Preauricular sinuses and cysts result from developmental defects of the first and second pharyngeal arches. This and other congenital ear malformations are sometimes associated with renal anomalies. They may be present in Beckwith–Wiedemann syndrome, and in rare cases, they may be associated with branchio-oto-renal syndrome.

Occasionally a preauricular sinus or cyst can become infected.

Most preauricular sinuses are asymptomatic, and remain untreated unless they become infected too often. Preauricular sinuses can be excised with surgery which, because of their close proximity to the facial nerve, is performed by an appropriately trained, experienced surgeon (e.g. a specialist General Surgeon, a Plastic Surgeon, an otolaryngologist (Ear, Nose, Throat surgeon) or an Oral and Maxillofacial Surgeon).

In dentistry, anodontia, also called anodontia vera, is a rare genetic disorder characterized by the congenital absence of all primary or permanent teeth. It is associated with the group of skin and nerve syndromes called the ectodermal dysplasias. Anodontia is usually part of a syndrome and seldom occurs as an isolated entity.

Congenital absence of permanent teeth can present as hypodontia, usually missing 1 or 2 permanent teeth, or oligodontia that is the congenital absence of 6 or more teeth. Congenital absence of all wisdom teeth, or third molars, is relatively common. Anodontia is the congenital absence of teeth and can occur in some or all teeth (partial anodontia or hypodontia), involve two dentitions or only teeth of the permanent dentition (Dorland's 1998). Approximately 1% of the population suffers from oligodontia. Many denominations are attributed to this anomaly: partial anodontia, hypodontia, oligodontia, the congenital absence, anodontia, bilateral aplasia. Anodontia being the term used in controlled vocabulary Medical Subject Headings (MeSH) from MEDLINE which was developed by the United States National Library of Medicine. The congenital absence of at least one permanent tooth is the most common dental anomaly and may contribute to masticator dysfunction, speech impairment, aesthetic problems, and malocclusion (Shapiro and Farrington 1983). Absence of lateral incisors represents a major stereotype. Individuals with this condition are perceived as socially most aggressive compared with people without anodontia (Shaw 1981).

In teratology, proboscis is a blind-ended, tubelike structure, commonly located in the midface.

Proboscis formation are classified in four general types: holoprosencephalic proboscis, lateral nasal proboscis, supernumerary proboscis, and disruptive proboscis.

- Holoprosencephalic proboscis is found in holoprosencephaly. In cyclopia or ethmocephaly, proboscis is an abnormally formed nose. In cyclopia, a single median eye is associated with arrhinia (absence of the nose) and usually with proboscis formation above the eye. In ethmocephaly, two separate hypoteloric eyes are associated with arrhinia and supraocular proboscis formation. In cebocephaly, no proboscis formation occurs, but a single-nostril nose is present.

- Lateral nasal proboscis (proboscis lateralis) is a tubular proboscis-like structure and represents incomplete formation of one side of the nose; it is found instead of a nostril. The olfactory bulb is usually rudimentary on the involved side. The lacrimal duct (tear duct), nasal bone, nasal cavity, vomer, maxillary sinus, cribriform plate, and ethmoid cells are often missing on the involved side. Ocular hypertelorism may be present. The proboscis lateralis is a rare nasal anomaly.

- Supernumerary proboscis (Accessory proboscis) is found when both nostrils are formed and a proboscis occurs additionally. Accessory proboscis arise from a supernumerary olfactory placode.

- Disruptive proboscis occur if an early embryonic hamartoneoplastic lesion arises in the primitive prosencephalon.

Midline cervical clefts are a rare congenital anomaly resulting from incomplete fusion during embryogenesis of the first and second branchial arches in the ventral midline of the neck. The condition presents as a midline cutaneous defect of the anterior neck with a skin projection or sinus, or as a subcutaneous erythematous fibrous cord. Surgical excision is the preferred treatment.

Clinical expressions of PPS are highly variable, but include the following:

- Limb findings: an extensive web running from behind the knee down to the heel (90%), malformed toenails, and webbed toes.

- Facial findings: cleft palate with or without cleft lip (75%), pits in the lower lip (40%), and fibrous bands in the mouth known as syngnathia (25%).

- Genital findings (50%): hypoplasia of the labia majora, malformation of the scrotum, and cryptorchidism.

Fleischer's syndrome is an extremely rare congenital anomaly characterized by displacement of the nipples, occasional polymastia, and hypoplasia of both kidneys.

Although there are no specific symptoms for this condition, common complains include progressively increasing pelvic pain during menstruation and haematocolpos due to the buildup of blood in the body. Other symptoms may include swelling of the abdomen, nausea and vomiting during menstruation, and pelvic pain. Fertility may also be affected.

The condition often leads to an increased need for C-sections due to the smaller uteruses.

Talon Cusp will show physical signs of the irregular dental formation of the teeth and cause other symptoms of the disease that could possibly lead to dental problems in the future depending on severity of the deformity. Most commonly, the extra cusp is located on the lingual surface, giving a three-pronged appearance which has been described as an eagle talon. Rarely however the extra cusp may be situated on the facial surface, or there may be extra cusps on both lingual and facial surfaces. There may be a deep groove between the talon cusp and the rest of the tooth. The extra cusp typically contains pulp tissue. When viewing talon cusp from the occlusal, the projection will appear "x-shaped" as well as appears conical and mimicking the shape of an "eagle's talon".

Symptoms of talon cusp include:

- Interference with occlusion or bite

- Irritation of soft tissues and tongue

- Accidental cusp fracture

- Susceptible to dental caries

This anomaly is large enough to be seen with the naked eye. One can see the projection on the incisal edge of a tooth looking into the mouth of the affected person. The structure is described to be "T'shaped" or "X-shaped" however will differ depending on its shape, size, structure, location and site of origin. X-rays and radiographs can also show evidence of the abnormality. The digital images would show a tooth with talon cusp as if it were "double teeth".

When looking at a radiograph some features to look for would be location, edge, shape and number. The location would be on an anterior tooth, the edge would be clear and well defined and can be seen even by the naked eye, and the shape would appear "talon-like" over the top portion or crown of the affected tooth. There could potentially be one, two or multiple protrusions depending on the type of cusp.

Talon cusp can fall under three categories: Type I, Type II and Type III. They are created based on the cusp formation shape and length of extension.

- Type I - Talon: The additional cusp or talon projects from the palatal surface of a primary or permanent anterior (front) tooth that extends at least half of the distance from the cemento enamel junction to the incisal edge.

- Type II - Semi Talon: The semi talon cusp measures about 1mm or more in length but extends less than half of the distance seen in Type I Talon.

- Type III - Trace Talon: The projection originates from the cingulum (also known as the "cervical third") of the root and is enlarged or prominent in any form (conical, or tubercle-like)

Since many cases of Talon cusp go unreported, it is hard to draw linkage maps but it is safe to assume that dental formation is influenced by genetic factors. Talon cusp is also seen in association with conditions such as Rubinstein-Taybi syndrome, Mohr syndrome, Ellis–van Creveld syndrome, Incontinentia pigmenti achromians, Berardinelli-Seip syndrome, and Sturge–Weber syndrome.

Cryptophthalmos is a rare congenital anomaly in which the skin is continuous over the eyeball with absence of eyelids. It is classified into three types: complete, incomplete and abortive. Failure of eyelid separation can be associated with maldevelopment of the underlying cornea and microphthalmia. Cryptophthalmos usually occurs on both sides and occurs in association with other multiple malformations collectively referred to as Fraser syndrome.

Causes a ‘white reflex’ in the affected eye (leukocoria), prompting further investigation.

Tooth pathology (or tooth diseases, tooth disorders or dental pathology), is any condition of the teeth that can be congenital or acquired. Sometimes a congenital tooth diseases are called "tooth abnormalities". These are among the most common diseases in humans The prevention, diagnosis, treatment and rehabilitation of these diseases are the base to the dentistry profession, in which are dentists and dental hygienists, and its sub-specialties, such as oral medicine, oral and maxillofacial surgery, and endodontics.

Reticular pigmented anomaly of the flexures (also known as "dark dot disease", and "Dowling–Degos' disease") is a fibrous anomaly of the flexures or bending parts of the axillae, neck and inframammary/sternal areas. It is an autosomal-dominant pigmentary disorder that may appear in adolescence or adulthood. This condition is due to mutations in structural/desmosomal proteins found within stratified squamous epithelium.

Dark dot disease is associated with "KRT5".

Common relevant features of acrocephalosyndactyly are a high-arched palate, pseudomandibular prognathism (appearing as mandibular prognathism), a narrow palate, and crowding of the teeth.

OHVIRA, or Herlyn-Werner-Wunderlich syndrome, is a rare anomaly of the Müllerian ducts. In most cases, it is presented as a double uterus with unilateral obstructed (or blind) hemivagina and ipsilateral renal agenesis. Although the true incidence is unknown, it has been reported to be between 0.1% and 3.8%.

Popliteal pterygium syndrome (PPS) is an inherited condition affecting the face, limbs, and genitalia. The syndrome goes by a number of names including the "popliteal web syndrome" and, more inclusively, the "facio-genito-popliteal syndrome". The term PPS was coined by Gorlin "et al.." in 1968 on the basis of the most unusual anomaly, the popliteal pterygium (a web behind the knee).

Nevus psiloliparus is a cutaneous condition, a rare scalp anomaly characterized by a variable degree of alopecia and an excessive amount of adipose tissue.

It is the main hallmark of encephalocraniocutaneous lipomatosis (ECCL), otherwise known as Haberland syndrome.

PRS is characterized by an unusually small mandible (micrognathia), posterior displacement or retraction of the tongue (glossoptosis), and upper airway obstruction. Incomplete closure of the roof of the mouth (cleft palate) is present in the majority of patients, and is commonly U-shaped.

This is rare and is usually due to mutations in the R-spondin 4 (RSPO4) gene which is located on the short arm of chromosome 20 (20p13). Clinically it is manifest by the absence (anonychia) or hypoplasia (hyponuchia) of finger- and/or toenails.

The cranial malformations are the most apparent effects of acrocephalosyndactyly. Craniosynostosis occurs, in which the cranial sutures close too soon, though the child's brain is still growing and expanding. Brachycephaly is the common pattern of growth, where the coronal sutures close prematurely, preventing the skull from expanding frontward or backward, and causing the brain to expand the skull to the sides and upwards. This results in another common characteristic, a high, prominent forehead with a flat back of the skull. Due to the premature closing of the coronal sutures, increased cranial pressure can develop, leading to mental deficiency. A flat or concave face may develop as a result of deficient growth in the mid-facial bones, leading to a conditir prognathism. Other features of acrocephalosyndactyly may include shallow bony orbits and broadly spaced eyes. Low-set ears are also a typical characteristic of branchial arch syndromes.

Anonychia is the absence of nails, an anomaly, which may be the result of a congenital ectodermal defect, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus, epidermolysis bullosa, or severe exfoliative diseases.

The most common malformation in patients with the syndrome is kidney hypodysplasia, which are small and underdeveloped kidneys, often leading to end-stage renal disease (ESRD). Estimates show approximately 10% of children with hypoplastic kidneys are linked to the disease. Many different histological abnormalities have been noted, including:

- decrease in nephron number associated with hypertrophy

- focal segmental glomerulosclerosis

- interstitial fibrosis and tubular atrophy

- multicystic dysplastic kidney

Up to one-third of diagnosed patients develop end stage kidney disease, which may lead to complete kidney failure.

Symmastia is a condition defined as a confluence of the breast tissue of both breasts across the midline anterior to the sternum. It can be surgically corrected by a plastic surgeon through symmastia revision.

Symmastia can either be a congenital anomaly or iatrogenic. Congenital symmastia is a rare condition with few published cases. Iatrogenic symmastia may occur following breast augmentation, forming what is also colloquially referred to as a "uniboob" or "breadloafing" as a result of the release of skin and muscle tissue around the sternum due to over-dissection.

The inflammatory lesions in Küttner's tumor may occur on one side (unilateral) or both sides (bilateral), predominantly involving the submandibular gland, but is also known to occur in other major and minor salivary glands, including the parotid gland.

Overall, salivary gland tumors are relatively rare, with approximately 2.5–3 cases per 100,000 people per year seen in the Western world; however, salivary gland malignancies account for 3–5% of all head and neck cancers. However, salivary tumors show a great deal of morphological diversity, as well as variations in the nature of the lesion (malignant vs. benign): approximately 20% to 25% of parotid tumors, 35% to 40% of submandibular tumors, and more than 90% of sublingual gland tumors are malignant. This situation underscores the diagnostic challenges in respect of Küttner's tumor; despite being benign, this condition mimics the clinical appearance of malignancy in the salivary gland.

The swollen masses of Küttner's tumor are generally painful, and patients are advised surgical resection (known as 'sialadenectomy') of a part or whole of the glandular tissue upon suspicion of possible malignancy. It is only upon post-surgical histopathology of the excised mass that the diagnosis of Küttner's tumor is definitively made.