Six diseases whose common link is restricted oral access

Fibrodysplasia ossificans progressiva (FOP) is characterized by congenital malformation of the great toes, short thumbs, and by a progressive postnatal heterotopic ossification of the soft tissues in characteristic anatomic patterns. It is an autosomal dominant disease that appears within the first decade of life following trauma-induced or spontaneous flare-ups. FOP is caused by mutations in the bone morphogenetic protein type 1 receptor ACVR1. The person is rendered immobile following progressive episodes of heterotopic ossification involving all major joints of the axial and appendicular skeletons. The temperomandibular joint is not spared immobility and all joint ossifications begin within the first decade of life. In this disease, overstretching of the jaws, mandibular blocks, and surgical trauma from resecting heterotopic bone can lead to episodes of explosive bone formation around those soft tissue sights. Abnormalities of the temperomandibular joint are noted early in life, even without heterotopic ossification. The dental issues of patients with FOP are the same as in the general population. They can develop caries, periodontal disease, and their teeth can be impacted as well.

Moebius syndrome is a rare congenital disorder primarily involving the facial (VII) and the abducent (VI) nerves. Occasionally the V, X, XI, and XII nerves are affected, causing difficulty in swallowing, chewing, and coughing. This often leads to respiratory complications. Some patients have mental retardation and autism. Also possible in this syndrome are opthalmolplegia externa, lingual palsey, clubfoot, branchial malformation, and ptosis. From a dental point of view, multiple missing teeth in both the primary and permanent dentitions, paralysis, and hypoplasia of the tongue can be manifested. A child with Moebius syndrome may not be able to close his mouth. There may be low muscle tone of the tongue, soft palate, pharynges, and the masticatory system. Hypoplastic teeth are common in both the primary and permanent dentitions. The primary teeth may be slow to exfoliate. The saliva may be thick or the patient may have dry mouth, leading to causes of tooth decay.

Pemphigus describes a group of autoimmune blistering diseases of the skin and mucous membranes. The main action is caused by circulating immunoglobulin G against keratinocyte cell surfaces. Patients with active disease have circulating and tissue-bound autoantibodies og IgG1 and IgG4 subclasses. There are three subsets of the disease: pemphigus vulgaris, pemphigus foliaceus, and paraneoplastic pemphigus. Pemphigus vulgaris accounts for 70% of the cases. The incidence of the disease is 0.5 to 3.2 cases per 100,000. It is seen worldwide with a predilection to Mediterranean people and Ashkenazi Jews. The mean age of onset is at 50 to 60 years. In the mouth, intact bullae are rare, but most patients have buccal or palatal erosions that are hard to heal. Dental management is complicated because of the oral mucosal involvement. There is increased risk of oral disease and great difficulty rendering dental care. Treatment is rendered using systemic cortcosteroids.

Rheumatoid arthritis (RA) is a chronic multisystem disease of autoimmune etiology. Medical complications caused by RA can affect the ability to provide oral health care. Women are three times more likely to be affected in a disease that appears between ages 35 and 50. Inflammatory disease affects small joints, leading to destruction of the cartilage and juxta-articular bone. In addition, patients feel fatigue, loss of appetite, and musculoskeketal pain. Treatment can involve physical therapy, surgery, and use of injected corticosteroids. Temperomandibular joint involvement is common. There is an increased incidence of alveolar bone involvement and teeth. There can be a decrease in salivary flow causing dental caries.

Hecht-Beals syndrome (HB) is a rare condition causing congenital oral trismus. It is caused by bilateral fibrous bands on the anterior border of the masseter muscles. The condition is inoperable as the bands recur after surgery.

Epidermolysis bullosa is a group of dermatologic diseases that are characterized by muccocutaneous fragility and blister formation. The blisters can occur spontaneously or by minimal mechanical trauma. Blistering repeatedly causes atrophy of the mucosa, causing microstomia, ankyloglossia, tongue denudation, and vestibule obliteration. The most severe form of Epidermolysis Bullosa is characterized by sub-lamina dura separation, caused by blistering below the basement membrane of the cell.

To summarize, presented are six diseases and conditions that relate as having limited access to the oral cavity. Some of the problems are a result of scarring and so the limitation is that of soft tissue. Some of the limitation is a result of attack on the bone, limiting oral opening where the soft tissue is normal.