It is phenotypically difficult to diagnose between TDO and Amelogenesis imperfecta of the hypomaturation-hypoplasia type with taurodontism (AIHHT) as they are very closely linked phenotypically during adulthood, and the only distinguishing characteristic is found during genetic analysis by Polymerase Chain Reaction (PCR) amplification. This type of test in diagnosis of TDO is only used during research or if there is a concern of genetic issue to a particular individual whose family member has been diagnosed with TDO.

TDO is a genetic based disorder it is diagnosed based on radiographic imaging, physical characteristics of the disease, and genetic testing if necessary. PCR amplification is used to check for normal and deletion allele, found in the 141 base pair allele. A four base pair deletion in exon 3 is also noted in patients with TDO; deletion in two transcription factor genes DLX-3 and DLX-7 gene (distal-less gene) that occurs by a frameshift mutation, makes this gene shorter than its normal length and non-functional. Radiographs such as cephalometric analysis or panoramic radiograph are used to detect skeletal abnormalities in TDO cases; these radiographs along with the phenotypic effects of the disease are often enough evidence for proper diagnosis. In TDO, radiologic imaging almost always shows evidence of hardening of bone tissue (sclerosis), lesions on the bone structures surrounding the teeth due to decay or trauma, or hard tissue mass. The radiographic testing is non-invasive, and involves the patient to be able to sit or stand in front of the radiographic device with their mouth closed and lips relaxed for approximately one minute. Oral abnormalities are diagnosed by a visual dental examination. A normal oral evaluation would show no signs of broken or fractured teeth, attrition of tooth enamel, no spacing between teeth, no soft tissue mass or sign of dental abscess, and a bite relationship where the mandibular (bottom) teeth interdigitate within a normal plane of 1-2mm behind and underneath the maxillary (top) teeth.

In disease states, maxillary prognathism is associated with Cornelia de Lange syndrome; however, so-called false maxillary prognathism, or more accurately, retrognathism, where there is a lack of growth of the mandible, is by far a more common condition.

Prognathism, if not extremely severe, can be treated in growing patients with orthodontic functional or orthopaedic appliances. In adult patients this condition can be corrected by means of a combined surgical/orthodontic treatment, where most of the time a mandibular advancement is performed. The same can be said for mandibular prognathism.

The most common treatment for mandibular prognathism is a combination of orthodontics and orthognathic surgery. The orthodontics can involve braces, removal of teeth, or a mouthguard.

The surgery required has led, in some cases, to identity crises in patients, whereby the new facial structure has a negative impact mentally on how the patients perceive themselves.

A child with posterior crossbite should be treated immediately if the child shifts his mandible on closing which is often seen in a unilateral crossbite as mentioned above. The best age to treat a child with crossbite is in their mixed dentition when their palatal sutures have not fused to each other. Palatal expansion allows more space in an arch to relieve crowding and correct posterior crossbite. The correction can include any type of palatal expanders that will expand the palate which resolves the narrow constriction of the maxilla. There are several therapies that can be used to correct a posterior crossbite: braces, 'Z' spring or cantilever spring, quad helix, removable plates, clear aligner therapy, or a Delaire mask. The correct therapy should be decided by the orthodontist depending on the type and severity of the crossbite.

One of the keys in diagnosing the anterior crossbite due to skeletal vs dental causes is diagnosing a CR-CO shift in a patient. An adolescent presenting with anterior crossbite may be positioning their mandible forward into centric occlusion (CO) due to the dental interferences. Thus finding their occlusion in centric relation (CR) is key in diagnosis. For anterior crossbite, if their CO matches their CR then the patient truly has a skeletal component to their crossbite. If the CR shows a less severe class 3 malocclusion or teeth not in anterior crossbite, this may mean that their anterior crossbite results due to dental interferences.

Goal to treat unilateral crossbites should definitely include removal of occlusal interferences and elimination of the functional shift. Treating posterior crossbites early may help prevent the occurrence of Temporomandibular joint pathology.

Unilateral crossbites can also be diagnosed and treated properly by using a Deprogramming splint. This splint has flat occlusal surface which causes the muscles to deprogram themselves and establish new sensory engrams. When the splint is removed, a proper centric relation bite can be diagnosed from the bite.

Macroglossia is usually diagnosed clinically. Sleep endoscopy and imaging may be used for assessment of obstructive sleep apnea. The initial evaluation of all patients with macroglossia may involve abdominal ultrasound and molecular studies for Beckwith–Wiedemann syndrome.

Literature states that very few crossbites tend to self-correct which often justify the treatment approach of correcting these bites as early as possible. Only 0–9% of crossbites self-correct. Lindner et al. reported that in a 50% of crossbites were corrected in 76 four year old children.

Crowding of the teeth is treated with orthodontics, often with tooth extraction, clear aligners, or dental braces, followed by growth modification in children or jaw surgery (orthognathic surgery) in adults. Surgery may be required on rare occasions. This may include surgical reshaping to lengthen or shorten the jaw (orthognathic surgery). Wires, plates, or screws may be used to secure the jaw bone, in a manner similar to the surgical stabilization of jaw fractures. Very few people have "perfect" alignment of their teeth. However, most problems are very minor and do not require treatment.

A jaw abnormality is disorder in the formation or shape of the jaw. It can involve malocclusion.

Types include:

- Micrognathism

- Prognathism

- Retrognathism

- Pierre Robin syndrome

To establish appropriate alignment and occlusion, the sizes of upper and lower front teeth, or upper and lower teeth in general, need to be proportional. Inter-arch tooth size discrepancy (TSD) is defined as a disproportion in the mesio-distal dimensions of teeth of opposing dental arches, which can be seen in 17% to 30% of orthodontic patients.

There is no standard treatment for the hand malformations in Apert due to the differences and severity in clinical manifestations in different patients. Every patient should therefore be individually approached and treated, aiming at an adequate balance between hand functionality and aesthetics.

However, some guidelines can be given depending on the severity of the deformities.

In general it is initially recommended to release the first and fourth interdigital spaces, thus releasing the border rays.

This makes it possible for the child to grasp things by hand, a very important function for the child's development. Later the second and third interdigital spaces have to be released.

Because there are three handtypes in Apert, all with their own deformities, they all need a different approach regarding their treatment:

- Type I hand usually needs only the interdigital web space release. First web release is rarely needed but often its deepening is necessary. Thumb clynodactyly correction will be needed.

- In type II hands it is recommended to release the first and fifth rays in the beginning, then the second and the third interdigital web spaces have to be freed. The clynodactyly of the thumb has to be corrected as well. The lengthening of the thumb phalanx may be needed, thus increasing the first web space. In both type I and type II, the recurrent syndactyly of the second web space will occur because of a pseudoepiphysis at the base of the index metacarpal. This should be corrected by later revisions.

- Type III hands are the most challenging to treat because of their complexity. First of all, it is advised to release the first and fourth webspace, thus converting it to type I hand. The treatment of macerations and nail-bed infections should also be done in the beginning. For increasing of the first web space, lengthening of the thumb can be done. It is suggested that in severe cases an amputation of the index finger should be considered. However, before making this decision, it is important to weigh the potential improvement to be achieved against the possible psychological problems of the child later due to the aesthetics of the hand. Later, the second and/or third interdigital web space should be released.

With growing of a child and respectively the hands, secondary revisions are needed to treat the contractures and to improve the aesthetics.

Treatment and prognosis of macroglossia depends upon its cause, and also upon the severity of the enlargement and symptoms it is causing. No treatment may be required for mild cases or cases with minimal symptoms. Speech therapy may be beneficial, or surgery to reduce the size of the tongue (reduction glossectomy). Treatment may also involve correction of orthodontic abnormalities that may have been caused by the enlarged tongue. Treatment of any underlying systemic disease may be required, e.g. radiotherapy.

Diagnosis of Crouzon syndrome usually can occur at birth by assessing the signs and symptoms of the baby. Further analysis, including radiographs, magnetic resonance imaging (MRI) scans, genetic testing, X-rays and CT scans can be used to confirm the diagnosis of Crouzon syndrome.

Omphalocele has been described in two patients with Apert syndrome by Herman T.E. et al. (USA, 2010) and by Ercoli G. et al. (Argentina, 2014). An omphalocele is a birth defect in which an intestine or other abdominal organs are outside of the body of an infant because of a hole in the bellybutton area. However, the association between omphalocele and Apert syndrome is not confirmed yet, so additional studies are necessary.

Brachygnathism or colloquially Parrot Mouth, is the uneven alignment of the upper and lower teeth in horses. In serious cases, the upper teeth protrude beyond the lower teeth. Problem with parrot mouth occur if the molars at the back of the mouth are also uneven, resulting in large hooks forming on the upper molars and the rear of the lower back molars. Horses with parrot mouth often require dental treatment at least every six months to remove the hooks and maintain alignment.

The equivalent conditions in humans are termed retrognathism or prognathism depending on whether the lower jaw is too far back or too far forward respectively.

Each child is different and it entirely depends on which sutures are fused and how it is affecting the child as to how it is treated. Some children have severe breathing issues due to shallow mid face and may require a tracheostomy. All should be treated at a specialist centre. Cranio bands are not used in the UK.

Surgery is typically used to prevent the closure of sutures of the skull from damaging the brain's development. Without surgery, blindness and mental retardation are typical outcomes. Craniofacial surgery is a discipline of both plastic surgery and oral and maxillofacial surgery (OMFS) . To move the orbits forward, craniofacial surgeons expose the skull and orbits and reshape the bone. To treat the midface deficiency, craniofacial surgeons can move the lower orbit and midface bones forward. For jaw surgery, either plastic surgeons or OMFS surgeons can perform these operations.

Crouzon patients tend to have multiple sutures involved, most specifically bilateral coronal craniosynostoses, and either open vault surgery or strip craniectomy (if child is under 6 months) can be performed. In the later scenario, a helmet is worn for several months following surgery.

Once treated for the cranial vault symptoms, Crouzon patients generally go on to live a normal lifespan.

People with Pyle disease are often asymptomatic. Dental anomalies may require orthodontic interventions. Skeletal anomalies may require orthopedic surgery.

Leontiasis ossea, also known as leontiasis, lion face or Lion Face Syndrome, is a rare medical condition, characterized by an overgrowth of the facial and cranial bones. It is not a disease in itself, but a symptom of other diseases, including Paget's disease, fibrous dysplasia, hyperparathyroidism and renal osteodystrophy.

The common form is that in which one or other maxilla is affected, its size progressively increasing, and thus encroaching on the cavities of the orbit, the mouth, the nose and its accessory sinuses. Exophthalmos gradually develops, going on later to a complete loss of sight due to compression of the optic nerve by the overgrowth of bone. There may also be interference with the nasal respiration and with the taking of food. In the somewhat less common form of this rare disease the overgrowth of bone affects all the cranial bones as well as those of the face, the senses being lost one by one and death finally resulting from cerebral pressure. There is no treatment other than exposing the overgrown bone, and chipping away pieces, or excising entirely where possible.

Surgeon Hutan Ashrafian from Imperial College London has analysed the Great Sphinx to identify that it may have represented an individual suffering from prognathism which may have been a reflection of a disease suffered by the sculpture’s human inspiration. Furthermore as the Sphinx represented a lion, the same person may have suffered from leontiasis ossea.

Metaphyseal dysplasia, also known as Pyle's disease, Pyle's syndrome, Pyle-Cohn syndrome, and Bakwin-Krida syndrome is a rare disease in which the outer part of the shafts of long bones is thinner than normal and there is an increased chance of fractures.

There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery

Genetic counseling and screening of the mother's relatives is recommended.

There are varying types of intervention for ankyloglossia. Horton "et al.," have a classical belief that people with ankyloglossia can compensate in their speech for limited tongue range of motion. For example, if the tip of the tongue is restricted for making sounds such as /n, t, d, l/, the tongue can compensate through dentalization; this is when the tongue tip moves forward and up. When producing /r/, elevation of the mandible can compensate for restriction of tongue movement. Also, compensations can be made for /s/ and /z/ by using the dorsum of the tongue for contact against the palatal rugae. Thus, Horton "et al." proposed compensatory strategies as a way to counteract the adverse effects of ankyloglossia and did not promote surgery. Non-surgical treatments for ankyglossia are typically performed by Orofacial Myology specialists, and involve using exercises to strengthen and improve the function of the facial muscles and thus promote proper function of the face, mouth and tongue

Intervention for ankyloglossia does sometimes include surgery in the form of frenotomy (also called a frenectomy or frenulectomy) or frenuloplasty. This relatively common dental procedure may be done with soft-tissue lasers, such as the CO laser. However, authors such as Horton "et al." are in opposition to it. According to Lalakea and Messner, surgery can be considered for patients of any age with a tight frenulum, as well as a history of speech, feeding, or mechanical/social difficulties. Adults with ankyloglossia may elect the procedure. Some of those who have done so report post-operative pain.

A viable alternative to surgery for children with ankyloglossia is to take a wait-and-see approach. Ruffoli "et al." report that the frenulum naturally recedes during the process of a child's growth between six months and six years of age;

Many features of gerodermia osteodysplastica (GO) and another autosomal recessive form of cutis laxa, wrinkly skin syndrome (WSS, ""), are similar to such an extent that both disorders were believed to be variable phenotypes of a single disorder.

Several delineating factors, however, suggest that gerodermia osteodysplastica and wrinkly skin syndrome are distinct entities, but share the same clinic spectrum.

While the prevailing feature of wrinkly, loose skin is more localized with GO, it is usually systemic, yet eases in severity with age during the course of WSS. Also, as the fontanelles ("soft spots") are usually normal on the heads of infants with GO, they are often enlarged in WSS infants.

While WSS is associated with mutations of genes on chromosomes 2, 5, 7, 11 and 14; GO has been linked to mutations in the protein GORAB. A serum sialotransferrin type 2 pattern, also observed with WSS, is not present in GO patients.

But perhaps the most notable feature, differentiating GO from WSS and similar cutis laxa disorders, is the age-specific metaphyseal peg sometimes found in GO-affected long bone, near the knee. Not appearing until around age 4–5, then disappearing by physeal closure, this oddity of bone is thought to represent a specific genetic marker unique to GO and its effects on bone development.

According to Horton "et al.", diagnosis of ankyloglossia may be difficult; it is not always apparent by looking at the underside of the tongue, but is often dependent on the range of movement permitted by the genioglossus muscles. For infants, passively elevating the tongue tip with a tongue depressor may reveal the problem. For older children, making the tongue move to its maximum range will demonstrate the tongue tip restriction. In addition, palpation of genioglossus on the underside of the tongue will aid in confirming the diagnosis.

A severity scale for ankyloglossia, which grades the appearance and function of the tongue, is recommended for use in the Academy of Breastfeeding medicine.

Treatment is usually supportive treatment, that is, treatment to reduce any symptoms rather than to cure the condition.

- Enucleation of the odontogenic cysts can help, but new lesions, infections and jaw deformity are usually a result.

- The severity of the basal-cell carcinoma determines the prognosis for most patients. BCCs rarely cause gross disfigurement, disability or death .

- Genetic counseling