Antenatal ultrasound (AUS) and the detection of cranio- and orofacial malformations—a scoping review

Introduction

Gestational ultrasounds (GUS), commonly referred to as “antenatal ultrasounds” (AUS), have been considered one of the most useful, cost-effective, and sustainable imaging techniques in obstetrics (1). Based on official recommendations endorsed by the Departments of Reproductive Health and Research, Nutrition for Health and Development, and Maternal, Newborn, Child and Adolescent Health of the World Health Organization (WHO), GUS are internationally recommended to be carried out before 24 weeks of gestational (also known as “early ultrasound”). The results derived from this early evaluation are useful in evaluating fetal growth parameters (2), early detection and the monitoring of fetal anomalies, recognizing the presence of multiparity, or identifying structural deviations relevant for the unborn child (3). Additionally, GUS scans have generated positive health-related outcomes in relation to a reduced induction of labor for post-term pregnancy, in addition to enhancing women’s gestational experiences in general (4). Nevertheless, a growing global trend in performing multiple fetal scans either during the mother’s first contact with medical personnel (up to 12 weeks of gestation) or during the third gestational trimester have been reported elsewhere (5). To note, as emphasized in the latest WHO list of recommendations on antenatal care for positive pregnancy experiences, the frequency and exact timing of antenatal care procedures should be aligned with local context, populational singularities, as well as relevant healthcare system characteristics (6).

In recent years, several publications (including systematic reviews and evidence-based guidelines) have reported data on the performance of AUS in detecting systemic fetal diseases and predicting postnatal outcomes (7-11). The International Society of Ultrasound in Obstetrics and Gynecology guidelines, a multicenter study involving more than 14 European countries, reported an overall accuracy of 56% in detecting major fetal anomalies through routine mid-trimester ultrasonographic examination in unselected populations (12,13). In addition, as suggested by Morris and colleagues in 2009, antenatal scans showed moderate performance in predicting postnatal renal function in congenital lower urinary tract obstruction, with sensitivity of 0.57 [95% confidence interval (CI): 0.37–0.76], specificity of 0.84 (95% CI: 0.71–0.94), and area under the curve of 0.78 (7). Likewise, a high-quality Cochrane-associated systematic review and meta-analysis (11) addressing the importance of routine ultrasounds (US) reported results from only one clinical trial from 1993 (14), which evaluated the rates of fetal abnormalities at the third gestational trimester. However, no additional emphasis was given to the relevance of the technique in detecting cranio- and orofacial fetal abnormalities.

Across the globe, there is an ongoing trend for policymakers and healthcare providers to prioritize oral health diseases and conditions, which are greatly preventable and suitable for early treatment. In this regard, multiple social actors have pioneered the global oral health status scene. For example, the Department of Noncommunicable Diseases, Universal Health Coverage/Communicable and Noncommunicable Diseases of the WHO stated that almost all countries (among the 194 WHO Member States) implemented actions for screening programs for early detection of oral diseases (15). More specifically, multiple enthusiasts in the field of dentistry, maxillofacial imaging, and oral pathology have demonstrated the potential and suitable correlation between GUS, the early detection of abnormalities, and the prompt and timely delivery of care as a promising approach within the field of public health (16). To date, several reports have suggested the effectiveness of GUS in recognizing oral abnormalities, including the presence of craniofacial asymmetries, oral dysfunctions, and minor or major pathologies (16). However, existing literature is fragmented and not adequately integrated. Consequently, there is an existing need for knowledge organization and aggregation to systematically clarify the current potential of AUS in early detecting oral abnormalities and orofacial malformations. Therefore, this scoping review seeks to evaluate and compile available evidence from primary studies regarding the applicability of GUS in detecting neonatal oral and craniofacial malformations. It is expected that this review will lay the foundation for more focused studies within this very under-studied area to expand the utilization and application of AUS worldwide. We present this article in accordance with the PRISMA-ScR reporting checklist (available at https://jphe.amegroups.com/article/view/10.21037/jphe-24-59/rc).

Methods

Review protocol and followed guidelines

This scoping review strictly adhered to the methodological guidelines for conducting a scoping review, primarily endorsed by Arksey and O’Malley (17). Additionally, this report followed the Joanna Briggs Institute Manual for Evidence Synthesis for Scoping Reviews (18). It is important to note that all of our results were reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR) (19). Before starting our reviewing process, we registered our protocol on PROSPERO (CRD42022341553) (20).

Search strategy and selection criteria

Our searches were conducted in the four leading scientific medical and dental-related databases (Embase, MEDLINE^®, Web of Sciences, and the Cochrane Library). Two independent authors screened titles and abstracts for eligible studies. Additionally, identified pre-selected studies were further evaluated for eligibility. We considered studies eligible if they: (I) reported the detection (with or without emphasizing the performance metrics) of cranio- and orofacial anomalies identified through AUS (either via 2-, 3-, or 4-dimensional scans); (II) enrolled pregnant women from the first to third trimester of gestation; and (III) enrolled at least 345 patients (either referred as pregnant individuals or fetuses). It is important to state that those studies reporting orofacial abnormalities as a subgroup of a major group of abnormalities (i.e., concomitant to reporting of cardiovascular, respiratory), were also considered valid, if the aforementioned criteria were met. However, for these studies reporting multiple malformations and fetal abnormalities, only the section regarding the identification of orofacial anomalies was extracted.

Moreover, we accepted original studies if they compared the use of morphological US to no intervention, magnetic resonance imaging, or any other diagnostic method to verify the existence of oral malformation during gestation, at any study design (including observational and randomized clinical trials). However, if a primary study did not compare the findings associated with AUS with another radiological or anatomical assessment arm, we also considered it eligible for inclusion. We did not exclude publications based on published language or publication date. We excluded conference proceedings, editorials, correspondences, and data not published in the format of an original research study. In addition, studies focusing on a subset of population patients (such as pregnant women expecting syndromic fetuses) were excluded.

Screening process was carried out throughout Covidence^®. A third party solved decisional conflicts. Search terms involved “Morphological Ultrasound”, “Prenatal Ultrasound”, “Facial Anomalies”, “Craniofacial Abnormalities”, and associated synonymous search identifiers. Our search was performed from database inception until October 2023. The search strategy (available in Appendix 1) was designed in collaboration with a group of experts and the information specialist. Bibliographies of records shortlisted for full-text analysis were evaluated to ensure an exhaustive search.

Data extraction

Included records underwent full data extraction by two review researchers, independently. Elementary data from included studies were abstracted, including (I) study identification; (II) publication year; (III) journal name; (IV) study design; (V) study objective; (VI) the number of included individuals being reported and evaluated; and (VII) setting and country where the study was carried out. In addition, as outlined in our protocol, the extracted and evaluated primary outcomes consisted of (I) the type of craniofacial morphology primarily considered and reported within the study; (II) number of detected cases among the total study sample; and (III) performance metrics associated with the performance of AUS; (IV) the main findings raised in each publication; (V) technical difficulties related to the execution of AUS; and (VI) implications of reported findings in maternal health and birth outcomes. For each included study, at least two investigators assessed the extracted data. Conflicts were resolved by discussion.

Data analysis and summarization

As primarily stated in our protocol, we performed a descriptive assessment of the acquired data and reported a summary of data as a written-based text. For those studies reporting performance metrics (including accuracy values, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios) we reported the range of identified values per type of abnormality. The same approach (descriptive reporting) for primary studies reporting prevalence values was carried out. The synthesis of relevant data among included studies is shown in Tables 1-3.

Results

Main characteristics of included primary studies

Figure 1 illustrates the PRISMA-ScR flowchart detailing the scoping review’s search approach. Initially, 3,672 studies were obtained from the search and reference list. Among these, 242 were identified and removed as duplicates. Subsequently, after scrutinizing the titles and abstracts of the remaining studies, 3,292 were excluded due to a failure of meeting the inclusion criteria. Upon thorough examination of the full texts of the remaining 138 studies, 87 were disqualified, as they also did not fulfill the inclusion criteria. Ultimately, 51 studies met the eligibility criteria and were included in the review for further in-depth analysis (Tables 1,2).

Figure 1 PRISMA-ScR flowchart.

The main characteristics of the included studies are presented in Table 1. Among the 51 eligible studies, the two oldest studies were published in 1986 (32) and 1997 (31)—two prospective trials on the incidence of facial abnormalities identified during routine screening. Six studies were published in 2023 (21,33,41,43,49,71), mostly investigating the performance of multiple-trimester US techniques in detecting in-uterus oral-related malformations. Geographically, 10 studies were carried out in China (30,35,40-43,45,62,69,70), and five in the USA (32,54,63,66,67). The remaining studies were conducted in various countries worldwide, including the UK (21,23,27-29,52,57,60,65) (n=9), France (29,44,56,58), Germany (29,36,46,48) and Israel (24-26,67) (n=4), Denmark (29,33,51) (n=3), India (37,38) and Austria (29,31) (n=2). These studies primarily focused on pregnant women in general or under high-risk gestations, either in the first, second, or third gestational trimester. Interestingly, some studies reported the number of evaluated patients, not reporting the number of pregnant individuals a priori. Among the reported studies, our scoping review encompasses data from 614,245 pregnancies, 680,986 fetuses or births, and 376,300 US examinations. Various assessment tools were used to evaluate the fetus’ morphology among enrolled women. Regular US images were performed evaluating 2 dimensions, while a small minority used more advanced techniques (3-dimensional ultrasonography).

Commonly reported skull types and orofacial abnormalities

The full description of the most frequently reported skull types and orofacial abnormalities among the included studies is presented in Tables 2,3. Our study identified a wide range of oro- and craniofacial abnormalities that might be diagnosed using routine GUS assessment. Most importantly, facial clefts or variations thereof (i.e., cleft lip, cleft palate, and orofacial clefts) were the most reported facial malformations detected via gestational imaging. Specifically, facial clefts in general and cleft lip associated with cleft palate were the second most frequently observed malformation reported among included studies (n=34; 66.7%) (21,23,24,32,38,39,41-45,47,52-54,58,61,63-67,70,71). We additionally collected data associated with micrognathia (26,42,44,46,56,60,69), associated with or without glossoptosis and cleft palate. Within these studies, authors mainly emphasized the impact of the malformations on breathing and feeding outcomes in neonates. Only one study reported data on orbital anomalies (63).

Detection rate and performance metrics reported within included primary studies

We observed extreme variability in the described performance values derived from the respective utilized techniques, with some studies reporting prevalence rates, while other studies provided more robust evaluations including sensitivity, specificity, and predictive positive and negative values. The identified metric values differentiated based on certain characteristics, including type of malformation, the gestational age by the time of screening, as well as the presence of underlying anomalies (multiple abnormalities). For instance, as far as cleft lip and palate detection rates are concerned, the report provided by Aldridge et al. suggested detection rates of fetal anomalies reaching 89.5% (95% CI: 87.8% to 90.9%), while antenatal up to 23^0/7 weeks detection rate was 90.9% (95% CI: 89.4% to 92.1%) (21) Likewise, as evidence in Bister and colleagues (23), the overall detection rate by AUS of facial clefts was 65% (particularly of 67% isolated cleft lip, 93% cleft lip and palate, and 22% isolated cleft palate), without any false positives. Additionally, based on the results emphasized in the study of Hjort-Pedersen et al. (33), all cases of cleft lip and multiple malformations were detected via prenatal screening, with no facial malformations being detected during the initial first trimester US. However, in the subsequent second-trimester US, 13 out of 17 malformations were successfully identified, constituting a 76.5% success rate (33). Notably, the detection rates differed significantly according to the type of facial malformation that was primarily identified. Some malformations, such as micrognathia, were detected in a significant number of patients through routine US evaluations, while others, such as facial clefts, showed high variation in sensitivity rates (24,70). Some studies reported data associated with accuracy performance metrics of US findings in detecting orofacial anomalies. For instance, as evidence in Gai et al. (30), the detection of orofacial clefts through AUS presented high performance values, with the total accuracy, true positive rate, true negative rate, positive predictive value, and negative predictive value of 99.9% (110,286/111,178), 81.9% (230/281), 99.9% (109,948/110,005), 80.1% (230/287), and 99.9% (109,948/109,999), respectively. Similarly, as proposed by Hafner et al. (31), based on a study conducted to shed light on the incidence of facial malformations, prenatal detection rate, and on the clinical implications of their detection, prenatal US had a sensitivity of 100%. In isolated facial malformations and particularly those involving the lips, alveolus, and palate, the sensitivity was, however, much lower (only two of five malformations were detected) (31). Lastly, Li et al. (40), after evaluating a Chinese cohort to evaluate the value of the prenatal US in the diagnosis of fetal malformation, observed that the prenatal US detection sensitivity of facial abnormalities was 68.09%, with 160/235 true positives, and 75/235 true negatives. Severe structural malformations were reported as associated with elevated sensitivity rates. According to the results demonstrated by Liao et al. (42,43) and Li et al. (40), first trimester detection rate of some facial abnormalities such as anencephaly, exencephaly, cephalocele, and holoprosencephaly reached sensitivity performance of 90%.

Interestingly, one report included in our review demonstrated an increase in detection rates of isolated oral malformations over time. As suggested in French results from Stoll et al., there was an improvement in detection rates from the period between 1979–1988 compared to 1989–1998 (5.3% to 26.5%, respectively) (58). We calculated the incidence of some diseases registered within included studies. Overall, the incidence rates of anomalies were considerably low, typically lower than 4% (as registered in the study of Liu et al.) (45). In general, the calculated incidence values ranged from 0.067% (25) to 22.5% (40), which varied based on the sample size enrolled in each trial. Even though the reported abnormalities are associated with low incidence rates, most studies still reported elevated accuracy performance metrics (such as sensitivity and specificity). For instance, Bronshtein et al. (24) evidenced that among the two cases of anomalies out of the 8,000 cases, both cases were detected through AUS, with no false negative results. This can be translated as clear evidence of GUS’s applicability and effectiveness in early detecting oro- and craniofacial anomalies during the in-uterus stage.

To note, the presence of multiple anomalies increased the detection rates of the registered anomalies. For example, GUS was shown to have a 100% sensitivity in the presence of multiple abnormalities such as reported by Luedders et al. (46). However, as the sample sizes of positive cases is considered to be limited, definite and conclusive statements might be taken carefully. Another detection modulator reported within included studies associations among the type of US technique employed during routine analyses. Primary studies’ findings showed that specialized US techniques or multi-step screening programs are more effective in detecting oro- and craniofacial conditions in early stages, specifically in high-risk pregnancies. For instance, the results provided by Liao et al. evidenced that from the 8,538 high-risk fetuses, 21 cases of cleft lip and palate were diagnosed by the four-step US screening method in the early stages of the second trimester (43). The authors defined the four-step evaluation based on the assessment of (I) median sagittal; (II) oblique coronal section of the posterior nasal triangle; (III) transverse section of the alveolar process of the maxilla; and (IV) cross-section of the horizontal plate of the palate. Lastly, we observed that the gestational age might also modulate the detection rates of facial and neck anomalies. For instance, some studies suggested benefits and high detection rates for certain conditions (i.e., cleft and lip palate) when imaging were performed and obtained in the first trimester (41,61,70).

Healthcare implications of early detection of cranio- and orofacial malformations

The healthcare-related implications originated by the performance of AUS was not widely reported among included primary studies. To note, pregnancy termination was the only medical and social implications registered among the identified trials (23,31,44,47,72). For instance, following the evaluation of more than 7,900 fetuses, Bronshtein et al. (24) stressed the fact that all cases (four pregnancies) in which glossoptosis and micrognathia were identified through in utero scanning coursed with birth termination.

Moreover, as reported in 1997 by Hafner et al. (31), prenatal screening identified eight malformations (72%) before birth, and among these cases, three pregnancies were terminated. In the study carried out by Hafner et al. (31), termination in these instances was not prompted by the facial malformation itself but based on factors such as chromosomal abnormalities in one case, amniotic constriction band syndrome in another, and hydrocephaly in a third case.

Technical limitations of performing US

Our research team rarely found information of potential technique limitations that might have hindered the execution of AUS in the included clinical trials. To note, Lakshmy et al. (38) reported barriers and difficulties facing while performing GUS and their potential implications for pathology detection. As evidenced in the publication, 14 cases involving palatine clefts in fetuses were identified during the study period (38). Initially, suspicion arose from 2-dimensional imaging, and in all 14 cases where positive markers were present, confirmation of the cleft abnormalities type and extent was achieved only through 3-dimensional evaluation (38). However, six volumes yielded unsatisfactory results due to maternal obesity, leading to poor overall image quality (38). Additionally, as stressed by Vial et al. (64) [2001], the training of healthcare professionals (potential technical and personnel limitations) involved in AUS is essential to guarantee high-performance.

Discussion

Our scoping review of the utilization of AUS evaluations targeting the identification of oro- and craniofacial abnormalities showed the effectiveness of this technique for multiple diseases, including orofacial clefts, facial and neck abnormalities, micrognathia, and glossoptosis, with relatively high-performance rates. In addition, we evidenced, based on a limited number of clinical trials, that the detection of certain orofacial conditions (i.e., cleft lip and palate) can be associated with relatively high sensitivity and accuracy values. Notably, we observed that the detection performance might vary based on the type of abnormality presented by the fetuses, the presence of coexisting anomalies, and the timing and/or method utilized for the US evaluation. Moreover, the collated evidence demonstrates that the performance of routine GUS and the early detection of morphological US might have direct implications on maternal decisions of pregnancy termination.

As reported in our study, facial clefts, palate deformities, micrognathia, and glossoptosis can be detected through antenatal screening, in multiple gestational stages. Although not systematically advocated by international health authorities and expert groups (73), the potential of AUS to detect a complex range of oro- and craniofacial abnormalities is both robust and promising. For example, the evaluation of tongue positioning (74,75), the assessment of the functional suctioning pattern (76,77), the appraisal tongue’s movements while suctioning the amniotic liquid or fingers (78,79), and the recognition of certain facial profile patterns (80) (i.e., retrognathic or prognathic patterns besides micrognathia or macrognathia) could complement the existing guidelines of best practice. It is worth mentioning that the tongue plays a very important role in stomatognathic development (81). As such, changes in stomatognathic system (particularly involving soft tissues and the palate) could already be observed in-uterus if ultrasonographers are “aware” and “sensibilized” of the facial structures that can be examined in both coronally and axially oriented sequences. Anomalies in tongue development and function, such as observed in patients with ankyloglossia, could affect breastfeeding, the development of the maxillary arch, and prompt future speech disorders, malocclusion, and gingival recession (82,83). Therefore, there is an important call for action from our research team “to expand the existing plan of facial structures to be examined during routine antenatal ultrasonography”.

Unlike the findings identified in our review, the body of literature discussing the barriers for evaluating the gestational ultrasonography images is currently vast and solid. First, some studies have suggested that the prenatal assessment of other structures rather than the currently prioritized by international societies might be time-consuming and with limited standardized and validated protocols (84). Nevertheless, methodology-focused trials, such as the one proposed by Macé et al. (84), demonstrated that technical validation of additional parameters of assessment is feasible, viable, and not burdensome (84). By describing the combination of a coronal view of the pharynx of the fetal upper airway, the authors suggested a new approach that might be useful to easily assess glossoptosis in fetuses (84). In addition, issues associated with quality assurance, technical or infrastructure limitations (especially in low- and middle-income countries), as well as maintenance and service or product supply are also important difficulties emphasized in the literature (85). Additionally, healthcare professionals’ (e.g., sonographers and technicians) willingness to receive constant and updated trainings hinders the applicability of new structures to be further evaluated during routine screenings (86,87). The highlighted barriers can be promptly overcome with adequate procurement and strong supply chain initiatives, the strengthening of healthcare governance, and the establishment of appropriate health policies. In addition, the analyses of multiple and more complex parameters derived from routine antenatal ultrasonography must be operationalized based on interdisciplinary collaboration and collective thinking. The collaboration among different healthcare experts, including dental specialists, gynecologists and obstetricians, fetal medicine physicians, and otorhinolaryngologists are essential and cannot be overstated. The timely diagnosis and intervention are crucial, particularly in growing children, to manage these conditions both effectively and promptly.

Over the past several years, dental specialists from across the globe have started encouraging healthcare providers to “early-timely-diagnose dental-related disorders”. Based on a systematic review published by Valério et al. following a timely diagnosis of malocclusion, the subsequential early treatment of these pathologies was shown to improve facial asymmetry, particularly in the lower part of the face, along with an increase in palatal volume and palatal surface (88). Additionally, the authors’ findings suggest that the benefits generated by early orthodontic interventions are associated with the improvement of craniofacial symmetry/bone structure, and a refinement in masticatory ability and performance (88). Regarding prenatal assessment using US, Chedid et al. suggested that this exam can be introduced in pediatric dentistry as a diagnostic tool to identify the risk of malocclusion, and during pregnancy dental care as a mode of education and motivational guidance for breastfeeding and healthy habits for parents (89). Similarly, different studies have highlighted the benefits of early detection of oral neoplasms, as they offer an effective mode of reducing the individual burden of disease, decreasing morbidity and mortality, and improving overall quality of life (90,91). Thus, by calling attention to the underused potential of routine GUS techniques, our study also endorses the aforementioned concept of timely diagnosis associated with orofacial disorders that can be verified while in utero, as this practice can significantly reduce short- and long-term dysfunctionality and improve both self-esteem and overall quality of life.

With the advancement and rapid improvement of healthcare technologies, 3- and 4-dimensional GUS and multiple digital technologies have become progressively more common in routine practice (91). The potential applicability of 3- and 4-dimensional GUS in dental care relies on their capability to review volume data interactively, utilize various section planes for assessing anatomical structures beyond the original acquisition plane, and rotate the volume dataset in order to facilitate examination of anatomical structures from diverse perspectives (91). In addition, 3D and 4D GUS can access a range of rendering methods. This enables examiners to visualize different characteristics of a single structure (for instance, revealing the external aspect of a meningomyelocele when rendered in surface mode or displaying underlying bones in the maximum-intensity mode using the same fetal back volume dataset). With regards to existing digital health technologies, their potential is even broader. For instance, machine learning and deep learning algorithms can efficiently evaluate GUS images, identifying several abnormalities and anomalies in fetuses (91). By using a wide spectrum of deep learning models [such as convolutional neural networks (CNNs), recurrent neural networks (RNNs), and others], these techniques have been able to increase the detection of different types of congenital abnormalities, including head and neck malformation, heart defects, pulmonary and renal diseases (91). They not only increase health-related outcomes on maternal and child health, but also support obstetricians and radiologists screen for problems and intervene early to improve fetal outcomes (91). Further, the application of artificial intelligence and machine learning algorithms in fetal ultrasonic disease diagnosis has become a reality, yet mostly within private practices and high-income countries. Artificial intelligence plays a supporting role in the identification of fetal facial features, craniofacial development, and the detection of congenital abnormalities. As proposed by Zhen et al., the utilization of the deep CNN method facilitated the automatic recognition of axial, coronal, and sagittal planes within the facial structure, significantly reducing section recognition time with an efficiency of 96.99% (92). In another publication by Tsai et al., image registration technology was employed to standardize fetal position, orientation, and size variations by pinpointing specific head and eye areas as reference points (93). Following this, craniofacial structures were automatically outlined using segmentation techniques, allowing for the precise measurement of five craniofacial diameter lines (biparietal diameter, occipitofrontal diameter, interorbital diameter, bilateral orbital diameter, and orbital-calvaria diameter) (93). This approach facilitated the diagnostic assessment of fetal facial characteristics. Apart from evaluating facial growth and abnormalities, artificial intelligence offers enhanced diagnostic effectivity by preprocessing US images, eliminating facial obstructions, and optimizing viewing angles swiftly via a single action, consequently enabling rapid, convenient, and efficient 3D imaging. Recent technologies, such as video US, have also emerged as a promising imaging procedure to evaluate suction patterns of the amniotic fluid during the gestational period (94). Relevant information about the fetal suctioning apparatus can be obtained and utilized for planning post-partum performance enhancement.

None of the identified studies reported the detection or appraisal of fetus positions or postures, during intrauterine life through AUS. The early detection of these habits is of the utmost importance because these vicious postures are likely to be maintained after birth and present as a risk factor for cranial asymmetries (95,96). In turn, plagiocephaly might be directly associated with developmental delays, practical difficulties in sports and everyday life, and significant deleterious impacts on children’s psychological functions (97). If promptly detected during GUS, a timely design can instead be developed through the collaboration of dental doctors, surgeons, neurologists, and rehabilitation therapists.

Apart from its associated clinical benefits, GUS images have also been shown to improve maternal relationships. Based on a randomized clinical trial carried out in a teaching hospital and clinic system-affiliated locations in Omaha (USA), maternal interaction with ultrasonographic materials (either regular 2D- or 3D-printed) led to more substantial enhancements in maternal-fetal attachment when compared to sole reliance on ultrasonography (98). Remarkably, the interaction effect between 3D-printed models suggested that the increase in the maternal antenatal attachment scale global score from the initial measurement was 3.75 points higher for the 3D-printed model group compared to the ultrasonography-only group (95% CI: 1.40 to 6.10, P value =0.002) (98). Similar outcomes were noted for the subscales concerning attachment quality and the duration spent contemplating the fetus. Considering these non-clinical outcomes, our research team believes that US images could alternatively be used for improving both professional observations and the parent/child relationship, particularly when an orofacial pathology is identified. The images themselves could prove useful in providing parents with a visualization of the neonates’ future facial characteristics and suggest potential interventions the neonate might need in the long run. Therefore, GUS offer not only a critical tool for ameliorated clinical practice, but also hold significant implications for parental relationships.

GUS serve as a cornerstone in fetal medicine, offering a primary and indispensable tool for the assessment of the developing fetus in utero (including orofacial features). Its predominant use (often by physicians) lies in its diagnostic capabilities, allowing healthcare professionals specialized in fetal medicine to closely monitor fetal growth and development. Nevertheless, the use of this imaging technique might (and should) be more utilized by dental doctors worldwide, suggesting an underutilization of these imaging exams to-date. Dental specialists have an intimate knowledge with cranial and facial development singularities and should be more familiarized with GUS images in routine clinical practice. Major reasons for the underuse of AUS within the field of dentistry to date might be associated with a lacking connection between sonographers and obstetricians, an insufficient number of screenshots targeting the craniofacial profile, or limited dental office visits during pregnancy. Therefore, we emphasize the importance of collaborative and patient-centered care delivery among different healthcare specialists, particularly physicians and dentists, to better detect and manage orofacial disorders.

The scoping review undertaken holds some limitations that warrant acknowledgment. Firstly, due to the nature of scoping reviews aiming for breadth rather than depth, there might be potential gaps in the comprehensiveness of the literature coverage. Despite employing systematic search strategies across multiple databases, the possibility of overlooking relevant studies cannot be entirely ruled out. Additionally, as scoping reviews involve a narrative synthesis of findings rather than a rigorous quality assessment, the quality and methodological rigor of included studies might vary significantly. This could impact the overall reliability and generalizability of the conclusions drawn from the reviewed literature. Additionally, we set a minimum number of patients to be enrolled in each individual study, which might have limited the amount of included studies. Despite the aforementioned limitations, our manuscript has extensively summarized the findings from various studies related to the detection and assessment of orofacial abnormalities using GUS techniques. It provides a comprehensive overview of the studies, their findings, and the effectiveness of US in identifying these abnormalities during different stages of pregnancy.

Conclusions

The findings emphasize how these AUS images can identify abnormalities, such as facial clefts, palate deformities, fetal micrognathia and glossoptosis. In addition, available evidence highlights the suitability of GUS in defining pregnancy termination based on major orofacial abnormalities. Ultimately, the need for continued advancements, standardized protocols, and interdisciplinary collaborations to enhance diagnostic accuracy is imperative to improve prenatal care for expectant parents worldwide.

Acknowledgments

The authors wish to thank Anneliese Arno (Evidence for Policy & Practice Centre, University College London, London, United Kingdom, and School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia) for granting complimentary access to Covidence^® (Veritas Health Innovation, Melbourne, Australia).

Funding: None.

Footnote

Reporting Checklist: The authors have completed the PRISMA-ScR reporting checklist. Available at https://jphe.amegroups.com/article/view/10.21037/jphe-24-59/rc

Peer Review File: Available at https://jphe.amegroups.com/article/view/10.21037/jphe-24-59/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jphe.amegroups.com/article/view/10.21037/jphe-24-59/coif). I.J.B.d.N. is an active Cochrane member and serves as an unpaid editorial board member of Journal of Public Health and Emergency from April 2024 to March 2026. The author affiliated with the World Health Organization (WHO) is alone responsible for the views expressed in this publication, which do not necessarily represent the decisions or policies of the WHO. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Royal College of Obstetricians & Gynaecologists. Ultrasound Screening for Fetal Abnormalities: Report of the RCOG Working Party. RCOG Press; 1997.
2. Dugoff L. Ultrasound diagnosis of structural abnormalities in the first trimester. Prenat Diagn 2002;22:316-20. [Crossref] [PubMed]
3. Salomon LJ, Alfirevic Z, Bilardo CM, et al. ISUOG practice guidelines: performance of first-trimester fetal ultrasound scan. Ultrasound Obstet Gynecol 2013;41:102-13. [Crossref] [PubMed]
4. Noguchi L, Bucagu M, Tunçalp Ö. Strengthening antenatal care services for all: implementing imaging ultrasound before 24 weeks of pregnancy. BMJ Glob Health 2023;8:e011170. [Crossref] [PubMed]
5. Kim ET, Singh K, Moran A, et al. Obstetric ultrasound use in low and middle income countries: a narrative review. Reprod Health 2018;15:129. [Crossref] [PubMed]
6. World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: World Health Organization; 2016 (accessed March 4, 2024). Available online: https://iris.who.int/handle/10665/250796
7. Morris RK, Malin GL, Khan KS, et al. Antenatal ultrasound to predict postnatal renal function in congenital lower urinary tract obstruction: systematic review of test accuracy. BJOG 2009;116:1290-9. [Crossref] [PubMed]
8. Afzal S, Fatima K, Ambareen M. Antenatal Ultrasound Diagnosis of Congenital High Airway Obstruction Syndrome: A Case Report and Review of Literature. Cureus 2019;11:e4772. [Crossref] [PubMed]
9. Robinson R, Walker KF, White VA, et al. The test accuracy of antenatal ultrasound definitions of fetal macrosomia to predict birth injury: A systematic review. Eur J Obstet Gynecol Reprod Biol 2020;246:79-85. [Crossref] [PubMed]
10. Roberts T, Henderson J, Mugford M, et al. Antenatal ultrasound screening for fetal abnormalities: a systematic review of studies of cost and cost effectiveness. BJOG 2002;109:44-56. [Crossref] [PubMed]
11. Bricker L, Medley N, Pratt JJ. Routine ultrasound in late pregnancy (after 24 weeks' gestation). Cochrane Database Syst Rev 2015;2015:CD001451. [Crossref] [PubMed]
12. Salomon LJ, Alfirevic Z, Berghella V, et al. ISUOG Practice Guidelines (updated): performance of the routine mid-trimester fetal ultrasound scan. Ultrasound Obstet Gynecol 2022;59:840-56. [Crossref] [PubMed]
13. Grandjean H, Larroque D, Levi S. The performance of routine ultrasonographic screening of pregnancies in the Eurofetus Study. Am J Obstet Gynecol 1999;181:446-54. [Crossref] [PubMed]
14. Ewigman BG, Crane JP, Frigoletto FD, et al. Effect of prenatal ultrasound screening on perinatal outcome. RADIUS Study Group. N Engl J Med 1993;329:821-7. [Crossref] [PubMed]
15. World Health Organization. Global oral health status report: towards universal health coverage for oral health by 2030. WHO Teams (Management-Screening, Diagnosis and Treatment, Noncommunicable Diseases, Rehabilitation and Disability). Available online: https://www.who.int/publications/i/item/9789240061484
16. Ranzini AC, Day-Salvatore D, Turner T, et al. Intrauterine growth and ultrasound findings in fetuses with Beckwith-Wiedemann syndrome. Obstet Gynecol 1997;89:538-42. [Crossref] [PubMed]
17. Arksey H, O’Malley L. Scoping studies: towards a methodological framework. International Journal of Social Research Methodology 2005;8:19-32. [Crossref]
18. Peters MDJ, Godfrey C, McInerney P, et al. Chapter 11: Scoping reviews. In: Aromataris E, Munn Z. editors. JBI Reviewer's Manual. JBI; 2020.
19. Tricco AC, Lillie E, Zarin W, et al. PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation. Ann Intern Med 2018;169:467-73. [Crossref] [PubMed]
20. do Nascimento IJB, Weerasekara I, Østengaard L, et al. The impact of digital health interventions on women's health-related outcomes: understanding its effects on health status and empowerment: a systematic review analysis. Available online: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=350883
21. Aldridge N, Pandya P, Rankin J, et al. Detection rates of a national fetal anomaly screening programme: A national cohort study. BJOG 2023;130:51-8. [Crossref] [PubMed]
22. Bardi F, Smith E, Kuilman M, et al. Early Detection of Structural Anomalies in a Primary Care Setting in the Netherlands. Fetal Diagn Ther 2019;46:12-9. [Crossref] [PubMed]
23. Bister D, Set P, Cash C, et al. Incidence of facial clefts in Cambridge, United Kingdom. Eur J Orthod 2011;33:372-6. [Crossref] [PubMed]
24. Bronshtein M, Blazer S, Zalel Y, et al. Ultrasonographic diagnosis of glossoptosis in fetuses with Pierre Robin sequence in early and mid pregnancy. Am J Obstet Gynecol 2005;193:1561-4. [Crossref] [PubMed]
25. Bronshtein M, Blumenfeld I, Zimmer EZ, et al. Prenatal sonographic diagnosis of nasal malformations. Prenat Diagn 1998;18:447-54. [Crossref] [PubMed]
26. Bronshtein M, Blumenfeld I, Kohn J, et al. Detection of cleft lip by early second-trimester transvaginal sonography. Obstet Gynecol 1994;84:73-6. [PubMed]
27. Cash C, Set P, Coleman N. The accuracy of antenatal ultrasound in the detection of facial clefts in a low-risk screening population. Ultrasound Obstet Gynecol 2001;18:432-6. [Crossref] [PubMed]
28. Chelemen OT, Pricop F, Butureanu S, et al. The impact of major fetal structural abnormalities on public health. Obstetrica si Ginecologie 2010;58:115-20.
29. Clementi M, Tenconi R, Bianchi F, et al. Evaluation of prenatal diagnosis of cleft lip with or without cleft palate and cleft palate by ultrasound: experience from 20 European registries. EUROSCAN study group. Prenat Diagn 2000;20:870-5. [Crossref] [PubMed]
30. Gai S, Wang L, Zheng W. Comparison of prenatal ultrasound with MRI in the evaluation and prediction of fetal orofacial clefts. BMC Med Imaging 2022;22:213. [Crossref] [PubMed]
31. Hafner E, Sterniste W, Scholler J, et al. Prenatal diagnosis of facial malformations. Prenat Diagn 1997;17:51-8. [Crossref] [PubMed]
32. Hegge FN, Prescott GH, Watson PT. Fetal facial abnormalities identified during obstetric sonography. J Ultrasound Med 1986;5:679-84. [Crossref] [PubMed]
33. Hjort-Pedersen K, Olesen AW, Garne E, et al. Prenatal detection of major congenital malformations in a cohort of 19 367 Danish fetuses with a complete follow-up six months after birth. Acta Obstet Gynecol Scand 2023;102:1115-24. [Crossref] [PubMed]
34. Kelekci S, Yazicioğlu HF, Oguz S, et al. Nasal bone measurement during the 1st trimester: is it useful? Gynecol Obstet Invest 2004;58:91-5. [Crossref] [PubMed]
35. Kong LJ, Fan L, Li GH, et al. Prevalence of congenital malformations during pregnancy in China: screening by ultrasound examination. Clinical and Experimental Obstetrics & Gynecology 2017;44:772-6. [Crossref]
36. Lachmann R, Schilling U, Brückmann D, et al. Isolated Cleft Lip and Palate: Maxillary Gap Sign and Palatino-Maxillary Diameter at 11-13 Weeks. Fetal Diagn Ther 2018;44:241-6. [Crossref] [PubMed]
37. Lakshmy SR, Rose N, Masilamani P, et al. Absent 'superimposed-line' sign: novel marker in early diagnosis of cleft of fetal secondary palate. Ultrasound Obstet Gynecol 2020;56:906-15. [Crossref] [PubMed]
38. Lakshmy SR, Deepa S, Rose N, et al. First-Trimester Sonographic Evaluation of Palatine Clefts: A Novel Diagnostic Approach. J Ultrasound Med 2017;36:1397-414. [Crossref] [PubMed]
39. Leiroz R, Aquino MA, Santos KP, et al. Accuracy of the mid-trimester ultrasound scan in the detection of fetal congenital anomalies in a reference center in Northeastern Brazil. J Gynecol Obstet Hum Reprod 2021;50:102225. [Crossref] [PubMed]
40. Li SL, Chen XL, Ouyang SY, et al. Analysis of 993 cases of fetal malformations from 1999 to 2006. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2008;30:69-74. [PubMed]
41. Li X, Xiu G, Yan F, et al. First-Trimester Evaluation of Cleft Lip and Palate by A Novel Two-Dimensional Sonographic Technique: A Prospective Study. Curr Med Imaging 2023;19:278-85. [Crossref] [PubMed]
42. Liao Y, Wen H, Ouyang S, et al. Routine first-trimester ultrasound screening using a standardized anatomical protocol. Am J Obstet Gynecol 2021;224:396.e1-396.e15. [Crossref] [PubMed]
43. Liao R, Liu D, Zhang Y, et al. Ultrasound Detection of Fetal Palate Development in the Early Stages of the Second Trimester and Its Clinical Application. Cleft Palate Craniofac J 2023; Epub ahead of print. [Crossref] [PubMed]
44. Lind K, Aubry MC, Belarbi N, et al. Prenatal diagnosis of Pierre Robin Sequence: accuracy and ability to predict phenotype and functional severity. Prenat Diagn 2015;35:853-8. [Crossref] [PubMed]
45. Liu HL, Yan F, Sun HP, et al. Ultrasonography of fetal cleft lip and palate in first-trimester. Clin Exp Obstet Gynecol 2017;44:408-12. [Crossref] [PubMed]
46. Luedders DW, Bohlmann MK, Germer U, et al. Fetal micrognathia: objective assessment and associated anomalies on prenatal sonogram. Prenat Diagn 2011;31:146-51. [Crossref] [PubMed]
47. Maarse W, Pistorius LR, Van Eeten WK, et al. Prenatal ultrasound screening for orofacial clefts. Ultrasound Obstet Gynecol 2011;38:434-9. [Crossref] [PubMed]
48. Merz E, Weber G, Bahlmann F, et al. Application of transvaginal and abdominal three-dimensional ultrasound for the detection or exclusion of malformations of the fetal face. Ultrasound Obstet Gynecol 1997;9:237-43. [Crossref] [PubMed]
49. Moreira T, Dias M, Von Hafe M, et al. Orofacial clefts: Reflections on prenatal diagnosis and family history based on a series of cases of a tertiary children hospital. Congenital Anomalies 2023;63:195-9. [Crossref] [PubMed]
50. Offerdal K, Jebens N, Syvertsen T, et al. Prenatal ultrasound detection of facial clefts: a prospective study of 49,314 deliveries in a non-selected population in Norway. Ultrasound Obstet Gynecol 2008;31:639-46. [Crossref] [PubMed]
51. Paaske EB, Garne E. Epidemiology of orofacial clefts in a Danish county over 35 years - Before and after implementation of a prenatal screening programme for congenital anomalies. Eur J Med Genet 2018;61:489-92. [Crossref] [PubMed]
52. Paterson P, Sher H, Wylie F, et al. Cleft lip/palate: incidence of prenatal diagnosis in Glasgow, Scotland, and comparison with other centers in the United Kingdom. Cleft Palate Craniofac J 2011;48:608-13. [Crossref] [PubMed]
53. Pilalis A, Basagiannis C, Eleftheriades M, et al. Evaluation of a two-step ultrasound examination protocol for the detection of major fetal structural defects. J Matern Fetal Neonatal Med 2012;25:1814-7. [Crossref] [PubMed]
54. Rabie NZ, Sandlin AT, Ounpraseuth S, et al. Teleultrasound for pre-natal diagnosis: A validation study. Australas J Ultrasound Med 2019;22:248-52. [Crossref] [PubMed]
55. Rodríguez Dehli C, Mosquera Tenreiro C, García López E, et al. The epidemiology of cleft lip and palate over the period 1990-2004 in Asturias. An Pediatr (Barc) 2010;73:132-7. [PubMed]
56. Rotten D, Levaillant JM, Martinez H, et al. The fetal mandible: a 2D and 3D sonographic approach to the diagnosis of retrognathia and micrognathia. Ultrasound Obstet Gynecol 2002;19:122-30. [Crossref] [PubMed]
57. Shaikh MA. Prevalence and Correlates of Intimate Partner Violence against Women in Liberia: Findings from 2019-2020 Demographic and Health Survey. Int J Environ Res Public Health 2022;19:3519. [Crossref] [PubMed]
58. Stoll C, Dott B, Alembik Y, et al. Evaluation of prenatal diagnosis of cleft lip/palate by foetal ultrasonographic examination. Ann Genet 2000;43:11-4. [Crossref] [PubMed]
59. Suresh S, Vijayalakshmi R, Indrani S, et al. The premaxillary triangle: clue to the diagnosis of cleft lip and palate. J Ultrasound Med 2006;25:237-42; quiz 243-4. [Crossref] [PubMed]
60. Syngelaki A, Chelemen T, Dagklis T, et al. Challenges in the diagnosis of fetal non-chromosomal abnormalities at 11-13 weeks. Prenat Diagn 2011;31:90-102. [Crossref] [PubMed]
61. Takita H, Hasegawa J, Arakaki T, et al. Usefulness of antenatal ultrasound fetal morphological assessments in the first and second trimester: a study at a single Japanese university hospital. J Med Ultrason (2001) 2016;43:57-62. [Crossref] [PubMed]
62. Tang J, Chen S, Ran SZ. Clinical value of ultrasound screening for fetus face malformations with ultrasound in early trimester. Chinese Journal of Medical Imaging Technology 2012;28:1890-3.
63. Trout T, Budorick NE, Pretorius DH, et al. Significance of orbital measurements in the fetus. J Ultrasound Med 1994;13:937-43. [Crossref] [PubMed]
64. Vial Y, Tran C, Addor MC, et al. Screening for foetal malformations: performance of routine ultrasonography in the population of the Swiss Canton of Vaud. Swiss Med Wkly 2001;131:490-4. [PubMed]
65. Wayne C, Cook K, Sairam S, et al. Sensitivity and accuracy of routine antenatal ultrasound screening for isolated facial clefts. Br J Radiol 2002;75:584-9. [Crossref] [PubMed]
66. Weedn AE, Mosley BS, Cleves MA, et al. Maternal reporting of prenatal ultrasounds among women in the National Birth Defects Prevention Study. Birth Defects Res A Clin Mol Teratol 2014;100:4-12. [Crossref] [PubMed]
67. Weiner Z, Goldstein I, Bombard A, et al. Screening for structural fetal anomalies during the nuchal translucency ultrasound examination. Am J Obstet Gynecol 2007;197:181.e1-5. [Crossref] [PubMed]
68. Wilhelm L, Borgers H. The 'equals sign': a novel marker in the diagnosis of fetal isolated cleft palate. Ultrasound Obstet Gynecol 2010;36:439-44. [Crossref] [PubMed]
69. Zhen L, Yang YD, Xu LL, et al. Fetal micrognathia in the first trimester: An ominous finding even after a normal array. Eur J Obstet Gynecol Reprod Biol 2021;263:176-80. [Crossref] [PubMed]
70. Zheng MM, Tang HR, Zhang Y, et al. Improvement in early detection of orofacial clefts using the axial view of the maxilla. Prenat Diagn 2018;38:531-7. [Crossref] [PubMed]
71. Zile-Velika I, Ebela I, Folkmanis V, et al. Prenatal ultrasound screening and congenital anomalies at birth by region: Pattern and distribution in Latvia. Eur J Obstet Gynecol Reprod Biol X 2023;20:100242. [Crossref] [PubMed]
72. Kansal K, Mittal M, Gupta A. Detection of Congenital Structural Anomalies by Mid Trimester Ultrasonography. Journal of Cardiovascular Disease Research 2022;13:1671-7.
73. Salomon LJ, Alfirevic Z, Da Silva Costa F, et al. ISUOG Practice Guidelines: ultrasound assessment of fetal biometry and growth. Ultrasound Obstet Gynecol 2019;53:715-23. [Crossref] [PubMed]
74. Zharkova N. Using ultrasound to quantify tongue shape and movement characteristics. Cleft Palate Craniofac J 2013;50:76-81. [Crossref] [PubMed]
75. Vincent-Rohfritsch A, Anselem O, Grangé G, et al. Prenatal diagnosis of a cleft of the tongue, lower lip and mandible. Ultrasound Obstet Gynecol 2012;39:110-2. [Crossref] [PubMed]
76. Levy DS, Zielinsky P, Aramayo AM, et al. Repeatability of the sonographic assessment of fetal sucking and swallowing movements. Ultrasound Obstet Gynecol 2005;26:745-9. [Crossref] [PubMed]
77. Müßig D. Die Sonographie-ein diagnostisches Mittel zur dynamischen Funktionsanalyse der Zunge. Fortschritte der Kieferorthopädie 1992;53:338-43. [Crossref] [PubMed]
78. Starikova NV, Nadtochiĭ AG, Ageeva MI. Prenatal cleft palate diagnostics by structural and functional peculiarities of the tongue. Stomatologiia (Mosk) 2013;92:70-5. [PubMed]
79. Starikova NV, Nadtochiĭ AG, Safronova IuA, et al. Tongue structure, position and function in cleft lip and palate children assessed by ultrasound examination. Stomatologiia (Mosk) 2012;91:56-60. [PubMed]
80. Goldstein I, Tamir A, Weiner Z, et al. Dimensions of the fetal facial profile in normal pregnancy. Ultrasound Obstet Gynecol 2010;35:191-4. [Crossref] [PubMed]
81. Yoon AJ, Zaghi S, Ha S, et al. Ankyloglossia as a risk factor for maxillary hypoplasia and soft palate elongation: A functional - morphological study. Orthod Craniofac Res 2017;20:237-44. [Crossref] [PubMed]
82. Cordray H, Mahendran GN, Tey CS, et al. The Impact of Ankyloglossia Beyond Breastfeeding: A Scoping Review of Potential Symptoms. Am J Speech Lang Pathol 2023;32:3048-63. [Crossref] [PubMed]
83. Barberá-Pérez PM, Sierra-Colomina M, Deyanova-Alyosheva N, et al. Prevalence of ankyloglossia in newborns and impact of frenotomy in a Baby-Friendly Hospital. Bol Med Hosp Infant Mex 2021;78:418-23. [Crossref] [PubMed]
84. Macé P, Bault JP, Quarello E. Tongue-filled pharynx sign: new simple ultrasound clue to assess glossoptosis in Pierre Robin sequence. Ultrasound Obstet Gynecol 2022;59:270-2. [Crossref] [PubMed]
85. Hediger ML, Fuchs KM, Grantz KL, et al. Ultrasound Quality Assurance for Singletons in the National Institute of Child Health and Human Development Fetal Growth Studies. J Ultrasound Med 2016;35:1725-33. [Crossref] [PubMed]
86. Swanson D, Lokangaka A, Bauserman M, et al. Challenges of Implementing Antenatal Ultrasound Screening in a Rural Study Site: A Case Study From the Democratic Republic of the Congo. Glob Health Sci Pract 2017;5:315-24. [Crossref] [PubMed]
87. Ginsburg AS, Liddy Z, Khazaneh PT, et al. A survey of barriers and facilitators to ultrasound use in low- and middle-income countries. Sci Rep 2023;13:3322. [Crossref] [PubMed]
88. Valério P, Poklepović Peričić T, Rossi A, et al. The effectiveness of early intervention on malocclusion and its impact on craniofacial growth: a systematic review. Contemp Pediatr Dent 2021;2:72-89. [Crossref]
89. Chedid S. An overview for clinical applicationof gestational ultrasonography in prenataldental care: A literature review. Education in Paediatric Dentistry. International Journal of Paediatric Dentistry 2021;31:248.
90. Cicciù M, Cervino G, Fiorillo L, et al. Early Diagnosis on Oral and Potentially Oral Malignant Lesions: A Systematic Review on the VELscope(®) Fluorescence Method. Dent J (Basel) 2019;7:93. [Crossref] [PubMed]
91. Yousefpour Shahrivar R, Karami F, Karami E. Enhancing Fetal Anomaly Detection in Ultrasonography Images: A Review of Machine Learning-Based Approaches. Biomimetics (Basel) 2023;8:519. [Crossref] [PubMed]
92. Yu Zhen, Ni Dong, Chen Siping, et al. Fetal facial standard plane recognition via very deep convolutional networks. Annu Int Conf IEEE Eng Med Biol Soc 2016;2016:627-30. [Crossref] [PubMed]
93. Tsai PY, Chen HC, Huang HH, et al. A new automatic algorithm to extract craniofacial measurements from fetal three-dimensional volumes. Ultrasound Obstet Gynecol 2012;39:642-7. [Crossref] [PubMed]
94. Leung KY. Applications of Advanced Ultrasound Technology in Obstetrics. Diagnostics (Basel) 2021;11:1217. [Crossref] [PubMed]
95. van Vlimmeren LA, van der Graaf Y, Boere-Boonekamp MM, et al. Risk factors for deformational plagiocephaly at birth and at 7 weeks of age: a prospective cohort study. Pediatrics 2007;119:e408-18. [Crossref] [PubMed]
96. Launonen AM, Aarnivala H, Kyteas P, et al. A 3D Follow-Up Study of Cranial Asymmetry from Early Infancy to Toddler Age after Preterm versus Term Birth. J Clin Med 2019;8:1665. [Crossref] [PubMed]
97. Martiniuk AL, Vujovich-Dunn C, Park M, et al. Plagiocephaly and Developmental Delay: A Systematic Review. J Dev Behav Pediatr 2017;38:67-78. [Crossref] [PubMed]
98. Coté JJ, Badura-Brack AS, Walters RW, et al. Randomized Controlled Trial of the Effects of 3D-Printed Models and 3D Ultrasonography on Maternal-Fetal Attachment. J Obstet Gynecol Neonatal Nurs 2020;49:190-9. [Crossref] [PubMed]