Parry–Romberg syndrome (PRS) is a rare developmental disorder characterized by the progressive shrinking of tissues on one side of the face. It typically begins with a patch of hardened skin on the forehead that leads to an indentation resembling a sword wound on the affected side of the face. In addition to facial atrophy, it can cause neurological and eye problems. While the cause is unknown, genetic and autoimmune factors may play a role. Treatment aims to stop further progression and repair facial deformities through immunosuppressants or reconstructive procedures once stabilization is achieved.

1. Parry–Romberg syndrome
Parry–Romberg syndrome (PRS) or progressive facial
hemiatrophy is a developmental craniofacial disorder
characterized by a slowly progressive unilateral facial
atrophy. It is associated with different systemic
manifestations particularly, maxillofacial, neurologic and
ophthalmologic abnormalities.
Prevalence
 There is an estimate that 1 in every 700.000 births present this syndrome
 Its onset occurs along first two decades of life.
 Higher incidence among women
 Affect most often the left side of the face.
Aetiology
 Unknown;
 although trauma, viral infections, genetic factors, autoimmunity, endocrine disturbances,
peripheral trigeminal neuritis, increase of cervical sympathetic nerve activity and cerebral
disturbance of fat metabolism are possible suggested factors playing a role in pathogenesis of
this condition
Features
 The syndrome often begins with a circumscribed patch of
SCLERODERMA in the frontal region of the scalp which is
associated with a loss of hair and the appearance of a depressed
linear scar extending down through the midface on the affected
side. This scar is referred to as a "coup de sabre" lesion.
 The indentation looks as though the person may have been struck
by a sword.

 Slow and progressive atrophy of facial tissues, generally
unilateral, including muscles, bones and skin
 The skin may become thin, dry and hyperpigmented

2.  Ocular involvement is common with enophthalmos as a main
manifestation
 Neurological manifestations such as trigeminal neuralgia,
epilepsy, facial paresthesia and migraine may be associated with
this condition
 There is deviation of the mouth and nose toward the affected side
 Atrophy of superior lip led to exposure of anterior teeth
 Intraorally there is a unilateral atrophy of muscle of the tongue, soft and hard palates in all
dimensions,
 Shortness and deficiency of the mandibular body and ramus.
 Delayed tooth eruption, root atrophy and retarded tooth formation
 Unilateral posterior crossbite,
Treatment
It is divided into two philosophies:
 The first consists in trying to stop the disease process through immunosupression which also
improve associated symptoms,
 The second regards the repair of acquired deformities after stabilization of the disease process.
For such, many reconstructive and esthetic procedures have been tried, such as free grafts,
microsurgery, fat transfer and alloplastic material grafting