口腔病学会雑誌
Online ISSN : 1884-5185
Print ISSN : 0300-9149
77 巻, 1 号
選択された号の論文の11件中1~11を表示しています
原著
  • 高島 真穂
    2010 年 77 巻 1 号 p. 1-6
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      The unilateral bolus passage through the upper esophageal sphincter (UES) is often observed in swallow evaluations of patients following neck dissection. Head rotation toward the paretic side was reported to be useful to prevent aspiration ; however, we often encounter cases of head and neck surgical patients in which the bolus passes through the non-surgical side. Therefore, we investigated UES flow after head and neck surgery to evaluate the laterality to find an effective treatment technique after a head and neck operation. Videofluoroscopic swallowing studies (VFSS) were conducted in 23 oral cancer patients who underwent unilateral neck dissection but not tongue resection. Patients comprised 12 males and 11 females, with a mean age of 62 (SD=14) years. Preoperative VFSS showed that none had a predominant side for UES flow. The laterality of the bolus flow through the UES was predominantly on the side of neck dissection in post-operation. Lateral VFSS showed elevation of the hyoid and the larynx on the non-dissected side was greater compared to the dissected side. Therefore, head rotation toward non-dissected side can be effective for head and neck surgical patients.

  • 古本 博嗣
    2010 年 77 巻 1 号 p. 7-13
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      Purpose of this study was to determine the relationship between food mixing ability and oral health-related quality of life (OHR QoL) in partially edentulous patients with removable partial dentures. One hundred and thirty one patients (mean age 67.1 years) participated in this study. The subjects comprised patients who were treated with removable partial dentures (RPDs) in an undergraduate program (n=52), those who were receiving oral maintenance care (n=57) and those who planned to replace current RPDs with new ones (n=22), and OHR QoL was measured using the oral health impact profile-Japanese version (OHIP-J). To evaluate food mixing ability, the subjects were asked to chew a two-colored paraffin wax cube as a test item. Mixing ability index was determined from the color mixture and shape of the chewed cube. Spearman rank correlation coefficient was used to test the relationship between mixing ability index and scores of OHIP-J. No significant correlations were found between mixing ability index and scores of OHIP-J in each group (p>0.08). The results suggest that association between food mixing ability and OHR QoL life is very weak in partially edentulous patients with RPDs.

  • 土屋 恭子
    2010 年 77 巻 1 号 p. 14-19
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      The connecting rigidity of the retainer and the denture supporting area may influence the distribution of the occlusal load. Three types of retainers (wrought wire clasp, Akers cast clasp and conical crown telescopic retainer) and three outline forms of denture bases designed for distal extension removable partial dentures were assessed in six patients with Kennedy Class Ⅱ situations. To evaluate the influence of oral function, mandibular displacement, abutment tooth displacement, and denture base exerted pressure were measured simultaneously during maximum voluntary clenching. The mandibular displacement increased when the connecting rigidity decreased or the size of the denture base was reduced. The abutment tooth displacement increased as the denture base was reduced with the Akers clasp. The denture base pressure increased as the denture base reduced with the wrought wire clasp. The conical crown telescopic retainer did not cause overloading to the supporting tissues even when the denture base was reduced. It was also revealed that the abutment tooth tended to displace distally when a distal occlusal rest was prepared on the abutment tooth.

  • 大竹 志保
    2010 年 77 巻 1 号 p. 20-26
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      Firm adhesion of composite resin and dentin is the basic premise for building up resin composite cores successfully. To assess the efficacy of several caries detective methods (stained with Caries Detector and probing with sharp probe) for caries affected root canal dentin, microtensile bond strengths of resin composite to caries-affected root canal dentin and failure mode distribution were analyzed in this study. Color and hardness were used for assessment of root caries as follows : Dye stain group (pale pink stained with Caries Detector), Probing group (probing with sharp probe) and Sound dentin group (Control). The bond strengths (mean±standard deviation) of the Probing group (64.6±11.9 MPa) and the Sound dentin group (68.7±11.1 MPa) were significantly higher than those of the Dye stain group (46.9±7.9 MPa, p<0.05). However, there is no significant difference in fracture mode between the Dye stain group and the Probing group (p<0.05). This could be attributed to that the thick smear layer caused a loss of hybrid layer strength. In conclusion, the caries removal technique of the root canal dentin affected the bond strength of the resin composite.

  • 工藤 雅範
    2010 年 77 巻 1 号 p. 27-34
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      The functions of articulation and mastication after glossectomy for tongue carcinoma were sequentially assessed.

      Longitudinal assessment of articulatory and masticatory functions was analyzed in 64 tongue cancer patients who underwent partial glossectomy (partial glossectomy group : 40 cases) or hemiglossectomy (hemiglossectomy group : 24 cases) in our department between January 2007 and August 2008. The mean age of the 64 patients (37 men, 27 women) was 56.9 years, ranging from 21 to 82 years. Tongue mobility was assessed using a tongue movement function test by Matsunaga's classification. Articulatory function was assessed using the monosyllable Japanese speech intelligibility test, while masticatory function was evaluated using color-changeable chewing gum and occlusal force score using Yamamoto's classification. The functions were evaluated preoperatively, and 1 month, 3 months, 6 months, and 12 months postoperatively.

      In all groups, both tongue movement and articulatory and masticatory functions were impaired 1 month after surgery, however they gradually recovered between 3 to 6 months and reached a plateau from 6 to 12 months.

      The values of the parameters in the partial glossectomy group and the hemiglossectomy group at 6 months postoperatively were respectively as follows : the tongue movement function scores were 6.9±0.4, 5.2±0.8 ; the speech intelligibility scores were 94.1±3.5%, 88.8±9.9% ; the occlusal force scores by Yamamoto's classification were 5.3±0.9, 3.7±1.0 ; and the values of a determined using the chewing gum were 13.8±2.4, 8.6±3.5.

      In addition, there was a correlation between speech intelligibility and the value of a, and between speech intelligibility and occlusal force scores by Yamamoto's classification.

  • 中村 紀子
    2010 年 77 巻 1 号 p. 35-45
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      The objective of this study was to clarify the relation between the occlusal force and the tooth displacement path just after unloading, and to estimate the occlusal force during mastication with healthy natural teeth.

      Three-dimensional occlusal force was calculated from the magnitude of the occlusal force measured by pressure-sensitive film, and from normal vectors of the occlusal contact areas recorded on the study model. The tooth displacement paths were measured using the three-dimensional tooth displacement transducer type M-3. Three male subjects aged 27, 38, and 46 were selected. The subject teeth were their upper left molars.

      There are two phases of tooth displacement just after unloading : instantaneous recovery, and the subsequent slow recovery. If the maximum tooth displaced position is R, the critical tooth position at the beginning of slow recovery is C, and the original tooth position is O, then re represents the vector RC(―→), and rv represents the vector CO(―→). The values of re and rv calculated for each unloading tooth displacement path just after clenching the pressure-sensitive film showed different physical properties. The dominant direction of re was to the buccal side, and that of rv was to the coronal side. The coefficient of correlation between the magnitude of occlusal force and re was 0.81-0.87, and that between the magnitude of occlusal force and rv was 0.20-0.63. Based on these physical properties, it was considered that re depends on the recovery of the distortion of alveolar bone, and rv depends on that of periodontal membrane.

     As described above, the occlusal force during mastication, which is fast movement, can be estimated from re.

  • 横田 嘉代子
    2010 年 77 巻 1 号 p. 46-52
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      A preliminary study revealed that an autopolymerization addition silicone resilient denture relining material (SI) had excellent shock absorption properties similar to those of thermoplastic materials commonly used for mouthguards (ethylene-vinyl acetate : EVA). The aim of the present study was to examine the bonding strength of SI and EVA using a newly-developed adhesive prototype. Delamination tests and tensile strength tests were performed to compare the bonding strengths of SI on EVA prepared under the following four conditions : 1) Control condition (no preparation ; C), 2) Sandblasting (S), 3) Bonding with the adhesive prototype (M), and 4) Combination of sandblasting preparation and bonding with the adhesive prototype (SM). The mean bonding strength (S. D.) of the delamination tests under the C, S, M and SM conditions were 0.167(0.003)N/mm, 0.273(0.034)N/mm, 0.242(0.027)N/mm and 0.506(0.113)N/mm, respectively. The mean bonding strength (S. D.) of the tensile strength tests under the C, S, M and SM conditions were 0.006(0.011)MPa, 0.081(0.105)MPa, 0.231(0.069)MPa and 0.590(0.041)MPa, respectively. Two-way analysis of variances and Tukey's HSD test detected that the combination of sandblasting preparation and bonding with the adhesive prototype significantly improved the bonding strength between SI and EVA. The results indicate that the self-curing addition silicone resilient denture relining material may adhere to the thermoplastic material prepared by combined application of sandblasting and the adhesive prototype, suggesting the potential of the dental silicone rubber material as a material for repairing mouthguards in clinical practice.

  • 柴田 真衣
    2010 年 77 巻 1 号 p. 53-58
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      Recently, it has been shown that prolonged feeding of a liquid diet after being weaned impedes the functional development and leads to immature mastication in growing rats. Since the jaw muscle spindles play an important role in the control of the jaw movement during the normal masticatory function, in this study we investigated the effects of prolonged feeding of a liquid diet after being weaned on the functional development of the jaw-closing muscle spindles in growing rats. Soon after weaning, 40 female Wistar rats were divided into two equal groups. The control group was fed a solid diet and the experimental group was fed a liquid diet. At 5, 7, 9 and 11 weeks, the rats were anesthetized and the response of the masseter muscle spindles to ramp-and-hold jaw stretches were recorded from the mesencephalic trigeminal nucleus. In the experimental groups, both the dynamic and the static indices were significantly lower than those of the control groups at the age of 5, 7, 9 and 11 weeks old. There was no significant change within the same group during the experimental period in both indices. These results suggest that the long-term masticatory functional change due to feeding of a liquid diet may impede the maturation of the functional properties of the jaw-closing muscle spindles, leading to immature mastication in growing rats.

  • 尾崎 卓
    2010 年 77 巻 1 号 p. 59-66
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      The purpose of this study is to clarify the effect of advance notice of contents of treatment on the patients' physiological stress during dental treatment. The subjects of our study comprised 34 non-dental professionals (22 female and 12 male). In simulated dental treatment, the subjects were exposed to predetermined stimulations comprised of blowing air on the molars, percussion on the premolar and usage of an air turbine next to the molar in randomized order, with/without advance notice. The skin potential level (SPL) of the subjects was measured as a physiological stress index during such simulated dental treatment. As a psychological profile, the stress-coping style of each subject was examined using Lazarus Type Stress Coping Inventory (SCI). The number of decayed, missing, filled teeth (DMF). and the experience of teeth extraction in the past of each subject was also recorded. The correlation among advance notice, order and kind of stimulation, factors of SCI, DMF, gender of the subject, the experience of teeth extraction, and the subjects' stress (SPL change) was statistically analyzed using the generalized estimating equation. As a result, the effect of advance notice on the subjects' stress was opposite when the stress-coping style differed ; therefore, dentists must pay attention to the patients' psychological characteristics when using advance notice for the purpose of relieving the patients' stress during dental treatment.

  • 森 浩路
    2010 年 77 巻 1 号 p. 67-70
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      Recently, new metal free materials for crown and bridges such as yttria stabilized tetragonal zirconia polycrystals (Y-TZP) have been introduced in the dental profession. These systems enable the fabrication of long-span bridges of more than 3 units in the posterior region. But occasionally chipping of the veneering porcelain was observed.

      The aim of this study was to analyze the influence of the design of the zirconia framework on the fracture strength of the veneering porcelain.

      Two types of Y-TZP framework were fabricated for the lower second premolar crown (normal type and support type) (Cercon base colored, DeguDent, Hanau-Wolfgang, Germany). The support-type framework has a 1 mm-wide collar around the margin to support the veneering porcelain. Twelve all-ceramic crowns were fabricated, six crowns for each group. The framework was covered by veneering ceramics (Vintage ZR Press Over, SHOFU INC., Kyoto, Japan) using the heat press method. All specimens were fixed using adhesive resin cement on the master die and the vertically loaded was measured at the distal ridge of the crown at a cross-head speed of 1 mm/min until fracture. The maximum compressive load required to cause a fracture was recorded for each specimen. The t test was used for the statistical analysis of the fracture loads, with a significance level of α=0.05.

      The following conclusion was obtained. The fracture strength of the all-ceramic crowns with a support-type Y-TZP framework was significantly higher than that of the normal type. This result suggests that the design of the Y-TZP framework is important for all-ceramic restorations.

  • 武井 秀典
    2010 年 77 巻 1 号 p. 71-80
    発行日: 2010/03/31
    公開日: 2025/01/17
    ジャーナル フリー

      Much research has been reported about post and core systems with composite resin, but the influence of the different types of prefabricated posts on the distribution of stress in the root has not yet been elucidated. It is necessary to clarify the influence of the relationship between core and crown materials to obtain combined restorations.

      The aim of this study is to analyze the influence of the combination of various post and core systems and different kinds of crown material on the stress distribution in the root.

      Six 2-dimensional photoelastic premolar models were designed. Three types of post and core systems (composite resin post and core, composite resin core with the fiber post, and composite resin core with a prefabricated stainless steel post) and two kinds of crown materials (metal and hybrid-type hard composite resin) were fabricated and cemented to each model.

      In these models, we applied a load of 200 N at an angle of 45 degrees to the tooth axis and analyzed the fringe order using a transmission polariscope. As a result, it has been clarified that the combination of the post and core and the crown plays an important role in preventing stress concentration within root. Stress concentration can be prevented using a crown fabricated with a high-elastic modulus for the post and core with a high-elastic modulus, and a crown fabricated with a low-elastic modulus for the post and core with a low-elastic modulus.

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