Osami Morita

Influence of oral appliances on craniocervical posture in obstructive sleep apnea–hypopnea syndrome patients

PURPOSE The existence of a relationship between head posture and mandibular function has been discussed by several authors. However, the relationship between head posture and the cervical spine in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) who are using oral appliances (OAs) remains unknown. The aim of this study was to evaluate the changes in the cervical spine associated with the use of OAs in patients with OSAHS. METHODS Fifteen patients (4 females and 11 males; mean age, 48 years) diagnosed with OSAHS were randomly selected. An OA was fabricated individually for each patient. Two lateral cephalometric radiographs were taken while the patient was sitting awake in an upright position. The first radiograph was taken in the intercuspal position and the second was taken while the subject was wearing the OA. Analyses based on the sella-nasion (SN) line were performed in the lateral cephalogram. Comparison of craniocervical angles in patients with and without the OA was performed using Wilcoxons signed-rank test. RESULTS Cephalometric analysis showed that the craniocervical angles (CVT-C2V and SN-C4) with OA were higher than those without OA (P<0.05). It seems that the OA caused a significant flexion of the cranium on the upper cervical spine. A significant increase in the craniocervical angle occurred in the fourth cervical segment. CONCLUSION The changes in forward flexion of the upper cervical spine found in this study imply that changes in the craniocervical relationship should be evaluated periodically after an OA has been inserted.

Influence of swallowing saliva repeatedly on oral moisture

PURPOSE The aim of this study was to examine the influence of repetitive saliva-swallowing for the level of oral moisture using an oral-moisture checking device. METHODS Subjects were 24 healthy adults (HA) and 20 patients with oral dryness, 10 of whom had Sjögren syndrome or who had undergone radiation therapy (ODSR) and 10 who had not experienced ODSR (ODNSR). Oral moisture was measured before swallowing saliva (B), and after swallowing saliva once (F), twice (S), and three times (T). Oral moisture was measured at the lingual mucosa using an oral-moisture checking device. Statistical analysis was performed using the Friedman test. RESULTS Oral moisture of the lingual mucosa of the HA differed significantly between B and T, and F and T, and the oral moisture level tended to be higher the more times saliva was swallowed. However, oral moisture of lingual mucosa in the ODSR was not different at the different times of measurement, but the level of oral moisture tended to be lower the more times saliva was swallowed. Oral moisture of the lingual mucosa in the ODNSR differed significantly between B and T. The trends for the changes of the oral moisture level in the ODNSR were similar to those in the HA. CONCLUSIONS The results of this study show that swallowing saliva repeatedly could lead the increase of oral moisture in HA and ODNSR not in ODSR.

A study on the fit of the base plate —Influence of canditions of storage—

The aims of this study was to define the effect of storage conditions of base plates, which consist of self-curing resin.Examinantions were made on the dimensional accuracy with the passage of time of base plate stored in water and air on a plaster model for standerdized maxillary edentulous. The following conclusions were obtained;1.The fit of base plate stored in water proved to be beter than that stored in air.2.No significant difference was noted among 7 times points.3.In terms of sites of measurement along the base plate, the more posteror the site of measurement, the greater the gap between a base plate and a cast, was observed.4.The best fitting base plate proved to be Ostron II. The second best fitting base plate proved to be Trayresin II.

Histocytological study of the guided bone regeneration using the rat mandible

Histological changes, localization of osteoblasts, and activating time at defective areas of rat mandible were studied with the GBR technique using absorptive (dura mater) and non-absorptive (GTAM) barrier membrane.We examined the rat-mandibles which had been operated by the GBR technique and obtained following results:1.Bone regeneration at both experimental sides promoted due to the obstruction of invasion of muscle tissue around the defect area.2.The regeneration of small vessels was observed in the defective area on the both experimental sides, especially at the GTAM side.3.Loose connective tissue was found for long periods on the both experimental sides.4.Regenerated bone began at the bony edge of the defect area, and irregular sponge-like new bone was detected on the both experimental sides and exhibited lamella structure due to a remodeling. New bone particles were scattered in the middle of bony defective at the GTAM side.5.ALPase of osteoblasts was detected at the bony edge of the defective area in the control and on both experimental sides. ALPase at the GTAM side was detected later than the others.

Influence of Posture and Respiration on the Morphology of Oropharynx -Analysis by Cephalometric Radiogram-

目的: 閉塞型睡眠時無呼吸症候群の歯科的治療に用いられる口腔内装置 (Oral appliance: OA) の効果に関する報告は, 多く認められる. しかし, 下顎前方位型装置 (Mandibular advancement device: MAD) の装着が口腔咽頭領域の形態に及ぼす影響について, 画像的に十分明らかにされていない. 本研究の目的は, 側方頭部X線規格写真 (セファログラム) 撮影時の体位および呼吸変化が, 口腔咽頭領域の形態に及ぼす影響を健常者について検討することである.方法: 被験者は, 自覚的, 他覚的にいびきを認めない健常者12名 (男性10名, 女性2名, 平均年齢27.3歳, 肥満度21.9kg/m2) とした. 被験条件は, 立位時の吸息と呼息および仰臥位時での吸息と呼息において, セファログラム撮影を行った. 撮影されたX線写真から得られた透写図上にて, 咽頭腔前後径とその面積, ならびに舌骨の位置の計測を行い, 体位と呼吸状態を2要因とする反復測定分散分析を用いて検討した.結果: 吸息時と呼息時の間に有意な差は認められなかった. しかし, 体位を立位から仰臥位に変化させると, 咽頭腔面積および口蓋垂後方の前後径と舌根部後方の前後径, 舌骨から下顎までの距離が有意に減少した.結論: 以上の結果から, 呼吸による影響は認められなかったが, 体位を立位から仰臥位に変化させることで口腔咽頭領域の形態に影響を及ぼすことが示された.

The Effects of Wearing Laminate Mouth Guard on Body Sway in Upright Posture with the Eyes Closed

目的: 本研究の目的は, ラミネートマウスガードの装着が閉眼時の静的平衡機能に及ぼす影響を明らかにすることである.方法: 被験者は健常有歯顎者11名である. 被験条件は, 閉眼時においてマウスガード非装着での咬頭嵌合位とマウスガードを装着して軽く咬合接触させる2条件とし, 各被験条件での直立姿勢の重心動揺を立位足底圧分布測定装置を用いて計測した. 計測項目は, 重心動揺の左右成分の標準偏差 (XS. D.), 前後成分の標準偏差 (Y-S.D.) および重心移動距離である.被験条件間の統計解析には, Wilcoxon の符号付順位検定を用いた.結果: マウスガード装着, 非装着時でのX-S. D., Y-S. D., 重心移動距離の中央値と四分位範囲は, マウスガード装着時では, 0.19 (0.13), 0.12 (0.10), 9.54 (3.90) cmであり, マウスガード非装着時では, 0.19 (0.11), 0.11 (0.11), 10.19 (4.68) cmであった. 検定の結果, すべての計測項目でマウスガード装着とマウスガード非装着間について有意な差を認めなかった.結論: 以上のことより, ラミネートマウスガードの装着による閉眼時の静的平衡機能への影響を見いだしえなかった.

Study on the Mandibular Rest Position. Changes of Mandibular Position with Tongue Space Narrows.

The purpose of this study was to investigate the effects of tongue space reduction on the mandibular positioning at the mandibular rest position. The three-dimensional positioning of the mandibular incisor tooth point and its variable range were determined at the mandibular rest position using three different tongue space reducing devices. The results were as follows:1. The vertical and anteroposterior components of mandibular positioning range at the mandibular rest position were increased by tongue space reduction.2. The lateral component of mandibular positioning range at the rest position was not significantly affected by hemilateral reduction of the tongue space.