In Scientology, an implant is a form of Thought insertion, similar to an engram but done deliberately and with evil intent. It is "an intentional installation of fixed ideas, contra-survival to the thetan".

The intention in the original engram or incident is to implant an idea or emotion or sensation, regarding some phenomenon etc. The intention in Scientology and Dianetics is to erase the compulsive or command effect of the idea, emotion, sensation, etc. so that the person can make a rational judgment and decision in the affected areas of life.

Scientology practices often have to do with addressing implants prior to the current lifetime — one of the most notable is the "R6 implant"; but in some cases current life implants are addressed. Examples of implants according to Scientology include Aversion therapy, Electroconvulsive therapy, hypnosis, various attempts at brainwashing, and the inducing of fear or terror. Note that this is not a complete list, as many kinds of incidents can include implants as an element.

Other important implants in Scientology doctrine include the Helatrobus implants, which Hubbard claimed occurred 382 trillion years ago to 52 trillion years ago by an alien nation called the Helatrobans, who sought to restrain human minds by capturing and brainwashing thetans. These implants are said to be responsible for the concept of Heaven.

As the grinding components cause metal flakes to shed from the system, the implant wears down. Metallosis results in numerous additional side effects:

- Confusion;

- Feelings of malaise;

- Gastrointestinal problems;

- Emotional disturbance;

- Recurring infections;

- Dizziness;

- Headaches;

- Problems in the nervous system (feelings of burning, tingling, or numbness of the extremities); and

- Cobalt poisoning (skin rashes, cardiomyopathy, problems with hearing, sight or cognition, tremors, and hypothyroidism).

Empty nose syndrome (ENS), one form of secondary atrophic rhinitis, is a rare clinical syndrome in which people who have clear nasal passages experience a range of symptoms, most commonly feelings of nasal obstruction, nasal dryness and crusting, and a sensation of being unable to breathe. People who experience ENS have usually undergone a turbinectomy (removal or reduction of turbinates, structures inside the nose) or other surgical procedures that interfere with turbinates; the overall incidence is unknown but it appears to occur in a small percentage of those who undergo nasosinal procedures. It appears to be a health care caused condition but its existence as a medical condition, cause, diagnosis and management are controversial.

All aspects have been subject to debate, including whether it should be considered solely rhinologic, or may have neurological or psychosomatic aspects. As of 2015 many ear, nose, and throat doctors do not recognize the condition.

Persons suffering from metallosis can experience any of the following symptoms:

- Extreme pain (even when not moving);

- Swelling and inflammation;

- Loosening of the implant;

- Dislocation;

- Bone deterioration;

- Aseptic fibrosis, local necrosis;

- Hip replacement failure;

- Metal toxicity from grinding metal components; and

- Necessary subsequent hip replacement revision or surgeries.

There are no objective physical examination findings that definitely diagnose ENS. Generally, one or more turbinates may be reduced or absent when viewed in medical imaging or via endoscope with no sign of physical obstruction, the mucosa will be dry and pale, and there may be signs of secondary infection.

Symptoms of ENS include a sensation of being unable to breathe, a feeling of nasal obstruction and dryness, and crusting, oozing, and foul smells inside the nose from infections. A person with ENS may complain of pain in their nose or face, an inability to sleep and fatigue, and of feeling irritated, depressed, or anxious; they may be constantly distracted by the sense that they are not getting enough air.

Very frequent signs

- Abnormal gastrointestinal tract

- Absent pectoral muscles

- Brachydactyly (Short fingers)

- Dextrocardia

- Diaphragmatic hernia/defect

- Humerus absent/abnormal

- Liver/biliary tract anomalies

- Maternal diabetes

- Oligodactyly/missing fingers

- Radius absent/abnormal

- Rhizomelic micromelia (relatively shorter proximal segment of the limbs compared to the middle and the distal segments)

- Sparsity or abnormality of axillary hair on affected side

- Syndactyly of fingers (webbing)

- Ulna absent/abnormal

- Upper limb asymmetry

- Abnormal rib

- Simian crease on affected side

Frequent signs

- Hypoplastic/absent nipples

- Scapula anomaly

Occasional signs

- Agenesis/hypoplasia of kidneys

- Encephalocele/exencephaly

- Abnormal morphology of hypothalamic-hypophyseal axis

- Abnormal function of hypothalamic-hypophyseal axis

- Microcephaly

- Preaxial polydactyly

- Ureteric anomalies (reflux/duplex system)

- Vertebral segmentation anomaly

The hallmark of the condition is a sunken appearance of the sternum. The most common form is a cup-shaped concavity, involving the lower end of the sternum; also a broader concavity involving the upper costal cartilages is possible. The lower-most ribs may protrude ("flared ribs"). Pectus excavatum defects may be symmetric or asymmetric.

People may also experience chest and back pain, which is usually of musculoskeletal origin.

In mild cases, cardiorespiratory function is normal, although the heart can be displaced and/or rotated. In severe cases, mitral valve prolapse may be present and physical capability may be limited due to base lung capacity being decreased.

Psychological symptoms manifest with feelings of embarrassment, social anxiety, shame, limited capacity for activities and communication, negativity, intolerance, frustration, and even depression.

Several symptoms are common but not specific:

- Dull, throbbing, ache in the joint which can be brought on by very strenuous exertion or simple household chores.

- Difficulty sleeping due to shoulder discomfort. The SLAP lesion decreases the stability of the joint which, when combined with lying in bed, causes the shoulder to drop.

- For an athlete involved in a throwing sport such as baseball, pain and a catching feeling are prevalent. Throwing athletes may also complain of a loss of strength or significant decreased velocity in throwing.

- Any applied force overhead or pushing directly into the shoulder can result in impingement and catching sensations.

Pectus excavatum is a congenital deformity of the anterior thoracic wall in which the sternum and rib cage grow abnormally. This produces a caved-in or sunken appearance of the chest. It can either be present at birth or not develop until puberty.

Pectus excavatum is sometimes considered to be cosmetic, but depending on the severity, it can impair cardiac and respiratory function and cause pain in the chest and back.

People with the condition may experience negative psychosocial effects, and avoid activities that expose the chest in some societies.

Poland syndrome, named after British surgeon Alfred Poland, is a rare birth defect characterized by underdevelopment or absence of the chest muscle (pectoralis) on one side of the body, and usually also webbing of the fingers (cutaneous syndactyly) of the hand on the same side (the ipsilateral hand). In most affected individuals, the missing part is the large section of the muscle that normally attaches to the upper arm on one side and the breastbone (sternum) on the other. Other abnormalities may occur on the affected side of the torso. In some cases, additional muscles in the chest wall, side, and shoulder are missing or underdeveloped.

There may also be rib cage abnormalities, such as shortened ribs, and the ribs may be noticeable due to less fat under the skin (subcutaneous fat). Breast and nipple abnormalities may also occur, and underarm (axillary) hair is sometimes sparse or abnormally placed. In most cases, the abnormalities in the chest area do not cause health problems or affect movement. Poland syndrome most often affects the right side of the body, and occurs more often in males than in females.

It is usually considered a unilateral condition. Some have claimed that the term can be applied in bilateral presentation, but others recommend using alternate terminology in those cases.

Kienböck's disease is a disorder of the wrist. It is named for Dr. Robert Kienböck, a radiologist in Vienna, Austria who described osteomalacia of the lunate in 1910.

It is breakdown of the lunate bone, a carpal bone in the wrist that articulates with the radius in the forearm. Specifically, Kienböck's disease is another name for avascular necrosis (death and fracture of bone tissue due to interruption of blood supply) with fragmentation and collapse of the lunate. This has classically been attributed to arterial disruption, but may also occur after events that produce venous congestion with elevated interosseous pressure.

A SLAP tear or SLAP lesion is an injury to the glenoid labrum (fibrocartilaginous rim attached around the margin of the glenoid cavity). SLAP is an acronym for "superior labral tear from anterior to posterior".

Some clinically observed signs and symptoms include:

- Orbital pain

- Eyes displaced posteriorly into sockets (enophthalmos)

- Limitation of eye movement

- Loss of sensation (hypoesthesia) along the trigeminal (V2) nerve distribution

- Seeing-double when looking up or down (vertical diplopia)

- Orbital and lid subcutaneous emphysema, especially when blowing the nose or sneezing

- Nausea and bradycardia due to oculocardiac reflex

False memory syndrome (FMS) describes a condition in which a person's identity and relationships are affected by memories that are factually incorrect but that they strongly believe. Peter J. Freyd originated the term, which the False Memory Syndrome Foundation (FMSF) subsequently popularized. The term is not recognized as a psychiatric illness in any of the medical manuals, such as the ICD-10 or the DSM-5; however, the principle that memories can be altered by outside influences is overwhelmingly accepted by scientists.

False memories may be the result of recovered memory therapy, a term also defined by the FMSF in the early 1990s, which describes a range of therapy methods that are prone to creating confabulations. Some of the influential figures in the genesis of the theory are forensic psychologist Ralph Underwager, psychologist Elizabeth Loftus, and sociologist Richard Ofshe.

Congenital cystic eye (also known as "CCE" or "cystic eyeball") is an extremely rare ocular malformation where the eye fails to develop correctly "in utero" and is replaced by benign, fluid-filled tissue. Its incidence is unknown, due to the very small number of cases reported. An audit by Duke-Elder of the medical literature from 1880 to 1963 discovered only 28 cases. The term was coined in 1937 by the renowned ophthalmologist Ida Mann.

Embryologically, the defect is thought to occur around day 35 of gestation, when the vesicle fails to invaginate. Dysgenesis of the vesicle later in development may result in coloboma, a separate and less severe malformation of the ocular structures.

CCE is almost always unilateral, but at least 2 cases of bilateral involvement have been described. Patients may also present with skin appendages attached to the skin surrounding the eyes. Association with intracranial anomalies has been reported.

Treatment of CCE is usually by enucleation, followed by insertion of an ocular implant and prosthesis.

Common medical causes of blowout fracture may include:

- Direct orbital blunt injury

- Sports injury (squash ball, tennis ball etc.)

- Motor vehicle accidents

Nasodigitoacoustic syndrome is congenital and is characterized by a number of nasal, facial and cranial features. These include a broad and high, sometimes depressed nasal bridge (top of the nose, between the eyes) and a flattened nasal tip. This can give the nose a shortened, arch-like appearance. Hypertelorism (unusually wide-set eyes), prominent frontal bones and supraorbital ridge (the eyebrow ridge), bilateral epicanthic folds (an extra flap of skin over the eyelids), a broad forehead and an overall enlarged head circumference have also been observed. A bulging of the upper lip with an exaggerated cupid's bow shape, and maxillary hypoplasia (underdevelopment of the upper jaw) with retraction have also been reported.

Several anomalies affecting the digits (fingers and toes) have been observed with the syndrome. A broadening of the thumbs and big toes (halluces) was reported in two brothers. The broadening was apparent in all distal phalanges of the fingers, although the pinkies were unaffected yet appeared to be clinodactylic (warped, or bent toward the other fingers). Additional eports described this broadness of the thumbs and big toes, with brachydactyly (shortness) in the distal phalanges of the other digits except the pinkies in affected individuals. On X-rays of a two-year-old boy with the disorder, the brachydactyly was shown to be caused by shortening of epiphyses (joint-ends) of the distal phalanges. The broadness and brachydactyly of the big toes in particular may give them a stunted, rounded and stub-like appearance.

The auditory, or "acoustic" abnormalities observed with the syndrome include sensorineural hearing loss and hoarseness. Two affected Turkish brothers with a mild form of this hearing loss, and a hoarse voice were reported. A laryngoscopic examination of both brothers revealed swelling of the vocal cords, and a malformed epiglottis. Sensorineural-associated hearing impairment and hoarsness was also observed in a 10-year-old girl and her father, and in a number of other cases.

Other characteristics seen with the syndrome include developmental delay, growth retardation, pulmonary stenosis (an obstruction of blood-flow from the right ventricle of the heart to the pulmonary artery) with associated dyspnea (shortness of breath), and renal agenesis (failure of the kidneys to develop during the fetal period). Undescended testes, hyperactivity and aggressive behavior have also been noted.

Phenotypic expression varies greatly between individuals with CFND. Some of the more prominent characteristics are:

- Craniosynostosis of the coronal suture(s) (fusion of the coronal sutures),

- Orbital hypertelorism (increased interocular distance),

- Bifid nasal tip,

- Dry frizzy curled hair,

- Longitudinal ridging and / or splitting of the nails,

- Facial Asymmetry.

Other characteristics that are less frequently seen are: broad nasal base, low anterior hair line, low set ears, crowding of the teeth, maxillary hypoplasia, rounded and sloping shoulders, pectus excavatum, scoliosis, high arched palate, orbital dystopia, low implant of the breasts with asymmetric nipples and volume, webbed neck, hand or foot abnormalities such as clinodactyly (most common is a curved 5th finger) and cutaneous syndactyly (webbed fingers / toes).

Females are more commonly and usually more severely affected than males. Males can however have (some of) the same symptoms as females, but this is not frequently seen. Most males have mild symptoms such as hypertelorism and a broad nasal base with bifid nose, but can also be a carrier of the mutation yet stay clinically unaffected.

Craniofrontonasal dysplasia (craniofrontonasal syndrome, craniofrontonasal dysostosis, CFND) is a very rare X-linked malformation syndrome caused by mutations in the ephrin-B1 gene (EFNB1). Phenotypic expression varies greatly amongst affected individuals, where females are more commonly and generally more severely affected than males.

Common physical malformations are: craniosynostosis of the coronal suture(s), orbital hypertelorism, nasal tip, dry frizzy curled hair, longitudinal ridging and/or splitting of the nails, and facial asymmetry.

The diagnosis CFND is determined by the presence of a mutation in the EFNB1 gene. Physical characteristics may play a supportive role in establishing the diagnosis.

The treatment is always surgical and is based on each patients specific phenotypic presentation.

False memory syndrome is a condition in which a person's identity and interpersonal relationships center on a memory of a traumatic experience that is objectively false but that the person strongly believes occurred.

The FMS concept is controversial, and the Diagnostic and Statistical Manual of Mental Disorders does not include it. Paul R. McHugh, member of the FMSF, stated that the term was not adopted into the fourth version of the manual due to the pertinent committee being headed by believers in recovered memory.

First described by David Lichtman et al. in 1977.

The purpose of this classification system is to guide treatment and to enable comparison of clinical outcomes.

1. Stage I Normal radiograph (possible lunate fracture).

2. Stage II Sclerosis of the lunate without collapse. (Portions of the lunate begin to deteriorate. This shows as a white blemish on x-rays.)

3. Stage IIIA Lunate collapse and fragmentation, in addition to proximal migration of the capitate.

4. Stage IIIB Lunate collapse and fragmentation, in addition to proximal migration of the capitate. In addition there is fixed flexion deformity of the scaphoid.

5. Stage IV Changes up to and including fragmentation, with radiocarpal and midcarpal arthritic changes.

For people, the relevance and functionality of teeth can be easily taken for granted, but a closer examination of their considerable significance will demonstrate how they are actually very important. Among other things, teeth serve to:

- support the lips and cheeks, providing for a fuller, more aesthetically pleasing appearance

- maintain an individual's vertical dimension of occlusion

- along with the tongue and lips, allow for the proper pronunciation of various sounds

- preserve and maintain the height of the alveolar ridge

- cut, grind, and otherwise chew food

Female breast ptosis or sagging is a natural consequence of aging. The rate at which a woman's breasts droop and the degree of ptosis depends on many factors. The key factors influencing breast ptosis over a woman's lifetime are cigarette smoking, her number of pregnancies, gravity, higher body mass index, larger bra cup size, and significant weight gain and loss. Post-menopausal women or people with collagen deficiencies (such as ehlers-danlos) may experience increased ptosis due to a loss of skin elasticity. Many women and medical professionals mistakenly believe that breastfeeding increases sagging. It is also commonly believed that the breast itself offers insufficient support and that wearing a bra prevents sagging which has not been found to be true.

Plastic surgeons categorize the severity of ptosis by evaluating the position of the nipple relative to the infra-mammary fold, the point at which the underside of the breasts attach to the chest wall. In the most advanced stage, the nipples are below the fold and point towards the ground.

Nasodigitoacoustic syndrome, also called Keipert syndrome, is a rare congenital syndrome first described by J.A. Keipert and colleagues in 1973. The syndrome is characterized by a mishaped nose, broad thumbs and halluces (the big toes), brachydactyly, sensorineural hearing loss, facial features such as hypertelorism (unusually wide-set eyes), and developmental delay. It is believed to be inherited in an X-linked recessive manner, which means a genetic mutation causing the disorder is located on the X chromosome, and while two copies of the mutated gene must be inherited for a female to be born with the disorder, just one copy is sufficient to cause a male to be born with the disorder. Nasodigitoacoustic syndrome is likely caused by a mutated gene located on the X chromosome between positions Xq22.2–q28. The incidence of the syndrome has not been determined, but it is considered to affect less than 200,000 people in the United States, and no greater than 1 per 2,000 in Europe. It is similar to Keutel, Muenke, Rubinstein and Teunissen-Cremers syndrome.

Edentulism or toothlessness is the condition of being toothless to at least some degree; in organisms (such as humans) that naturally have teeth (dentition), it is the result of tooth loss. Loss of some teeth is called "partial edentulism", whereas loss of all teeth is called "complete edentulism". Persons who have lost teeth are (either partially or completely) edentulous (edentate), whereas those who have not lost teeth can be called "dentate" by comparison. For example, a scientific study may include a partially edentulous group and a healthy dentate control group.

Organisms that never possessed teeth can also be described as edentulous, such as members of the former zoological classification order of "Edentata", which included anteaters and sloths, all of which possess no anterior teeth and either no or poorly developed posterior teeth.

In naturally dentate species, edentulism is more than just the simple presence or absence of teeth; it is biochemically complex, because the teeth, jaws, and oral mucosa are not static objects; they are dynamic (changing over time). Processes such as bone remodeling (loss and gain of bone tissue) in the jaws and inflammation of soft tissue in response to the oral microbiota are clinically important for edentulous people. For example, bone resorption in the jaw is frequently how the teeth were able to detach in the first place; the jaw in an edentulous area undergoes further resorption even after the teeth are gone; and insertion of dental implants can elicit new bone formation, leading to osseointegration. Meanwhile, bacteria and yeasts of the oral cavity and the immune system of their host create an immensely complicated and constantly changing interplay that presents clinically as gingivitis, caries, stomatitis, and other periodontal pathology.