Acceptance and discomfort in growing patients during treatment with two functional appliances: a randomised controlled trial

G. Idris, M.Y. Hajeer, A. Al-Jundi University of Albaath Dental School, Hamah, Syria Department of Orthodontics e-mail: myhajeer@scs-net.org Acceptance and discomfort in growing patients during treatment with two functional appliances: a randomised controlled trial abstract Aim To evaluate the levels of acceptance and discomfort between two types of functional appliances. Study design: Randomised controlled trial. Materials and methods A sample of patients who met the inclusion criteria were distributed randomly and equally into two groups: the Trainer for Kids made up of 26 patients with an average age of 10.3 years (Group A), and the modified Activator with 28 patients, with an average age of 10.6 years (Group B), as control. A special questionnaire including eight questions about tension, pressure, sensitive teeth, pain, impaired speech, impaired swallowing, oral constraint and lack of confidence in public caused by the appliance was administered at T1 (7 days), T2 (14 days), T3 (3 months), and T4 (6 months). Results The sensation of pressure, teeth sensitivity, pain and impaired speech declined significantly in Group A. All complaints decreased significantly in Group B, but the changes in lack of confidence in public were not significant. Moreover the sensation of pressure, teeth sensitivity, oral constraint and impaired speech were significantly higher in Group A than in Group B. Conclusion The modified Activator caused less discomfort than the Trainer for Kids and was more acceptable. Keywords Pain; Discomfort; Acceptance; Modified Activator; Trainer (T4K ); Questionnaire. Introduction During orthodontic treatment, patients may experience a considerable amount of discomfort [Sergl and Zentenr, 1998; Sergl et al., 2000]. Oliver and Knappman reported that 70% of the subjects in their study had at least some degree of pain, regardless the type of appliance worn [Oliver and Knappman, 1985]. It is known that removable appliances may cause discomfort including unpleasant tactile sensations, pressure on mucosa, stretching of soft tissues, displacement of the tongue, soreness of the teeth and pain [Johnson et al., 1998]. These side effects of the appliance act as adverse stimuli disturbing the process of adaptation and affecting acceptance of the orthodontic device [Sergl and Zentenr, 1998]. Discomfort caused by orthodontic appliances may significantly affect patients compliance with treatment. Pain, functional and aesthetic impairment are the primary reasons for poor cooperation [Egolf et al., 1990] and treatment discontinuation [Oliver and Knappman, 1985] or early termination [Brattström, 1991]. Clinicians might improve acceptance by selecting an appliance design, which would allow comfortable wear and facilitate adaptation to the appliance [Gosney, 1985]. Functional appliances, which are an established mode of treatment of modern clinical orthodontics, show a remarkable diversity of design. It appears from clinical experience that patients do not readily adapt to these appliances because of their large size and unfixed position in the oral cavity, and that patient adaptation might vary with the different types of functional appliances [Graber and Neumann, 1985]. During the last decades, better functional appliances have been developed and have been reported to produce significant changes in oral function, as well as to stimulate mandibular growth [Ramirez-Yanez, 2006]. In this context there are many modifications of the original design of the Activator which have been shown to produce better results with less bulky components. One of those modifications was suggested by Schmuth to reduce the size of the original Activator [Stockfisch, 1995] that made the appliance simpler and more acceptable [Sergl and Zentner, 1998]. The modified Activator has been used widely in Syria as an important functional appliance in the treatment of Class II deformities in growing patients. More recently, the Trainer for Kids (T4K, Myofunctional Research Co, Australia) has been introduced for early orthodontic treatment of functional problems. The T4K is a polyurethane prefabricated functional appliance, which is claimed to correct malocclusions at an early age by acting on muscular dysfunction and repositioning the mandible, and it is claimed by the manufacturer to be of easy use and multipurpose [Ramirez-Yanez, 2006; Das and Reddy, 2010]. The effects of functional appliances have been widely studied, and many comparisons were made between different types and designs of functional 219

IDRIS G. et al. appliances, but it seems that few studies have attempted to evaluate the levels of pain, discomfort and acceptance connected to these appliances. The aim of the current randomised controlled trial was to compare levels of pain and discomfort during the first six months of orthodontic treatment of skeletal Class II division 1 malocclusion in growing patients by employing the functional appliance Trainer for Kids (T4K ) in comparison with the widely used modified. Materials and methods Inclusion criteria Patients were recruited according to the following criteria: mandibular deficiency (ANB > 4 ); Class II molar relationship; overjet more than 4 mm; Witt s appraisal more than 2 mm; normal lower incisor/mandibular plane relationship (93±5); normal or reduced anterior facial height; no previous orthodontic or surgical treatment; at maximal pubertal growth at the beginning of treatment. Subjects Thirteen schools in Homs and Hamah cities (in the middle of Syria) were scanned and 188 children with Class II division 1 were invited to participate in the study. Ethical approval was obtained from the local Ethics Committee of AL Baath Dental School. Parents were given an information sheet and their informed consent was obtained. A sample of 60 skeletal Class II division 1 subjects was recruited and distributed randomly and equally into two groups: Group A (Trainer T4k ), and group B (modified ). However, the final sample consisted of 54 patients because 6 patients dropped out due to the following reasons: patient s poor cooperation (one patient failed to wear the appliance for the specified time), parent s poor cooperation (three patients missed several appointments), leaving the country (one patient) and occurrence of maxillofacial fracture during treatment. The resultant Group A (Trainer T4k ) included 26 patients (14 males & 12 females; with an average age of 10.3 years), whereas Group B included 28 patients (14 males & 14 females; with an average age of 10.6 years). The modified The modified (according to Schmuth) consisted of acrylic body two splints meeting each other in the occlusal plane, upper and lower labial bows, Coffin spring in the upper plate, and acrylic capping of the edges of lower incisors (Fig. 1) [Stockfisch, 1995]. Patients were asked to wear this appliance at least 15 hours per day. The Trainer (T4K ) The Trainer For Kids (T4K ) is specifically designed to correct myofunctional habits and also to assist the alignment of the erupting teeth in the mixed dentition stage. T4K is claimed to correct skeletal Class II problems by an active mandibular force [Usumez et al., 2004]. Trainer consists of the following components: tooth channels, labial bows, tongue tag, tongue guard, and lip bumpers (Fig. 2). T4K is a prefabricated appliance made in universal size for all children 6-11 years, and it is made of flexible material. Patietns were asked to wear the appliance everyday at night as well as two hours at least during daytime. The questionnaire To assess pain and discomfort levels during the treatment a special questionnaire was used, which was derived and further modified from the questionnaire used by Sergl et al. [Sergl et al., 1998; Sergl et al., 2000]. fig. 1 The modified Activator used in the current study. fig. 2 Trainer (Blue Soft appliance used in the first stage). 220

Acceptance and discomfort CONNECTED TO functional appliances It consisted of eight questions covering the following elements: feeling of tension, feeling of pressure, teeth sensitivity, pain, speech impairment, swallowing difficulties, oral constraint and lack of confidence in public. Questions were answered based on a four-point Likert scale: 1, not at all; 2, little; 3, much; 4, very much. Prior to application of the questionnaire in the main investigation, a pilot study was performed to detect any difficulties in understanding words and phrases, any new complaints caused by appliance wearing and to assess the possible need of modifications on the layout of the questionnaire. The sample of the pilot study consisted of 10 skeletal Class II division 1 subjects: 5 were treated with the T4K appliance and 5 with the modified. These questionnaires were completed at 7 and 14 days following appliance initial wear. The pilot study revealed that the following modifications were required: re-phrasing of some sentences that were translated from English into Arabic (the formal language in Syria); doublespacing between the lines to improve questionnaire s readability; colour-coding of questionnaire time of administration (T1 white, T2 blue, T3 pink, and T4 green) to enhance children s cooperation. All questionnaires were completed at the Orthodontic Department, Al-Baath University Dental School by patients with the aid of their parents (exclusively father or mother). Each parent was asked to sit on the doctor's chair to fill the questionnaire while the principal researcher (G.I.) was observing the procedure. Each subject completed the same questionnaire at the following times: 7 days (T1), 14 days (T2), three months (T3) and six months following initial appliance insertion (T4). Results The collected data were subjected to statistical analysis using Minitab software Version 15 (Mintab Inc., Pennsylvania, USA). Wilcoxon matched-pairs signedrank tests were used for intragroup comparisons (Tables 1, 2), whereas differences between the two groups were detected using Mann-Whitney U tests (Table 3). The tension sensation decreased in the Activator group significantly after six months of treatment, but changes in the Trainer group were insignificant (Fig. 3). The pressure on soft tissues caused by the Trainer was significantly greater than that caused by the Activator, and the pressure sensation decreased significantly in the Activator group (Fig. 4). Teeth sensitivity was significantly greater in the Trainer group compared with the Activator group at T3. It decreased significantly in the Activator group at T4, and this sensation was basically located in the upper and lower incisor regions at T1 and T2, and then moved into in the molar regions at T3. On the other hand, the upper incisors regions were the sensitive areas in the Trainer group at T1 and T2 (Fig. 5). When children were asked if the appliance had been painful or not, the answers revealed that the Activator and the Trainer caused low levels of pain and this sensation decreased significantly at T3 (Fig. 6). The most disturbing complaint with the Trainer was speech impairment; speech impairment was significantly greater in the Trainer group than the Activator group. Although the Activator caused a little amount of speech impairment, it decreased significantly at T3 and T4 (Fig. 7). The two appliances caused a little amount of swallowing impairment (Fig. 8) after 7 and 14 days of appliance first wear, but there were no significant differences between the two appliances at T3 and T4. Oral constraint was the highest uncomfortable sensation disturbing patients with the Activator. In general, the two appliances caused a moderate amount of oral constraint and little constriction to the lower jaw movements. There were no significant differences between the two groups (Fig. 9). The two appliances caused a little amount of lack of confidence in public Sensation (T1-T4) (T1-T3) (T1-T2) Tension 0.133 0.096 0.083 Pressure 4** 0.010** 0.812 Teeth Sensitivity 6** 0.747 0.673 Pain 0.034* 8** 0.781 Speech Impairment 7** 0.029* 0.112 Swallowing Impairment 0.157 0.336 1 Oral Constriction 0.165 0.196 0.405 Lack of Confidence in Public 0.532 0.399 0.207 P Values from Wilcoxon signed-rank tests of differences between assessment times in the Trainer group (*)Significant differences at P <.05, (**)Significant differences at P<.01 tab. 1 Significance of differences between assessment times in Group A. Sensation (T1-T4) (T1-T3) (T1-T2) Tension 0.046* 0.448 0.356 Pressure 1** 0.050* 0.011* Teeth Sensitivity 4** 0.371 0.454 Pain 7** 2** 0.379 Speech Impairment 2** 9** 0.165 Swallowing Impairment 8** 0.020* 0.873 Oral Constriction 7** 0.012* 0.957 Lack of Confidence in Public 0.361 0.112 1 P Values from Wilcoxon signed-rank tests of differences between assessment times in the Activator group (*)Significant differences at P <.05, (**)Significant differences at P<.01 tab. 2 Significance of differences between assessment times in Group B. 221

IDRIS G. et al. Sensation T4 T3 T2 T1 Tension 0.467 0.105 0.182 0.951 Pressure 0.197 0.646 7** 0.215 Teeth Sensitivity 0.294 0.038* 0.074 0.123 Pain 0.609 0. 793 0.516 0.279 Speech Impairment 0** 0** 0** 0** Swallowing Impairment 0.987 0.986 0.406 0.410 Oral Constriction 0.027* 0.191 0.768 0.658 Lack of Confidence in Public 0.271 0.115 0.401 0.755 P- Values from Mann-Whitney U tests when evaluating differences between the two groups at the four assessment times (*)Significant differences at P <.05, (**)Significant differences at P<.01 table 3 Significance of differences in the comparisons made between the two groups at each assessment time. TENSION SENSATION PRESSURE SENSATION 2.5 2.0 1.5 1.0 0.5 1.79 1.57 1.64 1.32 1.65 1.88 1.96 1.42 0.0 1.8 1.3 1.3 1.1 1.9 1.9 1.5 1.4 fig. 3 Intensity of the complaint tension sensation reported fig. 5 Intensity of the complaint teeth sensitivity reported (Fig. 10) and the differences between the two groups were insignificant. Discussion TEETH SENSITIVITY 1.86 1.68 1.68 1.29 2.19 2.12 2.15 1.46 From reviewing the literature, it can be concluded that discomfort caused by orthodontic appliance wear has fig. 4 Intensity of the complaint pressure sensation reported 1.80 1.60 1.40 1.20 0.80 0.60 0.40 0.20 PAIN 1.68 1.57 1.18 1.07 1.42 1.46 1.15 1.15 fig. 6 Intensity of the complaint pain reported for the two appliances. The evaluation was carried out after 7 days (T1), 14 days (T2), 3 months (T3), and 6 months (T4) after appliance insertion. a negative influence on the appliance acceptance and on patient s compliance [Egolf et al., 1990]. Reasons given for patients dropping out include pain (28%), dissatisfaction with the appearance (16%) and functional restrictions (7%) [Oliver and Knappman, 1985]. The aim 222

Acceptance and discomfort CONNECTED TO functional appliances of this investigation was to assess pain, discomfort and acceptance levels during orthodontic treatment of Class II division 1 malocclusion using the recently suggested functional appliance Trainer (T4K ) compared to the more commonly used modified Activator in Syria. When a patient wears the, the Class II facial features improve immediately after appliance insertion accompanied with a pleasant facial appearance because the Activator obliges the retruded mandible to be placed in a forward position. On the other hand, the Trainer has a negative effect on facial appearance immediately after appliance insertion because it stretches the labial profile and protrudes both lips. This is probably one of the reasons beyond the higher level of acceptance to the compared to the Trainer. The experienced pressure on facial soft tissues found in the current study with the two appliances has been documented in a previous study [Sergl et al., 1998], and the decrease of this sensation at T3 and T4 may be due to muscular adaptation with the new mandibular 4.00 3.50 3.00 SPEECH IMPAIRMENT 1.96 1.79 1.36 1.18 3.58 3.27 3.23 3.00 position. The two appliances caused pressure on the oral soft tissues in the first two weeks at T1 and T2. This sensation was stronger with the Trainer and this may due to the labial and vestibular oral screen in addition to the lip bumber, but on the other hand there were no equivalent elements in the to cause a high degree of pressure. These findings match with those of previous studies, which have shown that functional appliances cause undesirable effects due to pressure sensation [Heinen,1994; Sergl et al.,1998; Doll et al.,2000]. This sensation occurs mainly during the shortterm after appliance insertion (i.e. at T1 and T2) [Sergl et al., 2000], and there is a significant correlation between pressure sensation and the type of the functional appliance used [Heinen et al., 1994]. 1.60 1.40 1.20 0.80 0.60 0.40 0.20 IMPAIRED SWALLOWING 1.43 1.39 1.04 1.23 1.23 1.08 1.04 fig. 8 Intensity of the complaint impaired swallowing reported fig. 7 Intensity of the complaint impaired speech reported 1.80 1.60 LACK OF CONFIDENCE IN PUBLIC ORAL CONSTRAINT 1.40 1.20 0.80 0.60 0.40 0.20 2.04 1.64 1.25 1.32 2.08 1.96 1.88 1.88 1.58 1.81 1.77 1.69 fig. 9 Intensity of the complaint oral constraint reported for the two appliances. The evaluation was carried out after 7 fig. 10 Intensity of the complaint lack of confidence in public reported for the two appliances. The evaluation was carried out after 7 days (T1), 14 days (T2), 3 months (T3), and 6 months (T4) after 223

IDRIS G. et al. Teeth sensitivity may be due to the contact between the anterior teeth and the labial bows of the Activator in addition to its acrylic capping of the lower incisors, so that lower incisors received the action of mandibular anterior repositioning and the upper incisors received the reaction. This sensation moved onto the posterior regions at the following assessment times because of the induced extrusion of upper and lower molars making the occlusions resting on few posterior points. In the Trainer group, the teeth sensitivity was mainly located at the upper incisors, because of the elasticity of the Trainer. These findings are in line with previous studies which have confirmed that teeth sensitivity is a very common consequence of wearing functional appliances [Sergl et al., 2000]. The two appliances caused a little amount of pain during the short term (i.e. at T1 and T2). This has also been reported in previous studies evaluating functional appliances [Doll et al., 2000; Sergl et al., 2000; Sergl et al., 1998, Heinen et al., 1994]. The Activator caused a little amount of speech impairment and this may be due to its design in which the acrylic base extension did not cover the palatal rugae, whereas the Trainer caused a high level of speech impairment and this may be due to the double barriers (lingual and buccal oral screens) in addition to the presence of the tongue tag and tongue guard. The current study confirms that the modified Activator caused less speech impairment than the Trainer and this has also been shown in a previous study comparing different functional appliances in which the modified Activator was considered the least to cause speech difficulties [Sergl and Zentner, 1998]. The current findings go in line with those of Klock et al., who found that oral habit restricting appliances have been the most disturbing ones [Klock et al., 2000]. Oral constraint was not a major problem stated by participants in this study for both appliances at the first two assessment times. The feelings of oral restrictions decreased significantly in the Activator group and this may be due to the fact the Activator becomes gradually looser in the mouth after few weeks of its insertion in addition to the gradual trimming of the acrylic occlusal wings (which is usually performed several weeks following its application to promote guided eruption of posterior teeth). Therefore, adaptation in the Activator groups occurred to a greater extent than that in the Trainer group. Conclusions The two appliances caused a considerable amount of discomfort at T1 and T2. The highest uncomfortable sensation disturbing patients wearing the Activator was the oral constraint in the first two weeks. The main complaint with the Trainer was speech impairment which was high at all assessment times in spite of its significant decrease at T3 and T4. 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