Congenital malformations of the maxillofacial area in children. Statistics, etiology, pathogenesis, classification, clinical picture. Modern principles

Congenital malformations of the maxillofacial area in children. Statistics, etiology, pathogenesis, classification, clinical picture. Modern principles of treatment and rehabilitation of such children.

OVERVIEW I. OROFACIAL CLEFTS: - Cleft Lip & Cleft palate II. ANOMALIES OF TONGUE: - Microglossia & Macroglossia - Ankyloglossia - Hairy tongue - Fissured tongue - Lingual thyroid III. ANOMALIES OF ORAL MUCOSA: - Fordyce granules - Leukoedema

OROFACIAL CLEFTS

Development of face and oral cavity involves the development of various facial processes that fuse with each other. Any disturbance in growth of these processes can result in formation of orofacial clefts. Thus it is essential that facial development be reviewed in brief.

Central face begins to develop by 4 th week, when olfactory placodes appear on both side of frontonasal process. Gradually both placodes develop to form medial and lateral nasal processes. Upper lip is formed by 6 th week by fusion of two medial nasal processes in midline and the maxillary process of the 1 st branchial arch.

Primary palate also forms by fusion of medial nasal processes to form the premaxilla which includes the four incisor teeth.

Secondary palate is formed from the maxillary processes of the 1 st branchial arch. By the 6 th week bilateral projections emerge from medial aspect of maxillary processes to form palatal shelves.

Initially these shelves are vertically oriented on either side of developing tongue. As mandible grows, tongue drops down allowing palatal shelves to rotate horizontally and fuse in midline by 8 th week. Palatal shelves also fuse with the primary palate anteriorly and nasal septum superiorly.

Defective fusion of medial nasal process with the maxillary process leads to cleft lip (CL).

Similarly, failure of fusion of palatal shelves leads to cleft palate (CP).

Frequently, CL & CP occur together. Approximately 45% cases are CL + CP, while 30% are isolated CL and 25% isolated CP.

Both, isolated CL and CL associated with CP (CL+ CP) are thought to be etiologically related conditions and are considered as a group. Isolated CP appears to represent a separate entity.

Other rare facial clefts like lateral facial cleft occurs as a result of failure of fusion of maxillary and mandibular processes leading to a cleft from corner of mouth toward ear. Oblique facial cleft extends from upper lip towards the eye and is almost always associated with CP. Caused by failure of fusion between maxillary process with lateral nasal process. Midline cleft of upper lip is extremely rare and represents failure of fusion of medial nasal processes in the midline.

ETIOLOGY Cause is still being debated. Important to distinguish between isolated clefts and clefts associated with developmental syndromes. More than 250 syndromes are associated with orofacial clefts and account for 3% - 8% of orofacial clefts, e.g. Pierre Robin syndrome, Treacher-Collins syndrome etc. Environmental factors like alcohol consumption, viruses etc also may combine with developmental factors.

CLINICAL FEATURES RACIAL PREVALENCE: - Clefting is one of the most common congenital defects in humans. Prevalence varies between races, with whites having prevalence of 1 in 1000 births, while it is 1.5 times higher in Asians and least amongst blacks (0.4 in 1000 births). Isolated CP is less common than CL + / - CP.

SEX PREDILECTION: - CL + / - CP is more common in males. More severe the defect, greater is the male predilection. Male to female ratio for isolated CL is 1.5 : 1. M:F ratio for CL+CP is 2 : 1. In contrast, isolated CP is commoner in females with the M:F ratio being 1 : 2.

SIGNS & SYMPTOMS: - About 80% cases of CL are unilateral, with 70% of unilateral cases occurring on left side. A complete CL extends till the nose A CP shows considerable variation in severity, with the defect involving both hard and soft palate or soft palate alone.

The minimal manifestation of CP is a BIFID / CLEFT UVULA.

Cleft patients suffer from many direct as well as well as indirect problems. The most obvious problem is clinical appearance leading to psychosocial problems. Feeding and speech difficulties are common especially with CP. CP also causes collapsing of maxillary arch, missing of teeth, supernumerary teeth, leading to malocclusion.

TREATMENT & PROGNOSIS Treatment is multidisciplinary, involving Pediatrician, Otolaryngologist, Oral & maxillofacial surgeon, Pedodontist, Plastic surgeon, speech therapist and genetic counselor. Surgical repair involves multiple primary and secondary procedures throughout childhood, depending on severity of defect and philosophy of the team.

DEVELOPMENTAL ANOMALIES OF TONGUE

OVERVIEW OF TONGUE DEVELOPMENT The medial most parts of the mandibular arches proliferate to form two LINGUAL SWELLINGS. They are partially separated from each other by another swelling that appears in the midline, known as TUBERCULUM IMPAR.

Immediately behind the tuberculum impar, the epithelium proliferates to form down growth from which the thyroid gland develops. The site of this down growth is subsequently marked by the depression, called as FORAMEN CAECUM

Tongue is divided into two parts: 1) Anterior 2/3 rd of the tongue. 2) Posterior 1/3 rd of the tongue. Anterior 2/3 rd of tongue is formed by fusion of:- a) the tuberculum impar b) the two lingual swellings Anterior 2/3 rd of tongue derived from the mandibular arch.

Posterior one third of the tongue is derived from the cranial part of hypobranchial eminence (copula) In this situation, the second arch mesoderm gets buried below the surface. The third arch mesoderm grows over it to fuse with the mesoderm of the first arch. Posterior most part of tongue is derived from 4 TH arch.

MICROGLOSSIA Uncommon developmental anomaly of unknown cause, characterized by an abnormally small tongue.

In extremely rare cases, tongue may be entirely missing (Aglossia). Mild degrees of microglossia may be difficult to detect.

Usually associated with syndromes like oromandibular limb hypogenesis syndrome. This syndrome is characterized by hypodactylia (absence of digits) and hypomelia (hypoplasia of part or all of a limb). Microglossia is also associated frequently with hypoplasia of mandible and lower incisors may be missing.

TREATMENT & PROGNOSIS: - Depends on nature and severity of condition. Surgery and orthodontics may improve oral function. Speech development is quite good but depends on tongue size.

MACROGLOSSIA Characterized by enlarged tongue. Can be caused by both congenital malformations and acquired diseases. Most frequent causes are vascular malformations and muscular hypertrophy.

1. CONGENITAL & HEREDITARY: - Vascular malformations - lymphangioma - hemangioma Hemihyperplasia Cretinism Down syndrome Neurofibromatosis Multiple endocrine neoplasia, type 2B Beckwith-Weidmann syndrome

2. ACQUIRED: - Edentulous patients Amyloidosis Myxedema Acromegaly Angioedema Carcinoma and other neoplasia

CLINICAL FEATURES ; - Common in children. Can be mild to severe in degree. Manifested in children as noisy breathing, drooling, difficulty in eating and lisping speech. Tongue pressure against mandible can cause scalloped border of tongue, open bite and mandibular prognathism.

Patients with hypothyroidism or syndromes present with diffuse, smooth, generalized enlargement. Patients with amyloidosis, neoplasia and neurofibromatosis show nodular enlargement.

Tongue in lymphangioma patients appears as a pebbly surface with multiple vesicle like blebs.

Down syndrome patients show papillary fissured surface. In hemifacial hyperplasia, enlargement is unilateral.

TREATMENT & PROGNOSIS: - Depends on cause and severity of condition. Mild cases may not require any treatment. Speech therapy is helpful if speech is affected. Reduction glossectomy may be needed in larger enlargement.

ANKYLOGLOSSIA (TONGUE TIE) Characterized by a short, thick lingual frenum, resulting in limitation of tongue movement. Male to female ratio is 4 : 1. Reported to occur in 2-3 persons out of every 10,000 people.

CLINICAL FEATURES: - Ranges in severity from mild to severe, where the frenum is actually fused to floor of mouth due to absent frenum. Can result in speech defects. Usually however, the shortened frenum results only in minor difficulties as many people can compensate for limitation in tongue movement.

TREATMENT & PROGNOSIS: - Since most cases are mild, treatment is often unnecessary. Frenectomy is recommended if there are functional or periodontal problems.

LINGUAL THYROID Thyroid gland begins as an epithelial proliferation behind the tuberculum impar in the floor of pharyngeal gut by the 3 rd 4 th week of IUL. By 7 th week, the gland descends into the neck to its final resting place. The site where the embryonic bud invaginates, later becomes the foramen cecum at the junction of anterior 2/3 rd & posterior 1/3rd

CLINICAL FEATURES: - Male to female ratio is about 1 : 4. Symptoms develop by puberty, pregnancy or menopause. In 70% of cases, this piece of tissue is the only thyroid tissue in the patient.

Lingual thyroids may range from small, asymptomatic, nodular lesions to large masses that block airway. Common symptoms are dyspnea, dysphagia and dysphonia. No distinct features are present to differentiate it from other masses developing on the tongue.

Hypothyroidism has been reported in about 33% of patients. Diagnosis is established by thyroid scan using iodine isotopes or technetium 99m.

Biopsy is often avoided as the mass may be highly vascular and may represent the patients only functioning thyroid tissue

TREATMENT & PROGNOSIS: - No treatment required for small, asymptomatic masses. In larger lesions, suppressive therapy with supplemental thyroid hormone can often reduce the size of the mass.

FISSURED TONGUE Relatively common condition. Numerous grooves or fissures are present on dorsal surface of tongue. Cause uncertain, but heredity plays an important role. Aging or local environmental factors may also contribute to its development.

CLINICAL FEATURES: - Age incidence: Prevalence & severity increases with age. Sex predilection: slight male predilection seen.

Signs & symptoms: Multiple grooves / furrows on dorsal surface ranging from 2 6 mm in depth. In severe cases, tongue appears divided into multiple islands by the deep fissures. Condition usually asymptomatic. Strong association with geographic tongue.

HISTOPATHOLOGIC AL FEATURES: - Hyperplasia of rete ridges and loss of keratin hairs from surface of filliform papillae. Papillae vary in size and are often separated by deep grooves.

PMNLs can be noted migrating into the epithelium, forming micro abscesses. Mixed inflammatory infiltrate present in underlying lamina propria.

TREATMENT & PROGNOSIS: - Being a benign condition, no specific treatment is required. Patient should be encouraged to brush his tongue as food entrapped in the deep fissures of tongue may act as a source of irritation.

HAIRY TONGUE Characterized by marked accumulation of keratin on filliform papillae, resulting in a hairy appearance of dorsal surface of tongue. Represents probably an increase in keratin production or a decrease in normal keratin desquamation. Found in approximately 0.5% of adults.

ETIOLOGY: - Cause is uncertain, but many of affected patients are heavy smokers. Other possible associated factors include: - Antibiotic therapy - Poor oral hygiene - General debilitation - Radiation therapy - Use of oxidizing mouthwash / antacids - Overgrowth of fungal / bacterial organisms.

CLINICAL FEATURES: Commonly affects midline, just anterior to circumvallate papillae. Elongated papillae are brown, yellow or black as a result of growth of pigment producing bacteria or tobacco staining.

Condition is usually asymptomatic, although in severe cases, patients may complain of gagging sensation. Because of similarity in names, care must be taken to differentiate this condition from hairy leukoplakia (HL). HL occurs on lateral borders of tongue, is caused by Epstein-Barr virus and is usually associated with HIV infection or other immunosuppressive conditions.

HISTOPATHOLOGICAL FEATURES: - Characterized by marked elongation and hyperparakeratosis of the filliform papillae. Usually, numerous bacteria can be seen growing on the surface of epithelium.

TREATMENT & PROGNOSIS: - Benign condition with no serious sequelae. Esthetic concerns and associated bad breath problems should be taken care of. Desquamation can be promoted by periodic scraping with a toothbrush / tongue scraper.

DEVELOPMENTAL ANOMALIES OF ORAL MUCOSA

FORDYYCE GRANULES Considered ectopic collection of sebaceous glands occurring on the oral mucosa. However since 80% of the population shows their presence, their presence in oral mucosa must be considered a normal anatomic variation.

Present as multiple yellow or yellowish white papules. Occur most commonly on buccal mucosa and vermilion border of upper lip. More common in adults than children. Mostly asymptomatic lesions. Some patients may feel some roughness of the mucosa.

HISTOLOGICAL FEATURES: Appear similar to normal sebaceous glands except for absence of associated hair follicles. Acinar lobules located immediately beneath epithelial surface often communicating with the surface via a central duct. Sebaceous cells within acini are polygonal, with central nuclei and abundant foamy cytoplasm.

TREATMENT & PROGNOSIS: - As they are asymptomatic and represent a normal anatomic variation, no treatment is indicated. Biopsy also is not necessary as clinical appearance is characteristic. Occasionally, Fordyce granules may become hyperplastic or form keratin filled pseudo cysts.

LEUKOEDEMA Common condition of unknown cause. Occurs more in blacks than whites. Because it is so common, it can be considered a normal anatomic variation rather than a disease. Some studies indicate that it may be more common in heavy smokers.

CLINICAL FEATURES: - Age incidence: Children Sex predilection: Nil Racial predilection: More in blacks Site of occurrence: Primarily bilaterally on buccal mucosa. May occur on floor of mouth also.

Presents as diffuse, grayish white, milky opalescent appearance of oral mucosa. Lesions do not rub off. Surface appears folded, resulting in whitish streaks.

Can be diagnosed easily clinically because the white appearance greatly disappears when the cheek is everted and stretched.

HISTOPATHOLOGICAL FEATURES: - Epithelium appears thickened with pronounced intracellular edema of spinous layer. These cells appear vacuolated, having pyknotic nuclei. Epithelial surface is usually parakeratinized with broad and elongated rete ridges.

TREATMENT & PROGNOSIS: - Benign condition, needs no treatment. Can be distinguished from other common white lesions like leukoplakia, candidiasis by everting and stretching the mucosa.

BIBLIOGRAPHY 1. Soames JV, Southam JC. Oral pathology/. 3 rd ed. Oxford 2002. 2. Shafer WG, Hine MK, Levy BM. A text book of oral pathology. 6 th ed. W.B. Saunders Company. Phil, London, Toronto, 2005. 3. Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. 2 nd ed. WB Saunders Company. Phil, London, Toronto, 2007.

ACKNOWLEDGEMENT All pictures in this presentation are courtesy of authors mentioned in the bibliography and the following authors also: 1. Sadler, Langmans, Medical Embryology, Ed. 6. 2. James e Anderson, Grants Atlas of Anatomy. Williams & Wilkins

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Congenital malformations of the maxillofacial area in children. Statistics, etiology, pathogenesis, classification, clinical picture. Modern principles