About nasomaxillary hypoplasia

What is nasomaxillary hypoplasia?

Binder type maxillonasal dysplasia is a rare condition characterized by abnormal development (dysplasia) of the nasal and upper jaw (nasomaxillary) regions. Affected individuals typically have an unusually flat, underdeveloped midface (midfacial hypoplasia), with an abnormally short nose and flat nasal bridge; underdeveloped upper jaw; relatively protruding lower jaw (mandible); and/or a "reverse overbite" (class III malocclusion). In some reported cases, various additional abnormalities have also been present, particularly of the spinal column of the neck (cervical vertebral anomalies).

Many researchers suggest that Binder type maxillonasal dysplasia does not represent a distinct disease entity or syndrome, but, rather, is a nonspecific abnormality of the nasomaxillary regions. In most cases, the condition appears to occur randomly for unknown reasons (sporadically); rare familial cases have also been reported.

What are the symptoms for nasomaxillary hypoplasia?

Although researchers have been able to establish characteristic or “core” symptoms, much about Binder type nasomaxillary l dysplasia is not fully understood. Several factors including the small number of identified affected individuals, the lack of large clinical studies, and the possibility of other genes influencing the disorder prevent physicians from developing an accurate picture of associated symptoms and prognosis.

The characteristic finding of the disorder is the abnormal development (dysplasia) of the central or mid portion of the face. The midface appears abnormally flattened. In some patients the frontal sinuses may be underdeveloped or absent. Affected individuals have a Short nose and flattened bridge of the nose. The nasal bones may be underdeveloped or abnormally positioned. The bottom of the sheet of cartilage and bone (nasal septum) that separates the right and left nostrils is known as the columella. The columella is abnormally Short and the nostrils have a half-moon or comma-shaped appearance. In cases where the columella is severely short, the nostrils may appear triangular. The upper lips may be slanted backward. Despite the various nasal abnormalities, the sense of smell is unaffected.

Underdevelopment (hypoplasia) upper jaw (maxillary bone) is another key feature of Binder type nasomaxillary dysplasia. The maxillae are the large bones of that form the upper jaw and assist in the formation of the nasal cavities, the bony cavities of the eyes (orbits), and the roof of the mouth (palate). The maxillae also contain the sockets of the upper teeth. Hypoplasia of the upper jaw may cause the lower jaw (mandible) to appear to protrude or stick out (relative prognathism). However, in some individuals, the mandible may actually be longer than normal (true prognathism). Affected individuals also develop malocclusion, a condition in which the upper teeth are improperly positioned in relation to the lower teeth. More specifically, affected individuals may be predisposed to a Reverse overbite (class III malocclusion), in which the lower jaw is too far forward, the cusps of the lower back teeth are abnormally positioned in front of the corresponding upper teeth, and the lower front teeth (incisors) meet or lie in front of the corresponding upper incisors.

In some cases, additional symptoms and physical findings have been reported in association with this condition. Individuals with Binder type nasomaxillary dysplasia seem to be at an increased risk of various malformations of the spine (vertebrae). Less often, affected individuals exhibit hearing impairment, incomplete closure of the roof of the mouth (cleft palate), misalignment of the eyes (strabismus), structural malformations of the heart (congenital heart defects), mild intellectual disability, and other features. However, the exact relationship between these findings and Binder type nasomaxillary dysplasia is unknown and they may not represent symptoms of the disorder.

What are the causes for nasomaxillary hypoplasia?

The exact, underlying cause of Binder type nasomaxillary dysplasia is not fully understood. In many cases, the disorder is believed to occur spontaneously, for no apparent reason (sporadically). However, there have been reports in the medical literature of families in which more than one family member was affected. This suggests that genetic factors play a role in some affected individuals. Some researchers have suggested that Binder type nasomaxillary dysplasia is a genetic disorder inherited in either an autosomal dominant or recessive manner. Other researchers have suggested that the disorder is caused by complex genetic factors, specifically the interaction of many different genes, possibility in combination with environmental factors (multifactorial inheritance).

Researchers have identified several environmental factors that may be associated with Binder type nasomaxillary dysplasia including birth trauma, vitamin K deficiency, or exposure of a developing infant to an anti-seizure drug known as Phenytoin or to an anti-blood clotting (anticoagulant) drug known as warfarin. No suspected environmental agent has been conclusively linked to Binder type nasomaxillary dysplasia.

Some researchers believe that specific cases of Binder type nasomaxillary dysplasia may actually be mild forms or variants of chondrodysplasia punctata (CDP), a general term for a group of disorders characterized by abnormalities affecting the development of cartilage and bone (skeletal dysplasias). A variety of additional symptoms and physical features can develop. A characteristic finding of CDP is the formation of small, hardened spots of calcium on the “growing portion” or heads of the long bones (stippled epiphyses) or inside other areas of cartilage in the body. However, over time there is loss of epiphyseal stippling. Individuals who receive a diagnosis of Binder type maxillofacial dysplasia until their teen-age years or older may actually have CDP, but the distinctive epiphyseal stippling is gone so that a diagnosis of CDP is not considered.

What are the treatments for nasomaxillary hypoplasia?

The treatment of Binder syndrome is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Pediatricians or general internists, oral and plastic surgeons, craniofacial surgeons, specialists in the diagnosis, prevention, and treatment of crooked teeth (orthodontists), specialists in the diagnosis and treatment of disorders of the bones, joints, ligaments and muscles (orthopedists), and other healthcare professionals may need to systematically and comprehensively plan an affect child’s treatment. Psychosocial support for the entire family is essential as well.

There are no standardized treatment protocols or guidelines for affected individuals. Due to the rarity of the disease, there are no treatment trials that have been tested on a large group of patients. Various treatments have been reported in the medical literature as part of single case reports or small series of patients. Treatment trials would be very helpful to determine the long-term safety and effectiveness of specific medications and treatments for individuals with Binder syndrome.

Recommended treatment may include various orthodontic and surgical measures to help correct abnormalities of the jaw and nose. The specific therapeutic procedures performed will vary depending upon the nature and severity of the disorder in each individual including the specific anatomical abnormalities present, a patient’s general health, a patient’s age, patient preference, and other factors. Often more than one surgical procedure is necessary. The specific type and timing of an individual surgical procedure is determined based upon disease severity and patient age. Some affected children have been treated during childhood, while others are not treated until the late teen-age years, which is when the bone stops growing.

Some individuals may only require treatment with orthodontic devices such as braces that can straighten teeth or reposition the jaw. Nose (nasal) reconstruction can be accomplished with bone or cartilage grafts, or the implantation of alloplastic materials. In some cases, the grafting of cartilage from the ribs has been used successfully to reconstruct the nose (costochondral graft).

More severe cases require surgical procedures known as Le Fort I or II osteotomy. During Le Fort I osteotomy, the upper jaw is sectioned and repositioned to treat malocclusion and, if present, cleft palate. Le Fort II osteotomy involves repositioning the upper jaw and nose and correcting the backward displacement (retrusion) of the middle portion of the face.

Treatment of the nasal deformity usually involves adding cartilage grafts to the bridge and to support the tip to give more projection and shape. These may be from the ear, but in most cases one needs more cartilage and the rib may be used. The narrow nasal passages may also require treatment.

Is there a cure/medications for nasomaxillary hypoplasia?

Another term for Nasomaxillary is Binder’s syndrome. It is a hereditary abnormality that concerns the midfacial skeleton, involving underdeveloped nose and upper jaw. More casually known as dish-face deformity. It could be inherited as an autosomal recessive trait consisting of incomplete penetrance.

Nasomaxillary hypoplasia is often left undiagnosed or ends up with the wrong diagnosis, which makes it harder to accurately determine its frequency in the world. A tentative one is below 1 percent per 10,0000 births.

Cure/medications for Nasomaxillary Hypoplasia
Although single case reports are documented, the rarity of this disease hinders a large group of people from participating in treatment trials. There is no standardized regime and guidelines to follow in the procedure. Research is in progress.

Tentative treatment alternatives include:
1. Orthodontic & surgical measures: The candidate’s general health, age, preference, seriousness and nature of the disease are some of the factors based on which the specific therapeutic procedure will be performed. Some affected kids are treated during their childhood while others may have to wait till they reach the teen stage. 3. Orthodontic devices like braces could be used to align the teeth.

2. Bone/Cartilage grafts: Nose restructuring can be achieved through bone or cartilage grafts. Implanting alloplastic material is an alternative to this. In exceptional cases, the grafting of cartilage from the ribs led to the success of reconstructing the costochondral graft (nose).

3. Le Fort I Osteotomy: For the treatment of malocclusion (and cleft palate if visible), the upper jaw is subjected to sectioning and repositioning.

4. Le Fort II Osteotomy: With regards to the mid-portion of the face, the upper jaw and the nose are repositioned to correct the backward displacement (retrusion).

Abnormally short, flattened nose,Underdevelopment of the upper jaw bone (maxillary bone)
Underdeveloped midface and nose, which can appear as a flattened nose and shorter upper jaw

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