Issue 8.4

1 novembre 2010
posted by editor

The segmental mechanics – An efficient method to reduce
treatment duration in severely crowded cases literature

Segmental mechanics consists of multiple wire cross-sections in different segments of the
arch. The advantages of segmental mechanics in comparison with continuous mechanics are
a statically determinate force system, relatively constant force, minimal side-effects on the
anchorage unit, minimal arch wire fabrication, decreased treatment duration and enhanced
esthetics. Individual retraction of the canine using segmental mechanics prior to unraveling
of anterior teeth crowding helps in preventing round tripping of the anterior teeth and thereby
facilitating a reduction in treatment time. The following article presents several case reports
that highlight the efficiency of segmental mechanics in the reduction of treatment duration in
severely crowded case.

Treatment of Class II malocclusion in a non compliant patient
A case report with review of literature

Treatment of Class II malocclusion in a non compliant patient is perplexing and challenging. When planning treatment in such cases, the orthodontist often faces the dilemma of selecting the right functional appliance from the numerous options. This case report presents one such case (along with review of literature) of a non compliant patient treated with Forsus Fatigue Resistant DeviceTM (a fixed functional appliance), which has greater elasticity and flexibility; allows greater range of movement of mandible, is available in pre fabricated assembly of springs, tubes and rods and is a simple, effective and reliable corrective appliance that provides non-compliant solution for treatment of Class II malocclusion and benefits not only growing patients but also malocclusions that previously required extraction and headgears. Following treatment with this appliance molar correction was achieved very quickly and there was a marked improvement in patient’s smile, facial profile, lip competence, self confidence and quality of life.

Class II malocclusion, Non compliant patient, ForsusTM Fatigue Resistant Device.

Interceptive orthodontic correction of ectopically erupting permanent maxillary first molar.


During clinical practice, one can come across different developmental disorders pertaining to eruption of teeth. Ectopic eruption of the permanent maxillary first molar is one of the developmental disorders relating to tooth eruption. Permanent maxillary first molar in instances of otherwise ideal occlusion, may be located too far mesially in its eruption resulting in resorption of the distal root of the primary second molar. An 8½-year-old girl reported for routine checkup. Intraoral examination revealed that maxillary left permanent first molar was erupting ectopically. Periapical radiographic examination also confirmed the diagnosis of ectopic eruption. Severe distal root resorption of primary second molar was evident due to ectopic molar, strongly indicating some intervention. The condition of ectopic eruption of permanent molar was successfully corrected using the Modified Humphrey’s appliance. The permanent first molar completely erupted in normal occlusion with no other further damage occurring to the primary second molar.

Ectopic eruption, Humphrey’s appliance, Molar distalization, Permanent maxillary first molar.

A Marvel of Modern Technology: Finite Element Model


In the last decade the application of a well proven predictive technique the Finite Element Method, originally used in structural analysis has revolutionized dental biomedical research. The finite element method is a highly precise technique used to analyze structural stress. It has been used in civil and aerospace engineering for years. This method uses computers to solve large number of equations to calculate stress on the basis of physical properties and the structures being analyzed. Finite Element analysis has also been applied to the description of physical form changes in biologic structures particularly in the area of growth and development and orthodontics. Finite element method which is an engineering method of calculating stresses and strains in all materials including living tissues has made it possible to adequately model the tooth and periodontal structure for scientific checking and validating the clinical assumptions.

Key words: Finite element method, stress-strain level, orthodontic tooth movement

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