INTRODUCTION or gap in the upper lip, maxillary alveolus,

INTRODUCTION

            Orofacial
clefts are a congenital defect affecting the soft and hard tissues in the
mouth, lip and nose area. It is an abnormal space or gap in the upper lip, maxillary alveolus,
and/or palate (Hupp et al., 2014). Clefts of the lip and palate are one of the
most common congenital anomalies to affect the orofacial region (Colbert et al.,
2015). The lip, alveolar ridge, hard palate and soft palate are commonly
affected in oral clefts. Presentation of clefts ranges from a notch in the
upper lip to a wide, complete, bilateral cleft of the lip and palate (Colbert
et al., 2015). Due to the complexity of clefts a large multidisciplinary team
comes together to manage and correct this abnormality starting from patient’s
birth to early adulthood. The team is typically comprised of a general or pediatric
dentist, an orthodontist, prosthodontist, oral-maxillofacial surgeon and plastic
surgeon, audiologist, otorhinolaryngologist, pediatrician, speech pathologist,
nurse, neurologist, anesthetist, psychologist, and social worker (Hupp et al.,
2014; James et al., 2014). The treatment is aimed at addressing deficiencies in
patient’s appearance, speech, hearing, dental and facial development,
deglutition and psychosocial problems (Hupp et al., 2014; Colbert et al., 2015).

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ETIOLOGY AND INCIDENCE

            The
etiology of orofacial clefts is not completely understood (Hupp et al., 2014).
For most cleft conditions, there is not one single factor that causes the
defect. However, when considering etiology, it is important to distinguish
between isolated clefts (patient is healthy) and syndromic clefts (patients has
a syndrome or disorder). Clefts are associated with approximately 300 birth
disorders and syndromes most of which are rare (Hupp et al., 2014). Syndromes present as cleft palate 50% of the time and cleft lip and
palate cases 15% of the time (Hupp et al., 2014).  Non-syndromic clefts are
caused by genetic abnormalities in 20-30% of patient with cleft lip and/or
palate and of these individuals the cause is multi-genetic (Hupp et al., 2014). The major cause of non-syndromic
clefts appears to be a combination of a genetic predisposition and certain
environmental factors that are difficult to identify. Some environmental causes
that have been implicated during embryological development of lip and palate include
maternal health and nutrition, chemical exposures, radiation, numerous drugs,
hypoxia, and viruses (Hupp et al., 2014; James et al., 2014). Orofacial clefts are present in approximately 1 in
700 live births (Hupp
et al., 2014; Tolarova
& Cervenka, 1998). Interestingly, it occurs less frequently in African
Americans (1 in 2000) but is more common in Asians and Native Americans (1 in
500). In addition, orofacial clefts affect boys more often than girls and the
left side more than the right side both in a ratio of 2:1 (James et al., 2014).
Moreover, cleft lip and palate together affects boys twice as often as girls
whereas clefts of the palate alone affect girls slightly more than boys. In addition,
unilateral clefts account for 75% of defect whereas bilateral clefts account
for 25% (Hupp et
al., 2014).

EMBRYOLOGY

            It
is important to understand the normal embryological development of the nose,
lip, and palate to appreciate the malformation of these anatomical structures that
results in an orofacial cleft. When various prominences fail to fuse during
embryogenesis a cleft lip and/or cleft palate results (James et al., 2014). From
weeks five to ten of fetal life these aforementioned structures begin to form (Hupp et al., 2014). During the fifth week, two fast-growing elevations, the
lateral and medial nasal prominences, surround the nasal vestige. Over the next
2 weeks the maxillary prominences continue to grow medially thus compressing
the medial nasal swelling toward the midline resulting in these prominences
merging with each other and with the maxillary prominence laterally (Hupp et
al., 2014). Thus, the upper lip is formed
by the two medial nasal swellings and the two maxillary swellings. The medial
nasal swelling also give rise to the middle portion of the nose, the middle
portion of the upper lip, the middle portion of the maxilla and the entire
primary palate. The lateral nasal prominences form the alae of the nose (Hupp et al., 2014). In
addition, two shelf-like outgrowths from the maxillary swellings form the
secondary palate at the sixth week of development. During the seventh to tenth
weeks, the palatine shelves ascend to a horizontal position above the tongue
and then fuse with each other medially, and anteriorly fuse with primary palate
(Hupp et al., 2014). The incisive foramen is formed at this anterior junction.
The nasal septum above the palate is formed by the frontal prominence. Simultaneously,
the nasal septum grows inferiorly to join the superior surface of the newly
formed palate. Clefts of the primary palate therefore result from failure of the
medial nasal and maxillary prominences to fuse properly (Hupp et al., 2014). Whereas,
clefts of the secondary palate are caused by failure of the palatine shelves to
fuse with one another.

CLASSIFICATION

The most common clinical
classification of cleft lip and/or palate is based on describing the
characteristics of the cleft including terms like unilateral and bilateral as
well as microform, incomplete and complete (James, 2014).

MANAGEMENT/TREATMENT

            Treatment
begins early in life and may continue for several years. Appropriate management
for patients with clefts begins before birth with initial diagnosis (James et
al., 2014). Prenatal care and diagnosis has dramatically improved since the use
of modern three- and four-dimensional ultrasounds as early as 16 weeks (James
et al., 2014). At this point counseling regarding care and treatment of the
infant is discussed with the mother. On another note use of pre-surgical orthopaedic
devices may be used. Use
of pre-surgical orthopaedics is aimed at realignment of the malpositioned
alveolar processes and premaxilla prior to surgery (Jayaram & Huppa, 2012).
The theory is they lead to a more anatomically correct alignment of both the
hard and the attached soft tissues of the cleft, permitting  for a tension-free surgical repair. (Jayaram
& Huppa 2012). However, the use of
pre-surgical orthopaedic appliances is still quite controversial. Cleft lip and palate is managed
surgically so patients can live and function normally by improving aesthetics,
speech, and function. Timing of surgery is a highly debated issue among
surgeons, audiologists, speech pathologists and orthodontists (Hupp et al., 2014; Jayaram & Huppa, 2012). Most
surgeons follow the “rule of 10” to determine when an otherwise healthy baby is
ready for surgery (Hupp
et al., 2014; Jayaram
& Huppa, 2012). A baby is fit for surgery when they are 10 weeks old,
weighs 10 lbs and has at least 10g/dL hemoglobin in blood (Hupp et al., 2014). The palate repair is often referred
to as later or early. There are several advantages for early palatal closure such
as better palatal and pharyngeal muscle development, improvement of feeding,
better speech and phonetic development, better auditory tube function, better
hygiene when mouth and nose are not connected, and improved psychosocial state
for baby and parents (Hupp et al., 2014). Unfortunately, there are also several
disadvantages to closing palatal clefts early. Specifically, it is more
difficult to correct small structures surgically and scar formation causes significant
maxillary growth restriction (Hupp et al., 2014). Thus, a compromise in
surgical timing must be agreed upon. In general cleft lip is corrected as early
as possible around 2-6 months old, soft palate cleft is closed 8-18 months of
age (Hupp et al.,
2014; James et al.,
2014; Jayaram & Huppa, 2012). Hard palate repair timing is the most
controversial because if it is done too early, the incidence of maxillary hypoplasia increases
dramatically. However, if it is done too late, the patient may develop negative
speech articulation habits that are difficult to correct later in life (Jayaram
& Huppa, 2012; James et al., 2014). Thus, the hard palate cleft is repaired as late as
possible to allow the maxilla to grow unimpeded but not hinder speech
development; average age of repair is at 1 year (Hupp et al., 2014; James et al., 2014; Rohrich et al., 2000). In fact, Koberg and Koblin (1973) showed
in their large series of 2,000 patients that early surgery before 1 year did
not cause greater maxillary growth inhibition compared to surgery at other
ages. The main surgical
operations to repair a cleft lip and/or palate include cheilorhinoplasty (cleft
lip repair) and palatoplatsy (cleft palate repair).

Cheilorhinoplasty

            Cheilorhinoplasty
is a surgery to correct the cleft lip and is usually the earliest surgical
intervention. The orbicularis oris musculature is interrupted by the cleft in
the lip (Hupp et
al., 2014). This causes
parts of the maxilla to grow abnormally accentuating the cleft in the alveolus.
Thus, repair of the orbicularis oris has a favourable effect on the developing
alveolar segments (Hupp
et al., 2014). This
surgery aims to restore both function of the orbicularis oris muscle and
aesthetics of the upper lip (Hupp et al., 2014). A symmetric, well-contoured lip with vermillion tubercle, Cupid’s bow
and philtrum and minimal scarring are the main aesthetic goals of the surgery. Since
each cleft is unique the surgical procedures and techniques are adapted to the
individual. There are several techniques used to elongate the cleft margins to
facilitate closure of the cleft. Le mesurier technique is used for incomplete
unilateral cleft, tennision, wynn and millard operations are also used (Hupp et al., 2014). The most significant advancement in cleft lip repair was
made in the 1950s when Ralph Millard, a plastic surgeon, described the
rotational advancement technique where the philtral segment of the non-cleft
side is rotated inferiorly while advancing a quadrangular flap from the cleft
segment medially (James et al., 2014).

Palatoplasty

            Palatoplasty
is the surgical repair of the cleft palate, it can be performed in one or
occasionally two operations. In a two-surgery approach a staphylorrhaphy (soft
palate closure) is performed first and a uranorrhaphy (hard palate closure) is
performed second (Hupp
et al., 2014). The main
objective of this surgery is to create an apparatus efficient in speech and
swallowing without significantly delaying maxillary growth (Hupp et al., 2014). This is mainly achieved by
dividing the nasal and oral cavities and creating a competent velopharyngeal
mechanism. As with cleft lip repair there are several surgical techniques that
can be employed to achieve these goals. Techniques vary depending on the width
and completeness of the cleft, amount of hard and soft tissue available, and
length of palate (Hupp
et al., 2014). In the
Von Langenbeck operation soft tissue is incised along the cleft margin and flaps
are dissected from the palatal shelves until approximation over the cleft is
possible (Hupp et
al., 2014). Lateral
releasing incisions close to the dentition are often required during this
procedure. This is a one-layer closure technique so the superior aspect of the
palatal flaps re-epithelizes with respiratory epithelium because this surface
is lining the nasal floor (Hupp et al., 2014). It is more favourable to use a two-layer closure of the hard palate
cleft when possible (Hupp
et al., 2014). This
allows the nasal mucosa from the floor, lateral wall and septal areas of the
nose to be mobilized and sutured together before oral closure. A vomer flap
technique is used when the vomer is long and attached to the palatal shelf opposite
the cleft. A mucosal flap is raised from the vomer and sutured to the palatal tissue
on the cleft side producing minimal scar contraction (Hupp et al., 2014). Closure of the soft palate is the
most technically difficult operation due to access, visualization, and
retraction difficulties. The soft palate is always closed in three layers in order
of nasal mucosa, muscle then oral mucosa (Hupp et al., 2014). An incision at the margin of the cleft is made from posterior aspect
of the hard palate to at least the end of the uvula. The nasal mucosa is then
dissected from the underlying muscle and sutured to the nasal mucosa of the
opposite side. The musculature is inserted posteriorly and laterally along the margins
of the hard palate allowing the velopharyngeal mechanism to properly function (Hupp et al., 2014). 
If the soft palate is short and articulation with the pharyngeal wall is
impossible then W-Y push-back procedure (Wardill) and U-shaped push-back
procedure (Dorrance and Brown) are used to extend soft tissue element so of the
hard and soft palate lengthen posteriorly resulting in increased palatal length
(Hupp et al., 2014). Following cleft palate repair, the concentration of
treatment is directed to speech and language development (James et al., 2014).
Unfortunately, occasionally patients with cleft lip and palate continue to
present with hypernasal speech. This can be an indication of velopharyngeal
insufficiency and a speech surgery may be indicated at this time (James et al.,
2014). Depending on the results of the speech study, a pharyngeal flap or
sphincter pharyngoplasty may be performed. These procedures are done prior to
the child going to school because hypernasal speech may have negative
psychosocial effects (James et al., 2014).

Alveolar Cleft Grafts

            Maxillary
alveolar cleft defects are typically not corrected during the initial surgeries
to correct the cleft lip and palate.  This
may result in an oronasal fistula in this area (Hupp et al., 2014). There are several advantages to alveolar cleft bone graft. Firstly,
the segments are united and aid in preventing the collapse and constriction of
the dental arch. Secondly, it provides bone support for teeth that will erupt
into the cleft area and teeth adjacent to the cleft (Hupp et al., 2014). Next, the alveolar bone graft
closes the oronasal fistula and prevents substance exchange between the mouth
and nose. Lastly the augmentation of the alveolar ridge facilitates use of
dental prostheses and creates a foundation for the lip and alar base of the
nose (Hupp et al.,
2014). Boyne and Sands
(1972) describe grafting procedures with autogenous bone particulate during the
mixed dentition stage which is currently the standard approach to alveolar
ridge grafting to this day.  Grafting
procedures are usually performed when the patient is 6-10 years old because by
this time a major portion of maxillary growth has occurred (James et al., 2014). On the other hand, the graft
should be placed before the eruption of permanent canines into the cleft to
ensure maximal periodontal support is achieved. Ideally the graft is placed
when one half to two thirds of the unerupted canine root has formed (James et
al., 2014). Mucoperiosteal flaps of nasal, palatal and labial mucosa are raised
on each side of the cleft and cover the bone grafts into the alveolar cleft.
The bone is usually grafted form the patients’ ilium or cranium however some
surgeons use allogenic bone and bone morphogenic proteins (Hupp et al., 2014). Once the nasal and palatal mucosa
has been closed the graft particulate is packed into the defect and then
covered with the labial mucosa. Eventually the bone graft is replaced by new
bone that is indistinguishable from surrounding alveolar process (Hupp et al., 2014). Teeth are able to erupt into the
graft site as well as orthodontic movement of teeth is possible and implants
may also be placed.

Orthodontics

            During
the mixed dentition stage, the child is closely monitored by the orthodontist
for proper maxillary growth and tooth eruption. Phase I orthodontics may be suitable before alveolar
grafting (James et al. 2014). This phase may occur anywhere from 6 to 10 years
of age. The purpose of phase I orthodontics is to expand the maxilla in the
transverse dimension and occasionally encourage anteroposterior growth with reverse-pull
headgear (James et al., 2014). Once skeletal maturity is reached, the cleft
patient is again seen by the orthodontist to begin stage II orthodontics. The
goals of stage II orthodontics is to level and align the arches for appropriate
surgical setup (James et al., 2014). In many cases, orthognathic surgery marks
the end of a long surgical treatment regimen for patients with cleft lip and
palate. However, once skeletal position and supports have been finalized with
orthognathic surgery and alveolar grafting is complete, final rhinoplasty and
lip revisions may be appropriate (James et al., 2014).

CONCLUSION

            In conclusion, the management and
treatment of cleft lip and palate patients is a long journey that requires multiple
surgeries and requires the collaboration among various professionals to ensure
the success of these patients.