1 Introduction

Feeding poses a major challenge for children with cleft lip and/or palate (CLP). CLP is one of the most common facial oral deformities [1]. Moderate or severe feeding difficulties have been reported in > 70% of children with CLP [2] owing to inadequate suctioning and nasal reflux, which in turn lead to insufficient feeding volume, inadequate weight gain, prolonged feeding time, and infant fatigue [3]. Since breastfeeding infants with CLP who cannot apply sufficient suction pressure is difficult, caregivers often rely on bottle feeding. In a Nigerian study, > 80% of 65 mothers of children with CLP initiated breastfeeding, but only < 20% could continue owing to infant's inability to be fed in this manner [4]. This inability to continue breastfeeding has been reported in many countries [5-9]; bottle feeding has become the factual means of oral feeding. Children with CLP have a passage leading from the oral cavity to the fragile part of the nasal septum. An ulceration is likely to occur when the nipple directly makes contact close to the nasal septum during bottle feeding [10]. Moreover, since each child with CLP experiences unique feeding difficulties, bottle-feeding techniques should be tailored to the needs of each child.

Despite recent survey studies on parents of children with CLP, difficulties with bottle feeding have persisted. Parents in Ghana [11] and Turkey [12] lack knowledge related to CLP, and their children face problems stemming from feeding or related to nutrition. Similarly, lack of parental access to medical advice and counseling for CLP has been reported in various other countries, including Japan [13], Thailand [14], the United States [15, 16], Nigeria [4], India [17], and Norway [6]. Parents in such environments experience high levels of stress, depression, and anxiety related to the child's feeding [8, 16, 18, 19]. Therefore, the feeding difficulties faced by children with CLP have attracted significant attention worldwide.

A recent article has published a strategy for feeding children with CLP, called the Kumagai method, which involves the use of the Pigeon bottle with a long nipple (Long Nipple) [20]. However, the paper reported the basic procedures of the Kumagai method for an immobile doll, rather than for a moving child. We present the differences between the previous paper and this present study in Table 1. During feeding, children often move in various ways to express refusal, resistance, or related habits; improvements in feeding patterns cannot be expected unless appropriate measures are taken to address these movements. Thus, this study aimed to identify strategies for dealing with the various movements of children with CLP regarding bottle feeding.

2 Materials and Methods

3 Results

The five participants recruited in this study had 18–36 years of nursing experience. The mean duration of experience in caring for children with CLP using the Kumagai Method was 14.2 ± 9.37 years. All participants were female, with an average age of 46 ± 6.3 years. The average interview duration was 40.0 ± 10.6 min (range: 27.1–56.0 min).

The dealing strategies for each undesirable movement at each period are shown in Figures 1-3 and Tables 4–7. Techniques for which priorities existed were indicated by number. In Figure 1, the solid lines indicate favorable situations in which feeding can continue, whereas the dotted lines indicate unfavorable situations in which further action is required. The child's movements might be compounded (e.g., when the child vomits together with the child arching his/her back). Even in such cases, the problem could be resolved by addressing each movement individually.

3.3 Dealing With the Child's Gross Motor Movements During Feeding

After nipple insertion, if the child exhibited rhythmic sucking with a closed mouth or if the tongue wrapped around the nipple, the nurses determined that the nipple had been accepted and continued feeding. However, some children displayed various reactions even after nipple insertion. Tables 5 and 6 and Figure 2 outline strategies for managing undesirable movements during this phase.

When a child cried violently during nipple insertion, it indicated aversion to the nipple. In such cases, nurses attempted to stimulate the sucking reflex or tried feeding again when the child was in active sleep—neither fully awake nor asleep—to maximize milk intake (Table 5):

I pull it out and then I'll dandle the child.

— Nurse A

If the child starts crying when I put the nipple in, I often pull it out once. I then rock the child's body up and down and try to dandle the child.

— Nurse C

If the child cries even after the nipple is reinserted, I use the one-pressure method. This means that I pinch the nipple once, flow out milk, and pull it out immediately. This method is done when the child pushes out the nipple with the tongue or when the child moves violently and resists. If the child stops crying or cries less, I try the two-pressure method (pinch the nipple twice and pull it out immediately). Then, gradually increase the number of pinchings. If the child still cries violently, I stop feeding for a time and try to feed while keeping the child in a semi-awake state. If the child still moves, cries, or reacts in any way showing that the child does not want to be fed, I may have to decide to stop feeding.

— Nurse D

The nurses described how they attempted to maintain the nipple position consistency in the mouth even when the child's face was tilted or the child's body was arched. Additionally, they monitored the child's movements for signs that the child was reluctant to be fed or wanted to breathe (Figure 2, Table 6).

Regarding the situation “when the child arches their back” in Table 6:

Regarding arching the child's back, if the arching is done gradually while sucking continuously, I assess that this situation implies that the child is in the habit of drinking while arching their back. When the child arches their back and returns immediately, I consider that the movement is intended for the child's breath and the child is accepting the nipple. However, if the child does not suckle rhythmically while arching, I assess that the child is not accepting the nipple, so I deal with the same situation as “the case of crying violently.

— Nurse D

Regarding the situation “when the child's face is tilted toward the breast of the nurse” in Figure 2:

If the child's face is tilted too much, I place a towel (between the child's head and my breast) or pull the child's body toward myself in tighter to make it difficult for the child's face to move. If there is staff around, I ask them to help the child's face turn forward naturally by such a playing drum.

— Nurse E

The child sometimes stops their suckle without disgust, turns the face outward, or arches the body back for a moment, and then returns to the right position. It is because the child wants to breathe, so I remove the nipple and let the child breathe. When the child's body comes back and the breath becomes stabilized, I reinsert the nipple.

— Nurse D

3.4 Dealing With the Child's Oral Reactions During Feeding

Dealing strategies for the child's oral reactions are summarized in Table 7 and Figure 3. In Table 7, the child's movement to push the nipple out with his/her tongue proves that the child had not yet accepted the nipple. Therefore, the nurses first implemented the same strategy as that with “when the child cries violently.” However, the nurses reported that the last priority technique of “bending their knees” was not a gentle dandling action, such as rocking up and down or side to side. A quick knee-bending motion made to briefly distract or surprise a child is used instead (Figure 5). This is a method to immediately attract the child's attention and make the child forget about the unpleasant feeling of the nipple and swallow the milk:

The rejecting action toward nipple is very important sign to observe the child's response. When the child pushes the nipple out with the tongue, I assess that the situation is a very rejecting reaction. When this happens, I always pull the nipple out, and I reinsert it again correctly. Repeating this is the only way. It is also helpful if I apply pressure earlier than the normal speed (one-pressure method). It will be to encourage the sucking reflex immediately and prevent the tongue from feeling the tip of the nipple by concentrating on feeding. When I use the one-pressure method, combining it with a quick knee-bending movement is more effective in briefly distracting the child from the nipple. The next rejecting reaction is to swing the tongue from side to side. In this case, I press the nipple a little to get milk into the mouth and observe if the sucking is encouraged. The reaction that the child moves the nipple to the corner of the mouth with their tongue is also rejection but not as strong. When this happens, the nipple should be gently moved back to the center of the tongue.

— Nurse D

I pull it out. I reinsert the nipple and set it in the right position. There is no problem if the child can drink by doing so. If the child still pushes out after several attempts, I would often leave for a little while.

— Nurse B

When the child only licked the nipple without initiating a sucking reflex, the participants observed whether the reflex could be triggered by flowing a small amount of milk and then determined the next course of action.

The case of not sucking in the child means that the child does not know how to suck, or when the sucking reflex does not occur immediately or is slow. In these cases, I apply pinching the nipple one or two times to induce the child's sucking. Then, the child swallows the milk in the mouth and begins to suck. When the sucking stops, I pinch the nipple again to induce swallowing and the child's sucking restarts. I continue this. This attempt of pinching for inducing suckling is different from the one- or two-pressure method. In the one- or two-pressure method, I remove the nipple immediately after pinching it. But in this case, I observe the child's swallowing while still placing the nipple in the mouth. Especially when the child licks the nipple, it indicates that they are not completely averse to it and feel somewhat comfortable with doubtfulness. Therefore, if I pull the nipple out repeatedly, the child's motivation will be broken.

— Nurse D

If the nipple was collapsed or bent in the mouth while feeding, this proved that the child actively wanted to be fed. Therefore, the nurses attempted to not compromise the child's desires in that situation.

When the child vomited too much milk, the feeding had to be interrupted; however, the nurses restarted feeding after the child had calmed down and tried to get the child to drink as much milk as possible.

Importantly, the nurses mentioned the difficulty of putting the whole technique into words. The actual movements are even more complex; the nurses try and change their strategies accordingly. The Kumagai method has the potential for even deeper and more detailed latent techniques:

I communicated my techniques that work for most children but not completely. Certainly, there are techniques that are implemented according to the situations. It almost works by using the techniques I explained, but sometimes it does not I am sure there are more things I could not explain this time.

— Nurse D

4 Discussion

When bottle-feeding, children often refuse feeding or exhibit distress [23]. Feeding problems are common in children with CLP [1, 2]. Previous research has shown that hunger cues in infants include bringing their hands to their mouths, crying, and sucking, while satiety cues include a decrease in sucking frequency, relaxation, and closing of the eyes [24]. Although observing infant movements is crucial for assessing feeding cues, accurately interpreting these cues requires specialized knowledge and experience. Therefore, this study presents strategies tailored to each child's movements. It highlights techniques used by nurses to manage undesirable infant movements before, immediately before, and during feeding. Following the guidance provided in these tables and figures, caregivers can better understand what to observe and how to determine the next appropriate action. The Kumagai method, which utilizes a long-nipple feeding technique, is a practical approach for managing undesirable infant movements and aims to correct feeding posture [20]. Addressing the child's gross motor movements and responding promptly to each reaction, caregivers can maximize the child's ability to feed. Clinical practice has reported improvements in the feeding of children with CLP using the Kumagai method. In cases of bilateral CLP with feeding difficulties, the method has been shown to improve both the volume and speed of milk intake [25]. Additionally, more than half of infants with CLP and nasal septum ulceration were able to consume the required amount of milk, with ulceration resolution, using the Kumagai method [26].

Various feeding bottles have been developed as a tool to improve feeding in children with CLP. The most commonly used bottles are the Pigeon feeding bottle for children with cleft palate in Japan [27] and Medela Special Needs Feeder and Dr. Brown's Specialty Feeding System in other countries [28]. However, no significant difference was observed in the child's feeding volume regardless of the bottle used [28]. Therefore, the key to improving infant feeding is not principally influenced by the bottle used but by the nurse's feeding technique in how it is used. Previous studies have reported the basic posture during feeding, when to squeeze the bottle during feeding, and some points to be observed [29-31]. However, those studies did not mention the undesirable movements of children. Our study presented several undesirable child movements and clarified how to deal with them. Specifically, identifying the child's response of the nipple rejection was significantly important for continuing and facilitating future feeding. Moreover, the one- or two-pressure methods for this rejection were unique and only possible with a Long Nipple. These findings potentially address the real difficulties and concerns associated with bottle feeding children with CLP worldwide.

Recently, videos of various feeding strategies by parents or medical providers are available on social media platforms. Although these are accessible and convenient for the audience, most of the video contents are inappropriate [32]. Moreover, actual parents of children with CLP show ineffective coping strategies [12]. The medical providers as informants also lack such skills [33] and wish to acquire them [27]. The present study presents practical knowledge because the specialists revealed skillful techniques that were developed in actual clinical practice. As a result, we hope that this technique will greatly contribute in clinical and educational settings worldwide, particularly for less experienced caregivers.

According to a recent study by Kucukguven et al. Kucukguven et al., [3], three of four patients used the feeding bottle; more than half of the children with CLP had to undergo nasal tube feeding. The current practice is to switch to tube feeding if the child cannot be bottle fed. Although tube feeding is excellent for preventing weight loss, it also has various adverse effects, including decreased taste and smell functions [34], oral aversion [35], and infection due to decreased salivation [36], suggesting the need for keeping the duration of tube feeding as short as possible [37]. The Kumagai method presented in our study does not require switching to tube feeding. This is a testament to the insistence on feeding from the oral route and capability of feeding sufficient amounts without switching to tube feeding. Adherence to the Kumagai method will increase the number of children with swallowing ability who can be fed orally.

This study has some limitations. Although we described various infant movements observed during feeding, certain motor behaviors might have been triggered by the nurses rather than being intrinsic to the infants. Additionally, strategies for managing undesirable behaviors cannot be judged solely based on whether they occur during feeding. Adjustments may be needed depending on the specific stage of feeding, such as whether the child is swallowing or still holding milk in their mouth. Although we identified techniques adaptable to many cases, they may not be applicable to all children. In practice, feeding difficulties are influenced by multiple factors, and approximately one-third of patients with CLP have coexisting congenital conditions [38]. Depending on individual feeding difficulties, nurses may prioritize different strategies or develop new approaches.

Although all participants in this study were nurses from the same institution, they had all mastered the Kumagai Method, and no major differences were observed in how they responded to various feeding difficulties. This consistency suggests the reliability and standardization of the method among trained users. Since the aim of this study was to clarify and describe the Kumagai Method itself—rather than to examine a variety of bottle-feeding strategies—we believe the study fulfilled its primary objective. Nevertheless, to further assess the broader applicability of the Kumagai Method and to explore whether other effective strategies are used in different clinical contexts, future studies should include participants from multiple institutions with diverse training backgrounds. In particular, larger and more diverse samples from various clinical settings are warranted to validate and expand the method's generalizability.

In addition to institutional diversity, the potential for broader dissemination also depends on how accessible the method is to less experienced providers. While this study focused on expert nurses trained in the Kumagai method, but its applicability by less experienced healthcare providers and caregivers should also be considered. Although basic techniques such as posture stabilization or nipple insertion may be teachable with structured guidance, adaptive responses to infant movements require more nuanced skills, potentially needing hands-on practice and supervision. Systematically organizing techniques in a phase-specific and logical manner, this present study provides a foundation framework that may help less experienced caregivers apply the Kumagai method without omissions or inconsistencies. Future studies should explore how caregivers or less experienced staff could adopt these techniques and identify potential challenges in real-world settings.

Another limitation is the challenge of fully conveying their own techniques through oral explanations. Therefore, acknowledging that the techniques developed by Ms. Kumagai might not have been comprehensively detailed, as she mentioned in the Results section, is important. The present findings should be carefully interpreted when applied in clinical settings. Moreover, beyond the techniques explicitly recognized by experts, there may be additional implicit knowledge that nurses apply unconsciously. Further studies should include direct observations of feeding instructions to assess the frequency of undesirable infant movements, the actual strategies nurses use to address them, and the effectiveness of these interventions. Additionally, this study did not recruit other experts in the field. Future research should include quantitative studies to determine whether the Kumagai method is unique or widely practiced and whether other effective strategies exist. Moreover, evaluating whether this method could be effectively implemented in different populations and clinical settings is necessary. Despite these limitations, we hope that the present study could provide foundational insights into guiding future research. Ultimately, these findings might contribute to the development of clinical guidelines or learning tools.

5 Conclusions

This study showcased expert techniques of dealing with undesirable movements of children with CLP during bottle feeding. The techniques included details that exceeded our predictions; they were selected after deep assessments. The Kumagai method involves observing the child's reactions and movements, considering what these movements indicate, and selecting strategies of handling the child accordingly. These appropriate assessments and dealing strategies may help children with CLP develop a natural feeding posture and may contribute to the child's acceptance of and willingness to be fed with a long nipple bottle.

Author Contributions

Eri Nagatomo: investigation, validation, writing – original draft; writing – review and editing. Yukari Kumagai: validation, writing – review and editing. Yumi Hirai: validation, writing – review and editing. Shoko Miyauchi: investigation, validation, writing – review and editing. Takuro Inoue: investigation, validation, writing – review and editing. Qi An: investigation, writing – review and editing, supervision. Eri Tashiro: writing – review and editing. Junko Miyata: supervision, writing – review and editing. Shingo Ueki: conceptualization, methodology, formal analysis, investigation, writing – review and editing, project administration, funding acquisition.

Conflicts of Interest

The authors declare no conflicts of interest.