• The korean journal of orthodontics
• /
• v.25 no.3 s.50
• /
• pp.311-321
• /
• 1995

This study was undertaken to investigate the distribution of the chewing side preference and variations in the maximum bite force and facial morphology according to chewing side preference since unilateral chewing may cause morphologic and functional anomalies. 50 dental students who had no signs or symptoms of masticatory system and Angle's Class I relationship in posterior segments were selected, and divided into two groups, that is, 25 in bilateral chewing group(19 male and 6 female) and 25 in unilateral chewing group(10 male and 15 female). Maximum bite force was estimated ana posteroanterior cephalogram were measured ana statistically analyzed. The results were as follows : 1. Their were more students with bilateral chewing side preference($68\%$) and unilateral chewing side group consisted of right side preference($68\%$) and left side preference($32\%$). 2. There was no significant difference in the strength of max. bite force between the right and left side in bilateral chewing group. The bite force of the chewing side nab greater in the unilateral chewing group but less in the non-chewing side compared to those of bilateral chewing group with Bo significant difference. Max. bite force of chewing side was greater than that of non-chewing side in the unilateral chewing group(Female p<0.05). Max. bite force of males was about twice in that of females in both groups(p<0.05). Max. bite force of chewing side of the unilateral chewing group was similar to that of the bilateral chewing group, but that of non-chewing side was less than that of the bilateral chewing group. 3. In comparison of the facial morphology, there was no statistically significant difference in the size between the right and left side of the bilateral chewing group and between chewing and non-chewing side of the unilateral chewing group.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.42 no.1
• /
• pp.87-101
• /
• 2015

The premature loss of the mandibular primary canine is relatively frequent and a sign of the upcoming space problems in the transitional period. This situation is caused by the permanent lateral incisor resorbing the root of the primary canine during its eruption. Bilateral loss of primary canines in a crowded arch leads to the lingual tipping of the permanent incisors, with the consequent reduction in the arch perimeter and increase in overbite. When the loss of a primary canine is unilateral, tipping of the adjacent incisors occurs toward the space, resulting in midline deviation. In these situations, treatment possibilities, such as extraction of the antimeric tooth or placement of a passive lingual arch, can be applied; although there are some controversies concerning this. Most space problems with less than 4 mm can be resolved through preservation of the leeway space using sequential disking of the primary teeth and a passive lingual arch, regaining space or limited arch expansion in the late mixed dentition. In cases with 4~6 mm of space problems, arch expansion (A-P or transverse) can be applied. Space problems with more than 6 mm should be treated through diagnosis and treatment planning. Most of these cases will require extraction of permanent teeth including serial extraction (guidance of eruption).

• Journal of Dental Rehabilitation and Applied Science
• /
• v.31 no.3
• /
• pp.273-282
• /
• 2015

Centric occlusion-maximum intercuspation (CO-MI) discrepancy is one of main causes of evoking premature contact and resultant mandibular shift. These non-physiological conditions can induce temporomandibular disease, periodontitis, and non-carious cervical lesion. Therefore, if CO-MI discrepancy exists in patients who need extensive prosthetic rehabilitation, it must be corrected and then physiological occlusion must be restored. This report describes the treatment procedure of removing CO-MI discrepancy and prosthetic rehabilitation in a patient with 3.5 mm discrepancy, multiple caries and periodontitis. Proper mandibular position and modified opening & closing movement were confirmed by ARCUSdigma II and transcranial radiograph.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.32 no.4
• /
• pp.322-329
• /
• 2016

Reconstruction of the maxillectomy with an obturator is to restore masticatory, swallowing, phonetic and esthetic problems. Stress created by lateral forces is minimized by the proper selection of an occlusal scheme, elimination of premature occlusal contacts, and wide distribution of supporting area. It should be considered that properly designed retainers reduce the stresses transmitted to the abutment while the obturator is in function. The following clinical report presents palatal obturator treatment with implant assisted removable partial denture (IARPD) design that restores normal function and esthetics in patients who experienced maxillectomy and dental implant failure.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.4
• /
• pp.317-324
• /
• 2008

The objective of this study was to test effects of (1) where the occlusal contact points locate on a full veneer crown, and (2) which direction the contact forces are directed to, on the stresses within the luting cement layer that might suffer microfracture. A total of 27 finite element models were created for a mandibular first molar, combining 9 different locations of the occlusal contact points and 3 different loading directions. Type 3 gold alloy was used for crown material with a chamfer margin, and the luting cement material was glass ionomer cements in uniform thickness of $75{\mu}m$. Modeled crowns were loaded at 100 N. Different patterns in the cement stress were observed in the vicinity of the buccal and lingual margins. Whereas, the peak stress in buccal margin occurred approximately 0.5 mm away from the external surface, the highest stress in lingual margin was observed at approximately 1 mm. Significantly different distribution of stresses was recorded as a function either of the location of the occlusal contact points or of the loading direction. Higher stresses were produced by more obliquely acting load, and when the loaded point was in the vicinity of the cusp tip.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.4
• /
• pp.431-441
• /
• 2021

Full-mouth rehabilitation with increasing vertical dimension can be used for patients with severely worn teeth. In severely worn teeth also, the alveolar process can be elongated to compensate for the reduced vertical dimension, and the patient's vertical dimension of occlusion can be kept constant. However, full-mouth rehabilitation with increasing vertical dimension must be carefully chosen, because the vertical dimension can be reduced by tooth wear. It is important to establish a treatment plan with the systematic diagnosis of the change in the vertical dimension and gain space for the prosthesis. It is necessary to change the vertical dimension to secure the restoration space and select the minimum vertical dimension elevation for the esthetic and functional goal. In this case report, the patient complained of difficulty during chewing due to a worn dentition and wanted esthetic improvement of the short mandibular anterior teeth. After systematic evaluation and diagnosis, we performed full-mouth rehabilitation with minimum vertical dimension elevation to obtain the space for restoration. This resulted in a stable and harmonious occlusion, and the functional and esthetic problems of the patient were solved after treatment. The patient was satisfied with the results of the treatment and maintained stable occlusion during the follow-up period.

• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.3
• /
• pp.243-249
• /
• 2018

Excessive tooth wear results in unacceptable damage to the occlusal surface and can cause pulpitis, occlusal disharmony, dysfunction, and unesthetic result. Patients with severe attrition have to be classified as several types relative to the vertical dimension of occlusion (VDO) and the interocclusal distance for the prosthetic space. The patient in this case was a 80 - year - old woman who lost support of posterior occlusion and collapsed of the occlusal plane due to confrontation of the opposing teeth, accompanied by an increase in the number of remaining bristles, resulting in a loss of intermaxillary space for prosthesis. In this case, treatment with increased vertical dimension may have stability if the increase in vertical occlusal height is minimized within the required range, and a stable occlusal contact is provided after an increased vertical occlusal height stabilization period. After the new VDO had been confirmed under interim fixed restorations, definitive fixed restorations were produced. Through these treatment processes, we obtain satisfactory results that are functional and aesthetically pleasing.

• The korean journal of orthodontics
• /
• v.34 no.6 s.107
• /
• pp.481-487
• /
• 2004

The purpose of this study was to clarify morphologic characteristics between mandibular clinical arch forms in Koreans with normal occlusions. The study included data from 102 Koreans. The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The dental arches were classified into ovoid, square and tapered forms. The frequency distributions of the three mandibular arch form classifications were determined and compared between male and female subjects. No significant differences in arch form size were found between the sexes. However, there were a few differences in molar width. It was useful to classify mandibular clinical arch forms present in normal occlusion samples into ovoid, square and tapered categories. The frequency of the ovoid form was the highest, and that of the square form was the second highest. The tapered arch form was found in less than 10 percent of subjects. No significant differences in their frequency distributions and dimensions were shown between males and females.

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.2
• /
• pp.143-152
• /
• 2023

Although tooth wear is a normal process due to aging, severe tooth wear causes various complications such as increased tooth sensitivity, loss of tooth structure, and pulp complications. In the treatment of patients with excessive tooth wear, the evaluation of loss of vertical occlusal dimension should be prioritized. If it is necessary to increase the vertical dimension to secure the restoration space, it is important to establish a treatment plan with the comprehensive analysis and determine the minimum vertical dimension elevation. In this case, 66-year-old male patient with severe worn dentition wanted to restore masticatory function and improve esthetic restoration. In order to determine the appropriate vertical dimension of the patient, we evaluated oral examination, radiographic examination, and diagnostic cast examination, and performed rehabilitation with minimum vertical dimension elevation. As a result of observation for 8 months, the definitive prosthesis was completed with contact of all teeth in centric occlusion, and proper anterior/posterior guidance. Through the above process, satisfactory aesthetic and functional outcomes were obtained.

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.3
• /
• pp.234-244
• /
• 2023

Tooth wear refers to the loss of dental hard tissue caused by various physiological and pathological causes, and excessive pathological wear can cause complications such as pathological changes in dimensions, occlusal disharmony, loss of function, and aesthetic problems. The cause of tooth wear can be caused by attrition, abrasion, corrosion and abfraction, and it is known to act in a multifactorial etiology in interocclusal activity. In patients with excessive pathological wear, it is important to determine whether or not the vertical dimension of occlusion is reduced, and complete oral rehabilitation should be achieved with the adaptation of the neuromuscular and temporomandibular joint through accurate diagnosis and analysis. The patient in this case was a 63-year-old male patient, who presented discomfort to cold beverage due to severe tooth wear. After analysis of the patient's vertical dimension of occlusion, a full mouth rehabilitation was performed with increasing vertical dimension of occlusion. The goal of treatment was to improve the occlusal plane with the equal-intensity contact of all teeth, harmonious anterior guidance and immediate disclusion of all posterior contacts. After rehabilitation, the patient was satisfied with function and esthetic appearance.