Issue 10.1

13 ottobre 2013
posted by editor

Potential complications of miniscrew implants

Introduction of miniscrews to orthodontics has led to their extensive use in critical anchorage situations. However, their widespread use is not free from certain potential risks, which must be identified to avoid / manage them.  A thorough research of literature using electronic database was carried out and is being presented in combination with the author’s experience with miniscrews.
 Like all forms of medical and dental treatment, the placement of miniscrews is not free from certain potential risks, complications and limitations.

Factors influencing the decision for orthognathic surgery
 in cleft palate patients

In the complex rehabilitation of patients with cleft lip and palate, a secondary surgical correction is often necessary at the end of the growth period in order to optimize the skeletal jaw position.
The aim of this study was to retrospectively identify those factors in the initial diagnosis, treatment approaches and findings at the time of decision-making, which statistically describe the assignment of patients to a group receiving only orthodontic treatment and to a group receiving surgical correction of the jaw position.
The study assessed the findings and analyses of 55 adult patients with non syndromic cleft (38 who received orthognathic surgery at the end and 17 who only received orthodontic treatment). The 25 parameters, collected for the initial cleft formation, the treatment concept and the timing of the bone graft, also included additional parameters from cephalometrics and dental cast analysis.
A total of 1,210 items of the 55 patients were evaluated using a classification algorithm (CART analysis). The target was to identify the parameters that were responsible for assigning the patients to the specified groups.
As expected, both groups differed significantly in various parameters. However, an overbite depth indicator (ODI) of 73.7° can be interpreted as the threshold influencing assignment to the respective group. The probability that the patients who received orthognathic surgery were correctly assigned was 90% in contrast to all other parameters.
As a result, the ODI is a simple value which could be used to estimate the likelihood that a secondary surgical correction in cleft patients is needed.


Uprighting of Molars- A Clinical Challenge

All teeth are essential, yet in function and influence, some are of greater importance than others, the most important of all being the molars, especially the first permanent molar which according to E. H. Angle is the key to occlusion. Loss of a first permanent molar should be immediately addressed by prosthetic replacement or orthodontic space closure. Otherwise, the second and third molars will incline and rotate, canine and premolars will move distally into the molar space, and the opposing first molar will extrude. The over-all objective in molar uprighting is to optimally position the molars providing the space to restore the lost tooth thereby protecting the teeth against inflammatory periodontal diseases and occlusal traumatism, which together determine the optimal periodontal environment of the molars and improve the masticatory efficiency of the patient.
Dental alignment of the arches can facilitate prosthodontic as well as periodontal objectives, a strategy referred to as “facilitative orthodontics”. Molar uprighting is one such challenging facilitative orthodontic procedure that requires proper clinical, radiological, and biomechanical evaluation and a good appliance selection for successful treatment results. A sound knowledge of biomechanics is necessary in order to optimize the clinical outcome of uprighting mechanics. When uprighting mechanics are used it is absolutely necessary to consider the extrusive nature of force system. It is important to recognize the components of the individual problems, the force system that is needed to achieve the specific goal, and finally the design of an appliance that will assure these objectives. The uprighting mechanics presented are very simple and biomechanically efficient to be used in daily practice.
KEY WORDS: molar uprighting, sectional mechaincs, interdisciplinary orthodontics