Key points

Introduction: nature of the problem

Nasal surgery in children has been an ongoing topic of discussion in pediatric otolaryngology and facial plastic surgery. Central to this discussion is the effect of surgical manipulation of the nasal structures and the effects of this intervention on the growth and maturation of the nose. Several animal, clinical, and observational studies have attempted to elucidate the effect of intervention on the growing nose throughout the years. These interventions include resection and devascularization to the nasal septum and the growth centers of the nose. Despite the growing body of literature, the topic of pediatric septorhinoplasty and its indications remain an area of continued controversy.

Introduction: nature of the problem

Nasal surgery in children has been an ongoing topic of discussion in pediatric otolaryngology and facial plastic surgery. Central to this discussion is the effect of surgical manipulation of the nasal structures and the effects of this intervention on the growth and maturation of the nose. Several animal, clinical, and observational studies have attempted to elucidate the effect of intervention on the growing nose throughout the years. These interventions include resection and devascularization to the nasal septum and the growth centers of the nose. Despite the growing body of literature, the topic of pediatric septorhinoplasty and its indications remain an area of continued controversy.

Controversies

Pediatric septorhinoplasty continues as an area of controversy. Animal and clinical studies have demonstrated the importance of conservative manipulation on the growing nose. The timing and extent of surgery has been debated. There are certain indications for rhinoplasty where the benefit outweighs the risk of operating on the growing nose.

Anatomy and growth

The development and characteristics of the pediatric nose is essential in understanding the effects of septorhinoplasty on its growth. Around the fourth week of gestation, neural crest cells migrate caudally creating nasal placodes. The placodes are then divided into medial and lateral nasal processes. The medial process becomes the anterior septum, philtrum, and premaxilla. The lateral processes form the lateral nasal walls. The differentiation of the muscle, cartilage, and bony elements of the nose occur at 10 weeks gestation.

The septodorsal cartilages are the main supporting structure for the nasal dorsum and consist of the upper lateral cartilages and the nasal septum. The nasal septum in young children extends from the skull base to the nasal floor. Superiorly, the septum is based at the sphenoid at birth. As the perpendicular plate grows and ossifies, the septum in turn is based on the caudal edge of the perpendicular plate by adulthood.

The nasal bones in the neonate are fibrous and connected to the upper lateral cartilages. Interestingly, the upper lateral cartilages extend under nasal bones and attach to the anterior cranial base. As the child grows, the upper lateral cartilages migrate anteriorly from the skull base and are replaced by the ossifying cribriform plate. The degree of migration is not consistent from individual to individual, explaining the varying relationship between the nasal bones and upper lateral cartilages seen in adult rhinoplasty.

Growth of the nasal septum is at its maximum in the newborn and plateaus by the age of 20. In an anatomic study performed by van Loosen and colleagues, the cartilaginous septum shows the greatest velocity growth at the age of 2. Later growth of the nasal septum is owing to ongoing ossification of the septal cartilage at the sphenoethmoid region with concurrent growth and formation of new cartilage.

The nasal septal cartilage seems to be central in the growth of the midface. There are 2 growth zones of the nasal septum. These include the sphenodorsal zone, which extends from the sphenoid septum to the nasal dorsum, and the sphenospinal zone, which extends from the sphenoid to the anterior nasal spine. These 2 areas are thicker owing to mitotic activity and histologic maturation. Growth of the sphenodorsal zone seems to be responsible primarily for the increase in length and height of the nasal dorsum. Growth in the sphenospinal region of the septum drives growth of the premaxilla. Injuries to these pivotal growth centers demonstrate detrimental effects to the maxilla and nasal dorsum.

The maximum growth velocity of the nose in girls seems to vary from 8 to 12 years of age, whereas in boys it is around 13 years of age. The defined completion of nasal growth is a continued controversy. A study by Meng and associates in 1988 demonstrated near completion of growth in girls by the age of 16 and continuing to age 18 in males. However, there have been several other studies that draw varying conclusions on nasal growth, extending it to the age of 20 in females and 25 in males, and even some statistically insignificant growth of the nose in advanced age. Given the debate about when nasal growth is complete, growth after the mid teenage years is not likely clinically significant.

Animal studies

Animal models have been the basis in the understanding of nasal growth and the effects of trauma and surgery. Several models have been developed throughout the years to investigate the effect of septal resection on the growth of the nose and midface in several species of animals. These began as early as the 1850s, where Fick and his colleagues stated that growth of the hard palate was dependent on the nasal septum after investigation in growing dogs, cats, pigs, and goats.

Sarnat and Wexler in the 1960s used aggressive resection of the caudal cartilaginous septum and overlying mucoperichondrium in growing rabbits. This resection resulted in underdevelopment of the snout, saddle deformity, and mandibular prognathism. This type of radical resection of the septum in adult rabbits did not produce the same deformity. Similar studies have been performed in canine pups, baboons, and ferrets demonstrating detrimental effects on midface growth.

Although this rather radical approach to septal resection in these studies does not simulate directly the conservative approach taken on pediatric septorhinoplasty, it does give an indication that extensive resection of the mucoperiosteum and cartilage can have detrimental effects on skeletal growth.

Bernstein also performed septal resection preserving the mucoperichondrium. In canines with preserved perichondrium, no change in growth was noted, highlighting the importance of appropriate submucous resection and preservation of mucoperichondrial flaps. In juvenile ferrets, Cupero and colleagues demonstrated no difference in cephalometric analysis when selective submucoperichondrial removal of a small piece of cartilage and vomer was removed. However, these studies are limited by small numbers of study subjects. These animal models again demonstrate the importance of mucoperiosteal preservation in the growing nose.

Instead of resection, the question then arose to removal and replacement of the septal cartilage with cartilage autografts in prevention of growth restriction. In a study by Nolst Trenité and colleagues, septal reimplantation after cutting to the appropriate size was observed. This technique demonstrated growth of the cartilage but did not prevent shortening of the nose or saddling deformity. One benefit demonstrated was prevention of septal perforations. Crushed cartilage did not demonstrate prevention of subsequent deformities with time because it lacks the mechanical strength that intact cartilage has. Reimplanted cartilage has not been found useful in septorhinoplasty in pediatric animal models.

These animal studies demonstrate the essential role of the septum its growth zones in the development of the nose and midface. The evidence from these animal models show that preservation of the mucoperichondrium as well as limited resection and manipulation of the cartilages can affect nasal growth and now play an important role in our conservative approach to pediatric rhinoplasty. Interestingly, these studies are in conflict with clinically observed data in human populations, which will be covered in later sections of this article.

Clinical studies

Clinical evidence of the effects of intervention to the nose at a young age is varied. Investigation of these effects on the growth of the nose are difficult owing to the long-term follow-up needed, small sample size, and difficulty of randomized controlled trials. Given this paucity of clinical information, the traditional dogma has been to err on the side of conservative management, given observations of detrimental effects to growth of the midface in animal studies. Several observational studies regarding effects of trauma, nasal abscess, and loss of cartilage to the nasal septum and cartilaginous structures of the nose have been reported.