Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

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Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles Simona Tecco a,⇑, Aberto Baldini b, Stefano Mummolo c, Enrico Marchetti c, Maria Rita Giuca d, Giuseppe Marzo c, Enrico Felice Gherlone a a

University Vita-Salute San Raffaele, I.R.R.C.S. San Raffaele Hospital, Milano, Italy Unit of Orthodontics, University of Tor Vergata, Rome, Italy Department of Life, Health and Environmental Science, University of L’Aquila, Italy d Department of Surgical, Medical and Molecular Pathology and Clinics, University of Pisa, Italy b c

a r t i c l e

i n f o

Article history: Received 19 July 2013 Received in revised form 6 April 2015 Accepted 7 April 2015 Available online xxxx Keywords: Laser Orthodontics Lingual frenulectomy sEMG Masticatory muscles Sub-mental muscles Orbicularis oris muscle

a b s t r a c t This study aimed to assess by surface electromyography (sEMG) the changes in sub-mental, orbicularis oris, and masticatory muscle activity after a lingual frenulectomy. Rehabilitation exercises in subjects with ankyloglossia, characterized by Class I malocclusion, were assessed as well. A total of 24 subjects were selected. Thirteen subjects (mean age 7 ± 2.5 years) with Class I malocclusion and ankyloglossia were treated with lingual frenulectomy and rehabilitation exercises, while 11 subjects (mean age 7 ± 0.8 years) with normal occlusion and normal lingual frenulum were used as controls. The inclusion criteria for both groups were the presence of mixed dentition and no previous orthodontic treatment. The sEMG recordings were taken at the time of the first visit (T0), and after 1 (T1) and 6 months (T2) for the treated group. Recordings were taken at the same time for the control group. Due to the noise inherent with the sEMG recording, special attention was paid to obtain reproducible and standardized recordings. The tested muscles were the masseter, anterior temporalis, upper and lower orbicularis oris, and sub-mental muscles. The sEMG recordings were performed at rest, while kissing, swallowing, opening the mouth, clenching the teeth and during protrusion of the mandible. These recordings were made by placing electrodes in the area of muscle contraction. At T0, the treated group showed different sEMG activity of the muscles with respect to the control group, with significant differences at rest and during some test tasks (p < 0.05). In the treated group, an increase in sEMG potentials was observed for the masseter muscle, from T0 to T2, during maximal voluntary clenching. During swallowing and kissing, the masseter and sub-mental muscles showed a significant increase in their sEMG potentials from T0 to T2. During the protrusion of the mandible, the masseter and anterior temporalis significantly decreased their sEMG activity, while the sub-mental area increased significantly. No significant change was observed in the control group during the follow-up. The sEMG potentials of treated patients at T2 reached about the same values as those of the control group at T2. At T0 and T1 the differences between the two groups were more diffused, suggesting a clinical improvement of muscular functions after treatment. Lingual frenulectomy and rehabilitation exercises seem to affect the function of the orofacial muscles. Improvement in muscle sEMG potentials after treatment was demonstrated by sEMG, which can be considered the correct method to monitor this intervention. Ó 2015 Elsevier Ltd. All rights reserved.

1. Introduction Several studies have been undertaken for centuries to understand the relationship of form and function in orofacial development (Pagni and Baccetti, 1993). ⇑ Corresponding author at: University Vita-Salute San Raffaele, Milano, Via Olgettina 60, Italy. E-mail addresses: [email protected], [email protected] (S. Tecco).

In growing patients, orofacial myofunctional therapy (OMT) in combination with conventional orthodontic therapy allows achieving harmonious orofacial development during growing (Fournier and Girard, 2013). It is now well recognized that most dentomaxillofacial dysmorphism have a multi-factorial etiology. Among the environmental factors, uneven pressures caused by the behavior of the orofacial muscles are recognized as a dynamic cause. (Grabowski et al., 2007; Stahl et al., 2007). A correct function leads to trouble-free jaw development, whereas an impaired function

http://dx.doi.org/10.1016/j.jelekin.2015.04.003 1050-6411/Ó 2015 Elsevier Ltd. All rights reserved.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

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S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

may adversely influence the masticatory system. (Porticelli et al., 2009). Correcting dysfunctions may therefore be helpful in eliminating dysmorphism. Lingual frenulum acts on the muscle function of the tongue, which is a crucial factor in determining the way in which the jaws develop. (American Speech-Language-Hearing Association, 1993; Meyer, 2000). In cases of ankyloglossia interceptive treatments such as lingual frenulectomy and OMT lead to a more correct function of the tongue muscles through a neuromuscular re-education. This is obtained through rehabilitation exercises of the tongue during its movements, achieved by allowing the biological force naturally present in the tongue (Marchesan, 2012). It is ideal to release the restricted frenulum as early as possible – meaning at birth – because the tongue will achieve optimal function through the activity of breastfeeding, which promotes tongue–palatal contact and requires the back of the tongue to activate by making a suction seal (Kotlow, 1999). These actions promote optimal muscle function of the entire orofacial complex (Grabowski et al., 2007; Stahl et al., 2007). Interceptive treatments that can influence the function of orofacial muscles can be monitored through surface electromyography (sEMG), a useful aid for monitoring the correct evolution of these types of treatment (Saccucci et al., 2011; Cram and Kasman, 1997; Tecco et al., 2008). This study aimed to assess the changes in the sEMG potentials in the sub-mental, orbicularis oris, and masticatory muscles after lingual frenulectomy and OMT in subjects with ankyloglossia, characterized by Class I malocclusion. The working hypothesis was whether frenulectomy and OMT could generate changes in the sEMG potentials of masticatory, sub-mental, and orbicularis oris muscles during their functions, equaling their sEMG potentials to those detected in a control group of healthy subjects.

2. Material and methods 2.1. The sample Thirteen white Caucasian patients (9 males and 4 females) with Class I malocclusion (end-to-end or Class I relationships at the first permanent molars and deciduous canines) and ankyloglossia, examined at the Department of Oral Science of the University, and in a private study, between January 2008 and December 2009, were included in this study (treated group) and treated with lingual frenulectomy (Figs. 1 and 2) and an OMT protocol. The mean age of treated subjects was 7.0 ± 2.5 years. The patients included in the study group were diagnosed based on the diagnostic criteria of ankyloglossia according to Kotlow (1999) (the classification is based on the length of the frenulum measured in millimeters from the floor of the mouth to the sub-lingual attack), and showed grade 3 (called ‘‘severe tongue-tie”, about 4–8 mm) or grade 4 (called ‘‘complete tongue-tie”, 0–4 mm). The patients showed orofacial myofunctional disorders (American SpeechLanguage-Hearing Association, 1993) associated with ankyloglossia, which are atypical swallowing, low lingual posture, and, as consequence, small palatal diameter. They showed limited tongue movements (limited ability to protrude and retract the tongue, to touch the superior lip with the apex, to touch the right and left labial commissure and the upper molars; limited/absent ability to perform tongue apex vibration and suck against the palate) (De Felício et al., 2010; Bakke et al., 2007). Treatment was performed after obtaining informed consent from the parents. The patients were instructed to do orofacial myofunctional exercises before and after their surgical intervention. During daytime, they were invited to do 10–20 repetitions for 3 times in a day. Eleven children (9 males and 2 females) with normal occlusion (Class I occlusion without crowding, with normal overjet, overbite

Fig. 1. Very short and fibrous lingual frenum with ankyloglossia.

and midline position, and with normal lingual frenulum) were recruited as the control group. The mean age was 7 ± 0.8 years. In the control group, the lingual frenulum was considered normal based on the diagnostic criteria for ankyloglossia according to Kotlow (1999) showing score 0 (called ‘‘normal”: >15 mm). The control subjects were able to protrude and retract the tongue, and to touch the superior lip with the apex, the right and left labial commissure, and the upper molars. They could perform tongue apex vibration and suck against the palate. Their tongue showed an oblong or squared tip, with the frenulum visible only under the tongue, near the sublingual caruncles. Tongue behavior during deglutition was considered normal as the tongue was contained in the oral cavity. After the treatment, the tongue position and tongue movements were evaluated according to the Kotlow scores. The capacity of movement of the tongue was also evaluated based on protocols used by speech pathologists (De Felício et al., 2010; Bakke et al., 2007). The inclusion criteria for both groups were the presence of mixed dentition and no previous orthodontic treatment. The exclusion criteria for both groups were the presence of caries, dental anomalies, and craniofacial syndromes. With regard to the dental formula of the enrolled subjects, we did not observe important differences between the groups during the six months of follow-up.

2.2. Description of surgical procedure (Figs. 1 and 2) Laser treatment is preferred by children and their parents as anesthesia is not needed, no pain is associated with treatment, surgery time is often short, and there is no blood loss or post-surgical edema (Convissar and Goldstein, 2003). In these cases a laser fiber of 400 lm, with a power of 3 W in a continuous mode, was employed (Elanchezhiyan et al., 2013). In only two cases a local injection of carbocaine (Fl 10 ml 10 mg/ml) was made. The incision was created in the anatomical and muscular planes. A rhomboid cut was performed, with particular care taken to preserve the muscles and salivary glands. Soon after the surgical intervention, the OMT re-education protocol was prescribed for better results.

2.3. The re-education protocol The re-education protocol (Fournier and Girard, 2013) was explained by the same operator. It was necessary to repeat the procedure several times before the day of the surgical intervention, to enable patients to become familiar with the exercises and to help them recover after surgery.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

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Fig. 2. (A–E) Very short and fibrous lingual frenum with ankyloglossia. The incision was made with respect to the muscles, and the tongue was mobilized.

After the exercises are explained to the patient for the first time, it is necessary to obtain the patient’s cooperation, i.e., diligence in executing the exercises at home for three times a day and for four to five weeks post-surgery. A first control was carried out a week after surgery, then a second control at the end of the first month. If necessary, an intensification of the work of stretching, with an increase in the number of required exercises, can be requested. Otherwise the normal training is sufficient for a complete functional rehabilitation. The execution mode is crucial. For this it is necessary to insist on illustrating the protocol. Each exercise should be performed in a slow and energetic way, moving all the muscles of the tongue and maintaining the elongation for an adequate time. Asking the patient to do the exercises in front of a mirror can be useful, to realize the best mode for carrying out the requests. The following exercises should be repeated for at least 10–20 repetitions, three times a day: Exercise 1: Move the apex of the tongue forward and up as much as possible near to the nose, then to the bottom of the chin, then laterally toward the labial commissure, first to one side then to the other, turning the tip of the tongue at the bottom and the top of the lower third of the face. Exercise 2: Perform circular movements of the tongue in the clockwise and the counterclockwise directions, and on the labial surface of the teeth and outside of the lips. Exercise 3: Protrude the tongue until it takes on either a large form or a pointed form. Exercise 4: Place the tongue on the palatal landmarks (possibly with a rubber band), then, keeping it in position, without pushing against the teeth, open and close the mouth. Exercise 5: The following exercise is the cornerstone of rehabilitation, as it allows the distension of the scar area, maintaining the increase in lingual mobility obtained with the surgical intervention. Lift the tip of the tongue just behind the incisive papilla. Stick the back of the tongue to the palate. Suck air between tongue and palate to create a vacuum and increase adhesion. Slowly open

the mouth to stretch strongly the lingual frenulum, also trying to stretch it (the frenulum should be really tight; check this position in front of a mirror). Remove the tongue from the palate, producing an explosive sound very similar to a CIAK [’ʧak]. Exercise 6: Open the mouth slowly, touch the retroincisor papilla with the tip of the tongue and trying to do it faster and faster. Exercise 7: Place the tip of the tongue at the retroincisor papilla, then slide the tongue on the palate in the anterior-posterior direction until it touches the uvula, then forward again, repositioning it on the papilla.

2.4. Electromyographic recording The sEMG potentials were measured using an 8-channel Bio-pak EMG (BIOEMG 800TM, Bio research Assoc. Inc., USA), pass-band 5– 500 Hz. The sEMG assessment was performed using Myo Tronic Duo-Trode bipolar surface rectangular electrodes (10 mm
5 mm), Al/AgCl with gel, with a fixed inter-electrode gap of 10 mm (Cram and Kasman, 1997; Tecco et al., 2008, 2011). Before the examination, the skin was prepared with ethyl alcohol to decrease impedance, and then the electrodes were applied parallel to the direction of the fibers of the muscles. During the sEMG examination, the patient was seated in the usual position on a dental chair, corresponding to the position in which the backrest of the chair is a little more than 90° with respect to the support to sit (Tecco et al., 2011). The patient was invited to assume a ‘‘natural head position” to avoid undesired inclinations of the head. This position was obtained in this study by having the subjects look straight ahead at a small mirror at eye level, as described in the literature (Moorrees, 1994). The subjects were asked to make themselves comfortable, to relax their arms by their sides, and to look straight ahead and make no head or body movements during the test. With this arrangement, unintentional movements from other parts of the body were eliminated or reduced.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

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S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

The sEMG potentials of the upper and lower fascicles of the orbicularis oris muscle, sub-mental areas, masseter, and anterior temporalis (as masticatory muscles) were used to evaluate muscle activity during situations that involved effective lip participation (Fig. 3). Data of right and left muscles were averaged. The sEMG potential of the tested muscles in the treated and control groups was investigated during rest position, clenching of teeth, and during some functional tasks, as kissing, swallowing, opening of mouth and protrusion of mandible at T0 (before therapy for the treated group), and after 1 (T1) and 6 (T2) months of treatment for the study and the control groups. The rest position was included to evaluate the basal electric potential of the muscles. The sEMG channels were applied on the electrodes, while a single ground electrode was applied over the skin of the hand. The electrodes were then connected to the amplified control unit. Before the registration, electrodes were in place for a few seconds. All sEMG recordings were performed by the same operator (author S.T.). 2.4.1. Dynamic tasks For the dynamic tasks, prior to performing the movements, the patients were given instructions and practice, imitating the examiner. Each movement pattern (swallowing, kissing, protrusion and opening) had to be repeated by the patient for three repetitions to ascertain their stability (Saccucci et al., 2011; Tecco et al., 2008, 2011). Each repetition generated a sEMG recording of 1–2 s. For the analysis of the data, the first repetition was eliminated as the ‘‘learning” sequence, while the arithmetic means of the last two repetitions (each repetitions generated a recording of about 1– 2 s) were used as data of that patient. The calculation of the arithmetic mean was performed in an attempt to partially reduce (although it is impossible to avoid) the effects of the nonstationary nature of sEMG signals (Dantas et al., 2010). In particular, for each repetition/recording, the starting point was in habitual occlusion. Swallowing was on command and with

saliva in mouth; ‘‘kissing,” protrusion, and opening of the mouth were on command as well. Swallowing and kissing were included to evaluate the existence of contractions associated with the activation of the sub-mental muscles. Opening of mouth and protrusion of mandible were included to evaluate the sEMG potentials during movements that are expected to involve the sub-mental muscles. The computerized system allows raw data to be displayed on the screen, permitting a preliminary analysis of the waveform. The waveform was not treated (for example through a discrete wavelet transform), because each recording/repetition only lasted about 1–2 s, and did not involve serial repetitions of the same movement, but only a single repetition (i.e. a single swallowing, a single kissing, a single protrusion).

2.4.2. The normalization of data The data were represented as mV * 10. Recordings during maximal voluntary clenching (MVC) on cotton rolls provided reference EMG values for the subsequent normalization, as proved in 2006 (Ferrario et al., 2006). Two 10-mm-thick cotton rolls were positioned on the mandibular first molars of each patient, and MVC was recorded. This value was set at 100%, and the mean EMG potentials during an MVC on occlusal surfaces, and during the other tasks were expressed as a percentage of this value. The EMG normalized signals (X) were expressed as follows:

X ¼ Valuesðon occlusal surfaces recorded during all the tasksÞ =Valuesðon cotton rollsÞ  100: UnitðXÞ ¼ mV=mV  100: To avoid any fatigue effects, a rest period of at least 1 min was allowed between each task, so a total of about 10 min were necessary for the whole examination, not considering the time employed for the study of repeatability, for which other electrodes were employed.

Fig. 3. Positioning of the sEMG electrodes (masseter, anterior temporalis, sub-mental area, upper and lower orbicularis oris.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

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S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

groups. When the Friedman test was significant (p < 0.05), the Dunns post-hoc test was used to test the significance between different time periods. In addition, for inter-group comparisons, the Mann–Whitney U test was used to compare the sEMG values in the treated group vs. the control group at T0, T1, and T2. For the Friedman test, a correction of the value of vF2 was introduced in the statistical tests, to avoid false positive results due to repetitions of data. The correction value of vF2 (correction for ties) was obtained placing in the denominator the formula: (Myles and Wolfe, 1999).

2.5. The repeatability of the recording protocol The repeatability of the protocol was maintained by using a standard procedure for positioning the electrodes (Tecco et al., 2008). In particular, for the positioning of the electrodes, to ensure their positioning in the areas of contraction, the movement performed by the patients consisted of clenching (for the anterior temporalis and the masseter), ‘‘kissing” (for the puckering role of the orbicularis oris muscles in this movement), and swallowing (for the sub-mental area). A template was used to enable the exact reposition of the electrodes, in the occurrence of malfunctioning during the examination. Approximately 10% of the electrodes required a relocation after degreased, dry, jelly electrode fixation. Due to the noise inherent with the sEMG recording, special attention was paid to obtain reproducible and standardized recordings.

N  k  ðk þ 1Þ þ

PN PP

Nk

i¼1

3 j¼1 r ij

k1

where – N is the number of rows or observations per group, – K is the number of columns or groups, – P is the number of data with the same value, and thus with the same rank, in the same line; – rij is the size of the ranks repeated.

2.6. Data analysis The statistical power calculation determined that 11 subjects per group would provide a 70% power to detect a true difference of 0.5 between the two groups, assuming this value from the difference between the two measurements in the study of repeatability, which was 0.4 ± 1. Accordingly, a sample of 13 subjects was recruited in the test group to overcome the possibility of dropouts. The intraclass correlation coefficient (ICC) was calculated to evaluate the correlation between the first and the second measurements in the study of repeatability. The Friedman test was used to evaluate intra-group differences at different observation times within the treated and the control

Type I error was 0.05. Type II error was 0.3.

3. Results The data of the preliminary study confirmed the repeatability of the protocol. The repeatability of the studied tasks were comprised between 0.8 and 0.98 (as ICC).

Table 1 Root mean square of sEMG potentials (mV * 10) during maximal voluntary clenching (MVC) at T0, T1 and T2 in the treated group. MVC data are normalized. aData showed not normal distribution. Only data of Masseter are reported as changes were statistically significant. Treated group (T0)

Treated group (T1)

Treated group (T2)

Median

Median

Median

IQ range

IQ range

IQ range

T0 vs. T1

T0 vs. T2

T1 vs. T2

0.27

p = 0.04 P = 0.03

P = 0.04

NS

MVCa (normalized) Masseter a

1.66

0.31

1.9

0.28

1.89

Statistical comparisons (Friedman test) and Dunns post hoc test).

Data are normalized as % of MVC on cotton rolls.

Table 2 Statistically significant changes of the RMS of the sEMG potentials of the treated group at T0, T1 and T2 during swallowing, kissing and protrusion of the mandible (mV * 10). Data are normalized. aData showed not normal distribution. Treated group (T0)

Treated group (T1)

Treated group (T2)

Statistical comparisons (Friedman test) and Dunns post hoc test).

Median

IQ range

Median

IQ range

Median

IQ range

T0 vs. T1

T0 vs. T2

T1 vs. T2

0.74

1.63

0.69

1.74

0.94

1.58

P = 0.04

p = 0.001 P = 0.005

NS P = 0.04

Swallowing Masseter Sub-mental

0.41

0.97

0.56

1.81

0.74

1.6

NS

p = 0.03 P = 0.03

Masseter

0.86

1.67

0.91

1.97

0.93

1.78

NS

p = 0.001 P = 0.004

P = 0.004 NS

Kissing

Sub-mental

0.36

0.91

0.64

1.32

0.74

2.4

P = 0.03

p = 0.001 P = 0.005

1.71

6.2

1.17

3.6

1.34

3.5

P = 0.004

p = 0.001 P = 0.004

P = 0.004

P = 0.04

p = 0.001 NS

P = 0.004

P = 0.03

p = 0.001 NS

P = 0.04

Protrusion of the mandible Masseter Anterior temporalis Sub-mental a

0.94 0.62

1.4 3.5

0.71 0.61

1.3 0.92

0.62 3.8

1.6 2.7

Data are normalized as % of MVC on cotton rolls.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

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S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

Table 3 sEMG potentials and inter-groups comparisons with Mann Whitney U test. Data are normalized as % of MVC on cotton rolls. Data are reported as median and inter-quartile range, as they were not normally distributed. Confidence intervals (95%) are also reported. T0 (test group vs. control group)

T1 (test group vs. control group)

P Study group: Median (IQ range) (Confidence Interval 95%) At rest Masseter

0.33 (0.41) (±0.03)

Control group: Median (IQ range) (Confidence Interval 95%)

Study group: Median (IQ range) (Confidence Interval 95%)

*

0.16 (0.71) (±0.03)

0.15 (0.62) (±0.03)

NS

0.17 (0.52) (±0.03)

0.42 (0.44) (±0.03)

*

0.19 (0.52) (±0.03)

0.32 (0.38) (±0.04)

NS

0.27 (0.46) (±0.04)

NS

0.32 (0.43) (±0.03)

Study group: Median (IQ range) (Confidence Interval 95%)

0.14 (0.62) (±0.02)

0.32 (0.71) (±0.03)

0.27 (0.38) (±0.03)

0.31 (0.42) (±0.04)

OO upper

0.47 (0.34) (±0.02)

**

0.31 (0.37) (±0.03)

0.49 (0.29) (±0.03)

**

0.25 (0.3) (±0.03)

0.27 (0.41) (±0.05)

0.47 (0.39) (±0.03)

**

0.12 (0.41) (±0.03)

0.47 (0.38) (±0.03)

**

0.12 (0.43) (±0.04)

0.36 (0.4) (±0.04)

0.56 (0.38) (±0.04)

**

0.32 (0.41) (±0.02)

0.59 (0.39) (±0.03)

**

0.31 (0.38) (±0.03)

0.36 (0.41) (±0.04)

NS

0.33 (0.42) (±0.04)

1.66 (0.31) (±0.04)

**

1.89 (±0.04)

1.9 (0.28) (±0.04)

1.89 (0.35) (±0.04)

1.89 (0.27) (±0.04)

NS

1.89 (0.37) (±0.03)

Anterior temporalis

1.71 (0.36) (±0.03)

**

2.19 (0.31) (±0.03)

1.61 (0.38) (±0.03)

2.19 (0.37) (±0.04)

1.72 (0.35) (±0.03)

OO upper

0.24 (0.33) (±0.04)

NS

0.26 (0.36) (±0.03)

0.25 (0.39) (±0.02)

NS

0.18 (0.36) (±0.02)

0.26 (0.31) (±0.03)

NS

0.22 (0.29) (±0.03)

0.24 (0.22) (±0.04)

NS

0.25 (0.29) (±0.02)

0.26 (0.3) (±0.04)

NS

0.24 (0.28) (±0.02)

0.27 (0.26) (±0.02)

NS

0.23 (0.28) (±0.02)

0.37 (0.34) (±0.03)

NS

0.36 (0.38) (±0.04)

0.38 (0.35) (±0.03)

NS

0.33 (0.36) (±0.03)

0.41 (0.37) (±0.04)

0.93 (1.42)

0.69 (1.74) (±0.02)

0.94 (1.48)

(±0.04)

(±0.03)

0.94 (1.58) (±0.03)

NS

(±0.04)

0.87 (0.97) (±0.04)

0.85 (0.84) (±0.04)

NS

0.92 (0.82) (±0.04)

0.89 (0.93) (±0.03)

NS

0.93 (0.95) (±0.03)

Sub-mental MVC Masseter

OO lower Sub-mental Swallowing Masseter

0.74 (1.63) (±0.02)

NS

**

NS **

**

*

**

*

0.12 (0.42) (±0.03)

2.19 (0.32) (±0.04)

0.37 (0.35) (±0.03) 0.92 (1.32)

Anterior temporalis

0.92 (0.92) (±0.04)

OO upper

0.49 (1.22) (±0.05)

**

0.34 (1.12) (±0.06)

0.33 (1.15) (±0.05)

NS

0.34 (0.96) (±0.05)

0.33 (0.94) (±0.05)

NS

0.32 (0.92) (±0.05)

0.47 (0.91) (±0.04)

**

0.22 (0.83) (±0.03)

0.24 (0.86) (±0.04)

NS

0.23 (0.92) (±0.04)

0.25 (0.99) (±0.03)

NS

0.22 (0.84) (±0.05)

0.41 (0.97) (±0.03)

**

0.74 (1.63) (±0.04)

0.56 (1.81) (±0.05)

**

0.65 (1.62) (±0.05)

0.74 (1.6) (±0.06)

NS

0.73 (1.46) (±0.05)

0.86 (1.67) (±0.06)

**

0.74 (1.42) (±0.05)

0.91 (1.97) (±0.05)

**

0.71 (1.32) (±0.04)

0.93 (1.78) (±0.05)

OO lower Sub-mental

Kissing Masseter

NS

**

0.72 (1.12) (±0.04)

Anterior temporalis

0.42 (1.08) (±0.05)

NS

0.45 (0.92) (±0.05)

0.36 (0.75) (±0.06)

NS

0.47 (0.95) (±0.05)

0.44 (0.83) (±0.03)

NS

0.45 (0.81) (±0.06)

OO upper

1.02 (0.92) (±0.04)

NS

0.98 (1.24) (±0.03)

0.97 (1.23) (±0.06)

NS

0.99 (1.42) (±0.05)

0.98 (1.25) (±0.05)

NS

0.96 (0.92) (±0.06)

1.08 (0.95) (±0.05)

0.82 (0.94) (±0.02)

OO lower Sub-mental

0.84 (0.82) (±0.04)

*

1.06 (0.93) (±0.02)

0.81 (0.91) (±0.06)

0.36 (0.91) (±0.03)

**

0.69 (0.84) (±0.04)

0.64 (1.32) (±0.05)

NS

0.69 (1.13) (±0.06)

0.74 (2.4) (±0.04)

NS

0.73 (1.12) (±0.05)

*

1.34 (4.3) (±0.04)

1.17 (3.6) (±0.05)

NS

1.22 (5.1) (±0.06)

1.34 (3.5) (±0.05)

NS

1.33 (4.9) (±0.05)

NS

0.62 (4.1) (±0.05)

Protrusion of the mandible Masseter 1.71 (6.2) (±0.02)

*

*

1.09 (0.91) (±0.05)

Anterior temporalis

0.94 (1.4) (±0.06)

**

0.61 (4.1) (±0.05)

0.71 (1.3) (±0.04)

**

0.59 (3.8) (±0.04)

0.62 (1.6) (±0.06)

OO upper

0.47 (2.8) (±0.04)

**

0.23 (1.93) (±0.02)

0.36 (2.12) (±0.04)

*

0.22 (1.96) (±0.03)

0.31 (1.91) (±0.05)

0.57 (1.8) (±0.05)

**

0.31 (2.2) (±0.04)

0.35 (1.5) (±0.03)

0.32 (1.93) (±0.02)

0.34 (1.83) (±0.04)

NS

0.31 (2.21) (±0.05)

0.62 (3.5) (±0.04)

*

0.89 (2.93) (±0.05)

0.61 (3.8) (±0.06)

0.93 (2.84) (±0.05)

0.92 (2.7) (±0.02)

NS

0.92 (2.96) (±0.04)

OO lower Sub-mental *

P Control group: Median (IQ range) (Confidence Interval 95%)

Control group: Median (IQ range) (Confidence Interval 95%)

Anterior temporalis

OO lower

**

*

T2 (test group vs. control group)

P

NS **

*

0.23 (2.01) (±0.04)

p < 0.05. p < 0.01.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

After treatment none of the patients showed ankyloglossia, defined as lack of or minimal frenulum, or a frenulum attached to the apex of the tongue. None showed ‘‘short” or ‘‘anterior” or ‘‘short/anterior” frenulum. The Kotlow index (Kotlow, 1999) passed from 3–4 to score 0 (called ‘‘normal”: >15 mm) or score 1 (called ‘‘acceptable; 12–15 mm). After treatment, the patients were able to protrude and retract the tongue, to touch the superior lip with the apex, the right and left labial commissure, and the upper molars. They were able to perform tongue apex vibration and suck against the palate. At mandibular rest position, their tongue appeared in a correct position, completely contained in the oral cavity in the mouth (and not visible). All the patients showed an oblong and squared tip, and the frenulum was visible only under the tongue, near the sublingual caruncles. About the sEMG data, the treated group showed an increase in the sEMG potentials for the bilateral masseter muscle, from T0 to T2, during MVC (Table 1). Table 2 shows the statistically significant changes in the treated group during functional tasks. During swallowing and kissing, the masseter and sub-mental muscles showed a significant increase in their sEMG potentials from T0 to T2. During the protrusion of the mandible, the masseter and anterior temporalis significantly decreased their sEMG activity, while the sub-mental area increased significantly. No statistically significant changes were registered for the control group over time. Table 3 describes inter-group comparisons at T0, T1, and T2. The sEMG potentials of treated patients at T2 reached about the same values as that of the control group at T2, while the differences between the two groups were more diffused at T0 and T1. At mandibular rest position, no significant difference was observed at T2 between the treated and the control groups, except for the lower orbicularis oris muscle. During MVC, the masseter muscles showed no significant difference between the study and the control groups at T2. During swallowing, the differences between the study and the control groups significantly decreased during the follow-up for the orbicularis oris and the sub-mental muscles. During kissing, the differences between the study and the control groups remained about the same from T0 to T2. For the submental muscles, the differences significantly decreased during follow-up. During the protrusion of the mandible, the orbicularis oris and the sub-mental muscles registered a reduction of the differences between the two groups, from T0 to T2.

4. Discussion In the present study, the sEMG potentials of the masticatory, sub-mental, and orbicularis oris muscles in subjects with Class I malocclusion and ankyloglossia were evaluated before and after surgical intervention of frenectomy and OMT rehabilitation protocol. This group of patients was compared with a control group with normal occlusion. In the present study, lingual frenectomy and OMT improved tongue form and function in all the treated subjects, which underlines the importance of functional rehabilitation after surgical intervention, for better clinical results. When tongue function is restricted by a tongue-tie, the muscles adapt. Since the tongue cannot function the way it is supposed to, other muscles have to help compensate. There is a whole cascade of compensations and adaptations throughout the stomatognathic apparatus. When a tongue-tie is surgically treated, the patient has no muscle memory of how to use his/her tongue without the restriction there. It takes time for the brain to rewire itself and

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figure out how to suck effectively once the tie is released. OMT can obtain this functional re-education. During the 6-month follow-up the modifications of tongue form and position and the capacity of tongue movement obtained with frenulectomy and OMT protocol were accompanied by statistically significant changes in the sEMG potentials of the masticatory and sub-mental muscles in some tasks, particularly during MVC, kissing, and swallowing. No difference was observed in the control group during the entire follow-up. Moreover, sEMG seems useful in monitoring the appropriate development of these types of therapy. More specifically, the electromyographic monitoring of masseter, anterior temporalis and sub-mental muscles seems indicative of a good clinical rehabilitation of tongue tie. The following sEMG tasks seem to be more much indicative of a good result to be applied on frenulectomy follow-up: MVC, kissing, swallowing and mandibular protrusion. 4.1. The methods In this study, to obtain good intra-individual reproducibility of the orientation of the subject’s head, the sEMG recordings were obtained with the subjects in a standardized orientation called the ‘‘natural head position” (mirror position), as described above (Tecco et al., 2011; Moorrees, 1994; Madsen et al., 2008). No study on method error has been performed with regard to the positioning of subjects in the ‘‘natural head position”, as this method is generally considered one of the most repeatable, especially in adults (data about children are not so clear). In this study regarding the sEMG recordings of the functional tasks, the choice of making the patient carry on 3 repetitions for each movement pattern was made to ascertain their stability. Surface EMG is based on the extracellular recording of the motor unit action potentials by means of surface sensors (Cram and Kasman, 1997). Due to the non-stationarity of the EMG signal, data of all the tasks were normalized. 4.2. Interpretation of data In the present study, the increase in the standardized sEMG potentials for the bilateral masseter muscle, from T0 to T2, during MVC, could suggest a possible clinically relevant adaption of masticatory function after our treatment, possibly because of the changed neurological information from the periphery (Moeller, 2012). Tongue muscles originate from the somites, while masticatory muscles originate from the somitomeres. The latter develop late and are not complete even at birth, whereas tongue muscles develop before masticatory muscles and are complete by birth (Yamane, 2005). The hypoglossal nerve (Cranial Nerve XII) provides the motor innervation of the intrinsic and extrinsic tongue muscles; motor units within the hypoglossal motor system can be categorized as predominantly fast fatigue resistant (Smith et al., 2005). The extrinsic muscles of the tongue provide a scaffolding by which the intrinsic muscles can be moved around in the oral cavity, while the latter are continuously modifying their dimension and contour. The intrinsic muscles of the tongue have no attachments in bone. These muscles terminate either within each other or in the extrinsic muscle group. Intrinsic muscles are capable of assuming an infinite variety of shapes, but depend on the activity of the extrinsic muscles to be moved bodily through space. Restricted lingual frenum may cause the extrinsic tongue muscle function to develop and function incorrectly. Consequently, the function of intrinsic lingual muscles can also be affected by tongue tie. Human tongue innervation has been recently analyzed histologically and described as extremely dense and complex (Mu and Sanders, 2010). The transverse muscle group (intrinsic muscles)

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

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that comprises the core of the tongue was found to have the most complex innervation. The pattern of innervation of the human tongue also has specializations not found in other mammalian tongues, which allows for fine motor control of tongue shape and for an extreme sensitivity from periphery, for example from its ventral part is connected to the oral floor and sub-mental area by the frenulum. All these aspects explains the relationship between frenulum and tongue function. In addition, on a microscopic examination of tongue tie, the mucosa of the frenulum appears fibrosed, and fibrous tissue also seems to replace underlying fibers of genioglossus muscle to a varying degree (Hiiemae and Palmer, 2003). Also these data can give rise of the interaction between tongue tie and functional activity of sub-mental muscles. During our follow-up, a reduction in the differences between the study and the control groups was also registered for the orbicularis oris muscles (Table 1). In children with tongue tie, the tongue is thrust between the separated dental arches and is confined only by the contracting lips and cheeks during swallowing. This could give rise of the interaction between tongue function and the sEMG activity of orbicularis oris muscles. 4.3. The importance of O.M.T Although it is impossible to obtain certain information about the neuromuscular adaptation process of a muscle during a treatment, sEMG evaluations seem to put forth the interaction between tongue function and orofacial myofunctional status with more scientific data (quantitative data) through a noninvasive assessment, as recently assessed in subjects with temporomandibular disorders (De Felício et al., 2012). In normal conditions, the stomatognathic system shows neuromuscular harmony. However, this harmony may be disrupted, and alterations/dysfunctions of the appearance, posture, and mobility of the lips, tongue, mandible, and cheeks may occur. ‘‘Orofacial myofunctional disorders” serves as a collective label for these alterations (de Felício and Ferreira, 2008). Tight lingual frenulum have a critical impact on normal function and on the development of the orofacial complex (Romero et al., 2011; Northcutt, 2009; Rogers, 1950; Mathur et al., 1995). In these cases, when the tongue is restricted for a full range of mobility, a treatment with lingual frenulectomy is essential. Even more essential, as recently emphasized in cranio-mandibular practice, (Moeller, 2012) seems to be the follow-up with an OMT specialist so that a patient who has just undergone a lingual frenectomy may be assured success. The OMT specialist will work with the patient to re-pattern the muscles, ensure full range of motion of the tongue, and make sure the tissues do not re-attach after surgery (Moeller, 2012). 4.4. Limits of the study A limitation of this study is that it has not been included a group of untreated children with similar defects measured over the same period of time. Thus, certain clinical conclusions based on the different test conditions are not possible with our limited data. 5. Conclusions and applicability Although there are some limits, we can conclude that the use of standardized sEMG to study muscular activity represents quite an important instrument in understanding muscular sEMG potentials. The sEMG potentials of treated patients reached about the same

values as that of the control group, while before the treatment the differences between the two groups were more diffused. Further studies with a larger number of patients are needed to confirm the usefulness of sEMG in patients undergoing lingual frenectomy and the OMT protocol. Moreover, sEMG could be useful in monitoring the appropriate development of these types of therapy. More specifically, the electromyographic monitoring of masseter, anterior temporalis and sub-mental muscles seems indicative of a good clinical rehabilitation of tongue tie. The following sEMG tasks seem to be more much indicative of a good result to be applied on frenulectomy follow-up: MVC, kissing, swallowing and mandibular protrusion. References American Speech-Language-Hearing Association. Orofacial myofunctional disorders: knowledge and skills [guidelines, knowledge and skills]. Index terms: orofacial myofunction. http://dx.doi.org/10.1044/policy. GLKS199300058. Available from http://www.asha.org/policy; 1993. Bakke M, Bergendal B, McAllister A, Sjögreen L, Asten P. Development and evaluation of a comprehensive screening for orofacial dysfunction. Swed Dent J 2007;31(2):75–84. Convissar RA, Goldstein EE. An overview of lasers in dentistry. Gen Dent 2003;51:436–40. Cram JR, Kasman GS. Introduction to surface electromyography. Gaithersburg, MD: Aspen Publishers; 1997. p. 102–15. Dantas JL, Camata TV, Brunetto MA, Moraes AC, Abrão T, Altimari LR. Fourier and wavelet spectral analysis of EMG signals in isometric and dynamic maximal effort exercise. Conf Proc IEEE Eng Med Biol Soc 2010:5979–82. de Felício CM, Ferreira CLP. Protocol of orofacial myofunctional evaluation with scores. Int J Pediatr Otorhinolaryngol 2008;72:367–75. De Felício CM, Ferreira CL, Medeiros AP, Rodrigues Da Silva MA, Tartaglia GM, Sforza C. Electromyographic indices, orofacial myofunctional status and temporomandibular disorders severity: a correlation study. J Electromyogr Kinesiol 2012 Apr;22(2):266–72. de Felício CM, Folha GA, Ferreira CL, Medeiros AP. Expanded protocol of orofacial myofunctional evaluation with scores: validity and reliability. Int J Pediatr Otorhinolaryngol 2010;74(11):1230–9. Elanchezhiyan S, Renukadevi R, Vennila K. Comparison of diode laser-assisted surgery and conventional surgery in the management of hereditary ankyloglossia in siblings: a case report with scientific review. Lasers Med Sci January 2013;28(1):7–12. Ferrario VF, Tartaglia GM, Galletta A, Grassi GP, Sforza C. The influence of occlusion on jaw and neck muscle activity: a surface EMG study in healthy young adults. J Oral Rehabil 2006;33:341–8. Fournier M, Girard M. Acquisition and sustainment of automatic reflexes in maxillofacial rehabilitation. Orthod Fr September 2013;84(3):287–94. French. Grabowski R, Stahl F, Gaebel M, Kundt G. Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition. Part I: prevalence of malocclusions. J Orofac Orthop 2007;68(1):26–37. Hiiemae KM, Palmer JB. Tongue movements in feeding and speech. Crit Rev Oral Biol Med 2003;14:413–29. Kotlow LA. Ankyloglossia (tongue-tie): a diagnostic and treatment quandary. Quintessence Int 1999;30(4):259–62. Madsen DP, Sampson WJ, Grant C. Townsend craniofacial reference plane variation and natural head position. Eur J Orthod 2008;30:532–40. Marchesan IQ. Lingual frenulum protocol. Int J Orofac Myol 2012;38:89–103. Mathur R, Mortimore IL, Jan MA, Douglas NJ. Effect of breathing, pressure and posture on palatoglossal and genioglossal tone. Clin Sci (Lond) 1995;89:441–5. Meyer PG. Tongue lip and jaw differentiation and its relationship to orofacial myofunctional treatment. Int J Orofac Myol 2000;26:44–52. Myles H, Wolfe DA. Nonparametric statistical methods. 2nd ed. New York: John Wiley and Sons, Inc.; 1999. 14 + 787 pp. Moeller JL. Orofacial myofunctional therapy: why not? editorial. Cranio 2012;30:5–7. Moorrees CFA. Natural head position—a revival. Am J Orthod Dentofacial Orthop 1994;105:512–3. Mu L, Sanders I. Human tongue neuroanatomy: nerve supply and motor endplates. Clin Anat 2010;23(7):777–91. Northcutt M. Overview the lingual frenum. J Clin Orthod 2009;18:557–65. Pagni L, Baccetti T. Heredity and environment in the genesis, epigenesis and evolution of the orofacial area. Minerva Stomatol January–February 1993;42(1– 2):1–13. Porticelli M, Matarese G, Militi A, Nucera R, Triolo G, Cordasco G. Myotonic dystrophy and craniofacial morphology: clinical and instrumental study. Eur J Paediatr Dent 2009;10(1):19–22. Rogers AP. A restatement of the myofunctional concept in orthodontics. Am J Orthod November 1950;36(11):845–55. No abstract available. PMID: 14783191 [PubMed – indexed for MEDLINE].

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S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx Romero C, Scavone-Junior H, Garib DG, Cotrim-Ferreira FA, Ferreira RI. Breastfeeding and non-nutritive sucking patterns related to the prevalence of anterior open bite in primary dentition. J Appl Oral Sci 2011;19(2): 161–8. Saccucci M, Tecco S, Ierardo G, Luzzi V, Festa F, Polimeni A. Effects of interceptive orthodontics on orbicular muscle activity: a surface electromyographic study in children. J Electromyogr Kinesiol 2011;21(4):665–71. Smith JC, Goldberg SJ, Shall MS. Phenotype and contractile properties of mammalian tongue muscles innervated by the hypoglossal nerve. Respir Physiol Neurobiol 2005;147(2–3):253–62. Stahl F, Grabowski R, Gaebel M, Kundt G. Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition. Part II: prevalence of orofacial dysfunctions. J Orofac Orthop 2007;68(2):74–90. Tecco S, Epifania E, Festa F. An electromyographic evaluation of bilateral symmetry of masticatory, neck and trunk muscles activity in patients wearing a positioner. J Oral Rehabil 2008;35:433–9. Tecco S, Mummolo S, Marchetti E, Teté S, Campanella V, Gatto R, et al. sEMG activity of masticatory, neck and trunk muscles during treatment of scoliosis with functional braces. A longitudinal controlled study. J Electromyogr Kinesiol December 2011;21(6):885–92. Yamane A. Embryonic and postnatal development of masticatory and tongue muscles. Cell Tissue Res 2005;322:183–9.

Dr. Simona Tecco. Dr. Simona Tecco is actually Associate Professor in Odontostomatological Pathology (A.S.N. MIUR 2012). She is Researcher at the University Vita-Salute San Raffaele, Milano and works in the Dental School directed by Prof. Enrico Felice Gherlone. She was graduated in Dentistry at the University G.D’Annunzio, Chieti/Pescara. She obtained the Orthodontic Specialization Degree taken at the University ‘‘Cattolica del Sacro Cuore” in Rome, in 2006. She obtained the PhD degree in ‘‘Odontostomathological Science” taken at the University G.D’Annunzio, Chieti/Pescara, in 2003. She obtained a second PhD degree in ‘‘Physiology of mastication and dental materials” taken at the University of Torino. After graduation, she began her research and professional activity in 1999 at the University G.D’Annunzio, Chieti/Pescara in the fields of Orthodontics, Dentofacial Orthopedics, Posture, Pedodontics. She obtained many Research Scholarship in ‘‘Oral prevention” and ‘‘Orthodontics” from the academic years 2001-2002 to 2010-2011. She was the primary coordinator and researcher in a series of research projects realized at the University G.D’Annunzio, Chieti/Pescara. She is Author of many research articles about Orthodontics, Temporo-mandibular Disorders, Cervical Posture, Pedodontics and Orthodontic Materials.

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Dr. Enrico Marchetti. Born in Rome on 10/06/1075. Degrees in Dentistry at University of L’Aquila at 07/ 31/2001. Since november 2001 works with Giuseppe Marzo, professor of periodontology at University of L’Aquila, in the organizzation of didactic and research. During Academic Year 2003/04 has been nominated training assistant of periodontology at the University of L’Aquila. In 2004 frequented the first year of postgraduate course of oral surgery at maxillofacial division of san filippo neri hospital. In 2006, he obtained a postgratuate in ‘‘advanced anatomy and implantology with cadaver dissection” at State University of New York at Buffalo, NY, USA. He was nominated ‘‘contract professor” of Prosthetich Implantology 2 and 3 for AY, 2007/2008, AY 2009/2010. In 2010, he was Specialized in orthodontics at University of L’Aquila. In 2013 he obtained a PhD in electromyography and kinesiography of stomatognatich system. He was nominated ‘‘contract professor” of Prosthetich Dentistry for AY 2013/2014, and AY 2014/2015.

Prof. Maria Rita Giuca. She received her Bachelor degree at the University of Pisa, Italy. She actually is Professor of Pediatric Dentistry, Dental Clinics, Orthodontics at the Dental School of the same University. She is President of the Degree Course of Dental Hygiene. She is author of about 160 papers in national and international journals.

Dr. Alberto Baldini. Received his bachelor degree in 1989 at the University of Milano. He attended a courses of PhD, in Experimental Periodontology at the University of Milano-Bicocca in 2012. He is actually a resident in the Department of Orthodontics of Roma Tor Vergata, under the direction of Prof. Cozza Paola. He wrote many articles about the argument of gnathology and the evaluation between occlusion and posture.

Prof. Giuseppe Marzo. He is Full Professor in Odontostomatological Pathology (MED/28) at the University of L’Aquila, Italy. He obtained his Bachelor Degree in Medicine at the University of Bologna. He received Dental Specialization Degree at the University of Rome, ‘‘La Sapienza”. He collaborated with the Unit of Paediatric Dentistry of the Dental Clinic in Rome, directed by Professor Guido Gallusi, and since 1985 he dedicated his professional and research activity of the odontoatomatological pathologies in children. He is actually the Director of the School of Orthodontics for post-graduated students, at the University of L’Aquila, Italy. From 1995 to 2009 he has been national treasure of the Italian Society of Paediatric Dentistry (S.I.O.I.). He also was President of S.I.O.I. from 2012 to 2014. He is actually an active Member of the Pediatric Dentistry Italian Society (S.I. O.I.). Since 2002 he is scientific director of the European Journal of Paediatric Dentistry, official journal of S.I.O.I. He also is the Coordinator of the course in Parodontology, at the same University. He is author of many articles about pediatric dentistry, periodontology and orthodontics.

Dr. Stefano Mummolo. Born in Rome on 11/03/1076. Degrees in Dentistry at University of L’Aquila, 2000. Since november 2000 works with Giuseppe Marzo, professor of periodontology at University of L’Aquila, in the organizzation of didactic and research. During Academic Year 2001/02 has been nominated training assistant of periodontology at School of Dentistry of University of L’Aquila. In 2005, he was nominated ‘‘contract professor” of Preventive Dentistry and Community for AY 2005/2006. In 2006, he was nominated ‘‘contract professor” of Prosthetich Implantology I for AY 2006/2009. In 2009 he was Specialized in orthodontics at University of L’Aquila. In 2012, he obtained a PhD in electromyography and kinesiography of stomatognatich system., and was nominated ‘‘contract professor” of periodontology I for AY 2012/2013. He was nominated ‘‘contract professor” of Prosthetich Dentistry for AY 2013/2015.

Prof. Enrico Felice Gherlone. Full Professor of Clinical Dentistry, Vice-Dean Faculty of Medicine and Surgery, Dean of the Masters Degree in Dentistry and Dental Implantology, Dean of the Bachelor’s Degree in Dental Hygiene, Head of the Dentistry Unit, San Raffaele Scientific Institute, Born in Genoa, 20/01/ 1956; Medical Degree, University of Genoa, 1983. Postgraduate in Dentistry, University of Genoa, 1986. 1985/86 Professor of Clinical Dentistry, University of Madrid. From 1988 to 1996, Professor in Fixed Prosthodontics, Postgraduate Course in Dentistry, University of Genoa. From 1994 to 1996 Medical Executive, Dental Clinic, University of Genoa. From 1996 to 1997 Medical Executive, Head of Prosthodontics, Dentistry Unit, San Raffaele Scientific Institute. From 1998 Head of Dentistry Unit, San Raffaele Scientific Institute. From 1996 to 2003 Professor of Prosthodontics, Dentistry Degree Corse, University of Milan. From 2000 to 2004 President of the Italian Association for Clinical Gnathology. 2003: Associate Professor of Clinical Dentistry (Med 28), Vita-Salute San Raffaele University. 2004: Full Professor, of Clinical Dentistry (Med 28), Vita-Salute San Raffaele University. 2005: Dean of the Bachelor’s Degree in Dental Hygiene (Med 50) Vita-Salute San Raffaele University, Milan, Italy. 2005: Scientific Director of ‘‘Overland for Smile

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003

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S. Tecco et al. / Journal of Electromyography and Kinesiology xxx (2015) xxx–xxx

Project”, that regards dental assistance for orphanage people in underdeveloped countries. 2007: Scientific Director of the excellence Dental Center for handicapped people ‘‘San Raffaele Incontro” in Amelia (TR). From 2007 to 2009, President of the Italian Society for Prosthetic and Implant Dentistry. From 2008 to 2011, Referee for dentistry area ‘‘programming commission” Italian Ministry for Work, Health and Social Affairs, then Ministry for Health. From 2009, Co-Director of Bone

Physiopathology Program (BoNetwork) of San Raffaele Scientific Institute, on basic, translational and clinical research, for a better understanding on bone tissue homeostasis and physiopathology, in identification of potential therapeutical target and prognostical markers for skeletal diseases. From 2010 to 2013, Member of Italian Superior Council for Health, where He represents the dentistry area. From 2015, President of the Italian College of Professors in Dentistry.

Please cite this article in press as: Tecco S et al. Frenulectomy of the tongue and the influence of rehabilitation exercises on the sEMG activity of masticatory muscles. J Electromyogr Kinesiol (2015), http://dx.doi.org/10.1016/j.jelekin.2015.04.003