Functional and esthetic improvement through reconstruction of anterior guidance using the modified Dahl principle and copy-milled technique of CAD/CAM system: A case report / 대한치과보철학회지

The anterior guidance is one of the important factors in prosthodontic treatment of anterior teeth. The lingual surface shape of anterior restorations is so critical that small errors of treatment procedure can cause discomfort of the patient and disharmony of the dentition. If the anterior restorations are achieved harmonious anterior guidance through the fabrication and adjustment of provisional restorations, it is important to accurately reproduce the lingual surface shape of provisional restorations as the final prosthesis. In this case report, it was used the modified Dahl principle and copy-milled technique of computer-aided design/computer-aided manufacturing (CAD/CAM) system for systematic diagnosis and treatment. Therefore, we tried to reconstruct the restoration shape more precisely by setting the appropriate anterior guidance and superimposing the digital image of the abutment teeth and the provisional restorations. Thus, by promoting functional and esthetic recovery, this case report demonstrates satisfying results to both the patients and dentist.

Maxillary anterior prosthetic treatment concerning anterior guidance of a patient who lost stable holding contact / 대한치과보철학회지

Recently, many patients undergo anterior prosthetic treatment for esthetic reasons. In some patients complain about functional reasons such as inaccurate pronunciation and occlusal discomfort after the treatment. Anterior teeth are important esthetically but in the occlusal point of view, anterior guidance is the second most important factor in occlusion, next to centric relation. Failure to determine an appropriate anterior guidance might lead to posterior occlusal interference, which can highly affect the stability of the posterior teeth. Also, discomfort might occur if the customized interior guidance is not in harmony with the patient's envelope of function. The patient in this case complained of overall discomfort in the maxillary anterior area after prosthetic treatment. The expressed difficulty in pronunciation, unstable occlusion due to lack of stable holding contact and discomfort of the facial muscles. Maxillary anterior prostheses were refabricated through systematic diagnosis and treatment and thus, this case presents esthetical and functional satisfaction to both the patient and the dentist.

A case of full mouth rehabilitation with orthodontic treatment in patient with extensive tooth erosion and wear using monolithic zirconia prostheses / 대한치과보철학회지

Extensive dental erosion and wear will cause serious loss of function and aesthetics in the mouth. In order to recover this condition, careful analysis of the patient's bite relationship is required. In particular, a treatment plan should be established considering the possibility of reproduction of the vertical dimension and centric relation, and appropriateness of the occlusal plane and anterior guidance. Also, the choice of prosthetic materials is an important consideration in patients with severe wear. In this case, patients with overall wear and erosion on tooth was established anterior guidance by orthodontic treatment and fully restored with monolithic zirconia, without increasing vertical dimension.

Functional and esthetic improvement through systematic diagnosis and treatment procedures in patient with unaesthetic anterior teeth proportion because of tooth wear: A case report / 대한치과보철학회지

It is reported that the causes of unaesthetic proportion of anterior teeth vary widely. Especially, when the unaesthetic tooth proportion of the mandibular incisors arises due to the wear of the anterior teeth accompanied by the compensation of the alveolar bone, it may cause serious functional and aesthetic problems. In such case, it should be considered that the evaluation of vertical dimension and tooth proportion as well as smile line, soft tissue and hard tissue morphology. And, increase of vertical dimension or clinical crown lengthening followed by prosthodontic restorations is needed to improve the interdental mesial/distal, width/length ratio considering the anterior guidance. This case report demonstrates functional and aesthetic improvements through systematic diagnosis and treatment procedures in a 48-year-old male patient with unaesthetic anterior teeth proportion because of tooth wear accompanied by the compensation of alveolar bone and defect of several central incisors due to chronic periodontitis.

Re-establishment of occlusal plane in a patient with a failed implant prosthesis / 대한치과보철학회지

A non-physiological occlusal plane caused by continuous tooth loss, occlusal wear, and failure of a prosthesis may result in an unattractive appearance and functional problems, such as reduced masticatory efficiency and occlusal interference. Therefore, when undertaking prosthetic treatment for edentulous patients or patients with a collapsed occlusal plane, it is important to establish an occlusal plane that is compatible with masticatory function. The patient in this case report had undergone restoration of a completely edentulous maxilla using an implant-supported fixed prosthesis. On follow-up examination in the following 6 years, mechanical complications were observed in the existing implant prosthesis, including porcelain chipping, occlusal wear, and screw loosening. Moreover, due to occlusal wear and supraeruption of the opposing anterior teeth, as well as loss of some posterior teeth, the occlusal plane had collapsed. Following diagnosis, the patient underwent full mouth rehabilitation, involving additional implant installation in edentulous sites, recreation of the existing prosthesis, and prosthetic restoration of all remaining teeth.

Establishment of rat models with altered anterior guidance and observation of histological changes in temporomandibular joint synovium / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to establish a stable animal model with altered anterior guidance and investigate histological changes on temporomandibular joint (TMJ) synovium in rats.</p><p><b>METHODS</b>Thirty-two rats were divided into four groups, namely, control group, anterior-guidance-deficient group (T1), and anterior guidance inclined up to 15 degree (T2) and 30 degree (T3) groups. Metal crowns that add 15 and 30 degrees to the palatal side were cemented to the incisors of maxilla to increase the inclination of anterior guidance. The low-speed diamond wheel shorts for both upper and lower incisors of rats were applied to avoid contact between anterior teeth in all direction, thus establishing an anterior guidance deletion model. TMJ joints on one side of two animals in each group were harvested after 3, 7, 14, and 28 days. Pathological changes were investigated in the TMJ synovium using hematoxylin-eosin (HE) staining.</p><p><b>RESULTS</b>The weight of T1 decreased briefly at first, and then increased slightly (P<0.05). The weight of T3 obviously reduced and then slowly increased, but remained below the initial weight (P<0.05). T3 manifested obvious synovial lining proliferation and vascular dilation (P<0.05).</p><p><b>CONCLUSIONS</b>The rat model of anterior guidance inclined up to 30 degree could imitate the pathological features of TMJ synovium with excessive increase in anterior guidance. A higher inclination of anterior guidance might cause more damage of TMJ synovium. The effect of anterior guidance deletion on TMJ synovium is yet to be determined.
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Maxillary anterior implant restoration with appropriate anterior guidance using T-Scan in a patient with full fixed prostheses / 대한치과보철학회지

In implant restorations, it is difficult for the patient to percept any symptoms. In addition, they are absent of shock absorbers, which can lead to mechanical failure if stress distribution is not considered. Since maxillary anterior multiple-implant restorations play a significant role in guiding the functional movement of the mandible by distributing lateral force, it is crucial to form appropriate occlusion. The use of the T-scan system is more advantageous in assessing ‘dynamic occlusion’, such as the change of occlusion over time, the amount of tooth contact during functional movement, and assessing the occlusion in the less-visible posterior teeth. The case is reported as it has satisfactory results in harmonious anterior guidance of a maxillary anterior multiple-implant restoration using T-scan analysis.

The concept of “dynamic functional design”for anterior teeth restoration and its clinical application / 实用口腔医学杂志

This article introduces a new concept,named “dynamic functional design”(DFD)for the anterior guidance control of prosthe-ses.The concept was proposed from the deficiency of “digital smile design”as a complement.Four key points have been discussed to realize DFD in clinic by 1 0 real cases,and a new classification for anterior teeth restoration is presented according to DFD in this paper.

Application of ARCUS digma I, II systems for full mouth reconstruction: a case report

Transferring condylar and anterior guidance on an articulator is essential to the diagnosis of a patient for full mouth reconstruction. In this clinical report, ARCUS digma I system was used to measure inherent condylar guidance of a patient requiring full mouth reconstruction in preoperate treatment, and the patients was given provisional restoration based on a functional anterior guidance. Then, ARCUS digma II system was used to mount the final casting model on an articulator, and the definitive prosthesis was placed in the patient. An esthetic and functionally proper clinical result regarding inherent condylar path of the patient was observed, and results from comparison of the two systems are given in this case.

Rehabilitation of a patient with non-syndromic partial oligodontia

Oligodontia is defined as a congenital tooth agenesis with the absence of six or more permanent teeth. This clinical report describes a patient with non-syndromic partial oligodontia, with retained deciduous teeth and the absence of 16 permanent teeth. Anterior esthetic problems were caused by interarch tooth size discrepancy, interdental space, aberrant tooth dimensions, and the absence of centric contacts of the anterior teeth. Prosthetic restoration after orthodontic and implant treatment was performed with a multi-disciplinary team approach. Favorable functional and esthetic results were obtained using a definitive prosthesis.

The design of anterior guidance for anterior prostheses / 实用口腔医学杂志

This article systematically introduces the basic conception,classification and physiological significance of anterior guidance for anterior prostheses.A customized incisal guidance table was introduced to record and transfer the individual value of the patient to a virtual full-adjustable articulator system.The clinic effects of the individual value and average value were also compared.

Developing Occlusion in Removable Partial Denture Using Functionally Generated Path Technique

Providing harmonious group function occlusion in artificial teeth either in removable partial denture or fixed partial denture is a difficult task. Developing group function needs fully adjustable articulator, which is not possible in routine clinical practice. In such cases functionally generated path technique (FGP) is ideal. It is very simple if we do it in a precise and systemic method. Only minimal occlusal adjustments are required during the clinical try-in stage, which is a major advantage over the conventional technique. In this case I used FGP technique to produce occlusion in removable partial denture.

Visualización del plano oclusal y guía anterior en desdentados parciales en la telerradiografía lateral: descripción de la técnica a través de casos clínicos / Occlusal plane and anterior guidance visualization in lateral cephalometric radiographs in partially edentulous patients: technique description through case reports

El uso de la telerradiografía lateral ha tomado gran importancia en Rehabilitación Oral ayudando al clínico en el diagnóstico y planificación del tratamiento a través de la identificación del biotipo facial del paciente, la inclinación del plano oclusal, la relación anteroposterior entre maxilar y mandíbula, inclinación de los ejes dentarios y como ayuda complementaria en casos de alteraciones de la Dimensión Vertical. El problema surge cuando estamos frente a pacientes desdentados que han perdido puntos de referencia cefalométricos necesarios para el análisis. El presente trabajo muestra una técnica para poder visualizar radiográficamente el plano oclusal y la guía anterior utilizando láminas de plomo.

The use of lateral cephalometric radiographs has become very important in Oral Rehabilitation, helping the clinician in the diagnosis and treatment planning through the identification of facial biotype, occlusal plane inclination, sagittal relationship between maxilla and mandible, inclination of the dental axes, and a valuable help in assessing alterations of the vertical dimension of occlusion. The problem arises when treating partially edentulous patients who have lost their cephalometric reference points necessary for the analysis. This paper shows a technique to visualize the occlusal plane and anterior guidance in partially edentulous patients who have lost these anatomical landmarks in a lateral cephalometric radiograph, using lead sheets.