Daisuke Kanamori

PURPOSE: The purpose of this study was to elucidate the effects of the tongue-hold swallow (THS) on the pharyngeal wall by quantifying posterior pharyngeal wall (PPW) anterior bulge during the THS. In addition, the effect of tongue protrusion length on the extent of pharyngeal wall anterior bulge was analysed. METHODS: Thirteen healthy subjects (6 males and 7 females, 23-43 years) underwent 320-row area detector CT during saliva swallow (SS) and THS at two tongue protrusion lengths (THS1 protrude the tongue as much as 1/3 of premeasured maximum tongue protrusion length (MTP-L) and THS2 protrude the tongue as much as 2/3 of MTP-L). To acquire images of the pharynx at rest, single-phase volume scanning was performed three times during usual breathing with no tongue protrusion (rest), protrusion of the tongue at 1/3 of MTP-L (rTHS1) and protrusion of the tongue at 2/3 of MTP-L (rTHS2). Length from cervical spine to PPW (PPW-AP) and the volume of pharyngeal cavity was measured and was compared between rest, rTHS1 and rTHS2 and between SS, THS1 and THS2. Correlation between MTP-L and PPW-AP was calculated in three conditions, SS, THS1 and THS2. RESULTS: PPW-AP at rest, rTHS1 and rTHS2 was 2.9 ± 0.6 mm, 3.0 ± 0.5 mm and 3.0 ± 0.5 mm, respectively, showing no significant differences across swallows. PPW-AP at the maximum pharyngeal constriction was 8.1 ± 2.0 mm, 9.1 ± 2.4 mm and 8.7 ± 2.0 mm in SS, THS1 and THS2, respectively. Compared to SS, PPW-AP in THS1 was significantly larger (p = 0.04) and PPW-AP in THS2 was not significantly different (p = 0.09). Pharyngeal volume at rest, rTHS1 and rTHS2 was 16.4 ± 5.2 mm3 , 18.4 ± 4.5 mm3 and 21.3 ± 6.2 mm3 , respectively. It was significantly larger during rTHS2 compared with rest or rTHS1 (rTHS2-rest p = 0.007, rTHS2-rTHS1 p = 0.007). Pharyngeal volume was completely obliterated (zero volume) at maximum pharyngeal contraction in all except one subject. There was no correlation between MTP-L and PPW-AP in any of the three conditions (SS, THS1 and THS2). DISCUSSION: This study demonstrated that the expanded pharyngeal cavity due to the tongue protrusion was completely obliterated by the increase in anterior motion of pharyngeal wall during THS. It also became clear that the degree of tongue protrusion did not linearly correlate with the movement of PPW during THS. There was no relationship between PPW motion and the MTP-L, suggesting that the effect of tongue protrusion is better determined in each subject by analysing the motion of PPW using imaging tools.

In recent years, some research on postoperative computed tomography evaluations of secondary bone grafting into the alveolar cleft have been reported. Here we report a study on volumetric evaluation and the prognostic factors of bone bridge formation after secondary bone grafting into the alveolar cleft using computed tomography. For 60 patients with unilateral cleft lip and palate patients (30 with unilateral cleft lip and alveolar: UCLA, 30 with unilateral cleft lip, alveolar, and palate: UCLP), we performed computed tomography scanning pre- and post-operatively. We calculate bone bridging ratio from bone defect volume and evaluated the prognostic factors of it. The median of bone bridge ratio was 83.6% and 66.3% in UCLA and UCLP, respectively. Both from uni- and multi-variate analysis, the existence of cleft palate and preoperative bone defect volume were selected as statistically significant prognostic factors. The type of tooth inducted into alveolar cleft or its state of eruption were not related with prognosis.

正常な摂食中でも、食塊移送運動の伴わない咽頭運動が起こるか検討した。53名の健康な被験者に10mLの液体バリウムの随意嚥下、コーンビーフの咀嚼嚥下またはコーンビーフと液体バリウムの混合物の咀嚼嚥下を行わせ、嚥下過程をビデオ蛍光観察した。対象は60歳未満28名(男16名、女12名、年齢中央値42歳)と60歳以上25名(男17名、女8名、年齢中央値70歳)の2群に分けた。それぞれの嚥下について、食塊の移送を伴う連続咽頭期運動(CPS)または食塊移送を伴わない孤発的咽頭期嚥下運動(IPS)に分類した。嚥下開始時の食塊の位置についても観察した。307回の摂食において、681回の嚥下が観察され、43回がIPSで、638回がCPSであった。IPSは摂食の最初の嚥下として観察されたが、60歳以上と60歳以下でIPSの頻度に差はなかった。3種の摂食の間では、液体を含む食塊の混合物でIPSの頻度が高かった。以上より、IPSは正常な嚥下でも起こり、嚥下は単純な反射ではなく、複雑な反応であることが示された。