M. L. Jones

The pain and discomfort experienced during orthodntic treatment: A randomized controlled clinical trial of two intial aligning arch wires

A randomized controlled clinical trial was performed to compare the nature, prevalence, intensity, and duration of pain related to the use of a relatively recently developed superelastic arch wire and a more traditional multistranded steel arch wire. Other factors likely to influence the pain experience were also investigated. Forty-three subjects participated in the study, the pain response being assessed by each of the visual analogue scales, the questionnaires, and an analgesic consumption record. In 18 of the 43 subjects a standardized preliminary dental extraction procedure was used as a control. Subsequent to the random allocation of an initial arch wire in 43 patients, 22 of them underwent a second arch wire in the opposing arch, the wire again being determined by random allocation. It was found that the prevalence, intensity, and duration of pain after the insertion of the two types of wire was similar but much greater than in the postextraction control phase. The pain score peaked on the morning after the placement of the arch wire, lasting typically for 5 to 6 days. The pain and discomfort experienced after the insertion of the second arch wire was similar to that of the first, no conditioning response being evident. Overall a diurnal variation was found with a tendency to an increase in pain in the evenings and nights, although this did not greatly affect sleep. The pain response was found to be highly and consistently subjective, not related to the dental arch, crowding, sex, or social class; however, a statistically significant association was found between the age and the pain experienced.

An Assessment of the Fit of a Parabolic Curve to Pre- and Post-Treatment Dental Arches

Study casts of the teeth are routinely used for diagnosis and to assess treatment change: the crowding of the teeth or shortage of space available within the dental arch is usually assessed visually. A full cast analysis program has been developed previously, making use of the three-dimensional Reflex Plotter linked to a computer. This study examines the validity of the fit of computer generated parabolic curves to dental arches, as performed in the measurement of crowding. Using a visual analogue method it was found that the parabola appeared to fit lower post-treatment dental arches best. However, reservations regarding the fit of symmetrical curves are expressed and other solutions suggested.

CLINICAL COMPARISON AND PERFORMANCE PERSPECTIVE OF THREE ALIGNING ARCH WIRES

OBJECTIVES To clinically evaluate three commonly used orthodontic tooth aligning arch wires: 016 x 022 inch active martensitic medium force nickel titanium, 016 x 022 inch graded force active martensitic nickel titanium, and 0.0155 inch multistrand stainless steel. DESIGN A prospective randomized clinical trial. DATA SOURCE Measured serial study casts of dental arches for 112 assigned arch wires from 56 consecutive patients. Analysis based on completed records for 98 arch wires and 51 patients. METHOD A consecutive sample of 56 patients requiring both upper and lower fixed appliance therapy were randomly allocated two different arch wires from a possible three under trial. Good quality impressions were taken of the dental arches at the designated serial stages of alignment (start, T0; 4 weeks, T4; 8 weeks, T8). The resultant casts were measured on a Reflex Microscope to record the change in individual tooth alignment both in three and two dimensions (horizontal plane only). RESULTS The measurement error was within acceptable limits (range, 0.05 to 0.09 mm) and showed no significant bias. ANOVA statistical models were fitted to the data to adjust for a number of variables. No significant difference in aligning capability (p > 0.05), in either two or three dimensions, was demonstrated between the three arch wires in the trial. CONCLUSION Heat activated nickel titanium arch wires failed to demonstrate a better performance than the cheaper multistrand stainless steel wires in this randomized clinical trial. The failure to demonstrate in vivo superiority at the clinical level may be due to the confounding effects of large variations in individual metabolic response. Alternatively, it may be that in routine clinical practice NiTi-type wires are not sufficiently deformed to allow their full superelastic properties to come in to play during initial alignment.

Multiflex versus superelastic: a randomized clinical trial of the tooth alignment ability of initial arch wires.

Two arch wires commonly used for initial tooth alignment were compared with regard to their clinical effectiveness. The two arch wires tested were 0.0155-inch diameter multiple-stranded stainless steel wire (Dentaflex, Dentaurium, Optident, Yorkshire, England) and 0.014-inch diameter nickel-titanium alloy wire (NiTi, ORMCO Co., Monrovia, Calif.). Consecutive patients attending an orthodontic clinic for routine placement of a fixed appliance were randomly assigned one of these two initial arch wires. Good quality alginate impressions of the appropriate dental arch were taken before arch wire placement and also at the subsequent appointment, which was, on average, 6 weeks later. Seventy-four arches were used in this study. The degree of tooth alignment achieved for each wire type was compared with a Reflex Microscope (Reflex Measurement Ltd., Butleigh, England) to make detailed measurements on the resultant casts. The degree of initial alignment achieved with the two wires was similar over this 6-week period. However, some differences were found for the lower labial segment where the interbracket span is usually reduced and where the superelastic nickel-titanium wire was found to give improved alignment. No threshold of crowding was found where one arch wire performed better than the other.

Orthodontic treatment in Ehlers-Danlos syndrome.

The literature is briefly reviewed and the presentation and orthodontic treatment of a patient with Ehlers—Danlos syndrome is described. Surprisingly, in view of the nature of this collagen disorder, tooth movement appeared to progress normally; there was, however, a problem of mucosal ulceration which was alleviated through regular use of chlorhexidine mouthwash.

A comparison of two- and three-dimensional incisor angles.

Two- and three-dimensional incisor angulations are compared in 40 patients using lateral radiographs and direct dental cast measurement using the Reflex Metrograph coupled to a computer. The two-dimensional upper and lower incisor angulations to the occlusal plane were also compared by the two methods. It was found that: 1. The two-dimensional radiographic and three-dimensional dental cast inter-incisor angulation showed a significant difference at a probability level 0·01>p>0·001. 2. The two-dimensional radiographic and two-dimensional dental cast upper left and right incisor angulations to the functional occlusal plane showed a significant difference at a probability level of 0·01>p>0·001. The significant differences can be attributed to the measurement of the incisor crown angulation in the dental cast measurement and the incisor tip and apex assessment in the radiographic technique. The system of dental cast measurement arguably provides a more realistic and reliable assessment of incisal angles than conventional radiographic measurement techniques.

Canine Retraction with the Edgewise Appliance—Some Problems and Solutions

The common problems that occur during canine retraction with the edgewise appliance are identified and their possible causes examined. Some solutions are suggested to maintain the appliances momentum during this stage of treatment.

The bioprogressive technique in postgraduate teaching: 8 years of clinical experience.

The historical movement towards the adoption of the bioprogressive technique for postgraduate teaching on the Cardiff course is outlined. The departments experience in routinely teaching and using the appliance is described, with illustrations from a number of post-graduate cases. The advantages and disadvantages of a pre-adjusted sectional mechanics system are considered. The place of sectional mechanics in the future is discussed together with how such techniques may be included, with advantage, in any taught pre-adjusted appliance system.

The Screening and Categorization of Patients: A Case for Natural Selection?

A preliminary study was performed on the feasibility and validity of objective categorization of patients into basic ‘treatment types’. The Reflex Metrograph was used for a three-dimensional cast analysis, and an H.P. 9874 A digitizer was used for a two-dimensional radiograph analysis. In both measurement techniques the method error was found to be acceptable. Using the Ricketts 10 Factor Analysis, it was found that by means of ‘Clinical deviators’ radiographs could be used to distinguish orthognathic cases from the other treatment groups. The three-dimensional study cast analysis showed promise, distinguishing a number of statistically significant factors within the lower arch and between simple and fixed appliance cases. A number of variables which might have been expected to be significant were confounded by their range of values within the groups. Further investigation is required with an improved technique of initial categorization of patients, perhaps by means of a panel of clinicians, and more sophisticated statistical techniques.

Bioprogressive Brackets and Pentamorphic Arches

The problems associated with finishing cases treated with Bioprogressive incisor brackets when using the rectangular pentamorphic arch forms are illustrated and discussed, and possible solutions proposed.