The temporospatial relationship between mouse dental pulp stem cells and tooth innervation.

Background/purpose: Dental pulp stem cells (DPSCs) exhibit versatile differentiation capabilities, including neural differentiation, prompting the hypothesis that they may be implicated in the neurodevelopment of teeth. This study aimed to explore the temporospatial dynamics between DPSCs and tooth innervation, employing immunofluorescence staining and fluorescent dye injections to investigate the distribution of DPSCs, neural stem cells (NSCs), nerve growth cones, and sensory nerves in developing mouse tooth germs at various stages. Materials and methods: Immunofluorescence staining targeting CD146, Nestin, and GAP-43, along with the injection of AM1-43 fluorescent dye, were utilized to observe the distribution of DPSCs, NSCs, nerve growth cones, and sensory nerves in mouse tooth germs at different developmental stages. Results: Positive CD146 immunostaining was observed in microvascular endothelial cells and pericytes within and around the tooth germ. The percentage of CD146-positive cells remained consistent between 4-day-old and 8-day-old second molar tooth germs. Conversely, Nestin expression in odontoblasts and their processes decreased in 8-day-old tooth germs compared to 4-day-old ones. Positive immunostaining for GAP-43 and AM1-43 fluorescence revealed the entry of nerve growth cones and sensory nerves into the pulp in 8-day-old tooth germs, while these elements were confined to the dental follicle in 4-day-old germs. No co-localization of CD146-positive DPSCs with nerve growth cones and sensory nerves was observed. Conclusion: DPSCs and NSCs were present in dental pulp tissue before nerves penetrated the pulp. The decline in NSCs after nerve entry suggests a potential role for DPSCs and NSCs in attracting neural growth and/or differentiation within the pulp.

Histological analysis on tissues around orthodontically intruded maxillary molars using temporary anchorage devices: A case report.

Before progress was recently made in the application of temporary anchorage devices (TADs) in bio-mechanical design, orthodontists were rarely able to intrude molars to reduce upper posterior dental height (UPDH). However, TADs are now widely used to intrude molars to flatten the occlusal plane or induce counterclockwise rotation of the mandible. Previous studies involving clinical or animal histological evaluation on changes in periodontal conditions after molar intrusion have been reported, however, studies involving human histology are scarce. This case was a Class I malocclusion with a high mandibular plane angle. Upper molar intrusion with TADs was performed to reduce UPDH, which led to counterclockwise rotation of the mandible. After 5 months of upper molar intrusion, shortened clinical crowns were noticed, which caused difficulties in oral hygiene and hindered orthodontic tooth movement. The mid-treatment cone-beam computed tomography revealed redundant bone physically interfering with buccal attachment and osseous resective surgeries were followed. During the surgeries, bilateral mini screws were removed and bulging alveolar bone and gingiva were harvested for biopsy. Histological examination revealed bacterial colonies at the bottom of the sulcus. Infiltration of chronic inflammatory cells underneath the non-keratinized sulcular epithelium was noted, with abundant capillaries being filled with red blood cells. Proximal alveolar bone facing the bottom of the gingival sulcus exhibited active bone remodeling and woven bone formation with plump osteocytes in the lacunae. On the other hand, buccal alveolar bone exhibited lamination, indicating slow bone turnover in the lateral region.

Factors affecting the accuracy of anti-BRAF V600E immunohistochemistry results in ameloblastomas.

BACKGROUND: There are still some controversies about the results of anti-BRAF V600E-specific antibody immunohistochemistry in ameloblastomas. This study aimed to examine the accuracy of V600E-specific antibody immunohistochemistry in detection of BRAF V600E mutation in ameloblastoma tissue sections of different ages. METHODS: The BRAF V600E status of 64 ameloblastoma specimens was assessed using both Sanger sequencing and V600E-specific antibody immunohistochemistry, and the sensitivity, specificity, positive predictive value, and negative predictive value were calculated. The difference in V600E-specific antibody immunohistochemistry staining intensity among the three groups of ameloblastoma tissue blocks of different ages was evaluated by chi-square test. The consistency between V600E-specific antibody immunohistochemistry and DNA sequencing results and the V600E-specific antibody immunohistochemistry staining intensity of 15 paired newly-cut and 3-month storage sections of the same 15 ameloblastomas were also compared. RESULTS: For detection of BRAF V600E mutation, the V600E-specific antibody immunohistochemistry had high sensitivity (98.21% 55/56), specificity (87.5% 7/8), positive predictive value (98.21% 55/56), and negative predictive value (87.5% 7/8). Heterogeneity of the staining intensity was observed in the same tissue section, but all or none expression pattern was noticed in the solid tumor nests. The storage time of paraffin tissue blocks ranging from 2 to 14 years did not affect the V600E-specific antibody-positive staining intensity. However, the three-month storage sections showed a significant diminishment of V600E-specific antibody-positive staining signals. CONCLUSIONS: The BRAF V600E-specific antibody immunohistochemistry is suitable for routine detection of BRAF V600E mutation in ameloblastomas. The all or none expression pattern suggests the BRAF V600E mutation may be an early event in the pathogenesis of ameloblastoma.

High frequencies of vitamin B12 and folic acid deficiencies and hyperhomocysteinemia in Taiwanese male patients with oral submucous fibrosis.

Background: /purpose: Oral submucous fibrosis (OSF) is a betel quid chewing-caused oral mucosal disease with progressive collagen deposition. This study evaluated whether Taiwanese male OSF patients had high frequencies of vitamin B12 and folic acid deficiencies, hyperhomocysteinemia, and serum gastric parietal cell antibody (GPCA) positivity. Materials and methods: The blood hemoglobin (Hb), serum iron, vitamin B12, folic acid, homocysteine, and GPCA concentrations in 62 male OSF patients were measured and compared with the corresponding data in 124 age-matched male healthy control subjects. Results: We found that 5 (8.1%), 12 (19.4%), 32 (51.6%), 31 (50.0%), 22 (35.5%), and 6 (9.7%) of the 62 male OSF patients had Hb (<13 g/dL), iron (≤70 µg/dL), vitamin B12 (≤450 pg/mL), and folic acid (≤6 ng/mL) deficiencies, hyperhomocysteinemia (>12 µM), and serum GPCA positivity, respectively. Furthermore, OSF patients had significantly higher frequencies of Hb (P = 0.006), vitamin B12 (P < 0.001), and folic acid (P < 0.001) deficiencies, hyperhomocysteinemia (P < 0.001), and serum GPCA positivity (P = 0.030) than 124 healthy control subjects. Of the 22 OSF patients with hyperhomocysteinemia, 4 had vitamin B12 deficiency only, 7 had folic acid deficiency only, and 11 had both vitamin B12 and folic acid deficiencies. Conclusion: We conclude that Taiwanese male OSF patients have high frequencies of vitamin B12 and folic acid deficiencies, hyperhomocysteinemia, and serum GPCA positivity. The hyperhomocysteinemia in our OSF patients is predominantly due to deficiencies of either vitamin B12 or folic acid or both.

Nonsyndromic supernumerary teeth in patients in National Taiwan University Children's hospital.

Background/purpose: A literature review reveals limited data for supernumerary teeth in Taiwan. This study aimed to analyze the characteristics of nonsyndromic supernumerary teeth in patients in the National Taiwan University Children's Hospital. Materials and methods: This retrospective study analyzed the nonsyndromic supernumerary teeth in 1280 patients (710 boys and 570 girls) based on examination of mainly panoramic radiographs and related radiographs. Chi-square test was used for trend analysis. Results: The incidence of nonsyndromic supernumerary teeth was 11.25% (179 supernumerary teeth in 144 of the 1280 patients). There was a male predominance (4.33: 1, P < 0.0001) for our 144 patients. Most supernumerary teeth were single (63.69%), conical-shaped (78.77%), and unerupted (77.09%). Supernumerary teeth also tended to be located in the premaxilla (93.85%), fully developed (51.40%), invertedly oriented (45.25%), sagittally located in a palatal/lingual position (67.60%), and adjacent to the root and root apex of permanent teeth (70.39%). The supernumerary teeth with a normal orientation (64.52%) had a high potential to erupt into the oral cavity, but the majority of the supernumerary teeth with a transverse orientation (97.22%) or an inverted orientation (100%) were unerupted. Conclusion: The nonsyndromic supernumerary teeth occur most commonly in male patients with a male to female ratio of 4.33: 1. The incidence of nonsyndromic supernumerary teeth in our 1280 patients is 11.25%, and the most frequent location of supernumerary teeth is the anterior maxillary region. More than three quarters of supernumerary teeth are conical-shaped or unerupted. Inverted supernumerary teeth are all embedded in the jawbones.

Anemia, hematinic deficiencies, and hyperhomocysteinemia in younger and older burning mouth syndrome patients.

Abstract Background/purpose: Our previous study found that 19.8%, 16.2%, 4.8%, 2.3%, and 19.2% of 884 burning mouth syndrome (BMS) patients have anemia, serum iron, vitamin B12, and folic acid deficiencies, and hyperhomocysteinemia, respectively. This study mainly evaluated the anemia, hematinic deficiencies, and hyperhomocysteinemia in 272 younger (≤50 years old) and 612 older (>50 years old) BMS patients. Materials and methods: The blood hemoglobin (Hb) and serum iron, vitamin B12, folic acid, and homocysteine levels in 272 younger and 612 older BMS patients were measured and compared with the corresponding levels in 136 younger (≤50 years old) and 306 older (>50 years old) healthy control subjects (HCSs), respectively. Results: We found that 272 younger BMS patients had significantly lower mean blood Hb and serum iron, vitamin B12, and folic acid levels than 136 younger HCSs. Moreover, 612 older BMS patients had significantly lower mean blood Hb, and serum iron and vitamin B12 levels and significantly higher mean serum homocysteine level than 306 older HCSs. In addition, 272 younger BMS patients had higher mean blood Hb level (marginal significance, P = 0.056), significantly lower mean serum vitamin B12 and folic acid levels, and significantly higher frequencies of iron and folic acid deficiencies than 612 older BMS patients. Conclusion: The younger BMS patients do have higher mean blood Hb level, significantly lower mean serum vitamin B12 and folic acid levels, and significantly higher frequencies of serum iron and folic acid deficiencies than the older BMS patients.

Significantly higher frequencies of macrocytosis, anemia, serum vitamin B12 and folic acid deficiencies, and hyperhomocysteinemia in male than in female atrophic glossitis patients.

Background/purpose: Our previous study found that 19.0%, 16.9%, 5.3%, 2.3%, 11.9%, and 26.7% of 1064 atrophic glossitis (AG) patients have anemia, serum iron, vitamin B12, and folic acid deficiencies, hyperhomocysteinemia, and serum gastric parietal cell antibody (GPCA) positivity, respectively. This study evaluated the anemia, hematinic deficiencies, and hyperhomocysteinemia in 150 male and 914 female AG patients. Materials and methods: The blood hemoglobin (Hb) and serum iron, vitamin B12, folic acid, homocysteine, GPCA levels in 150 male and 914 female AG patients were measured and compared with the corresponding levels in 75 male and 457 female healthy control subjects (HCSs), respectively. Results: We found that 150 male AG patients had significantly lower mean blood Hb, serum iron, vitamin B12, and folic acid levels, and significantly higher mean serum homocysteine levels than 75 male HCSs. Moreover, 914 female AG patients had significantly lower mean blood Hb and serum iron levels and significantly higher mean serum homocysteine level than 457 female HCSs. In addition, 150 male AG patients had significantly higher mean blood Hb and serum homocysteine levels, significantly lower mean serum vitamin B12 and folic acid levels, and significantly higher frequencies of Hb, vitamin B12, and folic acid deficiency and hyperhomocysteinemia than 914 female AG patients. Conclusion: The male AG patients do have significantly higher mean blood Hb and serum homocysteine levels, significantly lower mean serum vitamin B12 and folic acid levels, and significantly higher frequencies of Hb, vitamin B12, and folic acid deficiencies and hyperhomocysteinemia than the female AG patients.

Comparison of past and current dental school curricula for dental students of National Taiwan University.

Background/purpose: The complete curriculum schedule of the School of Dentistry, National Taiwan University (NTU) appeared in 1960. This study aimed to understand the development of dental education in Taiwan by comparing the past and current dental school curricula of NTU. Materials and methods: This study collected the 1960, 1990 and 2020 dental school curriculum schedules for dental students of NTU from the related websites and used the documentary and secondary data analyses to further compare the obtained data. Results: The number of credits for all the curricula offered by NTU to undergraduate dental students decreased from 264 in 1960 to 243 in 1990 and further to 242 in 2020 with a total decrease of 22 credits by 8.3%. The number (proportion) of credits of medicine courses decreased from 102 (38.6%) in 1960 to 52 (21.4%) in 1990, and then increased to 60 (24.8%) in 2020, with a total decrease of 42 credits by 41.2%, while those of dentistry courses increased from 70 (26.5%) in 1960 to 122 (50.2%) in 1990 and further to 132 (54.5%) in 2020, with a total increase of 62 credits by 88.6%. Among them, clinical practice of dentistry had the greatest growth with a total increase of 42 credits by 233.3%. Conclusion: The increase of dentistry courses and the decrease of medicine courses are the general trends for modern dental education. The dental school of NTU has the ability to provide more refined dentistry courses to catch the world trend of dental education.

Dental education and special dental practitioner-cultivating system in Taiwan during the Japanese colonial period.

Background/purpose: During the Japanese colonial period, Taiwan had no dental school but had a medical school. This study explored the dental education and research activities in the medical school and special dentist qualification system in Taiwan during the Japanese colonial period. Materials and methods: This study analyzed the "related incidents and documents of dental education and research and dentist qualification system in Taiwan during the Japanese colonial period" and explored the dental education and research activities in the medical school and special dentist qualification system in Taiwan during the Japanese colonial period. Results: In 1914, Taiwan Government Medical School hired Dr. Kaname Ansawa, the earliest dental teacher in Taiwan, to teach dental courses in the medical school. In 1918, the "Theory of Dentistry" was considered to be the first independent "Dentistry" subject in the medical school. In 1936, the Faculty of Medicine of Taipei Imperial University listed "Dentistry & Oral Surgery" as an independent graduation examination subject. For dentist qualification system, a qualified physician who had finished dental courses and training could apply for a dental specialty license to work as a dentist. Taiwan Government Medical School (Dentistry) Research Department was the earliest department involved in the teaching and research of dentistry in the medical school and was also an educational institution for cultivating dental practitioners in Taiwan. Conclusion: In the Japanese colonial period, although no dental school was established in Taiwan, there were rich dental education and research activities in the medical school and a special dentist qualification system.

Anemia, hematinic deficiencies, hyperhomocysteinemia, and gastric parietal cell antibody positivity in burning mouth syndrome patients with normocytosis.

BACKGROUND/PURPOSE: Normocytosis is defined as having the mean corpuscular volume (MCV) between 80 fL and 99.9 fL. This study evaluated whether 770 burning mouth syndrome (BMS) patients with normocytosis (so-called normocytosis/BMS patients) had significantly higher frequencies of anemia, hematinic deficiencies, hyperhomocysteinemia, and serum gastric parietal cell antibody (GPCA) positivity than 442 healthy control subjects or 884 BMS patients. MATERIALS AND METHODS: Complete blood count, serum iron, vitamin B12, folic acid, homocysteine, and GPCA levels in 884 BMS patients (including 770 normocytosis/BMS patients) and 442 healthy control subjects were measured and compared. RESULTS: We found that 12.3%, 13.2%, 2.2%, 2.3%, 17.3%, and 10.5% of 770 normocytosis/BMS patients had blood hemoglobin (Hb), iron, vitamin B12, and folic acid deficiencies, hyperhomocysteinemia, and serum GPCA positivity, respectively. Furthermore, 770 normocytosis/BMS patients had significantly higher frequencies of blood Hb, iron, vitamin B12, and folic acid deficiencies, hyperhomocysteinemia, and serum GPCA positivity than 442 healthy control subjects (all P-values < 0.005). On the contrary, 770 normocytosis/BMS patients had significantly lower frequencies of blood Hb and vitamin B12 deficiencies than overall 884 BMS patients (both P-values < 0.01). CONCLUSION: We conclude that there are significantly higher frequencies of anemia, serum iron, vitamin B12, and folic acid deficiencies, hyperhomocysteinemia, and serum GPCA positivity in normocytosis/BMS patients than in healthy control subjects. On the contrary, normocytosis/BMS patients do have significantly lower frequencies of blood Hb and vitamin B12 deficiencies than overall BMS patients.

Comparisons of histological features among primary oral squamous cell carcinomas before and after adjuvant chemotherapy and their lymph node metastatic cancer lesions after adjuvant chemotherapy.

BACKGROUND/PURPOSE: Adjuvant chemotherapy has been used to control the primary oral squamous cell carcinoma (OSCC) size prior to surgical excision of the cancer. This study aimed to explore the histological changes of primary OSCCs and their cervical lymph node metastatic cancer lesions after chemotherapy. MATERIALS AND METHODS: Thirty-three OSCC patients with eleven having cervical lymph node metastases received adjuvant chemotherapy before surgical excision of their cancer lesions. Hematoxylin and eosin-stained tissue sections of incisional biopsy, surgical excision, and cervical lymph node metastatic cancer lesion specimens were compared microscopically to observe the histological changes in the cancer tissues after chemotherapy. RESULTS: Common histological features could be found in the primary OSCCs and their cervical lymph node metastatic cancer lesions after chemotherapy. These included direct killing of cancer cells by chemotherapeutic agents, resulting in cancer cell necrosis and degeneration in the early phase, and squamous and keratinizing metaplasia of drug-induced cancer cells, leading to individual cell keratinization and keratin pearl formation in the later phase. There were also small nests of drug-resistant proliferating cancer cells in the inflamed fibrous connective tissue stroma. The most characteristic histological feature in the metastatic lymph nodes after chemotherapy was the keratinizing metaplasia of the metastatic cancer cells, resulting in the formation of epidermoid cyst-like lesions. CONCLUSION: Although the cancer reduces its size after chemotherapy, residual cancer cells are consistently present in the primary OSCC lesions after chemotherapy. Therefore, wide surgical resection of the cancer is still needed to ensure the complete removal of all cancer tissues.

Anemia, hematinic deficiencies, and hyperhomocysteinemia in burning mouth syndrome patients with thyroglobulin antibody/thyroid microsomal antibody positivity but without gastric parietal cell antibody positivity.

BACKGROUND/PURPOSE: Our previous study found that 222 of 884 burning mouth syndrome (BMS) patients have thyroglobulin antibody (TGA) positivity and/or thyroid microsomal antibody (TMA) positivity but without gastric parietal cell antibody positivity (GPCA-TGA+/TMA+BMS patients). This study mainly assessed whether the serum TGA/TMA positivity was significantly associated with anemia, hematinic deficiencies, and hyperhomocysteinemia in GPCA-TGA+/TMA+BMS patients. MATERIALS AND METHODS: The complete blood count, iron, vitamin B12, folic acid, and homocysteine levels were measured and compared between 222 GPCA-TGA+/TMA+BMS patients and 553 GPCA-negative, TGA-negative, and TMA-negative BMS patients (GPCA-TGA-TMA-BMS patients) or 442 healthy control subjects. RESULTS: We found that 222 GPCA-TGA+/TMA+BMS patients had significantly lower mean corpuscular volume (MCV) and lower blood Hb and serum iron levels than 442 healthy control subjects and significantly lower MCV and lower serum homocysteine levels than 553 GPCA-TGA-TMA-BMS patients. Moreover, 222 GPCA-TGA+/TMA+BMS patients had significantly greater frequencies of microcytosis, macrocytosis, blood Hb and serum iron deficiencies, and hyperhomocysteinemia than 442 healthy control subjects and significantly higher frequency of microcytosis but significantly lower frequency of hyperhomocysteinemia than 553 GPCA-TGA-TMA-BMS patients. However, no significant differences in the frequencies of macrocytosis, blood Hb, serum iron, vitamin B12, and folic acid deficiencies were discovered between 222 GPCA-TGA+/TMA+BMS patients and 553 GPCA-TGA-TMA-BMS patients. CONCLUSION: We conclude that the disease of BMS itself does play a significant role in causing macrocytosis, anemia, hematinic deficiencies, and hyperhomocysteinemia in GPCA-TGA+/TMA+BMS patients. However, the serum TGA/TMA-positivity is not significantly associated with anemia and serum iron, vitamin B12, and folic acid deficiencies in GPCA-TGA+/TMA+BMS patients.

Distributions of dentists and physicians in Taiwan during the Japanese colonial period from 1923 to 1924.

BACKGROUND/PURPOSE: In 1896, the first dentist opened his dental clinic in Taipei City and this also opened a new era of Taiwan's dentistry. This study tried to assess the dentist manpower in Taiwan during the Japanese colonial period from 1923 to 1924, and hence to explore the appearance of Taiwan's early dentistry. MATERIALS AND METHODS: This study utilized the secondary data analysis to evaluate the numbers and distributions of dentists, physicians, and local practitioners in Taiwan from 1923 to 1924, to find the relationship among them, and further to explore the development of dentists in Taiwan at that period. RESULTS: The total numbers of dentists and physicians increased from 87 to 882 in 1923 to 97 and 927 in 1924, respectively. Moreover, the total number of local practitioners decreased from 583 in 1923 to 558 in 1924. Their Gini coefficients for dentists, physicians, and local practitioners were 0.18, 0.16 and 0.20 in 1923 and 0.27, 0.05 and 0.19 in 1924, respectively. From 1923 to 1924, dentists and physicians were mainly concentrated in the northern and southern regions of Taiwan, and dentists had more serious uneven distribution problem. CONCLUSION: We conclude that the uneven distribution of dentist in Taiwan is an old problem. After a hundred years of development, the number of dentists increases at a higher rate than the number of physicians and there is no shortage of dentists to date in Taiwan. However, the problem of uneven distribution of dentists still exists and is even more serious now.