**1.2 Anterior Plagiocephaly**

Anterior plagiocephaly occurs when the coronal suture fuses prematurely. Observable signs of this type of synostosis involve a flattening of the forehead on the affected side, a protruding forehead on the unaffected side, and a nasal septum deviation towards the normal side. If a radiograph is performed, anyone that has anterior

*A Review of Current Surgical Approaches and Diagnostic Features Associated… DOI: http://dx.doi.org/10.5772/intechopen.108685*

plagiocephaly will display a characteristic reading that is more commonly known as a Harlequin sign due to the high supraorbital margins that the affected have. In some cases where the "bicoronal fusion" closes prematurely, the condition is called brachycephaly" [1]. This type of synostosis affects girls more than boys in a 2:1 ratio.

### **1.3 Posterior Plagiocephaly**

"Posterior plagiocephaly is a unilateral lambdoid synostosis" [1]. Distinguishable signs to look out for include frontal or occipital bossing, a displacement of the ipsilateral ear and mastoid downwards, and depending on the severity of the posterior plagiocephaly, the head may look like a trapezoid when viewed from above.

#### **1.4 Trigonocephaly**

"Trigonocephaly results from a premature fusion of the metopic suture" [1]. Prominent features that are unique to the presence of trigonocephaly are a broad back of the head, a pointed forehead that appears to be triangular when viewed from above. The orbits are also closer together than normal which is commonly referred to as hypotelorism. The ratio of boys to girls affected by this type of synostosis is 3.3:1.

#### **1.5 Brachycephaly**

"Brachycephaly is a bilateral coronal synostosis" [1]. It is common for those affected by brachycephaly to display signs such as a flattened forehead or occipital bone along with a "frontal bone [that] is prominent and elongated in a vertical direction" [1]. The orbits are also further apart than normal which is commonly referred to as hypertelorism. This separation can be picked up on radiographs. Studies also tend to show that brachycephaly is typically a type of synostosis that is heavily influenced by genetics or develops as a result of syndromic craniosynostosis.


#### **Table 3.**

*Comparison of non-synostotic (deformational) plagiocephaly and synostotic plagiocephaly [4, 5].*

#### **1.6 Deformational Plagiocephaly**

Deformation or non-synostotic plagiocephaly is unlike any other type of plagiocephaly as it is not synostotic. **Table 3** summarizes the key differences between non-synostotic and synostotic plagiocephaly. It develops as a result of continuous pressure to one area of the head. It is hard to distinguish between the two as some of the physical changes that come about as a result of deformational plagiocephaly can be similar to those found in synostotic plagiocephaly. However, the physical changes that arise as a result of deformational plagiocephaly can be resolved with time and by changing the sides that the baby sleeps on whereas synostotic plagiocephaly requires surgery to remedy any physical changes. Due to the number of babies that sleep in a supine position in order to avoid the risk of cot death, the amount of deformational plagiocephaly cases rose from "20% to 48% since the early 1990's" [2, 6] which makes it harder to detect cases in which craniosynostosis is present.

### **2. Approaches to the management of craniosynostosis**

There are various approaches a surgeon should consider for treatment planning a patient with craniosynostosis.

#### **2.1 Surgical approaches**

Most occurrences require timely surgical correction. Various articles highlight the importance of the patient's age as the predominant factor when determining the surgical approach. Per Chong et al.: for patients younger than 6 months, a minimally invasive procedure should be considered. This most commonly involves a minimally invasive suturectomy with postoperative helmet therapy.

The goal of minimally invasive suturectomy is to release a fused suture with small exposure. Chong et al. outlines their approach to a case of sagittal craniosynostosis:

*"The patient is prepared with the head extended in a prone position. Skin preparation is done with povidone-iodine. Two transverse incisions are made of 3–4 cm length at 1 cm behind the anterior fontanelle and 1 cm in front of the lambdoid suture. An additional incision may be needed between the two sites to manipulate safely in a patient with a longer head. A subperiosteal dissection is made along the desired craniectomy site. Burr holes are placed over the fused suture at both incision sites. The dura is dissected and carefully detached from the fused bone. During these procedures, a fiber optic suction tip or endoscope is used for the safe and accurate manipulation of the compromising space. Strip craniectomy is performed using curved Mayo scissors, sternal scissors and straight rongeurs. The fused bone is removed from the anterior fontanelle anteriorly to the lambda posteriorly. The width of the craniectomy site is targeted to be between 3 cm to 4 cm. After the strip craniectomy, additional lateral wedge osteotomies or barrel stave osteotomies might be conducted according to the surgeon's preference. Bleeding from the diploic space is controlled by bone wax and monopolar electrocautery. With the insertion of a drain, the wound is closed layer by layer" [7].*

Postoperative helmet therapy is typically initiated after subgaleal swelling is reduced and all stitches are removed. The helmet is recommended to be worn for 12–18 months to account for this important rapid brain and skull growth period. One helmet may be sufficient depending on the procedure (such as following sagittal craniosynostosis) or the patient may require two or more helmet adjustments. An orthotist fits patients for the helmet.

#### *2.1.1 Fronto-orbital advancement*

The goal of the fronto-orbital advancement (FOA) surgical technique is to create space in the skull while reshaping the forehead and the orbit. FOA is indicated in unicoronal, bicoronal, or metopic craniosynostosis.

In this procedure, a coronal incision is performed using a sinusoidal pattern with hemostatic clips. Subperiosteal dissection is performed to raise the anterior scalp flap to expose the superior orbital rim and orbital roof bilaterally. Caution must be taken with the release of the supraorbital neurovascular bundle from its notch and retraction with gentle pressure on the globe. The subperiosteal dissection is then directed laterally to expose the fronto-zygomatic suture and lateral orbital wall and medially to expose the nasal root and medial orbital walls. The lateral canthus is released while the medial canthus must remain intact. A frontal craniotomy is performed, diligently avoiding the patent sutures, and frontal bone flap is removed with care to avoid damage to the sagittal sinus and the dura. Any bleeding from inadvertent damage to the dura must be controlled immediately after removal of the frontal bone. Superior osteotomy from anterior to posterior is created, followed by the lateral osteotomy through the zygomatic-frontal suture [8].

Intracranially, an osteotomy of the orbital roof is performed through the anterior cranial fossa while protecting the frontal lobe and globe, as well as the temporal lobe when extending laterally to the lateral sphenoid. A nasal frontal osteotomy is performed starting laterally and extending it medially to avoid damage to the dura. Once the osteotomies are released, the bones, except for the frontal bone, are gently bent to the desired contour, rearranged with overcorrection to avoid relapse. The frontal bone flap is transected, molded and reattached with absorbable hardware and/or sutures in an overcorrected anterior to posterior position to avoid relapse. The sites are irrigated with copious amounts of saline and closed in a layered fashion (**Figure 2**) [8].

#### *2.1.2 Posterior cranial vault distraction*

The posterior cranial vault distraction (PCVD) technique has been used with the goal of increasing intracranial volume while achieving desired cosmetic results. With low perioperative complications, this procedure allows for 25–30% increase in intracranial volume. Salokorpi et al. describes their method of PCVD with virtual surgical planning preoperatively for osteotomy lines, size of bone flap, direction of distraction and location of the distraction devices.

A coronal incision is performed in a weave fashion and the location of the incision should be placed to allow for front-orbital expansion procedure, if needed. The dissection in the occipital area is performed subperiosteally. Once marked, the osteotomy is performed using the preoperative plan. Burr holes are made with a ball drill with caution to avoid dural damage. The burr holes are also placed, bilaterally, on the lambdoid sutures. The dura is dissected through the burr holes and further craniotomy is performed starting from the temporal and extending to the sagittal suture. The craniotomy is then extended occipitally over the posterior sinus structures. Bleeding in the occipital area from the emissary veins must be managed with

**Figure 2.** *Bilateral fronto-orbtal advancement [A, B]. Total vault remodeling [C, D] [9, 10].*

bone wax and hemostatic matrix with thrombin. A short bone bridge is left to ensure stability during fixation of the distractors. After fixation, this bone bridge is cut [11].

Distractors are placed, parallel to each other, in the locations that were planned preoperatively. Salokorpi et al. preferred to position the devices with anterior positioning of the activation arms. The occipital movement of the flap is confirmed by activating the devices for a few millimeters. The bone is left attached to the dura as detachment increases the risk of bleeding from venous sinuses. Salokorpi reports that a full mobilization of the bone flap does not affect the ossification. Postoperatively, after a latency period of 5–7 days, the rate of distraction is performed at 0.5–1 mm/ day in one to two sessions per day. Once sufficient ossification is obtained, the devices can be removed with small skin cuts perpendicular to the coronal incision [11].

#### *2.1.3 Endoscopic strip craniectomy*

The goal of endoscopic strip craniectomy is to perform a strip craniectomy using an endoscope to minimize scalp incision, blood loss, operative times and postoperative recovery periods. The use of the endoscope to perform the strip craniectomy was described by Barone and Jiminez, published in Plastic and Reconstructive Surgery in 1999.

Two 2 cm incisions are placed; one of the posterior aspect of the anterior fontanelle and the other over the lambda. With the use of an endoscope, dissection is performed in the subgaleal plane between these two incisions and extending to the bitemporal regions. With endoscopic visualization, electrocautery is performed for hemostasis to create a dry subgaleal dissection. Then, blunt dissection is performed to separate the dura from the

### *A Review of Current Surgical Approaches and Diagnostic Features Associated… DOI: http://dx.doi.org/10.5772/intechopen.108685*

bony edge of the fontanelle. A rongeur is used to remove a thin strip of bone anterior to the lambdoid suture to avoid injury to the sagittal sinus. Dura is dissected off the lambda and posterior aspect of the sagittal suture. With direct visualization, the sagittal sinus is carefully peeled off the synostosed sagittal suture. Epidural dissection is extended laterally to the level of the squamosal suture. Once complete subgaleal and epidural exposure is obtained, a lateral paramedian osteotomy is made using bone cutting scissors and a midline strip measuring 1.5–7 cm wide and 7–12 cm long is removed. Wedges of bone are removed and the surgical field is irrigated with antibiotic solution prior to closure. Postoperatively, Barone and Jiminez describe that the patients were placed in custommade helmets with continued molding therapy for upto 8 months [12].

Lambdoid, metopic and coronal synostosis follow similar techniques except for some modifications. In lambdoid sutures, incisions are planned preoperatively using ECG and plain x-ray film and the patient is placed in a full prone position. In metopic and coronal synostosis, the patient is placed in supine position and an incision is made at the hairline centrally. Additionally, the subgaleal dissection is performed with the endoscope to the nasofrontal suture (**Figure 3**) [12].

#### *2.1.4 Spring-mediated cranioplasty*

Spring-mediated cranioplasty is a surgical technique employed for the correction of sagittal craniosynostosis to expand the parietal bones transversely to reverse midvault disproportion.

#### **Figure 3.**

*Patient with scaphocephaly treated with endoscopic-assisted suturectomy and osteotomies. Patient in modified prone position [A]. Surgical patties showing subcutaneous dissection [B]. Sagittal suture excision [C]. Excised sagittal suture [D] [10].*

#### **Figure 4.**

*Image of craniosynostosis surgery being performed on a patient with anterior plagiocephaly. Bicoronal flap exposing defect [A]. Completed skull reconstruction with resorbable plates [B] [13].*

Two transverse incisions are made posterior to the anterior fontanelle and anterior to the posterior fontanelle allowing easier access to the most distal anterior and posterior aspects of the sagittal suture to perform the craniectomy and placing the distractor springs. After identifying and elevating the subgaleal plane, burr holes are placed at the midline of the inferior and superior incisions. The inferior and superior incisions depend on the prone or supine positioning of the patient. A craniectomy is performed and three strips, 1.5 cm or less in width, are removed. Following this, cranial springs, that were selected preoperatively with the criteria of length, thickness and U bend, are placed in the anterior, mid-vault and posterior positions. The springs are placed 1 cm posterior to the anterior fontanelle, 1 cm anterior to the lambdoid sutures and at the parietal bone midpoint. Following copious irrigation, the incisions are closed in a layered fashion (**Figure 4**) [14].

#### **2.2 Combined surgical and orthodontic approach**

Treatment of craniosynostosis involves a care team that includes but is not limited to an oral maxillofacial surgeon, neurosurgeon, pediatric dentist, plastic surgeon, pediatric neurologist, geneticist, plastic surgeon, dentist, and orthodontist. As a result of the various medicinal disciplines that are involved in the care of a patient that has craniosynostosis, treatments that the patients undergo are a joint effort that requires the cooperation of those involved. A common collaboration that is vital to providing care for patients afflicted by craniosynostosis is that of dentists and surgeons. While surgeons perform operations on a patient, dentists can monitor the patient and keep record of the recovery process using "photographs, diagnostic models, and imaging records" [1]. Dentists are also heavily involved in ensuring that the teeth of the patient develop properly. **Table 4** below illustrates the reliance of providers on the various types of recommended interventions to manage orthodontic patients:

Severe cases of craniosynostosis (typically syndromic craniosynostosis) often present an array of problems that need to be dealt with in a timely manner to ensure that the patient does not suffer from any mortal symptoms. While the table above outlines a general treatment plan for a patient that has craniosynostosis, those that suffer from syndromic craniosynostosis require certain steps in their treatment plan


*A Review of Current Surgical Approaches and Diagnostic Features Associated… DOI: http://dx.doi.org/10.5772/intechopen.108685*

#### **Table 4.**

*Outline of a treatment plan for a patient with craniosynostosis [1].*

to be performed earlier or later. For example, patients with syndromic craniosynostosis tend to develop severe midface hypoplasia and suffer from "sleep apnea as a result of retropalatal airway collapse" [1]. In cases such as these, it is imperative that patients undergo premature midface advancement surgery in order to remedy the discomfort associated with sleep apnea along with fixing the patient's facial profile. In conjunction with the midface advancement surgery, orthodontic treatment is also performed in order to ensure that the patient can attain a normal occlusion. Typically, this process involves maxillary expansion to allow for incisors and molars to have space to grow in the mouth. "Depending on the severity of maxillary arch constriction, several rounds of expansion may be required" [1]. This process is outlined by Azoulay et al. in a case where they deal with a patient that has syndromic craniosynostosis as a result of Pfeiffer syndrome.

"It is best to use a 4-banded expansion appliance if adequate anterior (primary first molars or primary canines) and posterior abutments (permanent first molars) are present, and overexpansion (by about 30%) should be achieved to account for expected relapse. The expansion appliance (usually hyrax, W arch, or quad helix) should be in place for at least 3 months and a fixed transpalatal arch with mesial extension arms should be placed at the time of device removal. Hawley appliances (with acrylic covering of the palate) can also be used, but these need to be periodically adjusted as the primary teeth exfoliate and permanent teeth emerge. It is most efficient to correct transverse maxillary deficiency during the mixed dentition phase when the circum-maxillary and palatal sutures are patent. As the patient ages, the palatal suture becomes fused and there is a considerable amount of resistance from the circum-maxillary sutures to maxillary expansion. In such situations, a surgically assisted maxillary expansion may be required" [1].

The procedure described above outlines one of the phases of orthodontic treatment that a patient with craniosynostosis goes through. In addition to this treatment there are other steps that can be divided into presurgical orthodontics, orthognathic surgery, and postsurgical orthodontics. Before undergoing maxillary/mandibular surgery to fully correct the patient's occlusion it is necessary for some pre-surgery setup to be done. The objectives of this stage are to align and level both maxillary and mandibular arches, obtain compatible arch forms, remove dental compensations, and resolve crowding/spacing issues [1]. After the patient has undergone the necessary prerequisite treatments, single jaw or bimaxillary surgery is performed "to correct anterior/posterior, transverse, and vertical maxillary/mandibular discrepancies" [1]. Finally, the patient is left with a normal occlusion that needs minor touchup and detailing which is accomplished in the postsurgery phase of orthodontics.
