IgG4-related Dacryoadenitis and Sialadenitis with Palatal Gland Swelling.

Many cases of immunoglobulin G4-related disease (IgG4-RD) involve swelling of the salivary glands, often affecting the parotid and submandibular glands in the head and neck region, in addition to the lacrimal glands. Cases of IgG4-RD characterized by swelling of the palatal glands, however, are extremely rare. Here, we describe a case of IgG4-RD involving bilateral swelling of the palatal glands. An 83-year-old man presented at our hospital with bilateral swelling of the lacrimal and submandibular glands. A solid bilateral swelling of normal colour and unclear boundaries was observed in the hard palate. The lesion was diagnosed as IgG4-RD and steroid therapy initiated. A subsequent decrease in swelling of the palatal, lacrimal, and submandibular glands was confirmed by magnetic resonance imaging. These results indicate that dentists should suspect IgG4-RD in patients presenting with bilateral swelling of the palatal glands.

Sjögren's syndrome and ranula development.

OBJECTIVES: We hypothesized that the extravasation of saliva from damaged ducts with lymphocytic infiltration in patients with Sjögren's syndrome causes ranulas. There are too many uncertainties to support this hypothesis. The aim of this study was to investigate whether there is an association between Sjögren's syndrome and ranulas. MATERIALS AND METHODS: We observed three cases of patients with ranulas who were also diagnosed with Sjögren's syndrome at the same facility. These cases led to the question of whether there are other such cases, and thus, an exhaustive literature search was conducted. RESULTS: Three cases in two case reports of mucocele of the floor of the mouth associated with adult Sjögren's syndrome were noted. Including our cases, until now, there have been six cases of ranula with adult Sjögren's syndrome. CONCLUSIONS: It could be useful to investigate whether patients presenting with a ranula are also affected by Sjögren's syndrome and, conversely, investigate patients with Sjögren's syndrome longitudinally to see whether they develop ranulas.

Squamous Cell Carcinoma of Maxillary Gingiva Progressing to Disseminated Carcinomatosis of Bone Marrow.

Disseminated carcinomatosis of the bone marrow (DCBM) is characterized by diffuse metastasis to bone marrow and sudden mortality. To the best of our knowledge, no studies to date have reported progression of oral squamous cell carcinoma to DCBM. Herein, we report a case of squamous cell carcinoma in the maxillary gingiva suspected of progressing to DCBM. A 64-year-old woman presented with white lesions on the left maxillary gingiva. The lesions were diagnosed as squamous cell carcinoma (T2, N0, M0), and partial maxillectomy performed. Two years and 5 months after surgery, metastasis was noted in the left cervical lymph node and left radical neck dissection carried out. The subsequent diagnosis was right cervical lymph node metastasis and multiple bone metastases. The patient also presented with thrombocytopenia, anemia, and elevated levels of alkaline phosphatase, probably due to metastatic bone disease. Although various antitumor therapies were administered, the patient died 6 months after diagnosis of multiple bone metastases.

The effects of 2,3-dimercapto-1-propanesulfonic acid (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) on the nephrotoxicity in the mouse during repeated cisplatin (CDDP) treatments.

Previously, we reported that specific lower dose of sodium 2,3-dimercapto-1-propanesulfonic acid (DMPS) which is an antidote to heavy metal intoxication, inversely enhanced cisplatin (CDDP)-induced antitumor activity to S-180 cell-bearing mouse. This activity was only weak with meso-2,3-dimercaptosuccinic acid (DMSA), however. This study investigated the effects of lower doses of DMPS or DMSA on the nephrotoxicity and kinetics of CDDP. Kidney and blood isolated from female mice which received CDDP with or without DMPS or DMSA once daily for 4 days were provided for measuring levels of blood urea nitrogen (BUN) and transporter proteins (OCT2: organic cation transporter; MATE1: multidrug and toxin extrusion) mRNA, and CDDP-originated platinum, and TUNEL staining of renal tubular cells. DMPS or DMSA reduced effectively CDDP-induced BUN, and caused a moderate reduction of platinum in kidney. Additionally, both dimercapto-compounds restored the CDDP-reduced mRNA levels of transporter proteins (OCT2 and MATE1), and apparently suppressed the CDDP-induced apoptosis. These results suggest that DMPS, as well as DMSA, at approximate 17-fold dose (µmol/kg) of CDDP, has an enough potential to reverse the CDDP nephrotoxicity, and concomitant use of DMPS considering both dose and timing for administration is potentially useful for preventing nephrotoxicity and enhancing antitumor activity during CDDP chemotherapy.

Preliminary Study of Temporal Change in Free Flap Volume after Tongue Reconstruction.

The purpose of this study was to investigate three-dimensionally temporal change in flap volume after free flap reconstructive surgery in tongue cancer patients. The results revealed an average change in flap volume of 82.3% at 1 year postoperatively. Change in tongue volume at approximately 6 months postoperatively showed a correlation with triglyceride levels. A correlation was also found between albumin levels and tongue volume at 1 year onwards postoperatively. The goal of such surgery in patients with tongue cancer is to reconstruct a functional tongue. Taking postoperative change in tongue volume into consideration is therefore of importance in minimizing postoperative dysphagia.

Oral Cancer Chernoprevention: Current Status and Future Direction.

The aim of this study is to review the current status of cancer chemoprevention and its effectiveness in treatment of oral premalignant lesions and prevention of their progression to oral cancer. The challenges encountered in the different oral cancer chemoprevention clinical trials, including lack of surrogate endpoints, reversal of histologic premalignant changes as study endpoints, tobacco use, human papillomavirus, delivery system, adverse effects and risk of bias in clinical studies, are presented.

Expression of Cytokeratin 13, 14, 17, and 19 in 4-nitroquinoline-1-oxide-induced Oral Carcinogenesis in Rat.

The management of epithelial dysplastic spread around an oral squamous cell carci-noma is very important, particularly intraoperatively. Both cytokeratin (CK) 14 and CK19 are believed to be involved in the development of precancerous lesions, and their expression profiles are quite specific in these and early cancer lesions. Here, expression of CK13, 14, 17, and 19 was investigated in a rat model of 4-nitroquinoline-1-oxide-induced tongue cancer during a series of carcinogenetic processes to determine their value in assessing the features of epithelial dysplastic spread around a cancer. Based on tissue conditions, the results showed that expression levels of CK13 and 14 decreased in the order of no change, dysplasia, and cancer, whereas those of CK17 and 19 increased in the same order. Expression of CK13 showed a significant difference among no change, dysplasia, and cancer. This indicates that comparing the immunohistochemical staining profiles of CKs, especially CK13, could help in assessing the characteristics of epithelial dysplastic spread around a cancer.

Expression of Cytokeratin 14 and 19 in Process of Oral Carcinogenesis.

Cytokeratins (CK) are abundant in keratinized cells, particularly CK14 and CK19, which are expressed in stratified squamous epithelial cells. In this study, expression of CK14 and 19 was examined in human epithelial and dysplastic tissues. Surgical specimens from patients with clinically diagnosed oral leukoplakia or early cancer were stained with hematoxylin and eosin and classified into normal, low grade dysplasia (LGD), high grade dysplasia (HGD), or squamous cell carcinoma (SCC). The sections were examined by immunostaining and reverse transcription-polymerase chain reaction (RT-PCR) for CK14 and CK19. Expression and the results of RT-PCR for CK14 showed a decrease in the order of LGD, HGD, and SCC, whereas those of CK19 showed an increase in that order. These results suggest that decreased expression of CK14 and increased expression of CK19 serve as indicators of potential for malignant transformation.

Cytokeratin 13, Cytokeratin 17, Ki-67 and p53 Expression in Upper Layers of Epithelial Dysplasia Surrounding Tongue Squamous Cell Carcinoma.

Early detection of oral squamous cell carcinoma (OSCC) improves its prognosis and aids in selecting the appropriate treatment, which may also have a positive effect on quality of life. Early detection, therefore, is an important issue in the treatment of this disease. The purpose of this study was to investigate expression of cytokeratin 13 (CK13), CK17, Ki-67 and p53 as potential markers of tongue SCC. Five areas in 12 specimens were examined: the upper and lower layers of normal epithelium; those of dysplastic epithelial tissue surrounding the cancerous lesion; and the lesion itself. Strong expression of each of the following mRNAs and proteins was observed; CK13 in upper layers of normal epithelium; Ki-67 and p53 in lower layers of normal epithelium; CK13 and CK17 in upper layer of epithelial dysplasia; and CK17, Ki-67, and p53 in lower layer of epithelial dysplasia and cancerous lesions. These results indicate that the characteristic pattern of expression of CK13 and CK17 differs between normal and dysplastic oral epithelium. Oral epithelial dysplasia adjacent to OSCC has high malignant potential, and is similar to early-stage OSCC. This suggests that evaluation of these markers could be a useful secondary procedure for improving detection of early-stage OSCC.

Effects of professional oral health care on reducing the risk of chemotherapy-induced oral mucositis.

PURPOSE: Recent years have seen remarkable progress in cancer therapy, although treatment-induced adverse reactions and complications are not uncommon. Approximately 40 % of patients undergoing chemotherapy for cancer experience adverse reactions in the oral cavity, with nearly half of them developing severe oral mucositis that necessitates postponing therapy and/or changing the drug dosage. The objective of this study was to assess the usefulness of prophylactic professional oral health care (POHC) for preventing mucositis in patients undergoing chemotherapy. METHODS: Twenty-six female patients scheduled for chemotherapy for breast cancer were included in this study and randomized to the self-care or POHC groups. Assessment parameters included oral cavity photographs, plaque control records, Saxon test scores, Oral Assessment Guide scores, and grading using the Common Terminology Criteria for Adverse Events. Beginning before surgery and continuing through the completion of chemotherapy, the POHC patient group received weekly professional oral health care, including scaling, professional cleaning of the tooth surfaces, brushing instructions, and nutritional and lifestyle guidance. RESULTS: More patients in the self-care group developed oral mucositis than in the POHC group. The Oral Assessment Guide score, which was used as an index of oral mucositis, was also significantly lower in the POHC group. Based on the Oral Assessment Guide and plaque control records, there was almost no deterioration of the oral environment in the POHC group, whereas deterioration was observed in the self-care group. CONCLUSIONS: These findings demonstrate the efficacy of regular POHC in reducing the risk of oral mucositis in breast cancer patients undergoing chemotherapy.

Evaluation of superficial oral squamous cell malignancy based on morphometry and immunoexpression of cytokeratin 13 and cytokeratin 17.

OBJECTIVE: Evaluation of combined morphometry and immunoexpression of cytokeratin 13 (CK13) and cytokeratin 17 (CK17) for cytological identification of superficial oral squamous cells. STUDY DESIGN: Smears from 11 tongue squamous cell carcinoma patients were processed by liquid-based cytology, stained via the Papanicolaou method and divided into multiple specimens by cell transfer. Morphometric indices, including nuclear area, nuclear perimeter, nuclear circular rate, largest-to-smallest dimension ratio of the nucleus and nucleocytoplasmic ratio, were measured using a computerized analysis system. CK13 and CK17 were detected by immunostaining. Morphometric values were compared between cell populations with distinct staining and immunoexpression patterns. RESULTS: Most orange G-stained superficial cells were negative for CK13 (99.4%) and CK17 (98.6%). For light green-stained superficial cells, loss of CK13 was associated with greater cellular atypia in the nuclear area, nuclear perimeter and nucleocytoplasmic ratio (p < 0.01), while expression of CK17 was related to higher-grade cellular atypia in the same parameters (p < 0.01) as well as the nuclear circular rate (p < 0.05). CONCLUSION: Immunoexpression of CK13 and CK17 in light green-stained superficial cells was associated with more severe morphological atypia. Combined morphometry and immunoexpression of CK13 and CK17 might be useful for cytological diagnosis of this cell population.

A giant peripheral ossifying fibroma of the maxilla with extreme difficulty in clinical differentiation from malignancy: a case report and review of the literature.

BACKGROUND: Peripheral ossifying fibroma is a nonneoplastic inflammatory hyperplasia that originates in the periodontal ligament or periosteum in response to chronic mechanical irritation. Peripheral ossifying fibroma develops more commonly in young females as a solitary, slow-growing, exophytic nodular mass of the gingiva, no more than 2 cm in diameter. While various synonyms have been used to refer to peripheral ossifying fibroma, very similar names have also been applied to neoplastic diseases that are pathologically distinct from peripheral ossifying fibroma, causing considerable nomenclatural confusion. Herein, we report our experience with an unusual giant peripheral ossifying fibroma with a differential diagnostic challenge in distinguishing it from a malignancy. CASE PRESENTATION: A 68-year-old Japanese male was referred to our department with a suspected gingival malignancy presenting with an elastic hard, pedunculated, exophytic mass 60 mm in diameter in the right maxillary gingiva. In addition to computed tomography showing extensive bone destruction in the right maxillary alveolus, positron emission tomography with computed tomography revealed fluorodeoxyglucose hyperaccumulation in the gingival lesion. Although these clinical findings were highly suggestive of malignancy, repeated preoperative biopsies showed no evidence of malignancy. Since even intraoperative frozen histological examination revealed no malignancy, surgical resection was performed in the form of partial maxillectomy for benign disease, followed by thorough curettage of the surrounding granulation tissue and alveolar bone. Histologically, the excised mass consisted primarily of a fibrous component with sparse proliferation of atypical fibroblast-like cells, partly comprising ossification, leading to a final diagnosis of peripheral ossifying fibroma. No relapse was observed at the 10-month follow-up. CONCLUSIONS: The clinical presentation of giant peripheral ossifying fibromas can make the differential diagnosis from malignancy difficult. Proper diagnosis relies on recognition of the characteristic histopathology and identification of the underlying chronic mechanical stimuli, while successful treatment mandates complete excision of the lesion and optimization of oral hygiene. Complicated terminological issues associated with peripheral ossifying fibroma require appropriate interpretation and sufficient awareness of the disease names to avoid diagnostic confusion and provide optimal management.

A 5-year activity report from the Oral Cancer Center, Tokyo Dental College.

The Tokyo Dental College Oral Cancer Center was established on April 1st, 2006 at our Ichikawa General Hospital for the purpose of providing multimodal treatment for oral cancer. This report summarizes the Center's activities over the last 5 years. The total number of oral cancer patients treated was 360 (April 2006 to March 2011), with 205 primary cases. We investigated the following treatment-related items: 1) site, 2) age, 3) sex, 4) pathological examination, 5) staging, 6) systemic disorder, 7) double cancer, 8) treatment, and 9) prognosis. Out of 205 patients, 60% were men and 40% were women. Men in their 60s and women in their 80s were seen the most. The most common site was the tongue, at 42%, followed by the mandibular gingiva, maxillary gingiva, oral floor, and buccal mucosa. Squamous cell carcinomas were seen most frequently, at 94% (15% were stage I, 33% stage II, 15% stage III, and 34% stage IV). The most common treatment method was surgical treatment, at 83%. The 5-year survival rate at all stages was 85.4%. At the Oral Cancer Center, oral surgeons take the initiative in establishing treatment in cooperation with other departments and branches. Since the establishment of the Ambulatory Center for Maxillary Prosthetics in October 2011, 26 patients have undergone treatment. Related departments and branches work in teams, enabling comprehensive treatment, from the preoperative state to postoperative functional recovery. We wish to use these strengths to improve oral cancer treatment in Japan and will continue to work toward providing the best possible care for our patients.

Head and neck contrast-enhanced CT for identification of internal carotid artery stenosis progression on the affected side after treatment for oral squamous cell carcinoma.

OBJECTIVES: To determine the incidence of progressive internal carotid artery (ICA) stenosis by head and neck contrast-enhanced computed tomography (CT) in 82 patients who underwent surgery, chemotherapy, or combination therapy for oral squamous cell carcinoma (OSCC). METHODS: The study included 82 patients who underwent head and neck contrast-enhanced CT after surgery alone or combined surgery and chemotherapy for OSCC at the Department of Oral and Maxillofacial Surgery of Ichikawa General Hospital, Tokyo Dental College, or Tokyo Dental College Oral Cancer Center between December 2002 and March 2010. RESULTS: Comparison with previously obtained head and neck contrast-enhanced CT images revealed progressive arterial stenosis of the ICA in five patients with a mean age of 62.0 years. All five patients were male, and their OSCC sites were the tongue in two, the floor of the mouth in two, and the mandibular gingiva in one. Tumor resection and neck dissection were performed for four patients and tumor resection alone for one patient. Four patients underwent chemotherapy. ICA stenosis occurred on the same side as the tumor in all five patients. CONCLUSIONS: The results of this study suggest that, given the possibility of post-treatment vascular events, attention must be paid to subsequent changes in the ICA over time. The results also indicate the usefulness of head and neck contrast-enhanced CT in identifying such problems.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020.

The prevalence of sleep disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared in order to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Because sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020.

The prevalence of sleep-disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Since sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Effect of maxillomandibular advancement on morphology of velopharyngeal space.

PURPOSE: The objectives of the present study were to assess the changes in upper airway morphology and function in response to advancement of the maxilla and mandible. PATIENTS AND METHODS: Orthognathic surgery was performed. During the surgery, the maxilla and mandible were each advanced as a maxillomandibular advancement simulation. A total of 18 patients with a chief complaint of malocclusion were studied. The distance in jaw advancement and the anteroposterior and left-right diameters of the velopharyngeal space before and after jaw advancement were measured. After the anteroposterior and left-right dilation rates and area enlargement rates were calculated, we compared advancement of the maxilla with that of the mandible. RESULTS: Each of the jaw advancements resulted in statistically significant increases in the anteroposterior and left-right diameters of the velopharyngeal space, and the area was significantly enlarged. The anteroposterior dilation rate was significantly greater after advancement of the maxilla, and the left-right dilation rate was significantly greater after advancement of the mandible. The velopharyngeal space area enlargement rate was significantly greater with advancement of the maxilla. CONCLUSIONS: These data suggest that the mode of dilation of the velopharyngeal space differs between maxillary advancement and mandibular advancement. Jaw advancement affects the soft palate muscles, and the velopharyngeal space is expanded 3-dimensionally by each of those muscles. The difference in the pattern of expansion of the velopharyngeal space was related to differences in the functions of the soft palate muscles.

Review of systematic reviews on mandibular advancement oral appliance for obstructive sleep apnea: The importance of long-term follow-up.

The purpose of this review was to present the currently available information on oral appliance (OA) therapy for dentists, especially clinic-based dentists, to aid them in performing this treatment for the management of symptoms of obstructive sleep apnea (OSA). The clinical research evidence comprised of systematic reviews concerned with the mandibular advancement oral appliance (OAm). Continuous positive airway pressure (CPAP) is superior to OA therapy in improving OSA symptoms. It is necessary to survey the adherence of patients who stopped CPAP therapy to OAm therapy. There is little evidence supporting the theory that OAm therapy prevents cardiovascular disease or improves prognosis. There is still room to investigate the types of OAm. OAm therapy has clear dental and skeletal side effects with long-term use, and these are important for dentists. However, a certain percentage of patients discontinue consultations. Regarding consultation rate for follow-up and repair/adjustments of OAm, there are advantages for the clinic-based dentists treating OSA with OAm. We believe that enhancing under-graduate and post-graduate education on sleep medicine, and establishing a specialist system could be the strategies for enabling the dentists to handle OAm therapy in dental clinics.

Activation of PI3K-AKT pathway in oral epithelial dysplasia and early cancer of tongue.

Increasingly, cancers are being diagnosed at an early stage. Leukoplakia, a precancerous lesion, progresses to cancer in 5-10% of cases. We performed genetic analysis using cDNA microarray and immunohistochemistry in 6 patients, 3 with precancerous lesions and 3 with early tongue cancer, to evaluate the usefulness of these methods in the diagnosis of precancerous lesions and early cancer. Samples of normal epithelium, epithelial dysplasia, and cancer tissues were collected by laser microdissection, RNA was extracted, and the signals converted to numerical values. Immunohistochemical analysis was performed using antibody against phospho AKT (p-AKT), a component of the phosphoinositide 3-kinase (PI3K) signal pathway. Five genes showed a 2 times or greater level of increase in expression in epithelial tissue in comparison with in normal tissue, while 4 genes showed a 2 times or greater increase in early cancer tissues. In cancer tissues and epithelial dysplasia tissues, PI3K class III was expressed at 2.5 times and 11 times the level of that found in normal tissue, respectively. Histochemistry using p-AKT antibody revealed no positive cells in normal tissue. Positive cells were noted in the basal and parabasal cell layers, and partially in the spinous layer of epithelial dysplasia tissues, and in the spinous layer of early cancer tissues. These findings suggest that activation of the PI3K-AKT signal pathway is associated with oral carcinogenesis.

The Most Effective Amount of Forward Movement for Oral Appliances for Obstructive Sleep Apnea: A Systematic Review.

This systematic review clarifies the amount of effective protrusion in mandibular advancement devices of oral appliances required for obstructive sleep apnea (OSA). The systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Review Manager 5 and GRADEpro were used to combine trials and analyze data. The present review included three studies. In mild to moderate OSA cases, measured using the apnea-hypopnea index (AHI), 50% protrusion was more effective than 75% protrusion. However, 75% protrusion was more effective for severe cases. Sleep stage, Epworth Sleepiness Scale (ESS), snoring index, and side effects significantly differed between the groups. Additionally, 75% protrusion was more effective (AHI: 0.38, 95% CI: -0.89 to 1.65, p = 0.56; sleep stage 3: -1.20, 95% CI: 9.54-7.14, p = 0.78; ESS: 1.07, 95% CI: -0.09 to 2.24, p = 0.07; snoring index: 0.09, 95% CI: 0.05-0.13, p < 0.05; side effects: RR: 1.89, 95% CI: 0.36-9.92, p = 0.45). As per the AHI, 75% protrusion was effective in severe cases, whereas 50% protrusion was effective in moderate cases. Analysis of different surrogate outcomes indicated that 75% protrusion was more effective. Further, well-designed, larger trials should determine the benefits for patients. Additionally, investigations of adherence and side effects with long-term follow-up are needed.