Effects of isotretinoin on tooth movement, orthodontically induced and non-orthodontic root resorption: A micro-CT and study.

OBJECTIVES: This study aims to investigate whether cumulative dose-dependent isotretinoin (Roaccutane®) could affect orthodontic tooth movement (OTM) and root resorption. MATERIALS AND METHODS: Ninety male Wistar Albino rats were divided into 4 groups. While, the control (SALINE), solvent (SOYBEAN) and orthodontic drug (ISOTM) groups underwent orthodontic force, the non-orthodontic drug group (ISO) did not. The rats were administrated saline, soybean oil (SBO) and isotretinoin diluted in SBO (ISOTM, ISO) for 30 days, respectively. Six rats were euthanized in each orthodontic group. Fifty grams of orthodontic force was applied to the remaining rats' first molars using the incisors as anchorage. Six more rats in each group were euthanized on the 7th, 14th and 21st days of the force application. In the ISO group, six rats were euthanized on the 37th, 44th and 51st days of administration. Six rats that were euthanized for ISOTM on the 30th day were also used for ISO to reduce the number of rats used. Micro-computed tomography (micro-CT) and histological analysis were performed. RESULTS: Independent of orthodontic force, isotretinoin caused root resorption in the apical region. However, there was no statistically significant influence of isotretinoin on OTM and orthodontically induced root resorption (OIRR). CONCLUSIONS: Despite the lack of strong evidence supporting the orthodontically induced resorptive effect of isotretinoin, this study provided findings regarding the resorptive effects of isotretinoin on non-orthodontic root resorption. Therefore, the present results underscore the importance of close monitoring during orthodontic treatment to mitigate potential root resorption in patients who use isotretinoin because of acne complaints.

Evaluation of the relationship between mandibular condyle cortication and chronologic age with cone beam computed tomography.

PURPOSE: The aim of the present study is to evaluate the relationship between mandibular condyle cortication and chronologic age and gender via cone-beam computed tomography (CBCT) and to investigate the effectiveness of using the condylar cortication as a new method of age estimation. METHODS: CBCT images from 433 subjects aged 8 to 31 years were included in this study. The right and left condyle cortication were assessed on the sagittal plane separately for each individual by the same investigator via a new method that describes the cortication of the condyle. Type I: There is no cortication on the condyle. Type II: The bone that is on the superior surface of the condyle is seen less density than the structures around the condyle. Type III: The surface of the condyle is seen similar or higher density than the surrounding cortical areas. RESULTS: The type of the condyle cortication in the right and left mandible was similar for almost each subject and there was no statistically significant different between them (p = 0.375). When we evaluated the results without including these patients for male, Type I cortication of the condyle was seen at 14.14 ±â€¯2.3 years, Type II cortication of the condyle was seen at 16.11 ±â€¯3.18 years and Type III cortication of the condyle was seen at 19.39 ±â€¯3.96 years. For the female, Type I cortication of the condyle was seen at 13.01 ±â€¯2.16 years, Type II cortication of the condyle was seen at 15.52 ±â€¯2.71 years and Type III cortication of the condyle was seen at 17.95 ±â€¯3.13 years. The minimum age of Type III cortication was 11 and 15 years old for male and female, respectively. However, there are subjects, who are 30 year old man and 31 year old female, have no cortication as much as similar or higher than the surrounding the cortical areas. CONCLUSION: This study is the first investigation of the relationship between condyle cortication and chronologic age with CBCT in the Turkish population. The type of cortication in the right and left condyle may be different for the same individual. Chronologic age increased as the stages of the cortication process from Type I to Type III in male and female individuals, and all the stages of the cortication in the mandibular condyle of male occur later time according to female.

A comparison of the sagittal and vertical dentofacial effects of maxillary expansion produced by a memory screw and a hyrax screw.

AIM: The aim of the present study was to investigate and compare the cephalometric effects of a conventional Hyrax expansion screw and a memory screw on the skeletal and dentoalveolar structures and soft tissues of the face. METHODS: Thirty-two patients with a maxillary transverse deficiency were divided into two groups. A memory-screw group included 17 patients (nine females and eight males), while a Hyrax-screw group was comprised of 15 patients (eight females and seven males). The mean ages of the subjects in the memory-screw and Hyrax-screw groups were 13.00 ± 1.29 and 12.58 ? 1.50 years, respectively. Lateral cephalograms were taken of the patients at the beginning of the treatment (T1), at the end of expansion (T2) and retention periods (T3). The mean expansion period was 7.76 ± 1.04 days in the memory-screw group and 35.46 ± 9.39 days in the Hyrax-screw group. The Shapiro-Wilk Normality test was used to determine whether the investigated parameters were homogeneous. To determine the treatment changes within the groups, a paired test and Wilcoxon Signed Rank test were applied to the homogeneous and non-homogeneous parameters, respectively. A comparison between the groups was carried out using the Student's t-test for homogeneous parameters and the Mann-Whitney U test for all others. RESULTS: A results summary indicates that mid-palatal sutural opening and subsequent important skeletal and dental expansions were obtained in all patients. The maxilla moved anteriorly and inferiorly in both groups while the mandible rotated inferiorly and posteriorly but to a greater extent in the memory-screw group. CONCLUSION: The newly-developed memory expansion screw takes advantage of rapid and slow maxillary expansion protocols. The suture is opened and the maxilla expanded with relatively lighter forces over a shorter time. The RME using the memory screw resulted in similar sagittal and vertical changes to those produced by the Hyrax screw.

Does stinging nettle (Urtica dioica) have an effect on bone formation in the expanded inter-premaxillary suture?

OBJECTIVE: To determine whether systemically given stinging nettle (SN) has an effect on bone formation in response to expansion of the rat inter-premaxillary suture. MATERIALS AND METHODS: A total of 28 male Wistar albino rats were randomly divided into 4 equal groups: control (C), only expansion (OE), SN extract given only during the expansion and retention periods (SN group; a total of 17days), and SN extract given during the nursery phase before expansion (a period of 40days) and during the expansion and retention periods (N+SN group; a total of 57days). After the 5-day expansion period was completed, the rats in the OE, SN, and N+SN groups underwent 12days of mechanical retention, after which they were sacrificed, and their premaxilla were dissected and fixed. A histologic evaluation was done to determine the number of osteoblasts, osteoclasts, and capillaries, as well as the number and intensity of inflammatory cells and new bone formation. RESULTS: Statistically significant differences were found between the groups in all histologic parameters except the ratio of intensities of inflammatory cells. New bone formation and the number of capillaries were significantly higher in the SN groups than in the other groups. The statistical analysis also showed that the numbers of osteoblasts, osteoclasts, and capillaries were highest in the N+SN group. CONCLUSION: Systemic administration of SN may be effective in accelerating new bone formation and reducing inflammation in the maxillary expansion procedure. It may also be beneficial in preventing relapse after the expansion procedure.

Effect of Royal Jelly on new bone formation in rapid maxillary expansion in rats.

BACKGROUND: The aim of this study was to evaluate the effects of long and short term systemic usage of royal jelly on bone formation in the expanded maxillary suture in a rat model. MATERIAL AND METHODS: Twenty eight Wistar albino rats were randomly divided into 4 equal groups: Control (C); Only Expansion (OE), Royal Jelly (RJ) group, Royal Jelly was given to rats by oral gavage only during the expansion and retention period; Royal Jelly plus Nursery (RJN) group, Royal Jelly was given to rats by oral gavage during their nursery phase of 40 days and during the retention period. After the 5 day expansion period was completed, the rats underwent 12 days of mechanical retention. All rats were sacrificed in same time. Histological examination was performed to determine the number of osteoclasts, number of osteoblasts, number of capillaries, inflammatory cell infiltration, and new bone formation. RESULTS: New bone formation, number of osteoclasts, number of osteoblasts, and the number of capillaries in the expanded maxillary sutures were higher in the RJ and RJN groups than in the other groups. Statistical analysis also demonstrated that new bone formation and the number of osteoblasts was also highest in the RJN group. CONCLUSIONS: The systemic administration of Royal Jelly in conjunction with rapid maxillary expansion may increase the quality of regenerated bone.

Effect of St John's wort on bone formation in the orthopaedically expanded premaxillary suture in rats: a histological study.

BACKGROUND/OBJECTIVE: The aim of this study was to investigate the effect of systemic St John's wort (Hypericum perforatum) on bone formation in the expanded premaxillary suture in rats. MATERIALS/METHODS: A total of 28 rats were randomly divided into four groups of equal numbers: control (C); only expansion (OE); St John's wort extract given only during the expansion and retention period (a total of 17 days; SJW group); and St John's wort extract given during the nursery phase before expansion (a period of 40 days), and during the expansion and retention periods (a total of 57 days; N + SJW group). After the 5 day expansion period was completed, the rats in the OE, SJW, and N + SJW groups underwent 12 days of mechanical retention, following which they were killed, and their premaxilla dissected and fixed. Histological examination was performed to determine the number of osteoclasts and capillaries, as well as the number of osteoblasts, inflammatory cell infiltration, and the amount of new bone formation. RESULTS: Statistical analysis showed that the number of osteoclasts and capillaries, and the inflammatory cell infiltration, as well as new bone formation, were higher in the SJW and N + SJW groups than in the other groups. However, statistical analysis demonstrated that among these two groups, all parameters, with the exception of the number of capillaries, were higher in the N + SJW group than the SJW group. CONCLUSIONS/IMPLICATIONS: Although more effective in long-term usage, systemic use of St John's wort hastens new bone regeneration at the premaxillary suture and may help prevent relapse after expansion.

Three-dimensional evaluation of the mandibular third molars' development in unilateral crossbite patients: A cone beam computed tomography study.

OBJECTIVES: The aim was to investigate mandibular third molar (3M)'s maturation in the crossbite and normal sides by two- and three-dimensional analyses using cone beam computed tomography (CBCT). MATERIALS AND METHODS: A retrospective study was performed using CBCT of 25 patients (16 females and 9 males; mean age: 16.8 ± 2.9 years) with unilateral posterior crossbite. The formation stages and the volume of the mandibular 3Ms were evaluated by means of CBCT data of the patients without knowing the crossbite side of the patients. RESULTS: Statistically no significant differences were found in the development of the 3Ms between the crossbite and the control sides, whereas the volume of 3M was found to be less in the crossbite side than in the normal side (P = 0.021). CONCLUSIONS: A volume of 3M was found to be less in the crossbite side than in the normal side.

An evaluation of condylar and ramal vertical asymmetry in adolescents with unilateral and bilateral posterior crossbite using cone beam computed tomography (CBCT).

AIMS: The primary purpose was to evaluate condylar and ramal vertical asymmetry in adolescent patients displaying unilateral posterior (UCB) and bilateral posterior crossbite (BCB) malocclusions. A secondary aim was to compare the findings with a matched control group exhibiting normal occlusion (CG) using cone beam computed tomography (CBCT). MATERIAL AND METHODS: The study groups consisted of (1) 30 patients (Mean age: 14.49 +/- 1.91 years) with a UCB, (2) 29 patients (Mean age: 14.57 +/- 1.84 years) with a BCB, and (3) 36 patients (Mean age: 14.24 +/- 2.42 years) as a matched control group (CG). Condylar, ramal, condylar-plus-ramal height and index measurements were performed using CBCT images following the method of Habets et al. A paired t-test was performed for side comparison in each group. Oneway ANOVA (Analysis of Variance) was used to determine statistically-significant differences between the groups for asymmetry index measurements and Tukey's HSD test was employed for individual group differences. RESULTS: There was no statistically significant difference in condylar height (CH), ramal height (RH), and condylar plus ramal height (CH + RH) measurements between the right and left sides of the UCB group and CG, except for the RH in the BCB group (p = 0.045). Tukey's HSD test showed that the ramal asymmetry index (RAI) and the condylar plus the ramal asymmetry index (CRAI) were statistically significantly different between the UCB and BCB groups (p = 0.035 and p = 0.015, respectively). CONCLUSIONS: Although the condylar asymmetry index (CAI) values were found to be high in the groups of UCB (13.84 +/- 11.33), BCB (9.38 +/- 8.56), and CG (10.58 +/- 9.48), the comparisons amongst the groups were not statistically significant. The asymmetry between the UCB and BCB groups was observed for RAI and CRAI values, rather than CAI values.

Effects of early unilateral mandibular first molar extraction on condylar and ramal vertical asymmetry.

OBJECTIVE: The objective of the following study is to investigate the mandibular vertical asymmetry in a group of patients with early unilateral mandibular first molar extractions. MATERIALS AND METHODS: Mandibular asymmetry index measurements (condylar, ramal and condylar-plus-ramal) were performed on the panoramic radiographs of a study group including 51 patients (mean age: 18.60 ± 1.11 years) and a control group of 51 patients (mean age: 18.53 ± 1.29 years). Group I included patients with a unilateral mandibular first molar extracted before the age of 12 years. Group II included patients with no extractions and had excellent Class I relationships, no missing teeth and slight or moderate anterior crowding. A paired t-test was used to determine possible statistically significant differences between the sides for the measurements. Student's t-test was used for the comparison of asymmetry index values between the groups and genders. RESULTS: No group showed statistically significant sex-or side-specific differences for posterior vertical height measurements. Condylar asymmetry index and ramal asymmetry index measurements were not statistically different between the groups, while condylar-plus-ramal asymmetry index (CRAI) measurements were statistically different between the groups (P = 0.019). CONCLUSIONS: A slight difference for CRAI value was found in patients with early unilateral mandibular first molar extractions.

Effects of face mask treatment with and without rapid maxillary expansion in young adult subjects.

OBJECTIVES: To investigate the skeletal, dental, and soft tissue effects of the face mask (FM) treatment with and without rapid maxillary expansion (RME) in young adult subjects with maxillary retrognathia. MATERIALS AND METHODS: Pretreatment and posttreatment cephalometric radiographs from 32 subjects who had a skeletal Class III malocclusion were analyzed. The subjects were divided into two groups: FM group (N  =  17; 3 male and 14 female subjects; mean [SD] age 14.47 [0.89] years) was treated with FM only, while the RME+FM group (N  =  15; 3 male and 12 female subjects; mean [SD] age 14.67 [1.28] years) was treated with both FM and RME. Ten cephalometric linear and nine angular variables were measured to assess dentofacial changes. Within-group and between-group comparisons were determined by a paired t-test and Student's t-test, respectively. RESULTS: Forward displacement of the maxilla and a clockwise rotation of the mandible occurred in both groups. The maxillary-mandibular relationship improved and soft tissue changes resulted in a more convex profile. The maxillary incisors were more proclined in the FM group than in the RME+FM group, the only difference between the two groups. Notably, the mandibular incisors moved backward in both groups. CONCLUSIONS: Forward movement of the maxilla can be obtained in young adults after face mask treatment. However, there was no difference in this phenomenon between the FM and RME+FM groups.

Comparison of the effects of rapid maxillary expansion caused by treatment with either a memory screw or a Hyrax screw on the dentofacial structures--transversal effects.

The aim of the present study was to investigate and compare the effects of conventional Hyrax screw treatment and memory screw treatment on skeletal and dentoalveolar structures. Thirty-two patients with maxillary transversal deficiency were divided into two groups. The memory-screw group included 17 patients (nine females and eight males), while the Hyrax-screw group comprised 15 patients (eight females and seven males). Mean ages of the subjects in the memory-screw and Hyrax-screw groups were 13.00 ± 1.29 and 12.58 ± 1.50 years, respectively. Plaster models and postero-anterior cephalograms were taken from the patients at the beginning of the treatment (T1) and at the end of expansion (T2) and retention periods (T3). The mean expansion period was 7.76 ± 1.04 days in the memory-screw group and 35.46 ± 9.39 days in the Hyrax-screw group. 'Shapiro-Wilk Normality test' was used to determine whether the investigated parameters were homogeneous or not. To determine the treatment changes within the group, 'paired t-test' and 'Wilcoxon signed-ranks test' were applied to the homogeneous and non-homogeneous parameters, respectively. Comparison between the groups was carried out using 'Student's t-test' for homogeneous parameters and 'Mann-Whitney U-test' for the rest. Rapid maxillary expansion was carried out successfully in both the groups. However, the use of memory screw may be advantageous because it shortens the maxillary expansion period, provides additional expansion in the retention period, and generates light forces relative to the conventional Hyrax screw.

Permanent first molar extraction in adolescents and young adults and its effect on the development of third molar.

OBJECTIVES: The aim of the present study was to determine the prevalence of permanent first molar (P1M) extraction among Turkish adolescents and young adult subpopulation, and to investigate the effects of P1M extraction on development of the third molars (3Ms) in the same quadrant. MATERIALS AND METHODS: A retrospective study including 2,925 panoramic radiographs (PRs) taken from patients (aged 13-20 years) who were examined to identify cases of had at least one maxillary or mandibular P1Ms extracted was performed. Additionally, 294 PRs with the maxillary or mandibular unilateral loss of a P1M were used to assess the developmental grades of the 3Ms. Statistical analyses were performed by means of parametric tests after performing a Shapiro-Wilks normality test to the data. RESULT: A total of 945 patients (32.3 %) presented with at least one P1M extraction with no gender difference (P = 0.297). There were more cases of mandibular P1Ms extracted (784 patients, 1,066 teeth) than maxillary P1Ms extracted (441 patients, 549 teeth) (P < 0.001). The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated when compared with the contralateral teeth (P = 0.000, P = 0.000, respectively). No statistically significant differences were found in the differences in the developmental of the 3Ms between the maxilla and mandible (P = 0.718). CONCLUSIONS: High prevalence of P1Ms extraction among Turkish adolescents and young adults shows a need for targeted dental actions, including prevention and treatment. The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated. CLINICAL RELEVANCE: To date, no information about prevalence of P1Ms extraction among Turkish adolescents and young adults is documented. In addition, the present study has a larger population and complementary information about 3Ms development than previous studies.

Condylar and ramal vertical asymmetry in adolescent patients with cleft lip and palate evaluated with cone-beam computed tomography.

INTRODUCTION: The aims of this study were to evaluate condylar and ramal mandibular vertical asymmetry in a patient group affected by unilateral (UCLP) and bilateral (BCLP) cleft lip and palate, and to compare the findings with a well-matched control group with normal occlusion. METHODS: The study groups included 20 UCLP patients (12 male, 8 female), 21 BCLP patients (12 male, 9 female), and a control group of 21 subjects with normal occlusion (10 male, 11 female). Measurements of condylar, ramal, and condylar plus ramal heights and asymmetry indexes were examined on cone-beam computed tomography images. One-way analysis of variance was used to determine potential statistical differences among the groups for condylar, ramal, and condylar plus ramal asymmetry index measurements. The post-hoc Tukey HSD test was used to determine individual differences. RESULTS: No investigated group showed a statistically significant sex difference for any asymmetry index (P >0.05). There was a statistically significant difference between the normal and cleft sides in the ramal height and ramal plus condylar height measurements in the UCLP group (P = 0.004 and P = 0.006, respectively). The Tukey HSD test showed a statistically significant difference between the UCLP and BCLP groups in terms of ramal asymmetry index values (P = 0.018). CONCLUSIONS: The ramal height and ramal plus condylar height measurements were significantly lower in the cleft side in the UCLP patients, and there was a statistically significant difference in ramal asymmetry index values between the patients affected by UCLP and BCLP.

Isolated oligodontia in monozygotic twins.

This case report defines a case of isolated oligodontia of 9 and 10 permanent teeth in 9-year-old monozygotic twin sisters and gives information about the possible genetic and environmental etiology, related dental anomalies and treatment options. The twins have a negative family history of hypodontia and oligodontia in their parents, as well as their paternal and maternal grandmothers and first cousins. No other dental anomalies could be detected in either of the twins. With the occurrence of similarly located tooth agenesis, except for one tooth, in monozygotic twins, one may consider the influence of genetic and/or environmental factors in their etiology. Hereditary relationships associated with oligodontia could help the clinicians to predict the possibility of its occurrence in other family members and in the next generations. However, clinicians should consider oligodontia when it is not hereditary.

Effects of early bilateral mandibular first molar extraction on condylar and ramal vertical asymmetry.

OBJECTIVES: This study aims to investigate the mandibular vertical asymmetry in a group of adult patients who had early bilateral mandibular first molar extractions. METHODS: Mandibular asymmetry index measurements (condylar, ramal, and condylar plus ramal) were made on the panoramic radiographs of a study group including 30 subjects (mean age, 18.22 ± 1.30 years) and a control group of 25 subjects (mean age, 18.24 ± 1.17 years). Group I comprised the control group patients with no extractions and had excellent class I relationships, no missing teeth, and slight or moderate anterior crowding. Group II included patients with a bilateral mandibular first molar teeth extracted before the age of 12 years. Student's t test was used for the comparison of asymmetry index values between the groups. A paired t test was used to determine possible statistically significant differences between the sides for condylar, ramal, and condylar plus ramal height measurements. RESULTS: No group showed statistically significant side-specific differences for posterior vertical height measurements. Condylar asymmetry index (CAI), ramal asymmetry index, and condylar plus ramal asymmetry index measurements were not statistically different between the groups (p > 0.05). CONCLUSIONS: CAI values were significantly high when compared with the 3 % threshold value in the both groups, but comparisons between the groups were not statistically significant. CLINICAL RELEVANCE: This article investigates the effects of early bilateral mandibular molar teeth extraction that has never been investigated in the literature. The present study showed that the lengths of the condylar, ramal, and condylar plus ramal height were less in the study group than in a well-matched control group of without extraction.

Maxillary expansion with the memory screw: a preliminary investigation.

OBJECTIVE: The purpose of this study was to investigate the effects of a newly developed rapid maxillary expansion screw-the memory screw-over 6 months. METHODS: Five subjects, aged between 11.7 and 13.75 years, were enrolled in this study. All subjects underwent placement of a maxillary expansion appliance containing superelastic nickel-titanium open-coil springs in its screw bed. The parents of the patients and/or the patients themselves were instructed to activate the expansion screw by 2 quarter-turns 3 times a day (morning, midday, and evening; 6 quarter-turns a day). The mean expansion period was 7.52 ± 1.04 days. Dentoskeletal effects of the procedure, including dentoalveolar inclination, were evaluated. Measurements of all the parameters were repeated after 6 months of retention in order to check for relapse. RESULTS: Sella-Nasion-A point (SNA) and Sella-Nasion/Gonion-Menton angles increased, and Sella-Nasion-B point (SNB) angle decreased in all the subjects during the expansion phase. However, they approximated to the initial values at the end of 6 months. On the other hand, the increments in maxillary apical base (Mxr-Mxl) and intermolar widths was quite stable. As expected, some amount of dentoalveolar tipping was observed. CONCLUSIONS: The newly developed memory expansion screw offers advantages of both rapid and slow expansion procedures. It widens the midpalatal suture and expands the maxilla with relatively lighter forces and within a short time. In addition, the resultant increments in the maxillary apical base and intermolar width remained quite stable even after 6 months of retention.

The effects of face mask therapy with and without rapid maxillary expansion in adolescent patients.

OBJECTIVE: To examine the effects of face mask therapy with and without associated rapid maxillary expansion (RME) in adolescent patients presenting with skeletal Class III malocclusion characterised by maxillary retrognathism. METHODS: Case records consisting of lateral cephalograms and hand-wrist films of 43 patients with hypoplastic maxillary Class III malocclusions treated using a face mask with and without an RME were analysed. The patients were divided into two groups; Group A (N = 27) were treated with a face mask coupled with rapid maxillary expansion and patients in Group B (N = 16) were treated with a face mask appliance only. Ten cephalometric linear and 9 angular variables were measured to assess the dentofacial changes. Within group and between groups comparisons were determined by a paired t-test and Student's t-test, respectively. RESULTS: Forward displacement of the maxilla and a clockwise rotation of the mandible occurred in both groups. The maxillary-mandibular relationship improved and soft-tissue changes resulted in a more convex profile. The maxillary incisors moved forward only in Group B subjects but the mandibular incisors moved backward in both groups. CONCLUSIONS: Face mask therapy with and without an associated RME improved skeletal Class III malocclusion by a combination of skeletal and dental changes. These results suggested that the use of an RME should be based on clinical criteria rather than assisting the Class III correction.

Subjective symptoms of RME patients treated with three different screw activation protocols: a randomised clinical trial.

AIMS: The purpose of the present study was to evaluate the subjective symptoms of patients during the active phase of rapid maxillary expansion (RME) treatment, and further, to assess the differences between three different RME activation protocols. MATERIALS AND METHODS: The clinical sample consisted of 60 patients (mean age 13.5 years) with maxillary transverse deficiency requiring expansion. The subjects were randomly divided into three groups on which different expansion protocols were performed. An evaluation of the subjective symptoms was carried out by a Numerical Rating Scale (NRS). The patients completed questionnaires after the first, fifth, tenth, twentieth and final activations. A Shapiro-Wilk test was applied to evaluate homogenity; a Kruskall Wallis test was performed for gender-related differences and to compare the different activation schedules. The Wilcoxon test was used to compare the activations at the various time intervals. RESULTS: No gender-related differences were found. Ninety-eight percent of the patients reported pain during RME. There were no specific differences between groups except for the pain perceived at the twentieth activation. In all groups, pain, the sensation of pressure and its duration were highest at the fifth activation. Subjective symptoms tended to decrease after the fifth and tenth activations. Headache and dizziness were minimal. CONCLUSION: Different activation protocols did not appear to alter subjective symptoms encountered during RME. The majority of the patients undergoing RME suffered pain and pressure sensations especially after the fifth activation.