MALOCCLUSIONS

TRANSIENT

Transient malocclusions

These are self-correcting

malocclusions encountered during the

development of the dental occlusion,

which are normal for that age.

TRANSIENT MALOCCLUSIONS

PREDENTATE PERIOD

IN THE

Retrognathic Mandible

When neonatal jaws are closed, there is contact only in the posterior region of the gum pads & the mandible is severely retruded in relation to the maxilla.

This retrognathia is for the most part corrected by the increased pace of forward growth of the mandible as compared to that of the maxilla seen in most people.

Although the mandibular deficit (ANB) may approach 14 at birth, by adulthood it is reduced to only 2.

Infantile SwallowingInfantile Swallowing

The ability to feed from the breast is present in the new born child. During the process of suckling the nipple is drawn into the mouth by negative pressure. The tongue lies over the lower gum pads & protrudes between the nipple & lower lip.

The milk is directed continuously to the pharynx by an automatic peristaltic movement of the tongue & mylohyoid muscle. During the process, regular breathing continues. The milk passes between the faucial pillar & the lateral channel of the pharynx.

The infantile swallowing pattern changes to the mature or adult type during the first year of life with the introduction of solid foods in the diet.

Anterior open bite of the gum pads

Clinch & Sillman have shown that there is rarely any contact between the gum pads anteriorly when they are approximated, contact being found only in the first molar region.

The open bite is corrected when the primary incisor teeth erupt.

TRANSIENT MALOCCLUSIONS

PRIMARY DENTITION

IN

THE

Anterior Deep Bite

Primary teeth are upright i.e. they have an almost vertical inclination with an interincisal angle of about 150 between the maxillary and mandibular primary central incisors. The primary incisors generally erupt into a rather deep overbite.

This deep bite is reduced by the eruption of the primary molars & attrition of the incisal edges of the primary anterior teeth.

Spacing The primary dentition may classified as

Type I (spaced) Type II (closed)

- Baume (1950)

Spaces in the primary dentition may be generalized

(developmental/physiological spaces) or

localized (primate spaces)

Primate spaces:

Spaces found mesial to the primary canine in the maxilla & distal to the primary canine in the mandible

So called because most subhuman primates have these spaces throughout life

Also known as anthropoid or simian spaces

Significance of spacing

Spacing in the primary dentition is essential to the normal eruption & alignment of the larger permanent successors.

Failure of incisor spacing to appear before 5 years of age usually indicates crowding in the permanent dentition.

Spaces that exist between the primary molars usually close by the time of eruption of the first permanent molars, whereas those between the primary incisors persist until these teeth are replaced.

Edge-to-edge bite

At 2 years, the overjet is on average 4 mm, with a range of 2-6mm. With attrition of the teeth, lengthening of the ramus & downward & forward growth of the mandible, the overjet exhibits a steady decrease up to the age of 5 years, where an edge-to-edge incisor relationship is common.

This edge-to-edge incisal relationship is corrected when the permanent incisors erupt.

Flush terminal plane

When the distal surface of maxillary and mandibular deciduous second molar are in the same vertical plane. this is the normal molar relationship in the primary dentition because the mesiodistal width of mandibular molar is greater than maxillary molar.

TRASIENT MALOCCLUSION

MIXED DENTITION PERIOD

IN

Anterior deepbite

Deepbite because of larger permanent incisors and shedding of primary molars which is usually alleviated following exfoliation of second primary molars.

Crowding in upper and lower anterior region

After exchange of the canines which is usually alleviated following exfoliation of the second primary molars.

Ugly-Duckling Stage

It is an ugly arrangement of the anterior teeth which is a merely a temporary phase during the process of normal development. Here the developing permanent canines especially the upper canines cause mesial displacement of the roots of permanent incisors around the age of 8 to 9 years. This cause a distal divergence of crown of the incisors.

Initial end-on relationship

It is of the upper and lower first permanent molars which is later corrected when the lower first molar moves mesially by utilizing the physiological spaces.

TRASIENT MALOCCLUSION

PERMANENT DENTITION

IN

Increased Overjet

It is the horizontal distance between the

lingual aspect of the maxillary incisors

and labial aspect of mandibular incisors.

During the transition of deciduous

anteriors with the permanent incisors

causes increased overjet beyond 2mm-

3mm.

Increased Overbite

It is the distance which the incisal edge of

the maxillary incisors overlap vertically past

the incisal edge of the mandibular incisors.

During the transition of deciduous incisors

with the permanent incisors causes

increases overbite 2-3mm

References:-

• Textbook of Pedodontics - Shobha Tandon-

1st edi. – pg. 113-15

• Orthodontics The Art & Science – S.I.

Bhalajhi – 3rd edi. – pg.129-40