The oral cavity, an intersection between medicine and dentistry, continuously interacts with the entire body [1]. Moreover, deteriorating oral health can directly impact a patient’s overall quality of life, especially in cases of chronic physical and mental health conditions as well as in physical disabilities [2,3]. Numerous studies have shown that patients with systemic diseases who have received treatment or have been hospitalized for extended periods often have poor oral hygiene, leading to an increase in the dental plaque index and gingival inflammation index [4,5]. Consequently, these patients become more susceptible to dental caries and gum disease, and experience oral pain, difficulty in chewing, and challenges in daily activities [3,6]. To address this issue, it is essential to improve the quality of life for patients through regular dental check-ups and dental treatments involving sedation or general anesthesia [2,7].

In pediatric patients, their immature physical and mental development predisposes them to poor oral health and oral diseases [8]. However, dental treatment is less likely to be provided due to its lower priority compared to medical treatment, indifference from both guardians and doctors, and a lack of cooperation from these patients [9]. Thus, without professional preventive and therapeutic dental services, the overall condition of pediatric patients may worsen, leading to costly dental treatments or even making treatment impossible [10]. Just as physicians generally have a limited understanding of patients’ oral conditions, pediatric dentists also typically have a limited understanding of patients’ overall systemic conditions. Therefore, it is important to communicate through interdisciplinary consultations and find ways of improving the patient’s condition and oral health [11,12].

According to the studies conducted by Hayes et al. [13] and Kanuga et al. [14] in the Seattle Children’s Hospital, 63% and 54% of dental consultations, respectively, for pediatric patients hospitalized over the course of 1 year were conducted by the Hematology-Oncology Department, with the most common reason being oral examination. Moreover, Nicopoulos et al. [15] in a study conducted at Carolinas Medical Center that entailed oral examinations of pediatric inpatients over 7 months revealed that 42% of the patients had dental caries and 59% of them had soft tissue abnormalities. According to the Korean studies by Song et al. [16] and Joo et al. [17] conducted at the Yonsei University Hospital, dental consultations for patients hospitalized over the course of 1 year revealed that the majority of referrals came from the Pediatric Hematology-Oncology and Rehabilitation Medicine Departments. Among the referred patients, the most common diagnosis was dental caries, and the proportion of patients who received caries treatment increased after 5 years.

Globally, according to the ‘World’s Best Specialized Hospitals 2024’ by Newsweek [18] Korean university hospitals ranked third for pediatrics, and numerous pediatrics-related papers have been published from these hospitals. However, aside from studies on dental consultations for hospitalized pediatric patients over the course of approximately 1 year, there is little research on the collaboration between pediatrics and pediatric dentistry. Therefore, this study aims to analyze the status of dental consultations for inpatient and outpatient pediatric patients at Seoul Asan Medical Center (AMC) over the past 3 years and provide foundational data on this subject. Through this, we expect to establish a more efficient collaboration and dental treatment system for pediatric patients.

This retrospective study was conducted with the approval of the Institutional Review Board of AMC (IRB No. S2024-0881-0001).

Consultations involve at least two departments working together to treat a patient, requiring communication between physicians from each department [11]. This also applies to collaboration between medical and dental departments. It is particularly critical for pediatric patients with medical conditions, as they are more vulnerable to oral health issues [19]. The pediatric dentistry at AMC was established in 2013 within the pediatrics and dentistry department. Approximately one-fifth of the patients who visited the pediatric dentistry over the past 3 years were referred from 31 different departments. All departments in the hospital utilize the same unified electronic medical records system, including for prescriptions and billing. Authorized medical staff can access patient records from all departments during the permitted period, with instant access available upon request outside that timeframe. Referrals are processed through a single electronic form, with a notification appearing on the patient’s chart until the referral is addressed. Pediatric dental referrals are handled daily, with dental hygienists scheduling appointments. Previously, consultations were only available through professor-specialized appointments, but since 2021, with the recruitment of pediatric dental residents, consultations have become faster and more readily available at various times each day.

The average duration till treatment for outpatient consultations was much longer than that for inpatient ones (3.7 days for inpatients vs 54.6 days for outpatients). The reasons for this can be understood as follows: First, the departments that send more outpatient referrals (such as MG and PS) are less likely to issue emergency referrals due to the nature of their cases. Additionally, for inpatients, since they are already in the pediatric hospital and the pediatric dentistry is in the same building, it is easier for them to be seen. If the patient is unable to move, residents visit the wards to provide immediate response and appropriate dental care. As a result, there was no correlation between the increase in the length of hospital stay, which is usually associated with the severity of the patient’s condition, and the response time to the referral (Table 3). In contrast, outpatients often visit the pediatric dentistry on the same day they visit other departments, which may delay their visit. Lastly, it has been observed that many outpatients tend to delay or cancel their appointments as they often first visit a nearby dental clinic to address their symptoms or do not consider dental treatment important at all. Consequently, the worsening of oral health often leads to delays in medical treatment or a worsening prognosis [1,20]. To prevent this, it is important to first provide thorough oral hygiene education to patients and guardians, emphasizing the importance of regular dental visits for ongoing care [7,21]. Additionally, we must encourage pediatric healthcare providers to reconsider the importance of dental care [9].

Between 2021 and 2023, approximately 44% of the 1,145 pediatric dental consultations were for patients aged 0 ‒ 4 years, and over half of the 44% were for patients aged 0 ‒ 1 years (Table 2). Additionally, the NEO accounted for the second-highest number of referring departments at 12% (Fig. 1). This is likely because the hospital has been operating the largest neonatal intensive care units with 62 beds across units 1, 2, and 3, as well as PICUs with 29 beds across units 1 and 2 and the largest pediatric emergency medical center in the country. This setup utilizes advanced medical equipment and specialized pediatric personnel, enabling treatment for a large pool of young patients and smooth collaboration. The results of the study showed that referrals for neonatal teeth and the lingual frenulum were common in the 0 ‒ 4 age group. Well-fixed neonatal teeth should generally be maintained and should only be removed if they interfere with eating and feeding or if they are highly mobile, posing a risk of aspiration [22]. In most of the consultation cases, the natal teeth were left intact (Fig. 6). For cases of ankyloglossia, a frenectomy is recommended for Class Ⅳ and Ⅴ [23]. Also, removing a thin anterior frenulum during the neonatal period is a simple and safe procedure that reduces the likelihood of more complex frenectomy in the future [24]. Among the 28 cases referred for lingual frenulum issues, frenectomy was performed in 11 (39%) cases (Fig. 6). According to Ferrés-Amat et al. [23] after a frenectomy, only 28% of patients showed improvement in speech and movement; 95% of them showed improvement after participating in orofacial rehabilitation exercises. Thus, even after performing a frenectomy, clear benefits can only be achieved through rehabilitation training and the patient’s efforts.

Among the patients referred to the pediatric dentistry, 46 (5% of the total patients) died, which is double the rate reported in previous studies by Song et al. [16] and Joo et al. [17], at 2.4% and 2.6%, respectively. This is likely because approximately 13% of all referred patients had been admitted to the PICU, indicating a high proportion of severe cases. It was also found that many severe patients returned to their primary residences for palliative care after their treatment at our hospital, suggesting that the actual number of deaths is probably higher than what is reported. Many pediatric patients diagnosed with life-threatening illnesses flock to metropolitan hospitals because of the shortage of hospital beds in rural areas and a preference for large hospitals in the capital region [25]. However, if their condition does not improve after treatment and patients want to return to their hometowns, they may leave the hospital.

Children in the PICU who are dependent on intubation and mechanical ventilation are known to have an increased risk of pneumonia due to poor oral hygiene and increased oral bacteria [26,27]. However, these patients rely on the medical team for their daily needs, and their medical treatments are prioritized. As a result, the primary reasons for referral were either simple examinations or addressing issues such as tube biting, soft tissue injuries, and tooth mobility due to neuropathic movements. When primary teeth become loose naturally or due to tube biting or bruxism, swallowing them can cause respiratory distress and potentially lead to death[28]. Therefore, in children who cannot expel foreign bodies on their own, extracting these teeth in advance or producing a custom-made mouth guard may be necessary if their medical condition permits [28,29]. Also, if possible, education on oral hygiene management for resident healthcare providers is necessary to prevent the deterioration of systemic health caused by oral infections [21].

Approximately 30% of all referrals were from the PHO, which was the highest number, consistent with previously published studies (Fig. 1). Almost 34% of pediatric patients with cancer in Korea suffer from leukemia, myeloproliferative, and myelodysplastic disorders; however, with the advancements in medicine, their survival rate increased from approximately 82.0% in 2001 ‒ 2007 to 85.1% in 2008 ‒ 2015 [30,31]. Consequently, the number of pediatric cancer survivors visiting pediatric dentistry has also been on the rise. Children with hematologic malignancies often undergo peripheral blood stem cell transplantation to reconstruct the hematopoietic system damaged by high-dose chemotherapy or radiation therapy [32]. Before transplantation, a dental examination should be conducted to remove sources of oral infection (in the teeth, soft tissues, and prostheses) at least 1 ‒ 2 weeks prior to reduce the risk of bacteremia [20,33]. If treatment cannot be completed within this period due to the patient’s decreased health status or lack of time, the application of silver diamine fluoride, fluoride, disinfectants, or the extraction of primary teeth that may be a source of infection is recommended [34]. Additionally, pediatric cancer patients undergoing chemotherapy have a high risk of developing dental caries because of their frequent consumption of sugar-containing medications, frequent vomiting, dry mouth, and poor oral hygiene [35]. They are also prone to mucositis, graft-versus-host disease, and opportunistic infection due to immunosuppression, and more than 85% of patients experienced oral pain due to various factors [35-37]. Moreover, Lee et al. [38] reported that approximately 68% of pediatric cancer survivors exhibited dental abnormalities, with microdontia, abnormal root development, and tooth agenesis being the most common. Therefore, regular dental check-ups are necessary, and if treatment is needed, it should be coordinated with the PHO team.

The MG, which accounted for approximately 10% of referrals, had the third-highest number of referrals after the PHO and NEO (Fig. 1). This resulted from the expansion of the MG in 2010 and having dedicated genetic counselors, which enhances multidisciplinary collaboration, care, and research for genetic disorders, following the first clinic’s establishment in the country in 1999. Among the most common reason for referrals, ‘examination,’ approximately 30% were for patients with syndromes (Fig. 3). These patients usually have unique oral characteristics and often have poor cooperation. Although there are many types of syndromes, almost 1/3 of the patients were Down syndrome. They are susceptible to gingivitis, tooth agenesis, and delayed development and often require orthodontic treatment because of narrow arches and Class III malocclusion tendencies [39,40]. Congenitally, these patients have a 30 ‒ 40% chance of heart disease, so it is important to be cautious about infections [39]. Dealing with these children is not easy, but if efforts are made to communicate with the patient and minimize pain during treatment, it would be possible to achieve fairly good cooperation that allows for orthodontic treatment in the dental clinic.

In this study, the prevalence of dental caries was 31%, which is lower than the values by Song et al. [16] and Kanuga et al. [14] (45% and 42%, respectively). This is likely due to the presence of many severe medical cases, which make caries detection challenging, such as hospital room visits, patient cooperation issues, and the inability to perform radiographic imaging. Moreover, 43% of patients received treatment for dental caries, a proportion that is slightly lower than that reported in a previous study [16]. This is also presumed for the same reason mentioned above. Except for cases where dental treatment was postponed due to severe systemic conditions, caries treatment and conservative treatment were administered (Fig. 5). Additionally, inpatients received caries treatment slightly more often (43%) than outpatients (41%). It may be prompt treatment was prioritized for inpatients who needed transplants or surgeries within a short period [32].

Examining the treatments, a total of 128 cases of dental caries were treated, with 32 cases (25%) performed under GA. According to Lee et al. [41] and Mallineni and Yiu [42] the number of dental treatments performed under GA for pediatric patients is continuously increasing, and more than half of these children have some kind of disease or disability. For those who require extensive dental treatment but have low cooperation or need to complete treatment in one visit, utilizing GA for dental procedures is recommended [16]. However, children with severe disabilities often have their treatments concluded with extractions or are more likely to undergo repeated GA. Therefore, regular check-ups and oral hygiene management must be thoroughly conducted [43,44].

Unlike previous studies that investigated the status of pediatric dental consultations for inpatients over short periods, the significance of this study lies in its detailed examination and classification of a large number of pediatric consultations over 3 years. However, this study has limitations. First, this is the first retrospective study conducted since the establishment of the pediatric dentistry at AMC, making comparisons with the situation before 2021 impossible. Additionally, consultations were conducted by various practitioners, which may have led to differences in patients’ diagnosis and treatment. Moreover, only 31% of patients have continued visiting the pediatric dentistry, making it challenging to follow up on the majority of the patients after their consultations. Furthermore, there may be differences in the dental consultation systems with other hospitals in Seoul and other regions, indicating the need for further research.

Nevertheless, this study demonstrated that active collaboration is occurring between 31 departments within the hospital and the pediatric dentistry. Consultations were conducted for various reasons, and appropriate treatments were administered accordingly. Therefore, as pediatric dentists, we must develop the capability to understand systemic diseases and manage dental issues effectively.

Additionally, we observed that many dental issues faced by pediatric patients were often unresolved due to worsening patient conditions, the prioritization of medical treatments over dental care by guardians and doctors, or a lack of cooperation [16]. To address this, we must strive to ensure effective dental treatment and improve the oral environment of pediatric patients through education for patients and guardians, active communication with physicians, and the proactive use of the consultation system and various treatment methods including general anesthesia.

This study analyzed the status of pediatric patients referred for dental consultation at the pediatric dentistry of Seoul AMC over the last 3 years. We confirmed that pediatric patients with different systemic diseases were referred from various pediatrics-related departments for a variety of reasons, and that a range of treatments was provided depending on the patients’ conditions. Therefore, to address these situations, pediatric dentists at university hospitals need to enhance their ability to understand the systemic conditions of pediatric patients and effectively manage a range of dental issues. Additionally, they should emphasize the importance of oral health and work toward establishing smooth collaboration and a robust dental care system to improve the quality of life of pediatric patients.