Bma Illustrated Medical Dictionary

Treatment is with a splint or with tem-

porary insertion of wire through the

bones to hold the finger straight. The

injury heals within 2–3 months.

mallet toeSee claw-toe.

malleusOne of the 3 tiny bones (known

collectively as the auditory ossicles)

that are situated in the middle ear.

The malleus, together with the incus

and the stapes, transmits sound vibra-

tions from the eardrum to the inner ear.

Mallory–Weiss syndromeA tear at

the lower end of the oesophagus, caus-

ing vomiting of blood. The syndrome is

commonly caused by retching and vom-

iting after drinking excessive amounts

of alcohol. Less often, violent coughing,

a severe asthma attack, or epileptic

convulsions may be the cause.

An endoscopeis passed down the

oesophagus to confirm the diagnosis.

The tear generally heals within 10 days

and no special treatment is usually

required. However, a blood transfusion

may sometimes be necessary.

malnutritionSee nutritional disorders.

malocclusionAn abnormal relation-

ship between the upper and lower sets

of teethwhen they are closed, affecting

the bite (see occlusion) or appearance.

Malocclusion usually develops during

childhood. It is inherited, or is caused by

thumb-sucking or a mismatch between

the teeth and jaws – for example, the

combination of large teeth and a small

mouth (see overcrowding, dental).

Orthodontic appliances (braces) may

be used to move teeth into the proper

position, and if there is dental over-

crowding, some teeth may be extracted.

Orthognathic surgeryis used to treat

severe recession or protrusion of the

lower jaw. Treatment is best carried out

in childhood or adolescence.

malpresentationA condition in which

a baby is not in the usual head-first

position for childbirth. Malpresentation

includes breech presentation (in which

the baby’s bottom appears first), face

presentation, and shoulder presenta-

tion (in which the baby is lying across

the uterus). Breech presentations are

the most common. A breech baby may

be born by breech deliveryor caesarean

section. A shoulder presentation baby

usually requires a caesarean section.

malta feverOlder term for brucellosis.

mammary glandSee breast.

mammographyAn X-ray procedure for

examination of the breast. The breast is

gently flattened between an X-ray plate

and a plastic cover so that as much tis-

sue as possible can be imaged. The

procedure is used to investigate breast

lumps, and to screen for breast cancer,

because it allows the detection of

MALLET TOE MAMMOGRAPHY

M

MAMMOGRAPHY

Plastic

cover

X-ray beam

Plastic cover

Mammography

technician

DETAIL

Compressed

breast

X-ray

plate

X-ray machine