Cleft lip and palate and their management

1. Introduction

Cleft lip and palate is an early embryopathy that variably affects the upper lip, dental arch, palate and soft palate.

This is the most common congenital facial anomaly. It results in an interruption of the bone and muscle structures, and thus determines a dynamic imbalance within the facial structure. The dental surgeon in general, and the orthodontist in particular, must be familiar with the anatomical, clinical and syndromic subtleties

prerequisites for establishing a treatment plan.

Embryological reminder
1. Formation of the stomodeum

The face is built from facial buds which delimit between them an orifice called the stomodeum or

“primitive mouth”.

There are five of them at the beginning of the 4th ^week of UI , initially separated by furrows, which gradually fill in. All facial buds are made up of tissue of mesodermal origin covered with epiblastic tissue . They will first increase in volume individually, meeting each other, then will fuse by mesodermization or “cell death”.

2.2 Formation of the upper lip and primary palate

-At the end of the 4th week ^, two epiblastic thickenings called olfactory or nasal placodes appear on the frontal bud, which will later delimit the internal and external nasal buds around the 5th-6th ^week .

-During the 6-7th ^week , the two maxillary buds grow in a medial direction, which causes the fusion on the midline of the two internal nasal buds, resulting in the formation of the “intermaxillary segment”.

The ectodermal contact between these different buds constitutes the “Hochstetter epithelial wall”.

The disappearance of the latter, during the 6th ^week , allows the constitution of a continuous mesenchymal cell mass originating from the neural crest called “primary palate”.

2.3- Formation of the secondary palate

Behind the incisive foramen, the palate forms between ^the 8th and 12th week ^.

secondary, from outgrowths of the maxillary buds called palatine processes.

They are temporarily oblique and run under the tongue. They will then become horizontal to lie above the tongue, and normally fuse by mesodermization between them from front to back, at the level of the median palatine raphe.

At the same time, a process of vertical partitioning occurs, by a mesenchymal layer originating from the internal nasal buds, this is the embryonic nasal septum , which descends sagittally and vertically from the lower surface of the frontal bud and separates the two nasal fossae.

This merger requires:

Sufficient volumetric development of the buds.
The ability of the ectoderm to ensure cell adhesion or “gluing”, then to evolve by apoptosis under the pressure of the underlying mesoderm.
Physicochemical properties of amniotic fluid favorable to ectodermal contact.

Embryopathogenesis of cleft lip and palate

The clefts result from an abnormality in the fusion of the buds between the ^5th^and 12th week in utero .

From the 12th week , ^the labio-naso-maxillary region has an appearance very close to that observed at birth, whether there is an anomaly or not.

If the cleft is present at 12 weeks, it will be present at birth, if there is no cleft at 12 weeks, there will be no cleft at birth.

Prenatal diagnosis :

Diagnoses could be made as early as the 12th ^week by transvaginal ultrasound.

However, most often the diagnosis is made during morphological ultrasound between the 20th ^and 24th ^week of pregnancy.

Incidence :

It is the most common congenital anomaly of the facial mass, with a prevalence showing some racial and geographic variations.

-The highest incidence is in Japanese populations (1/500 to 250).

-Lowest in black populations (1/3333).

-In the European population, it varies between 1/1500 and 1/700.

– In Arab countries, it is 0.3 to 2.4 / 1000.

Etiologies

It is considered that 70% of cleft lips or cleft palates are isolated anomalies known as

“non-syndromic”.

The remaining 30% are part of about 300 different malformation syndromes in which the cleft is one anomaly observed among others (Crouzon syndrome, Apert syndrome, Pierre Robin syndrome, Trisomy 13, Trisomy 18, etc.)

Genetic factors.
Indeed, environmental factors, such as exposure to teratogenic products during pregnancy (alcohol, tobacco or medications), can modulate genetic susceptibility.
Folic acid deficiency during pregnancy.
Infectious agents (rubella, toxoplasmosis, influenza, measles).
Chemical agents (cortisone, anticancer drugs, anti-epileptic drugs.)
Physical agents (hyperthermia, hypoxia, ionizing radiation).
In vitro fertilization.
Not forgetting metabolic factors: stress, emotional shock, maternal age.

Others: Insulin-dependent diabetes (MALEK), Maternal epilepsy.

Classification : The labiomaxillary divisions present a stable topography and a clinical polymorphism which are the subject of variable classifications (Kernahan and Stark classification – Benoist classification – Chancholle classification, etc.)

* VEAU classification : It schematizes the anatomical disorders caused by facial clefts, without taking into account purely labio-alveolar clefts.

Four classes are described.

Simple division of the veil.
Division of the veil and the palatine vault.
Division of the soft palate and palatine vault associated with a unilateral cleft lip and alveolar cleft.
Division of the soft palate and the palatine vault associated with a total bilateral cleft lip and alveolar cleft.
Clinical Forms
1. Simple cleft lip

It only affects the lip, without alveolar abnormality. It can be unilateral or bilateral.

The cleft follows the path of the upper lip reliefs, which are residual markers of normal embryology and nasolabial development.

Cleft lip and nostril

The absence of normal insertion of the nasolabial and orbicularis muscles.

A deviation of the anterior part of the nasal septum and the columella on the healthy side; A deformation of the nostril wing.

8.3- Unilateral cleft lip and alveolar cleft

Consequence of a defect in the fusion of the internal and maxillary nasal bud.

A more or less marked sagittal orientation of the premaxilla under the effect

contralateral muscle traction, with underdevelopment of the muscle on the split side

8.4- Cleft palate : Results from an anomaly in the fusion of the palatine processes

*Complete or total form (veil and palatine vault):

It combines a complete division of the veil and a bony cleft extending to the immediate vicinity of the palatine papilla.

*Simple or velar form:

Ranges from simple bifidity of the uvula to the separation of all the muscular elements of the veil.

8.5 – Complete unilateral lunge :

It combines, more or less completely, the two forms described previously.

This results in a tissue deficit of varying intensity and extent, as well as a solution of continuity, responsible for a breakdown of balance, both at the level of the soft, cutaneous, muscular and mucous membranes, as well as at the level of the deep, osteo-cartilaginous and dental structures.

8.6 – Complete bilateral lunge :

The bilateral cleft, when complete, involves the upper lip (interrupting the muscle strap), the gum, the alveolar bone and the anterior part of the bony palate on both sides, then becoming median up to the soft palate.

Consequences

9.1 – Muscular consequences

Abnormal position of the tongue

At rest, its base is set back, between the stumps of the soft palate, and its tip rises into the cleft of the vault. These anomalies become more pronounced during swallowing and lead to bone deformities.
The introduction of the tip of the tongue into the fissure causes the partial verticalization of the palatine blades and opposes the growth of their internal edge, making subsequent closure of the vault impossible without traction.

9.2 – Functional consequences Eating disorders:

Breastfeeding is only possible in cases of cleft lip. In other cases, the lack of a mouth seal prevents milk from being expelled.
The presence of a communication between the oral cavity and the nasal cavities induces the presence of milk in the latter during food intake. A simple cleaning with physiological serum after each meal will prevent any superinfection.

Swallowing disorders – It is disturbed because only the tongue and pharynx are involved.

Speech disorders :

-The presence of a cleft causes air to pass directly into the nasal cavities, making it more difficult to produce intelligible sounds. This is called “rhinolalia”.

Hearing disorders

The presence of a cleft palate can cause, by deformation of the Eustachian tube, poor drainage of the middle ear, which will therefore lead to the accumulation of fluid causing local inflammation (serous otitis) and at worst a real local infection with potentially serious consequences on hearing function.

Breathing disorders

9.3- Maxillary growth disorders

An impact on the growth of the upper jaw may occur. This will most frequently manifest itself as a lack of transverse and also sagittal growth.

9.4 – Dental anomalies

– Shape anomalies (rhizoid lateral incisors, dysplasias).

-Ectopia teeth, canines and lateral incisors on the cleft side are often included.

-Supernumerary lateral incisor, or often agenesis on the side of the cleft.

-The eruption chronology is disturbed.

9.5 Psychological consequences:

The arrival of a child with a cleft in a family is often felt to be a disaster.

Most parents manage to overcome the difficulties, but the child will have to face the gaze of others.

Treatment of cleft lip and palate

The rehabilitation treatment of facial clefts can only be carried out within a homogeneous team (orthodontist, surgeon, speech therapist, ENT specialist).

– The orthodontist plays a key role in this team. He or she is the one who fits the first appliance during the first month.

– The surgeon has a spectacular role, the quality of the aesthetic and functional result depends on his skill.

– The speech therapist intervenes from the age of 3 months for parental guidance. The actual rehabilitation will begin at the age of 18 months with breathing exercises and joint assembly.

-The ENT monitors hearing and the condition of the cavum from the first months and particularly before and after the interventions.

10.1 – Pre-operative care

Pre-surgical orthopedic time

It consists of the placement of palatal plates , the role of which is:

-To close the slit, thus allowing feeding by separating the respiratory tract from the digestive tract,

– Obtain a realignment of the tongue; lowering and advancing its tip, it no longer insinuates itself into the cleft,

-This allows a redistribution of the thrusts exerted and a lowering of the palatal blades allowing a straightening of their growth .

-They are made from birth and worn continuously until the palate closes.

-They will be changed every 6 weeks to support growth .

Nasal orthopedics

Since this cartilage only acquires its definitive structure a few weeks after birth, it seems logical, as for several authors, to consider the conformity of the wing of the nose before the cartilages of the tips have matured.

An ambitious primary rhinoplasty which, thanks to nasal conformation for 4 months, gives high-performance and very consistent functional and aesthetic results.

Labial adhesion (minor cheiloplasty).
Primary cleft surgery : The operative schedule varies greatly depending on the author:

Too early operations deform the jaws which are poorly ossified before the age of 6 months.
Neonatal anesthesiology studies recommend operating only for vital reasons during the first 3 months .

-Restore the essential functions of oral speech, such as nasal ventilation, labial and velopharyngeal skills, and stimulate them through rehabilitation; Guide the occlusal relationship through ongoing orthodontic monitoring.

* Primary cleft palate surgery

In partial or narrow forms, closure is performed in a single operation between 3 and 18 months depending on the authors. The existence of an associated cleft lip often leads to closure of the entire cleft around the age of 6 months.

* Velopharyngeal closure : Its aim is to reconstruct the muscular structure of the veil.

* Cheiloplasty : the main aim is to reconstruct a functional labial muscular plane and to obtain a symmetrical lip with a well-defined cutaneous-mucosal line.

*Gingivoplasties / Gingivoperioplasties: Restoring bone and gingival continuity in labiomaxillary or labiomaxillopalatine clefts should be a major concern of the surgeon.

Bone grafting at this stage is questionable due to the difficulty in finding a donor site free from morbidity.

*Primary rhinoplasty : priority must be given to the nose thanks to nostril conformation for 4 months, giving high-performance and very consistent functional and aesthetic results.

Orthodontic treatment :

Orthodontic treatment for children with FLP is carried out in the temporary dentition, mixed dentition and permanent dentition.

The difficulties encountered during the treatment of cleft lip, maxillo-palate are varied;

-Realization of asymmetric expansion

-The problem posed by the agenesis of the lateral incisor on the side of the cleft,

-Correction of brachygnathia

-And finally, the decision for additional surgery.

In temporary dentition:

Cross direction :

-Treat endoalveolitis, or endognathia with a Quad’hélix or Disjoncteur on a gutter.

-Supernumerary teeth must be kept because they provide bone volume .

Sagittal direction: -Treat skeletal Class III, anterior crossbites with the Delaire mask.

In mixed dentition

The quad helix is placed just before the operation and left in support for a period of 3 to 6 months.

-Correction of maxillary incisor malpositions, using a removable appliance or a multi-attachment device, often makes it possible to re-establish an anterior lock, necessary to hope for harmonious maxillomandibular growth.

-For maxillary growth deficit = posterior-anterior orthopedic traction.

In permanent dentition

-After correction of the transverse dimension, the multi-attachment treatment allows the alignment and placement of the canines on the arch.

-In the absence of the lateral incisor, maintenance of the space of the lateral incisor with a prosthetic restoration .

Treatment of the after-effects of cleft lip and palate

-Subject in growth period Maxillary osteotomy will only occur at the end of growth followed by nasal surgery.

-Adult subject Orthodontic preparation must be immediately put in place so that the osteotomy can be done as soon as possible. During this ODF preparation, cheiloplasty and gingivoplasty will be performed.

– Pharyngoplasty will be postponed, if necessary, one year after the maxillary osteotomy and will be followed by rhinoplasty which can possibly be done simultaneously.

11. Conclusion

Knowledge of embryopathogenesis, the different classifications, clinical forms, as well as the different stages of cleft treatment, remains essential for any orthodontist able to treat a patient with a cleft lip and palate.

The latter is an important player in the multidisciplinary team, within which coordination and communication skills are essential.