植中心从2007年1月至2011年1月进行上颌前牙修复患者共60例,其中30例为种植后半年延期修复（延期修复组）,30例为种植后当天即刻修复（即刻修复组）,随访1年,通过牙龈乳头外形、骨吸收状况及满意度调查,评价两组患者的美学效果和满意度。结果随访1年时,即刻修复组牙龈乳头外形明显好于延期修复组（P〈0．05）;即刻修复后骨吸收小于延期修复（P〈0．05）;即刻修复组患者满意率高于延期修复组。结论在严格掌握适应证的前提下,即刻修复可很好地恢复美学区龈乳头外形,与延期修复相比骨吸收量较少,具有更佳的美学效果。     

Growth and development considerations for craniomaxillofacial surgery

The purpose of craniomaxillofacial surgery is to improve function, occlusion, craniofacial balance, and aesthetics. Accurate diagnosis, assessment, and careful treatment planning are essential in achieving a successful outcome, and an understanding of the pattern of facial growth is integral in this process. Patients with craniofacial congenital dysmorphologies, posttraumatic asymmetries, or disturbances of facial balance from radiation may have functional and/or aesthetic issues that require treatment. Understanding the complexities of growth in the skull and face is a key component to appropriate treatment planning for these disorders. This article reviews growth and development in the craniofacial skeleton.     

计算机辅助下单侧腓骨修复双侧下颌骨放射性骨坏死1例报告及文献复习

下颌骨放射性骨坏死是放疗晚期出现的一种常见并发症,严重影响头颈部肿瘤患者的生活质量。本文报告1例鼻咽癌放疗后双侧下颌支广泛坏死的病例,术前行虚拟手术计划,运用获取的数据为患者定制手术切除导板和复位导板,然后创造性地用一侧腓骨制作成2个独立的游离腓骨肌皮瓣,成功修复双侧下颌骨缺损,获得良好的美观和功能效果。     

Multidisciplinary management of anterior diastemata: clinical procedures.

Anterior diastemata may compromise the harmony of a patient's smile. Consideration of etiologic factors, previous gingival conditioning, and individual treatment planning are essential in the proper management of anterior diastemata. An integrated orthodontic-restorative approach may enhance the aesthetic results when orthodontic therapy itself is not feasible. This article presents integrated orthodonticrestorative solutions of anterior diastemata, associated with the conditioning of the gingival tissue with composite resin, and discusses the most relevant aspects related to their etiology and treatment planning.