Cleft Lip And Palate: Online Exam! Quiz

Explanation
Most isolated cleft lip/palate deformities follow a multifactorial model of genetic transmission (some do transmit in an autosomal dominant or autosomal recessive fashion). Therefore, the risk that this patient will have a child with a cleft is only slightly higher than the general population. Families with Van der Woude syndrome, for example, are known to have an autosomal-dominant clefting mutation. If this were the case, this patient would then have a 50% chance of transmitting the cleft locus to a child. Similar Mendelian genetic models would apply to other scenarios.

Explanation
Within the normal soft palate (velum), the levator veli palatini muscle forms a dynamic sling that elevates the velum toward the posterior pharyngeal wall during the production of certain sounds. In children born with cleft palate, there is a division of the musculature of the velum into separate muscle bellies with abnormal insertions along the posterior edge of the hard palate. The goals of cleft palate repair during infancy are twofold. The first goal is to establish a complete, watertight closure of the secondary palate for separation of the oral and nasal cavities. The second goal is to reorient and repair the levator musculature to allow for normal speech formation. The muscularis uvulae is also repaired in cleft palate repair. However, this muscle is typically not reoriented. Instead, it is simply approximated in the midline.

Explanation
Errors occurring during the main embryonic period are responsible for major craniofacial anomalies. Cleft palate, which results from a failure of the palatine shelves to fuse, occurs primarily during weeks 7 to 8. Errors during weeks 1 to 2 result in death of the embryo. Clefting of the lip occurs during weeks 5 to 6. Ear and eye abnormalities occur during weeks 10 to 12.

Explanation
The A flap is marked on the medial lip element and is the rotation flap. This flap is designed as a gentle curve from the height of Cupid’s bow on the cleft side of the medial cleft element to the junction of the philtrum and columella. This incision approaches the normal philtral collum as much as needed to derotate and level Cupid’s bow. If more rotation is needed to level Cupid’s bow, a back cut is made, but the normal philtral collum is not violated. This incision is used in philtral subunit reconstruction and leveling Cupid’s bow.

Explanation
The B flap is made on the non-cleft, lateral lip element and is the advancement flap. This flap is the “wedge” that is placed in the defect created above the rotation flap as the medial lip element is derotated to level Cupid’s bow. This flap is marked by first finding the point on the white roll that will correspond to the height of Cupid’s bow on the medial cleft element. This point is found where the fullness of the lateral lip element begins to fade. A line is drawn from this point cephalad and is the same length as the normal philtral collum as well as the marked edge of the A (rotation) flap.

The C flap or columellar flap is made from the tissue medial to the A flap incision. This small flap is rotated into the columella, lengthening the cleft side of the columella. It is also sewn to the D flap (alar base flap).

The D flap or alar base flap is cut along the alar facial groove, and this incision corresponds to the cephalad portion of the edge of the B flap (advancement flap). This alar groove incision is made as small as possible and long enough to allow differential rotation of the D flap and the B flap.

The L flap is the leading edge of the lateral lip that can be used to fill the nasal lining defect. The M flap is the medially based flap from the rotation.

Explanation
By definition, a submucus cleft palate involves the anomalous insertion of the levator palatini muscles onto the posterior aspect of the hard palate. In normal anatomy, these muscles would be oriented in a transverse fashion, decussating in the midline. Nevertheless, not all children with submucous cleft will develop speech difficulty or velopharyngeal incompetence.

The tensor palatini muscles and posterior tonsillar pillars (the palatopharyngeal muscles) are in relatively normal location in children with submucous cleft. Their function is impacted by the incorrectly positioned levator. Children with a submucus cleft have normal palate length.

Explanation
The developing fetus has five facial prominences that are populated by neural crest cells: frontonasal, paired maxillary, and paired mandibular. The frontonasal prominence gives rise to the nasal pit or placode, around which develops the medial and lateral nasal processes. A failure of fusion between the maxillary prominence and the medial nasal process results in a common cleft of the lip.

Explanation
Velopharyngeal competence results from sufficient apposition of the velar mucosa against the posterior pharyngeal wall and from motion of the lateral pharyngeal wall that causes sphincteric closure of the velopharyngeal port. Many patients with velopharyngeal insufficiency after cleft palate repair have a shortened, scarred velum, resulting in a deficiency in the anterior-posterior coronal closure pattern. Other patients, such as those with velocardiofacial syndrome, have generalized pharyngeal dysfunction with poor lateral pharyngeal wall motion, which contributes to a large central gap that leads to velopharyngeal incompetence.

To correct velopharyngeal insufficiency in this patient, a sphincter pharyngoplasty is most appropriate. In this procedure, the posterior tonsillar pillars (palatopharyngeus muscles) are bilaterally dissected from the tonsillar fossae and rotated 90 degrees medially. Then they are affixed in an overlapping fashion against the posterior pharyngeal wall. Because the palatopharyngeus muscles are a continuation of the soft palate and lateral pharyngeal walls, this procedure narrows the entire pharyngeal port in a sphincteric fashion and augments the posterior pharyngeal wall.

In a patient with little or no motion of the lateral pharyngeal wall, augmentation of the posterior pharynx is not appropriate. Although it may decrease the anterior-posterior coronal deficiency, it does nothing to treat the poor lateral wall motion. In addition, augmentation of the posterior pharynx has been attempted with multiple materials (including fat, Teflon, and silicone) in the past, without success. Today, the procedure has all but been abandoned.

Likewise, a posterior pharyngeal flap (whether inferiorly based or superiorly based) is not appropriate because it may not completely correct the hypernasality associated with velopharyngeal insufficiency. This is true because it does not allow the lateral pharyngeal walls to move medially and seal off the lateral ports between the pharyngeal flap and lateral pharyngeal walls.

V-Y pushback palatoplasty would not adequately correct the problem.

Explanation
The risk of cleft lip +/- palate in a child with a sibling who has

bilateral cleft lip and palate = ~ 4%
no cleft palate and/or unilateral = lower
bilateral cleft lip WITHOUT cleft palate = 6.7%
unilateral cleft lip & palate = 4.9%
unilateral cleft lip WITHOUT cleft palate = 4.0%

If two affected children with cleft lip +/- palate, risk for the third child is > 9%.

The overall incidence of cleft lip +/- palate

in Caucasians = 1:1000
in a first-degree relative = 40:1000
in a second-degree relative = 7:1000
in a third-degree relative = 3:1000

However, the risk is increased when

more than one relative is affected
if family member has severe form
if family member is of gender least likely to be affected
if parents are consanguineous

If one parent is affected, the risk of having one child with cleft lip +/- palate is 4%, and the risk for a second child increases to 17%.

Explanation
The zona pellucida is formed by parallel bulges of anterior-posterior muscle on either side of the soft palate in the midline. Between these paired and cleft levator veli palatini muscles is a bluish two-layered mucosal bridge, which is the submucous cleft palate. With abnormal morphology, the levator veli palatini muscles insert into the posterior edge of the hard palate, causing Veau’s cleft muscle as is seen in the typical cleft palate. The levator veli palatini muscles originate from the petrous portion of the temporal bone and the medial surface of the auditory tube and insert in the middle soft palate. Inferiorly, they form a V-shaped sling that suspends the velum from the base of the cranium and pull the soft palate up and back.

The other muscles listed are unrelated to submucous cleft palate. The muscularis uvulae runs longitudinally along the medial palate from the tensor aponeurosis to the uvula. During speech, it functions as a flexible beam, lifting and bending the palate back and modifying the stiffness of the palate.

The palatopharyngeus muscle originates from the palatal aponeurosis and runs to the posterior pharyngeal pillar. It functions to depress the palate and displace it backward. It is used to perform the sphincter pharyngoplasty.

The superior pharyngeal constrictor muscle is a continuation of the posterior buccinator and tongue. This muscle curves back and up, ending in a tendinous median raphe attached to the occipital bone. It serves to pull the lateral and posterior pharyngeal walls medially, narrowing the pharynx. In patients with velopharyngeal insufficiency, a horizontal bend in this muscle elevates the mucosa to form ridge at the junction of the nasopharynx and oropharynx. In patients with cleft palate, this hypertrophied area is called Passavant ridge.

The tensor veli palatini muscle originates from the scaphoid fossa, medial pterygoid plate, and spine of the sphenoid. It courses inferiorly around the hamulus to form the palatal aponeurosis. It acts to tighten the palate so the tongue has a firm surface against which to create a bolus of food. It is primarily involved in swallowing, rather than in speaking.

Explanation
In the 7-week-old embryo, the two palatal shelves lie vertically. Starting with the eighth week, the neck straightens from its flexed position, the tongue drops posteriorly, and the shelves rotate superiorly to a horizontal position as they fuse from an anterior to posterior direction.

Explanation
One of the characteristic findings in the unilateral cleft deformity is a shortened columella. The C flap is designed to lengthen the columella. Other findings in the unilateral cleft nose include deviation and distortion of the septum (corrected with presurgical orthodontics), dislocation and slumping of the alar cartilage (corrected by dissecting the medial part of the cartilage and constructing a medial crus by suturing to the normal side), and flaring of the alar base (corrected with the alar cinch procedure).

Explanation
The levator veli palatini originates from the petrous portion of the temporal bone and the eustachian tube. It travels alongside the eustachian tube to enter the soft palate. This muscle elevates the velum toward the posterior pharyngeal wall to close the velopharyngeal mechanism and pull the eustachian tube open.

The palatoglossus muscle arises from the lateral margin of the tongue. It travels in the anterior tonsillar pillar to enter into the soft palate and functions to pull the soft palate downward.

The posterior tonsillar pillar is created by the palatopharyngeus. The palatopharyngeus muscle arises from fibers that commingle with the superior pharyngeal constrictor. It enters the soft palate, where its fibers intermingle with those of the levator. The palatopharyngeus functions to depress the soft palate and provide inward motion of the lateral pharyngeal wall. In a sphincter pharyngoplasty, superiorly based flaps are elevated from the posterior tonsillar pillar, sutured together, and inset into the posterior pharyngeal wall. These flaps contain the palatopharyngeus muscle.

The superior pharyngeal constrictor originates from the posterior pharyngeal raphe and courses downward and forward to insert into the medial pterygoid plate, the pterygomandibular raphe, and the posterior part of the hyoid. The stylopharyngeal muscle arises from the styloid process. It inserts between the fibers of the superior and middle pharyngeal muscles in the pharyngeal wall. These muscles play a role in swallowing.

Explanation
Isolated cleft palate has an incidence of 1:2000 without ethnic preference and has a higher incidence of associated anomalies than cleft lip and palate (CL/P). Approximately half of the cases of cleft palate with associated anomalies will fall into established syndromes. Patients with CL/P are more common than those with cleft palate alone; the incidence is 1 in 1000 Caucasians, 1 in 2000 African-Americans, and 1 in 500 Asians. Associated anomalies in children with CL/P is approximately 10% to 15%. The type of associated anomalies would include musculoskeletal, cardiac, and neurological.

Both cleft lip and cleft palate are controlled by multifactorial inheritance. Therefore, there is no distinctive pattern of inheritance within a single family. The risk to first-degree relatives can be estimated as the square root of the population risk. The risk is much lower for a second-degree relative. Higher chance of occurrence is also seen with greater degree of severity in the affected relative. The risk for development in a sibling of an affected child increases if more than one family member has the condition.

Explanation
Because cleft palate does not disrupt the palatopharyngeus muscles, they do not need to be repaired. Cleft palate repair aims to eliminate the oronasal fistula and optimize the function of the soft palate. The fistula is closed by creating a lining for the nasal and oral sides of the fistula. The abnormal attachments of the levator veli palatini and tensor veli palatini muscles to the hard palate are released, and the muscles are repaired in the midline, giving them a more functional transverse orientation. Finally, the musculus uvulae is repaired in the midline. This muscle provides bulk on the upper surface of the soft palate during velopharyngeal closure. Although the palatopharyngeus muscles are involved in velopharyngeal closure, they are not disrupted by cleft palate.

Explanation
The most appropriate management is reconstruction with an Abbe flap. This lip-switch flap has been designed specifically to create a functional philtrum in patients who have tightness of the upper lip following cleft lip repair. After the abnormal philtrum is excised, redundant tissue is harvested from the lower lip to replace the resultant defect as an aesthetic subunit. The Abbe flap is pedicled on the submucosal labial artery of the lower lip at the superior edge of the inner free border of the lip. The pedicle is subsequently divided during a delayed second procedure, which is performed a minimum of 10 days to four weeks after flap transfer. In adults, the reconstructed philtrum should be no wider than 10 mm and no longer than 15 mm; however some surgeons advocate using a smaller flap that has a width of 7 to 9 mm at the cupid’s bow and 4 to 5 mm at the labial-columellar junction. Banked fork flaps were used previously for bilateral lip reconstruction. At the time of primary lip repair, extra tissue on either side of the new philtrum from the prolabium was “banked” within the creases of the alar base to be used as forked flaps for columellar reconstruction at a later date. However, it was subsequently determined that the columella in fact lies within the nasal region and that primary nasoplasty should be performed instead at the time of lip repair to create the columella. In addition to primary nasoplasty, adequate preoperative nasoalveolar molding has been determined to be more appropriate, and banked fork flaps are no longer used. The Gilles fan and Karapandzic flaps are oral circumference advancement flaps that were originally designed for lower lip reconstruction, but are also used for upper lip defects. These flaps rotate around the commissure and narrow the oral aperture. They are not designed for the reconstruction of the philtrum as an aesthetic subunit. The nasolabial flap is a transposition flap that is derived from the nasolabial crease. It is most often used for reconstruction of the nasal alar subunit and has limited indications for lip reconstruction. It is not typically used for aesthetic subunit reconstruction of the philtrum.

Explanation
In this child who is scheduled to undergo sphincter pharyngoplasty, the palatopharyngeus muscle is incorporated within the flap. Two techniques are used primarily for reconstruction of the pharynx in patients with velopharyngeal insufficiency. The sphincter pharyngoplasty elevates and insets the posterior tonsillar pillars, which contain the palatopharyngeus muscles, into the posterior pharyngeal wall to create a sphincter. In contrast, during pharyngeal flap reconstruction, a flap of tissue from the posterior pharyngeal wall is elevated and attached to the palate. This procedure is typically reserved for correction of deficits of the central palate.

The levator veli palatini muscle, which is found in the midline of the soft palate, is used only for pharyngeal flap reconstruction, not for sphincter pharyngoplasty. The buccinator muscle lies anterior to the pterygomandibular raphe, the palatoglossus muscles are contained within the anterior tonsillar pillars, and the tensor veli palatini is located anterior to the levator veli palatini. None of these muscles are used in sphincter pharyngoplasty.

Explanation
The tensor veli palatini muscle descends from the base of the skull at a point adjacent to the eustachian tube, courses around the hamulus of the pterygoid, and then forms a broad aponeurosis with the contralateral muscle within the anterior soft palate.

The levator veli palatini passes posterior to the pterygoid hamulus and creates a muscular sling that is critical to palatal function. The palatoglossus and palatopharyngeus muscles are components of the palate but do not pass around the hamulus. The musculus uvula is confined within the soft palate and acts to alter the shape of the uvula.

Explanation
In patients who have nasal deformities associated with complete unilateral cleft lip, the ala is displaced laterally, inferiorly, and posteriorly. The orbicularis oris inserts onto the alar base abnormally, on the lateral cleft side, and pulls the ala laterally and inferiorly. The medial orbicularis inserts on the nasal spine and caudal septum and pulls these structures to the contralateral side. The piriform rim, which normally supports the ala, is also deficient, allowing the ala to be displaced posteriorly on the side of the cleft.

Explanation
A child with an unrepaired alveolar cleft will exhibit collapse of the maxillary arch. The arch is deficient in all dimensions: anteroposterior, transverse, and vertical. Therefore, this child will have posterior crossbite of the maxillary dentition with respect to the mandibular dentition. In patients with a crossbite, the lower dentition is positioned labial to the upper dentition; this is the opposite of normal occlusion. The arch form should be corrected orthodontically and dental compensation should be eliminated prior to bone grafting of the alveolar cleft. The Angle classification of occlusion is based on the relationship of the mesiobuccal cusp of the maxillary first molar to the buccal groove of the mandibular first molar. In patients with class I (normal) occlusion, the mesiobuccal cusp of the maxillary first molar lies in the buccal groove of the mandibular first molar. Angle class II malocclusion is defined as the mesiobuccal cusp of the maxillary first molar located mesial (anterior) to the buccal groove of the mandibular first molar. This classification of malocclusion has two divisions; in class II, division 1, the lateral incisors are flared labially, and in class II, division 2, the incisors are lingually inclined. In Angle class III malocclusion, the mesiobuccal cusp of the maxillary first molar lies distal (posterior) to the buccal groove of the mandibular first molar and is located instead in the buccal groove of the mandibular second molar. Overbite describes the distance between the maxillary and mandibular incisors in the vertical plane with the jaws in centric occlusion, and overjet describes the distance between the maxillary and mandibular incisors in the horizontal plane with the jaws in centric occlusion.

Explanation
The nasal structures form during the sixth week of gestation as the medial nasal processes enlarge and coalesce in the midline. Any abnormalities that occur during the formation of the nasal structures may result in deformity, such as cleft nasal deformity. The nasal alae arise from the lateral nasal processes. The medial nasal processes give rise to the columella, nasal tip, philtrum, and premaxilla. The bridge and root of the nose arising from the frontonasal processes.

Explanation
This neonate has the triad of symptoms associated with Pierre Robin sequence: retrogenia, glossoptosis, and respiratory distress. Approximately 50% of neonates with Pierre Robin sequence have a high-arched cleft in the midline of the soft palate; clefting of the hard palate also occurs in some patients. Glossoptosis is associated with airway obstruction, increased expenditure of energy, and impaired feeding resulting from decreased caloric intake. These feeding difficulties and failure to thrive can be fatal if not managed properly. The most appropriate initial management of airway obstruction is to place the neonate in the prone position, which relieves the glossoptosis and opens the airway. In some infants, this position must be maintained constantly, even during feeding, bathing, and diaper changing. Intubation may be necessary if prone positioning does not resolve the respiratory distress. Lip-tongue adhesion, tracheostomy, and mandibular distraction osteogenesis are secondary procedures that should only be considered if prone positioning is unsuccessful.

Explanation
During embryologic development, the nasal structures form during the sixth week of gestation as the frontonasal and medial nasal processes enlarge and coalesce in the midline. Any abnormalities occurring during this gestational stage are likely to lead to the development of a cleft nasal deformity or other nasal deformities.