Conventional versus laser gingivectomy in the management of gingival enlargement during orthodontic treatment: a randomized controlled trial.

OBJECTIVES: To compare the use of diode laser with conventional surgery evaluating the effectiveness of gingivectomy as an adjunct to non-surgical periodontal treatment in the management of gingival enlargement (GE) during orthodontic treatment. TRIAL DESIGN: Prospective three-arm parallel group randomized clinical trial with 1:1:1 allocation ratio. METHODS: Sixty subjects (33 males and 27 females), with a mean age of 14.4 ± 1.9 years, were selected according to inclusion criteria: overgrown gingivae on the labial side of the anterior teeth secondary to fixed appliance therapy, six maxillary anterior teeth present, and healthy non-smokers patients. Patients were enrolled in the study and randomly assigned to three groups by a computer-generated randomization list and by a block size of 4. The allocation information was concealed in opaque and sealed envelopes by the statistician. In the first group, all subjects underwent a conventional scalpel gingivectomy of the maxillary anterior sextant. In the second group, all subjects were treated using laser-assisted gingivectomy; while subjects assigned to the third group underwent only non-surgical periodontal treatment and served as control group (CG). The observer who performed all the measurements was blinded to the group assignment. Blinding was obtained by eliminating from the elaboration file every reference to patient group assignment. Intergroup comparisons of changes in the periodontal parameters were conducted at 1, 3, and 6 months using ANOVA with repeated measures and Tukey's post hoc tests. The significance level was set at P <0.05. RESULTS: After 1 month, the TGs showed a significant improvement of all periodontal parameters when compared with the CG. No statistically significant differences were observed between the two TGs. At the 3-month observation, a relapse occurred in the TGs, while the CG showed the greater improvement of soft tissue health. In the 6-month versus 3-month evaluation, no significant differences between the three groups were found for any periodontal measurements. In the long-term evaluation (6 months versus baseline), a significant greater reduction of pockets were found in the TGs when compared with the CG. CONCLUSIONS: The adjunct use of both scalpel gingivectomy and laser gingivectomy was more effective in controlling gingival inflammation than non-surgical periodontal treatment alone at 1, 3 and 6 months. In the control group, greater improvement in the periodontal parameters were observed within 3 months, depending on a self-care approach for the management of GE. LIMITATIONS: This study was a short-term study (6-month follow-up). TRIAL REGISTRATION: ClinicalTrials.gov (registration number: NCT03514316).

Evaluation of masseter muscles in relation to treatment with removable bite-blocks in dolichofacial growing subjects: A prospective controlled study.

INTRODUCTION: The aim of this prospective study was to evaluate the effects of posterior bite-blocks on masseter muscles and on facial growth in prepubertal dolichofacial subjects. METHODS: The treatment group comprised 21 consecutive prepubertal dolichofacial patients treated with rapid maxillary expansion followed by mandibular removable bite-blocks. Lateral cephalograms and ultrasonographic scans of the masseter muscles were made before (T1) and after (T2) treatment with bite-blocks. The treatment group was compared with a control group of 21 subjects matched for sex, age, and skeletal vertical pattern. An independent samples t test was used to compare the T1 to T2 changes in ultrasonographic scan measurements between the treatment group and the control group, and the T1 to T2 cephalometric changes in the treatment group. Regression analysis was performed to investigate associations between masseter muscle thickness and cephalometric treatment outcomes. RESULTS: Masseter muscle thickness showed a statistically significant decrease (-0.7 mm) in the treatment group compared with an increase (+0.6 mm) in the control group. A significant anterior rotation of the mandibular plane was observed in the treatment group as well as significant increases in overbite (1.8 mm) and total posterior facial height (1.5 mm). No significant associations were found between masseter muscle thickness and treatment outcomes apart from a tendency for overbite to increase more in subjects with thicker muscles. CONCLUSIONS: Treatment with removable bite-blocks produced a decrease in masseter muscle thickness and a reduction in vertical facial dimensions due to upward and forward rotation of the mandible. No significant correlation was found between the pretreatment masseter muscle thickness and the T1 to T2 cephalometric changes in the treatment group.

Three-dimensional evaluation of masseter muscle in different vertical facial patterns: a cross-sectional study in growing children.

The aim of the present study was to analyze the anatomical three-dimensional (3D) characteristics of masseter muscle in growing subjects with different vertical patterns by using an ultrasound (US) method. The sample comprised 60 prepuberal subjects (33 males, 27 females) with a mean age of 11.5 ± 1.6 years with late mixed or permanent dentition and Class I molar and skeletal relationship. For each subject, a lateral cephalogram was required, and according to the mandibular plane angle (Frankfort horizontal plane/mandibular plane angle [FMA]), the subjects were divided into three groups of different underlying vertical facial patterns: brachyfacial: FMA < 22°, mesofacial: 22° ≤ FMA ≤ 28°, and dolichofacial: FMA > 28°. For each subject, an US scan was carried out to analyze the width, the thickness, the cross-sectional area, and the volume of the masseter muscle. Mean differences in measurements between vertical facial subgroups were contrasted by means of analysis of variance (ANOVA) with Tukey's post hoc tests (p < 0.05). Measurements of the whole masseter in dolichofacial patients were significantly smaller when compared with brachyfacial and mesofacial individuals during relaxation and contraction. The volume of the masseter decreased significantly by 10% going from the brachyfacial group to the mesofacial group and from the mesofacial group to the dolichofacial group with no difference between the left and the right sides. A significant negative correlation was found between the US measurements and the divergency (FMA°). Ultrasound is a technique indicated in children for evaluating muscles of mastication in vivo. Growing patients with a dolichofacial vertical pattern present with a reduced dimension of the masseter when compared with brachyfacial and mesofacial subjects.