Your Resources: Academic Research Articles

An evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention

Published by: American Journal of Orthodontics and Dentofacial Orthopedics

Pretreatment, end of treatment, IO-year postretention, and 20-year postretention records of 31 four premolar extraction cases were assessed to evaluate stability and relapse of mandibular anterior alignment. Crowding continued to increase during the lo- to 20-year postretention phase but to a lesser degree than from the end of retention to 10 years postretention. Only 10% of the cases were judged to have clinically acceptable mandibular alignment at the last stage of diagnostic records. Cases responded in a diverse unpredictable manner with no apparent predictors of future success when considering pretreatment records or the treated results.

Authors: Robert M. Little,  Richard A. Riedel, and Jon Artun

premolar extraction, postretention, mandibular anterior alignment, robert m little, evaluation of changes

ORTHODONTICS and ‘THE PINOCCHIO FACTOR’

Published by: Dr Robert Cerny, BDS, MDSc. Specialist Orthodontist.

When Pinocchio lies, his nose grows longer... Applying the Pinocchio factor to orthodontics, how long would its nose be today?
Orthodontics became the first dental specialty in 1900 thanks to Dr EH Angle. The 'laws of orthodontics' were developed from trial and error assessments, opinions and anecdotal claims. Most of the laws have never being scrutinised or validated scientifically.

Author: Dr Robert Cerny

‘laws of orthodontics, dr robert cerny, orthodontic literature, pinocchio factor

Influence of Pre-Orthodontic Trainer treatment on the perioral and masticatory muscles in patients with Class II division 1 malocclusion

Published by: European Journal of Orthodontics

The aim of this follow-up study was to evaluate the effects of Pre-Orthodontic Trainer (POT) appliance on the anterior temporal, mental, orbicularis oris, and masseter muscles through electromyography (EMG) evaluations in subjects with Class II division 1 malocclusion and incompetent lips.

Authors: Tancan Uysal, Ahmet Yagci, Sadik Kara and Sukru Okkesim

malocclusion, perioral and masticatory muscles, class II division 1, pre-orthodontic

Application of functional orthodontic appliances to treatment of “mandibular retrusion syndrome"

Published by: Japanese Journal of Clinical Dentistry for Children

There have recently been an increasing number of parents complaining of their children’s health-related problems other than caries, such as decline in exercise ability, open-mouth posture, slow eating, allergy and misaligned teeth. Indeed, studies have shown increases in the number of children with difficulty masticating hard chewy food or inability to swallow correctly.

Authors: Akira Kanao, Masanori Mashiko and Kosho Kanao

maxillary protrusion, misaligned teeth, mandibular retrusion syndrome, functional orthodontic appliances

Orthodontic intervention in the early mixed dentition: A prospective, controlled study on the effects of the eruption guidance appliance

Published by: American Journal of Orthodontics and Dentofacial Orthopedics

A prospective, controlled cohort study was started in 1998 to investigate the effects of orthodontic treatment in the early mixed dentition with the eruption guidance appliance.

Authors: Katri Keski-Nisula, Riitta Hernesniemi, Maritta Heiskanen, Leo Keski-Nisula, and Juha Varrelae

controlled study, early mixed dentition, eruption guidance appliance, intervention

Prevalence of malocclusion and orthodontic treatment need in children and adolescents in Bogota, Columbia.

Published by: European Journal of Orthodontics

The aim of the study was to assess the prevalence of malocclusion in a population of Bogotanian children and adolescents in terms of different degrees of severity in relation to sex and specific stages of dental development, in order to evaluate the need for orthodontic treatment in this part of Colombia.

Authors: Birgit Thilander, Lucia Pena, Clementina Infante, Sara Stella Parada and Clara de Mayorga

malocclusion, orthodontic treatment, colombia, epidemiological study

Prevalence and distribution by gender of occlusal characteristics in a sample of Italian secondary school students: a cross-sectional study

Published by: European Journal of Orthodontics

The aim of this study was to describe the prevalence and distribution, by gender, of occlusal traits in a sample of Italian students aged 11–14 years (mean 13 ± 1 years). Using standardized and validated recording criteria, a single operator measured the overjet, overbite, open bite, anterior and posterior crossbites, crowding, coincidence of the upper and lower midlines, and diastema, in 810 secondary school students (53.6 per cent males).

Authors: Fabio Ciuffolo, Lamberto Manzoli, Michele D’Attilio, Simona Tecco, Filippo Muratore, Felice Festa and Ferdinando Romano

occlusal characteristics, secondary school students, gender, cross-sectional study

Non-invasive 3D facial analysis and surface electromyography during functional pre-orthodontic therapy: a preliminary report

Published by: Journal of Applied Oral Science

OBJECTIVES: Functional orthodontic devices can modify oral function thus permitting more adequate growth processes. The assessment of their effects should include both facial morphology and muscle function. This preliminary study investigated whether a preformed functional orthodontic device could induce variations in facial morphology and function along with correction of oral dysfunction in a group of orthodontic patients in the mixed and early permanent dentitions.

Authors: Gianluca M. Tartaglia, Gaia Grandi, Fabrizio Mian, Chiarella Sforza and Virgilio F. Ferrario

surface electromyography, pre-orthodontic therapy, 3d facial analysis, non-invasive

The effects of myofunctional appliance treatment on the perioral and masticatory muscles in class II, division 1 patients

Published by: World Journal of Orthodontics

This study aims to evaluate the effect of a myofunctional appliance - the pre-orthodontic trainer (POT) - on the perioral and masticatory muscles by electromyography (EMG) in individuals with an Angle Class II, Division 1 malocclusion.

Authors: Ahmet Yagci, Tancan Uysal, Sadik Kara and Sukru Okkesim.

germàn o. ramirez-yañez, perioral and masticatory muscles, myofunctional appliance, class I, division 1

The Trainer System™ in the context of treating malocclusions

Published by: Ortho Tribune (August/September 2009)

Functional Maxillary Orthopedics (FMO) is the subject in dentistry studying the treatment of malocclusions by stimulating or inhiiting the activity of the masticatory and/or facial muscles, as well as jaws development, and through that action, to stimulate modelling and remodeling of the maxillaries permitting a better tooth alignment.

Author: Dr Germàn O. Ramirez-Yañez

trainer system, german ramirez-yañez, treating malocclusions, functional maxillary orthopedics

The key to facial beauty and optimal patient health - two part series

Published by: Australasian Dental Practice

We require five patterns to optimise healthy growth of the jaws and face which include the lips together at rest; teeth in or near contact; the tongue resting in the roof of the mouth; breathing through the nose; and no muscle movement around the mouth on the subconscious swallow. Research shows that much of the orthodontic treatment used to correct the position of the teeth will further lengthen the face. It is also known that lengthening the face will produce a less attractive face.

Author: Dr John Flutter, BDS

john flutter, optimal patient health, facial beauty, subconscious swallow

The Effects of Early Preorthodontic Trainer Treatment on Class II, Division 1 Patients

Published by: Angle Orthodontist

The aim of this study was to clarify the dentoskeletal treatment effects induced by a preorthodontic trainer appliance treatment on Class II, division 1 cases. Twenty patients (10 girls and 10 boys, mean age 9.6 6 1.3 years) with a Class II, division 1 malocclusion were treated with preorthodontic trainer appliances (Myofunctional Research Co., Queensland, Australia).

Authors: Serdar Usumez, Tancan Uysal, Zafer Sari, Faruk Ayhan Basciftci,  Ali Ihya Karaman and Enis Guray

malocclusion, dentoskeletal treatment, class II division 1, pre-orthodontic trainer

Early Treatment of a Class II, Division 2 Malocclusion with the TRAINER for Kids (T4K™): A Case Report

Published by: The Journal of Clinical Pediatric Dentistry

This paper reports a Class II, division 2 malocclusion case successfully treated at an early age and in a relatively short period of time using the Trainer for Kids (T4K™), 
a prefabricated functional appliance. Skeletal changes observed in the before and after treatment cephalic radiographs were compared with the expected changes produced by the patient’s natural growth. The functional appliance’s effects resulting in the outcomes observed in this clinical case, as well as the importance of identifying the etiological factors when treating a malocclusion will be discussed.

Authors: German O  Ramirez-Yañez, Paulo Faria

malocclusion, early treatment, t4k, case report, class II division 2

Combining Functional and Fixed Appliances to Improve Results in Open Bite Treatment

Published by: The American Association for Functional Orthodontics

Open bite is one of the most challenging malocclusions and its treatment must aim to improve occlusion and muscular function in the masticatory system, producing a satisfactory and stable result. This clinical report presents a patient with an open bite in mixed dentition associated with a Class II, division 1 malocclusion and a posterior unilateral crossbite. By combining functional and fixed appliances, the open bite was closed, a good occlusion was reinstated and muscular activity was improved in a simpler way.

Author: Dr. German O.Ramirez-Yañez

germàn o ramirez-yañez, open bite treatment, fixed appliances, combining functional

Soft Tissue Dysfunction: a Missing Clue when Treating Malocclusions

Published by: International Journal of Jaw Functional Orthopedics (2005)

Contemporaneous treatment of malocclusions concerns about the effect of the muscular activity in the occlusion. Treatment of malocclusion involves dental alignment, jaw repositioning, stabilization of the activity of the masticatory muscles, the muscles of the tongue and the muscles of the cheeks and lips in order to achieve a balance between the forces delivered on the arches and teeth by all the muscles involved in oral functions.

Authors: Dr German O. Ramirez-Yañez & Dr Chris Farrell

malocclusion, germàn o ramirez-yañez, soft tissue dysfunction, dental alignmen, muscular activity

Influence of growth hormone on the craniofacial complex of transgenic mice

Published by: The European Journal of Orthodontics

Growth hormone (GH) secretion affects bone and cartilage physiology. This study investigated the effect of GH on the size of the craniofacial structures and their angular relationship. Three different models of mice with a genetically altered GH axis were used: GH excess (giant), dwarf GH antagonist (dwarf-Ant), and dwarf GH receptor knockout (dwarf-KO) mice.

Authors: German Omar Ramirez-Yañez, Joseph R. Smid, William George Young and Michael J. Waters

growth hormone, transgenic mice, bone and cartilage physiology, craniofacial complex

Periodontal treatment needs in a native island community in Colombia determined with CPITN

Published by: International Dental Journal (2004)

Aims: To identify the prevalence and different degrees of periodontal disease in an isolated community (Isla Grande, Colombia) with no dental services and low educational level with the use of CPITN, and to establish periodontal treatment needs in different age groups.

Authors: A.H. Orozco, A.M. Franco and G.O. Ramirez-Yañez

colombia, cpitn, periodontal treatment, native island community

Incisor disocclusion in rats affects mandibular condylar cartilage at the cellular level

Published by: Archives of Oral Biology

The effect of altered occlusion on the mandibular condylar cartilage remains unclear. This study investigated the effect of unilateral incisor disocclusion on cartilage thickness, on mitotic activity and on chondrocytes maturation and differentiation in the mandibular condylar cartilage of rats.

Author: G.O. Ramirez-Yañez, T.J. Daley, A.L. Symons and W.G. Young

germàn o ramirez-yañez, mandibular condylar cartilage, cellular level, Incisor disocclusion

Influence of Growth Hormone on the Mandibular Condylar Cartilage of Rats

Published by: Archives of Oral Biology (2004)

Growth hormone (GH) stimulates mandibular growth but its effect on the mandibular condylar cartilage is not well understood. This study was designed to understand the influence of GH on mitotic activity and on chondrocytes maturation. The effect of GH on cartilage thickness was also determined.

Authors: Germàn O. Ramirez-Yañez, William G. Younga, Terry J. Daleya and Michael J. Waters

germàn o ramirez-yañez, mandibular condylar cartilage, growth hormone, human craniofacial growth

The Mandibular Condylar Cartilage: a Review

Published by: International Journal of Jaw Functional Orthopedics (2004)

The condylar cartilage is the most important growing site in the mandible. This does not deny that other areas play an important role in mandibular growth, and influence the amount and direction of that growth. However, the condylar cartilage is responsible for the final length of the mandible. The purpose of this paper is to review the actual knowledge about the physiology of the mandibular condylar cartilage and how this cartilage responds to extrinsic and intrinsic stimulus.

Author: Dr. German O. Ramirez-Yañez

germàn o ramirez-yañez, mandibular growth, intrinsic stimulus, condylar cartilage

Growth Hormone and Epidermal Growth Factor in Salivary Glands of Giant and Dwarf Transgenic Mice

Published by: Journal of Histochemistry & Cytochemistry

Epidermal growth factor (EGF) in rat salivary glands is regulated by testosterone, thyroxin, and growth hormone (GH). Salivary glands of 45-day-old giant and dwarf male and female transgenic mice were examined histologically and by immunohistochemistry (IHC) for EGF. Male giants showed no significant differences from wild-type (WT) parotid and submandibular glands.

Authors: William G. Young, German O. Ramirez-Yañez, Terry J. Daley, Joseph R. Smid, Karen T. Coshigano, John J. Kopchick, and Michael J. Waters

germàn o ramirez-yañez, growth hormone, dwarf transgenic mice, william g young, salivary glands, epidermal growth factor

Planas Direct Tracks for Early Crossbite Correction

Published by: Journal of Clinical Orthodontics

This article describes the use of composite inclined planes called Planas Direct Tracks (PDTs) to correct more complex cases of crossbite in the deciduous dentition. PDTs should be used in the deciduous dentition only, as they cover the occlusal surfaces of the molars, resulting in a flat posterior occlusion until the molars are exfoliated.

Author: Dr. German O. Ramirez-Yañez

dr german ramirez-yañez, early crossbite correction, planas

Condylar Fracture: Nontreatment Case Followed Over 23 Years

Published by: World Journal of Orthodontics

This article describes a case of early mandibular condylar fracture in a female patient. Follow-up visits over about 23 years without treatment showed completely re-stabilized anatomy and function after the pubertal growth spurt. Temporary ankylosis and lack of growth with severe deviation and facial asymmetry had been initially observed. The management philosophy of pediatric condylar fractures is discussed and a conservative approach is suggested for such cases.

Authors: German Omar Ramirez-Yañez, Phillip James Saxby and William George Young

dr german ramirez-yañez, Condylar Fracture

Early Myofunctional Approach to Skeletal Class II

Published by: Mondo Ortodontico

Therapy aimed at skeletal Class II subjects is carried out at the Odontology Clinic of Milan University in accordance with studies conducted by Petrovic and Stutzmann
(12, 13), with an initial orthopaedic phase focussing on condylar growth. Such a therapeutic phase is made to coincide with the peak of pre-pubertal growth, which we have identified by evaluating skeletal age by X-raying the wrist and hand, following the method according to Gianní (5). This is performed for the purpose of obtaining the greatest possible growth period, coupled to an acceptable duration of therapy.

Authors: C. Quadrelli, M. Gheorgiu, C. Marchetti, V. Ghiglione

early treatment, soft tissue dysfunction, skeletal class ii, mondo ortodontico

Dental Arches Expansion With Ortho-System

Published by: Dental Asia (March/April 2006)

Maxillary and mandibular expansion has been proposed to increase the arch perimeter and to avoid extractions during orthodontic treatment. This paper describes a novel method to produce expansion of the dental arches, and at the same time, to treat muscular dysfunctions which may be the etiological factor of the malocclusion. Two cases treated with the Ortho-System are described and the advantage of this method of treatment is discussed.

Authors: Dr German O. Ramirez-Yañez & Dr Chris Farrell

dr chris farrell, dr german ramirez-yañez, avoid extractions, dental asia, maxillary and mandibular expansion, treating muscular dysfunctions

Dimensional Changes in Dental Arches After Treatment with a Prefabricated Functional Appliance

Published by: The Journal of Pediatric Dentistry

The purpose of this study was to determine the effect of the T4K, a prefabricated functional appliance, on the transverse and anterior-height dimensions of the maxillary and mandibular dental arches. Dimensions before and after treatment were measured on the sample, then, natural growth was subtracted from the treatment effects and compared with twice the error of the method. A clinically significant increase of both dimensions was observed in the maxilla and mandible when Class II malocclusion patients were treated with the T4K. Therefore, this retrospective study demonstrates that T4K is a valid treatment choice at an early age when transverse expansion is part of the treatment goal.

Authors: G Ramirez-Yañez, A Sidlauskas, E Junior and J Flutter

dr german ramirez-yañez, journal of pediatric dentistry, jopd, dentofacial orthopedics, functional appliance, transverse expansion

Insights Into Orthodontic Treatment

Published by: Dental Asia (July/August 2006)

Almost a century was necessary to find some new alternatives for orthodontic treatment. Since the introduction of brackets, the most significant change in orthodontic industry has been moving from weld brackets to resin bonded brackets and some improvements in wires features. However, the philosophy of treatment did not change as the only purpose of treatment was to move teeth and to expect that the whole oral system might adapt to the performed changes.

Author: Dr. German O. Ramirez-Yañez

orthodontic treatment, dr german ramirez-yañez, trainer system™, dental asia