Nasoalveolar Molding

1. Introduction

Orofacial clefts are congenital craniofacial differences. Since 2018, the term “anomalies” has changed to “differences” to be more inclusive and to respect craniofacial differences [1]. Cleft lip and/or palate (CL/P) is caused by embryological defects in face formation, affecting the upper lip, premaxilla, hard palate, and/or the floor of the nose [1].

CL/P has been classified into three general categories according to anatomical characteristics: cleft palate alone (CP), unilateral or bilateral cleft lip with (CL), and unilateral or bilateral cleft lip and palate (CLP) [2].

When the cleft is wide and affects the lip and palate, the patient has a more esthetic compromise, especially the nose. It is a particular challenge to the interdisciplinary group to fulfill a functional and esthetic outcome [1].

2. Oral health

The pediatric dentist is part of the primary interdisciplinary care group. They are fundamental in longitudinal and holistic health care, emphasizing the child’s well-being with CL/P and their family [3].

Oral health care is essential in the interdisciplinary treatment of children with CL/P because oral health is vital in the final results of the interdisciplinary treatment process [1].

Children with CL/P present a higher risk of oral diseases due to different risk factors such as enamel hypoplasia [4], structural anomalies in the teeth close to the cleft that favor the formation of food residue retention niches [5], hinder tooth self-cleaning and the presence of orthopedic appliances in the mouth that present colonization with cariogenic bacteria [6].

The prevalence of dental caries is greater in individuals with CL/P, in the primary and permanent dentition, expected due to anatomical factors, poor oral hygiene, prolonged duration of use of orthopedic appliances, and level of lowest socioeconomic status of families [5].

3. Presurgical orthopedics

The use of early presurgical orthopedics as a preliminary technique in treating patients with CL/P has been discussed since it was first proposed by McNeil in 1948 [7] and developed by Burston in 1958 [8].

Since its introduction, it has been part of interdisciplinary care in some CL/P care teams. There is controversy about its use in different interdisciplinary groups. In Europe, about 54% of the 201 centers used it. Almost half of the centers registered in the Eurocleft project used presurgical orthopedics, of which 65% used it routinely. Most of the obturators used were of Hotz type [9].

Some of the goals of presurgical orthopedics are to reduce the width of the cleft, to accomplish a harmonious arch form in the first 3 months of childhood before cheiloplasty, to permit surgical repair with minimal tension, to normalize the swallowing pattern, to prevent position the tongue in the cleft, position the columella, and aid the surgery [10, 11].

Early presurgical orthopedics has constantly evolved since McNeil’s time. Appliances can now be classified as passive or active, presurgical or postsurgical and extraoral or intraoral [12].

Grayson and Cutting combined the concept of preoperative orthopedics and the treatment of nasolabial cleft before surgery. They developed the idea of nasoalveolar molding (NAM), which combined a nasal molding device with a Hotz-type obturator [13]. The preoperative nasoalveolar molding treatment theory is based on Matsuo’s research that auricular cartilage is elastic in the early neonatal period [14]. Labial tape adhesion is a technique in which the tape approaches the lip segments, and it is used in addition to this procedure to approximate cleft lip, reduce stress on surrounding tissues, and facilitate surgical procedures. NAM helps to minimize the defect, reduce the width of the nasal base, bring the columella toward the center of the face, enhance the symmetry of nostrils, and get close to the labial segments [15].

Some authors state that presurgical orthopedics is a complicated therapy that is not based on evidence, generating more appointments, follow-up, and compliance during the first year of the child’s life [16].

Prahl, in his prospective randomized controlled clinical trial, compared the maxillary dimensions of a group of patients with unilateral cleft lip and palate who used a passive obturator with those who did not receive presurgical orthopedic treatment. He concluded that early presurgical orthopedics temporarily affect maxillary arch dimensions that do not persist after palate surgery [17].

Mishima et al. suggested that the maxillary segments could grow if the patient used orthopedic appliances during the postnatal 4 months [18].

In the literature, there are positive and negative statements related to the need and effectiveness of early presurgical orthopedics. Dental models have been used as the primary tool to evaluate the results; however, the methodological difference between the analysis of dental models in two-dimensional and three-dimensional studies and the evaluation of the three-dimensional spatial relationship with measurements in two dimensions limits the findings [19].

4. Procedure

The dentist takes the first impression with a silicone material during the first weeks after birth. An anesthesiologist is always present to assist with the impression if an airway emergency occurs. The tray is removed when set, and the mouth is examined for residual impression material. A cast of the palate is made with dental gypsum [20].

The obturator is fabricated using the dental gypsum model. It is made of hard acrylic and is lined with a thin coat of soft acrylic. The nasal stent can be added when the alveolar cleft gap is reduced to 5 mm or less when the Grayson technique is used [20]. When using the modified technique, the nasal stent is included from the beginning [21]. The stent is made of 0,036 round stainless steel wire and has the shape of a swan neck if the Grayson technique [20] or a round form if the modified technique was used [21]. The intranasal part was made from hard acrylic. It is applied a soft acrylic layer over the hard acrylic to give comfort. When using the Grayson technique, the upper lobe enters the nose and elevates the dome. The lower lobe of the nasal stent elevates the strip apex and silhouettes the top of the columella [20]. When using the modified technique, the round acrylic part enters the nostril [21].

The NAM appliance was held extraoral to the bilateral cheeks skin by surgical tapes, which have an orthodontic elastic band at one end. There was an elastic loop that supported the anterior part of the plate. The retention arm is located 40-angled down from the horizontal plane to obtain correct activation and prevent movement from the palate of the appliance. Every day, the tapes and elastics were changed [20].

When the tape system engages the retention arms, the 1/4 inches of elastics should be stretched to double the size of the elastic for two ounces of activation force. The amount of pressure may change depending on the clinical purpose and the mucosal correction. The back movement of the premaxilla in bilateral cleft individuals requires greater elastic traction force than is required for the closure of a unilateral alveolar gap. The tape should be applied to the noncleft side first, then move toward the cleft side, bringing the philtrum and columella to the midline of the face [20].

The treatment requires a weekly visit. The dentist added the hard and soft acrylic to the nasal extension during the NAM follow-up appointments when needed. NAM was activated intraorally by removing acrylic in the area where alveolar bone apposition was required. Soft acrylic was added to the region where the alveolar bone should be reabsorbed.

Two retention arms and nasal stents were used in the bilateral NAM Grayson’s technique. The assembly process is the same as those related to the unilateral cleft. Each nasal stent arises from the molding plate at the base of the retention arm. The main goal of treatment in patients with bilateral cleft lip and palate after the nasal stents are added is to achieve the elongation of the columella without surgery. A horizontal band of soft denture material is added to join the nasal stents, stretching the base of the columella. Tape is applied to the prolabium and pulled downward to place the retention arms with elastics. The force of the tape down to the prolabium helps to lengthen the columella and vertically lengthens the prolabium. When the prolabium is well positioned, it is kept with tape in place [20].

The plate must be used full time, and it is explained to the parents that take it out for washing with cold, clean water and soap every day [20].

Initially, feeding the infant with the plate in the mouth may take longer, but the child quickly adjusts. It is challenging to achieve exclusive breastfeeding with NAM (Figures 1 and 2) [22].

5. NAM in the unilateral cleft lip and palate

In unilateral cleft lip and palate (UCL/P), López et al. evaluated the response of nasal soft tissues using NAM. The presurgical nasoalveolar molding technique improves alar cartilage depression, nasal tip projection, deviation of the columella, and nostril symmetry in patients with CL/P in a South American population [23].

Cerón et al. found that the maxillary segments can respond to presurgical orthopedic treatment during the early postnatal period. They compared the effects of NAM and Hotz-type obturators in the maxillary arch. Significant reduction of the cleft in the anterior part was observed with the NAM and Hotz-type obturators, which were less effective than those of the NAM. No restriction was observed in the transverse growth of the arches because of the therapy performed. In contrast, a transverse increase was found in the posterior region without being statistically significant and stable in the canine area. After the follow-up of the treatment with presurgical orthopedics at 1 year with NAM and Hotz-type obturators of 32 patients with LPHU, it was concluded that with NAM, better results were achieved in reducing the amplitude of the anterior part of the cleft, more stability in the canine area and less increase in cleft depth [24].

Nhu Dinh et al. assessed the effectiveness of the presurgical NAM appliance among infants with unilateral cleft lip and palate. All casts were scanned and measured using 3D technology before and after treatment. They found an increase in the nostril height on the cleft side, reduced the nostril width and the columella angle, and minimized the cleft width and midline deviation after the treatment [25].

Passucci Ambrosio et al. evaluated the effects of NAM, Hotz-type obturators, and patients without intervention on the dental arches of children with unilateral cleft lip and palate in the first year of life. They found that pre and postsurgical orthopedics may help achieve a more optimal palatal shape. Participants treated with the Hotz plate alone and those treated with NAM and the Hotz plate had the most significant transverse reduction in the anterior part of the palate without a collapse of the palatal segments [26].

6. NAM in the bilateral cleft lip and palate

Nasoalveolar molding in bilateral cleft lip and palate (BCL/P) is a challenge. Garfinkle et al. retrospectively compared the nasal morphology of individuals treated with NAM followed by primary lip/nasal reconstruction with a control group of noncleft patients of the same age. Patients with BCL/P treated with NAM and primary nasal reconstruction have nearly normal nasal morphology up to 12.5 years of age [27].

Mancini et al. utilized 3D photography to retrospectively evaluate nasolabial changes in individuals with bilateral cleft lip and palate who underwent NAM. They found that after NAM therapy, there were statistically significant changes in the position of the subnasale and improved nasolabial symmetry. NAM relieved the nasal tip projection. The columella lengthened from 1,4 to 4,71 mm following NAM [28].

7. Complications

Garcés Alvear studied complications during NAM treatment in nonsyndromic individuals with UCL/P. They found complications in soft tissues, such as irritation, ulceration, and gingival bleeding. It is also found in some patients Candidiasis. They reported an overexpanded nostril. The most recurrent complications were lip and cheek skin irritation due to surgical tape and gingival ulceration due to excessive acrylic pressure. They found misalignment in alveolar segments. Complications due to care were inadequate device retention, adherence to treatment, poor or excessive caregiver care, lack of patient acceptance of the device, feeding, and socioeconomic problems [29].

8. Conclusion

NAM is an efficient presurgical orthopedic treatment for cleft lip and palate. Since the 1990s, the evidence has been growing and may enhance the nasal and dental arches. It is essential to conduct longitudinal random control research with patients with unilateral and bilateral cleft lip and palate treated with NAM. The surgical lip and palatal techniques have taken advantage of the NAM procedure.

Conflict of interest

The authors declare no conflict of interest.