• Journal of Oral Medicine and Pain
• /
• v.19 no.2
• /
• pp.153-168
• /
• 1994

The aim of the present study was to investigate a relation between occlusal wear area and occlusal contact patterns. For the purpose, occlusal wear area were measured in 58 dental students and in 129 patients with temporomandibular disorders(TMDs) from dental casts. Teeth used in this study were from canine to second molar on both sides in upper arch, totally ten. Occlusal wear area on casts was marked by pencil and photocopies, and then, the area was measured with planimeter. Occlusal relation was clinically examined with regard to Angle's classification, chewing side preference, lateral guidance pattern and bruxing and/or clenching habit. T-Scan, electronic occlusal contact analyzer, was used to record occlusal contact number, contact force, contact time and occlusal balance that is TLR(total left-right statistics) during tooth contact. All measurement were repeated 3 times and the average value was used for data processing. The obtained results were as follows : 1. Mean value of occlusal wear area did not differ significantly between dental students and patients. 2. There ws not significant difference in wear area between chewing side and non-chewing side in both groups. 3. Occlusal wear area was significantly increased with age in both groups. 4. Three subgroups divided by Angle's classification did not show any difference in occlusal wear area among them, but three subgroups divided by lateral guidance pattern showed slightly significant difference between canine guide subgroup and group function subgroup in patients. Occlusal wear ares\a in group function subgroup wear larger than canine guide subgroup. 5. Mean value of wear area in patients with bruxing and/or clenching habit did not differ from those in patients without such habit. 6. Correlationship among items related to occlusal contact pattern were highly consistent and significant in dental students and only one item significantly correlated with occlusal wear area was tooth contact time.

• The Journal of Korean Academy of Prosthodontics
• /
• v.34 no.2
• /
• pp.299-308
• /
• 1996

In order to epidemiologically verify the tensile that cervical abfraction is developed from the tensile stress during lateral excursion, comparisons between the experimental group with cervical abfraction and the control group without cervical abfaction was made by exmining the occlusal wear and patterns from the dental cast. 1. The degree of occlusal wear in the experimental group with cervical abfraction was higher than that of control group without cervical abfraction.(p<0.05) 2. No significant difference in the occlusal wear pattern was found between the experimental group and the control group. 3. Higher degree of occlusal wear was found in the age group of abov 40 than that of below 40.(p<0.05) 4. There was a correlation between the degree of occlusal wear and the degree of cevical abfraction.(p<0.05) 5. There was a correlation between the age and the degree of cevical abfraction.(p<0.05) It can be concluded that occlusal stress is the etiologic factor of cervical abfraction, but no clear distinction was made between the relationship of tensile stress and cervical abfraction.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.3
• /
• pp.328-342
• /
• 1999

This study was performed to investigate the factors related to tooth wear. For this study, 78 patients with temporomandibular disorders and 76 dental students without any signs and symptoms of temporomandibular disorders were selected as the patients group and as the normal group, respectively. Preferred chewing side, Angle's classification, lateral guidance pattern, head and shoulder posture were observed clinically. Electromyographic activity of anterior temporalis and masseter muscle were recorded with $BioEMG^{(R)}$ and occlusal status were recorded with $T-Scan^{(R)}$. Wear facet area of each tooth was measured from working model of upper arch corresponding to the occlusal status from T-Scan. Wear facet area were measured with planimeter in $mm^2$. Total area were divided into incisal, canine, posterior tooth area. Anterior wearfacet area was incisor area plus canine area, and unilateral area was anterior area plus posterior area. The data collected were analyzed by SAS statistical program and the results of this study were as follows: 1. There was no significant difference between the two groups in total werafacet area, and male subjects showed tendency to have larger area in the normal group but female subjects showed tendency vice versa. 2. There was no significant difference related to preferred chewing side and Angle's classification, however some difference was observed by lateral guidance pattern. Anterior wear facet area in subjects of canine guidance was the largest in the three subgroups. 3. Subjects with head tilting to right side had larger posterior and total area, and subjects with higher shoulder in right side had larger canine and anterior area than any other subgrous. 4. Electromyographic activity of masseter muscle was more correlated with wear facet area than anterior temporalis muscle, and tooth contact number and force were significantly correlated with wear facet area, but the most important factor affecting tooth attrition was age.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.33 no.3
• /
• pp.238-244
• /
• 2017

Pathologic attrition leads to pathologic damage on occlusal plane, functional disorders, occlusal disharmony, esthetic problems, pulpal lesion, temporomandibular joint (TMJ) disorder. In this case, treatment plan should be considered for possibility of vertical dimension loss, occlusal pattern, esthetics, phonetics, amount of vertical dimension increase. This case report was a 71-year-old man who had severely worn dentition. Full mouth rehabilitation was carried out with vertical dimension increase due to limited space for prosthesis. After evaluation of provisional restorations for patient's compliance, final restorations were fabricated and routine clinical assessments were made. This case presents that a satisfactory clinical result was achieved by restoring the worn dentition.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.19 no.3
• /
• pp.239-245
• /
• 2003

The occurrence and pattern of tooth wear are related to cultural, dietary, occupational, and geographic factors, Excessive occlusal wear can result in pulpal exposure, occlusal disharmony, functional inability. Surface loss can be differentiated into 3 general causal categories: i) mechanical loss, which includes attrition, ii) abrasion chemical loss including erosion, and finally iii) a proposed biomechanical category described as abfraction. Considering that mechanical wear is frequently asymptomatic, patients may have parafunctional habit. Structured clinical decision analysis in fixed prosthodontics, as other branches of dentistry do, allows the practitioner to consider the patient's problems more thoroughly based on the clinical data and extenuation factors. This discipline of decision making is intended to complement the experience level and educational background of the clinician in assisting the patient through the decision process. Additionally, CDA helps the clinician define not only the pre-existing condition of the patient prior to irreversible therapy, but also better treatment strategies for the patient over an extended period. The systematic nature of decision analysis stimulates the dentists to pay further attention to those factors, which is germane to the overall complexity of the case, and exclude factors, which have little influence on its final outcome. Further implementation of computerized databases, procedural outcome probabilities based on clinical and laboratory studies and the clinical experience of those who use it, may provide quite a promising future in the field of structured and formalized clinical decision analysis.

• The Journal of Korean Academy of Prosthodontics
• /
• v.62 no.3
• /
• pp.224-233
• /
• 2024

The patient was a 69-year-old male who had decreased VDO and overbite of the anterior teeth due to severe teeth wear. Complete mouth rehabilitation was planned to restore esthetics and function. Due to the presence of a subgingival finish line, poor fit of the margin of the temporary crown, and insufficient oral hygiene management, gingival overgrowth and bleeding occurred in many teeth, and inaccurate impressions were taken. After dividing each arch and taking partial impressions, a transfer coping was made using pattern resin on each working model die, and after being placed on the abutment teeth, a master cast was made through pick-up impression taking to produce prosthesis. In this case, the final prosthesis produced on the second master cast were fitted in terms of proximal contact, marginal fit, vertical occlusal dimension, facial appearance, esthetics, and occlusion. After complete mouth rehabilitation, the patient was satisfied with function and esthetic appearance.