Maxillary Central Incisor Eruption Failure Due to Supernumerary Teeth and Pericoronal Hamartoma: A Report of a Rare Case.

Impaction of permanent teeth during the replacement period is a relatively common occurrence in clinical practice. Tooth impaction occurs in the presence of factors that inhibit tooth eruption, such as supernumerary teeth or tumors. This is a report of permanent tooth impaction due to supernumerary teeth and pericoronal myxofibrous hyperplasia (PMH), a type of pericoronal hamartomatous lesion. An eight-year-old girl was diagnosed with an unerupted right maxillary central incisor. An inverted supernumerary tooth was present on the palatal side of the impacted central incisor, and PMH developed on the labial side of the central incisor. Interestingly, the alveolar bone on the labial side had completely disappeared. After the extraction of the supernumerary tooth and the removal of the PMH, the central incisors erupted, and the labial alveolar bone regenerated normally. Treatment for impacted teeth typically involves the removal of any existing lesions. This case is unique in that the alveolar bone of the impacted tooth regenerated following the extraction of the supernumerary tooth and removal of the PMH.

Formation of hydrotalcite in aqueous solutions and intercalation of ATP by anion exchange.

The formation reaction and the intercalation of adenosine triphosphate (ATP) were studied for hydrotalcite (HT), a layered double hydroxide (LDH) of magnesium and aluminum. Hydrotalcite with nitrate ions in the interlayer (HT-NO(3)) was formed (A) by dropwise addition of a solution of magnesium and aluminum nitrates (pH ca. 3) to a sodium hydroxide solution (pH ca. 14) until the pH decreased from 14 to 10 and (B) by dropwise addition of the NaOH solution to the solution of magnesium and aluminum nitrates with pH increasing from 3 to 10. The precipitate obtained with method B was contaminated with aluminum hydroxide and the crystallinity of the product was low, possibly because aluminum hydroxide precipitates at pH 4 or 5 and remains even after HT-NO(3) forms at pH above 8. With method A, however, the precipitate was pure HT-NO(3) with increased crystallinity, since the solubility of aluminum hydroxide at pH above and around 10 is high as dissolved aluminate anions are stable in this high pH region, and there was no aluminum hydroxide contamination. The formed HT-NO(3) had a composition of [Mg(0.71)Al(0.29)(OH)(2)](NO(3))(0.29).0.58H(2)O. To intercalate ATP anions into the HT-NO(3), HT-NO(3) was dispersed in an ATP solution at pH 7. It was found that the interlayer nitrate ions were completely exchanged with ATP anions by ion exchange, and the interlayer distance expanded almost twice with a free space distance of 1.2 nm. The composition of HT-ATP was established as [Mg(0.68)Al(0.32)(OH)(2)](ATP)(0.080)0.88H(2)O. The increased distance could be explained with a calculated molecular configuration of the ATP as follows: An ATP molecule is bound to an interlayer surface with the triphosphate group, the adenosine group bends owing to its bond angles and projects into the interlayer to a height of 1 nm, and the adenosine groups aligned in the interlayer support the interlayer distance.

Improvement in cognitive impairment after cataract surgery in elderly patients.

PURPOSE: To evaluate whether cognitive impairment improves in elderly patients who have cataract surgery with intraocular lens (IOL) implantation. SETTING: Kouki Hospital, Yamaguchi, Japan. METHODS: A prospective observational study evaluated patients' scores on the Revised Hasegawa Dementia Scale (HDS-R) and the HDS-R minus 1 item regarding immediate regeneration (ie, function of vision and memory). Twenty patients (6 men, 14 women) with cognitive impairment had cataract surgery in 1 eye between March 1996 and July 2001 at Kouki Hospital, Japan. The mean age of the patients was 81.8 years (range 61 to 90 years). Twenty patients (4 men, 16 women) with cognitive impairment who did not have cataract surgery were selected as a control. The mean age in the control group was 84.3 years (range 70 to 93 years). The HDS-R was administered twice between March 1996 and July 2001. RESULTS: The mean HDS-R scores in the cataract surgery group improved from 12.5 points +/- 5.3 (SD) preoperatively to 16.6 +/- 6.2 points postoperatively; the improvement was significant (t = -5.02; P<.0001). After cataract surgery, the grade of cognitive impairment improved in 12 patients (60%), was unchanged in 7 (35%), and was worse in 1 (5%). CONCLUSION: Cataract surgery improved cognitive impairment in elderly Japanese patients.

Cytogenetic heterogeneity and progression of esophageal squamous cell carcinoma.

It is widely believed that most human tumors, including esophageal squamous cell carcinoma (ESCC), arise through multistep genetic and cytogenetic alterations. The time sequence of these alterations, however, is still unknown. The present study was designed to differentiate common early changes from uncommon later ones with combined comparative genomic hybridization (CGH) and ploidy analyses in multiple or single samples of 12 ESCCs. We first demonstrated that the mean copy numbers of chromosomes 3 and 11, determined directly by fluorescence in situ hybridization, showed linear correlation with the mean copy numbers calculated from the G/R ratio of CGH and DNA ploidy (R(2)=0.714, P<0.0001). On this basis, we estimated the absolute copy numbers of chromosomal parts by applying the ploidy-dependent threshold criteria to the G/R ratio data after the criteria were corrected by the percentage of tumor cells in each sample. One-copy changes in the DNA-diploid stage may give large shifts of the G/R ratio, even after tetraploidization, whereas those after tetraploidization undergo small shift. Using the tumors with multiple samples, it was actually demonstrated that most of the gains common to the samples in individual tumors showed the large shifts. Though early changes varied from tumor to tumor in the nine informative cases, it was found that gains of 3q (5/7: number of cases with large-shift 3q+/total number of cases with 3q+), 8q (3/4), 11q13 (4/5), and 14q (3/4) were early events, while losses of 3p (2/8), 5q (1/5), 13q (1/5), and 21q (1/5), and gains of 1p (1/4) and Xq (1/4) were later events in progression of individual tumors.

Retinal pigment epithelial tear involving the fovea with preserved visual function.

Tears of the retinal pigment epithelium are known to occur either spontaneously or after laser photocoagulation in eyes with retinal pigment epithelium detachment. A 65-year-old man with preexisting retinal pigment epithelium detachment developed a retinal pigment epithelium tear after dye laser retinal photocoagulation. The tear gradually expanded to involve the fovea, but his best-corrected visual acuity remained 0.7 in the left eye during 20 months. Optical coherence tomography showed a defect of the retinal pigment epithelium with absence of regeneration. Scanning laser ophthalmoscopy revealed his fixation approached intact retinal pigment epithelium, but was still beneath the fovea. This case may indicate that the retinal pigment epithelium directly beneath the central macula is not essential for maintenance of the overlying foveal function under some conditions.