PRESENTATION OF THE CSS SYSTEM (COMPLIANCE SCIENCE SYSTEM) AS A WAY TO EVALUATE THE USE OF HEADGEAR ANCHORAGE APPLIANCES

Carlos Rodrigues Júnior ¹
Karina S. Mundstock ²
Carlos A. Mundstock ³

The aim of this paper is to present an evaluation system for the use of headgear appliances. This system is called the Compliance Science System (CSS) and it consists of a headgear neckstrap with an electronic module timer, a reader of this module that is connected to the computer and software that reads the information gathered by the module. The purpose of the CS system is to quantify the timing of headgear use and for determining patient cooperation during daily use. Two (2) clinical cases with a skeletal Class II malocclusion and severe overjet, treated with the use of a cervical-pull Kloehn headgear, were presented to illustrate the use of the CS system.

The headgear appliance has been used in Orthodontics since the last century. From the first headgear appliances a number of modifications were done, but the patient cooperation factor remained unchanged. Poor patient cooperation can influence the final result of the orthodontic treatment, as well as lengthen the duration of treatment.

The efficacy of headgear anchorage appliances has been scientifically proven. One of the principal uses of the headgear appliance is for growth modification. Patient compliance is the most common problem encountered when utilizing headgear appliance therapy. In addition, it is very difficult to evaluate patient cooperation. The most frequently used subjective methods of evaluating the degree of headgear compliance are: dental mobility, cleanliness of buccal tubes, cleanliness of the neckstrap, space created between posterior teeth, position of the molars compared to their pre-treatment position in the casts, evaluation of the maintenance or loss of anchorage and patient answers to questions about the hours of use.

Today, in addition to the subjective methods, we can use objective methods to measure the level of patient cooperation with the use of headgear appliances.

Northcut⁵ tried a headgear timer that was made of a miniature electronic watch with a memory circuit. According to the author, the patients increased the number of hours of use of their headgears when they were informed that they had been monitored. The number of hours of use increased from 35-50 hours per week to 100 hours per week.

Cureton et. al. ¹ concluded that orthodontists that monitored their patients, without informing them, had a way to evaluate their motivational techniques in relation to the use of headgear appliances. Another study was done by Cureton et. al. ² comparing the subjective evaluation performed by experienced orthodontists, assistants and graduate students with the objective evaluation performed by a headgear timer. The results showed that patients used their headgears half of the time that was prescribed.

In another study, Cureton et. al. ³ used headgear timers to monitor 28 patients: 14 patients used a headgear calendar to evaluate the number of hours of daily use and 14 patients were not monitored daily. The final result showed that the ones that were monitored every day through the use of a headgear calendar were more inclined to wearing their headgears.

In 1997, Güray and Orban ⁴ did a study using a headgear timer with the objective to know the duration of headgear use. They concluded that the patients that were measured by using the headgear timer had increased their use of the appliance from 10 to 14 hours per day. In other words, the net increase was 26% more hours of use per day than the ones that did not know that their compliance was being measured.

In 1974, Northcutt ⁵ used a headgear timer made by Aledyne Corporation (Aledyne Timers), and Cureton et al. ^1,2,3 used a home made monitor: Seiko Lorus Quartz watch mounted on a headgear neckstrap.

In 1998, Orthokinectics Corporation brought out a new type of headgear timer that is called the "Compliance Science System" (CSS). The aim of the CSS is to inform the orthodontist and patients, in an objective way, the number of hours the headgear anchorage appliances are being worn⁶.

To test the efficiency of the Compliance Science System (CSS) we are developing a research project in the orthodontic graduate clinic of the Federal University of Rio Grande do Sul (UFRGS) in Brazil. For this project a sample of Class II patients have been selected and treated with headgear appliances. Two cases of the sample are presented in this article to describe the CS system. The objective of this research project is to evaluate the cooperation of the patients in relation to the use of headgear appliances and its efficiency. In addition, to determine the ideal protocol for using headgear appliances.

CASE 1

Patient: 9y 2m, female, at the end of mixed dentition, with Class II, Division 1 malocclusion, with an 8mm. overjet and a 4mm. overbite (figure 2). The patient presented the following cephalometric measurements: SNA 87.2°, SNB 80.3°, ANB 6.9°, SND 75°, 1/-NA 27.4°, 1/-NA 5mm, /1-NB 33.1°, /1-NB 5.8mm, SN.GoGn 28.3°(figure 3).

Figure 2 (a and b) – plaster models, right and left sides respectively, before treatment.

Figure 3 – Patient C.M.’s pre-treatment cephalometric tracing.

Treatment was planned without extractions, with fixed orthodontic appliances and the Class II malocclusion was corrected by the use of a cervical-pull headgear appliance. It was recommended to the patient to use the headgear 14 hours per day. The patient was cooperative, showing clinical signs of Class II correction during a period of 5 months (figure 4). According to the CS system reading the median time of use was 10.6 hours/day, instead of the 14 hours/day that was initially recommended (figure 5). The use of the headgear was basically at night, and is demonstrated in the graphic in figure 6. The patient concentrated her effort in sessions between 9-12 hours and 12-15 hours. In a subjective evaluation the patient was asked about the frequency and timing of headgear use, and her answers confirmed the information given by the CS system. In addition, clinical signs of headgear wear were checked such as: mobility of the first permanent maxillary molars (16, 26) and diastemas between the premolars.

Figure 4 (a and b) – Intraoral photographs, right and left sides respectively, after 5 months of extra-oral appliance use with the CS system.

CASE 2

Patient F.R.P., 8y 4m, female, in the mixed dentition, with a Class II, Division 1 malocclusion, with a 9mm. overjet and a 2mm. overbite (figure 7). The patient presented the following cephalometric measurements: SNA 85.7°, SNB 76.3°, ANB 9.37°, SND 73.3°, 1/-NA 25.5°, 1/-NA 7.3mm, /1-NB 26.3°, /1-NB 5.7mm, SN-GoGn 37.9° (figure 8).

Figure 7 (a and b) – Pre-treatment intra-oral photographs, right and left sides respectively.

Figure 8 – FRP’s pre-treatment cephalometric tracing.

A non-extraction treatment plan included fixed orthodontic appliances, cervical-pull headgear to correct the Class II malocclusion and the overjet. It was recommended to the patient to use the headgear 18 hours per day. The patient used the headgear very well, showing clinical signs of Class II correction.(Figure 9) This clinical information was confirmed by the CS system reading that demonstrated a median of 14.3 hours of daily use. (Figure 10) The major use was between 9-12 hours and a complement of 0-3 hours.(figure 11) It demonstrates that the patient concentrated the use of the headgear during sleeping hours.

Figure 9 (a and b) – Intra-oral photographs after 5 months’ treatment, right and left sides respectively.

Analyzing the short-term clinical results obtained by the CS system, we can start to have doubts about the number of hours that we should prescribe for daily use of the headgear appliance.