Overview

For most of us, the face can be the mirror of the soul, but what about those who cannot express themselves freely because of partial paralysis of the facial muscles? This is the challenge faced by those with Parry-Romberg syndrome.

Parry-Romberg syndrome, also known as hemifacial atrophy, is characterised by the loss of fat, muscles, and cartilage on one side of the face. This condition occurs sporadically within families. 

Epidemiology

• There is a probable incidence of 0.3 -2.5 cases per 100000 population per year¹
• It is three times more prevalent in women than in men¹
• The syndrome is often diagnosed at age 13, although symptoms usually appear at age two and continue to progress until age 20

Etiology 

A series of events that cause increased, unregulated activity of the sympathetic nervous system, which in turn causes localised atrophy of the sensory trunks of the trigeminal nerve, can lead to hemifacial atrophy.

• Localised trauma during the growth of an infant or child can lead to localised disturbances in the blood circulation, which hampers growth
• Heredity can be a factor, although it sometimes skips a generation or two
• It is an autoimmune disorder that can be seen in conjunction with other autoimmune conditions such as scleroderma and vitiligo
• There is inflammation in the blood vessels associated with the nerves (termed neurovasculitis), and there are malformations of the blood vessels in the brain

Viral infections like herpes zoster and herpes simplex can also contribute to this condition.

Clinical features

Coup de sabre: It is the most distinguishing sign helping in the early diagnosis of Parry-Romberg syndrome. This is a cleft in the skin of the forehead near the midline of the face. It marks the boundary between the normal and affected parts of the face. 

• The skin overlying the atrophied part may have a bluish hue
• There is atrophy of the skin, muscles, fat, bone, and cartilage on the affected side
• It can also involve the tongue, salivary glands, ear, larynx, esophagus, diaphragm, kidney, and brain
• Enophthalmos (sunken eye) occurs in about 15% of patients with Parry-Romberg syndrome

Speech

Speech is crucial for humans to communicate their feelings, needs, and wants through language. Speech occurs when three mechanisms work in tandem with each other to produce sound, namely:

• Respiration (breathing)
• Phonation ( production of sound)
• Articulation ( sound refining)

A video demonstrating the complex mechanism of speech can help us better understand it. (https://www.youtube.com/watch?v=JF8rlKuSoFM).⁹

Respiration is primarily a function of the lungs and the diaphragm. A controlled release of inhaled air is quintessential to clear speech. Phonation, or sound production, is controlled by the vibrations of the laryngeal folds( voice box). 

The final modification of sound into sibilants and constants is a function of the teeth, tongue, hard palate, soft palate, and lips. 

For example, the sound of “fa” requires the incisal edges of the upper incisors to touch the vermilion border of the lower lip. The sound “ba” needs the vermilion borders of both the lips to touch and seal the oral opening. Same for the sound “ma”. The sound “la” would need the tip of the tongue to touch the palatal surfaces of the upper central incisors. 

Impact of Parry Romberg syndrome on Speech:

The facial muscles and the muscles of mastication and speech are also involved in Parry-Romberg syndrome, but there are no significant effects on the speech function.¹⁰ The asymmetry of the face, however, causes a significant deformity of the face, which can cause a psychological impact on the patient with Parry-Romberg syndrome. Some individuals with Parry-Romberg syndrome may experience aphasia due to neurological involvement, especially affecting the trigeminal nerve.¹

Swallowing

Swallowing is a complex process of ingestion of food, followed by processing it to make it ready for digestion in the stomach and intestines. There are three phases in the swallowing process. 

• The first is the oral phase, where the ingested food is chewed, mixed with saliva, and made into a bolus, which is pushed towards the back of the throat
• The second phase is the pharyngeal phase, during which the bolus is pushed towards the trachea after the soft palate closes off the nasal cavity, the epiglottis shuts the airway, and the bolus is further pushed towards the oesophagus
• The third phase is the esophageal phase, during which the bolus is transported to the stomach with the help of muscle movements, called peristalsis, in the walls of the pharynx and esophagus

Impact of Parry-Romberg syndrome on Swallowing

The impact of Parry Romberg syndrome is mainly psychological as it impacts the appearance of the patient. Although the muscles of deglutition(swallowing) are involved in Parry-Romberg syndrome, there is no significant change in the swallowing function. ¹⁰

Clinical Presentation

Initial patient physical examination and history reveal that the facial growth disparity typically starts at two to three years of age and then occurs sporadically up to 25 years of age.

Facial examination

• Coup de sabre is the identifying feature of Parry Romberg syndrome, where a scar tissue line demarcates the normal side from the affected side
• It usually starts from the forehead and extends up to the chin
• The muscles on the affected side look atrophied, the skin looks stretched and dehydrated, and sometimes wrinkled
• The eye is sunken on the affected side
• Speech and hearing are normal
• The ear can be smaller on the affected side
• There can be hyperpigmented lesions or port-wine(nevus flammeus) stains on the affected side
• The smile is lopsided
• There is an interpupillary cant
• Both the jaws and zygomatic arches seem sunken on the affected side
• There may be sparse hair or eyebrows on the affected side

Eye examination

• Ocular muscles may lead to eyelid atrophy or pseudo-apoptosis
• There are changes in the uvea and inflammation in it
• Enophthalmos is a consistent finding in these patients due to loss of fat and bone around the eye’s musculature

Intraoral examination

• Intraoral examination shows collapsed arches on the affected side.
• There may be teeth missing on the affected side
• There could be overcrowding of the teeth on the affected side due to less space for eruption
• The present teeth may be hypoplastic and have closed apices, even though they have not erupted
• The midline of the teeth is usually shifted
• The tongue may or may not be involved in Parry-Romberg syndrome

Patient Management

The psychological effects of Parry-Romberg syndrome are profound. An individual with the condition needs physical rehabilitation and counseling to address the daily challenges they face.

A team of a neurologist, a dentist, and a counselor together can have a holistic approach towards the patient and their overall well being.

The neurologist can assess the extent of neurological damage incurred and try to reduce the pain due to trigeminal neuralgia and facial pain.

A speech therapist can help with aphasia or other speech abnormalities if present. 

The dental team consists of an orthodontist, a prosthodontist, and a periodontist to provide an optimum level of oral hygiene and balanced occlusion. The orthodontist can correct the asymmetrical jawline and align the crooked teeth. The prosthodontist can provide the means to replace the missing teeth through implants, crowns and bridges, veneers, etc. The periodontist can help salvage the existing dentition and keep it optimum for long term use.

A counselor can go a long way in providing self confidence and emotional support. Support groups can also provide a safety net, and the patient knows that he/she is not alone. 

Summary

Parry-Romberg syndrome is a very rare, sporadic, and self-limiting disorder. Very few individuals have been diagnosed and studied, so we cannot generalise that all symptoms are present in every individual with the condition. The condition requires extensive rehabilitation. Early diagnosis and intervention can provide maximum comfort, self confidence, and understanding between individuals and their care team. A team of neurologists, speech therapists, dentists, and counselors can help support and improve the quality of life for individuals with Parry-Romberg syndrome.