Assessment of dental arches in patients with Class II division 1 and division 2 malocclusions using 3D digital models in a Syrian sample.

AIM: (1) to evaluate the applicability of using 3D digital models in the assessment of Class II Division 1 (Cl II-1) and Class II Division 2 (Cl II-2) malocclusion in a Syrian sample, (2) to detect any significant differences between the two groups in tooth and arch widths, anterior (ABR) and overall Bolton ratios, PAR Index, and (3) to detect any gender differences in these variables. DESIGN AND SETTING: observational, cross-sectional study for descriptive and analytical purposes at the Orthodontic Dept., University of Al-Baath Hamah Dental School, Hamah, Syria. PARTICIPANTS: A disproportionate multi-stratified random sampling was employed to select 36 Cl II-1 and 36 Cl II-2 patients (female-to-male ratio was 1:1 in each group). 3D digital models (O3DM) with a dedicated programme were used to measure dental arch variables. RESULTS: Significant differences were observed between the two groups in the mesiodistal widths of some teeth but not in the dental arch widths. The prevalence of 'discrepancy cases' in Anterior Bolton Ratios (ABRs) was 33.33% and 41.67% in Cl II1 and Cl II2 groups, respectively. The mean PAR Index score was 25.36 and 20.82 for Cl II1 and Cl II2 groups, respectively (p=0.009). CONCLUSIONS: (1) 3D digital models enabled fast, accurate and reliable measurements of dental arch characteristics in patients with Class II malocclusion. (2) Insignificant differences between Cl II1 and Cl II2 patients were observed regarding Bolton's ratios and transverse arch measurements. (3) Sexual dimorphism was observed in mesiodistal tooth widths and in dental arch widths, but not in Bolton's ratios and PAR Index scores.

Assessment of pain and discomfort during early orthodontic treatment of skeletal Class III malocclusion using the Removable Mandibular Retractor Appliance.

AIM: To determine the degree of pain and discomfort during the orthodontic treatment of skeletal Class III malocclusion using the Removable Mandibular Retractor (RMR). MATERIALS AND METHODS: The sample consisted of 33 skeletal Class III patients (17 males and 16 females; average age: 7.5 ± 1.33 years) who had been assigned to the RMR treatment group in a randomised controlled trial comparing this treatment versus a control group of no treatment at the Orthodontic Department, University of Al-Baath Dental School in Syria. Pain and discomfort were assessed using standardised questionnaires at the following assessment times: 7 days (T1), 14 days (T2), 6 weeks (T3), 3 months (T4) and 6 months (T5) after appliance insertion. RESULTS: Levels of pain and discomfort decreased gradually by time in general. No significant changes in the levels of pain, tooth sensitivity and soft tissues tension were detected, whereas a significant decrease in the levels of pressure, impaired speech, impaired swallowing and lack of confidence in public was observed two weeks following appliance insertion. Mandibular constraint feeling required three months to decrease significantly. No difference was found between males and females with regard to acceptance. CONCLUSION: The RMR is well accepted by Class III patients in the early mixed dentition.

Short-term soft- and hard-tissue changes following Class III treatment using a removable mandibular retractor: a randomized controlled trial.

OBJECTIVE: To evaluate the effects of a Class III functional appliance [the removable mandibular retractor (RMR)] in the early treatment of skeletal Class III deformities. SET-UP: Randomized controlled trial. SETTING: Orthodontic Department, University of Al-Baath Dental School, Hamah, Syria. MATERIAL AND METHODS: Sixty-seven skeletal Class III patients were recruited, distributed randomly into two groups: 1) treatment group (T) with the RMR: 33 patients (17 males and 16 females) with a mean age of 7.5 ± 1.33 years, 2) control group (C): 34 patients (15 males and 19 females) with a mean age of 7.3 ± 1.58 years. Lateral cephalograms were taken at the start of treatment (T1-T) or at the start of the observation period (T1-C) and after 14.5 ± 0.1 months (both groups). Soft- and hard-tissue changes in both groups were evaluated. RESULTS: The main significant findings in the treatment group were 1) anterior morphogenetic rotation of the mandible as a result of upward and forward condylar growth; 2) significant increase in maxillary length; 3) significant increase in maxillary dentoalveolar protrusion; 4) significant decrease in mandibular dentoalveolar protrusion; 5) significant protrusion of the upper lip; 6) significant retrusion of the lower lip; and 7) significant reduction in nasolabial angle. CONCLUSION: The RMR is an effective appliance in the treatment of skeletal Class III patients in the early mixed dentition in the short term.

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

AIM: To evaluate the levels of acceptance and discomfort between two types of functional appliances. STUDY DESIGN: Randomised controlled trial. MATERIALS AND METHODS: A sample of patients who met the inclusion criteria were distributed randomly and equally into two groups: the Trainer for Kids™ made up of 26 patients with an average age of 10.3 years (Group A), and the modified Activator with 28 patients, with an average age of 10.6 years (Group B), as control. A special questionnaire including eight questions about tension, pressure, sensitive teeth, pain, impaired speech, impaired swallowing, oral constraint and lack of confidence in public caused by the appliance was administered at T1 (7 days), T2 (14 days), T3 (3 months), and T4 (6 months). RESULTS: The sensation of pressure, teeth sensitivity, pain and impaired speech declined significantly in Group A. All complaints decreased significantly in Group B, but the changes in 'lack of confidence in public' were not significant. Moreover the sensation of pressure, teeth sensitivity, oral constraint and impaired speech were significantly higher in Group A than in Group B. CONCLUSION: The modified Activator caused less discomfort than the Trainer for Kids™ and was more acceptable.

Osteogenic uni- or bilateral form of the guided rapid maxillary expansion.

Surgically assisted rapid palatal expansion is an important treatment procedure in patients with constricted maxillae. Several surgical methods have been proposed to expand the maxilla bilaterally. A new technique was developed for performing a symmetric or asymmetric maxillary expansion guided by the stability of the mid-palatal area employing two osteotomy cuts on either side of mid-palatal suture. A Hyrax-type expansion device was used post-operatively. Seventeen patients were included in the study (9 males, 8 females) with a mean age of 30.7 years. Inter-canine and inter-molar widths were evaluated at three assessment intervals: before treatment (T1), immediately after appliance removal (T2) and at six months follow-up (T3). Between T1 and T2, a mean expansion of 7.1 and 9.9mm was achieved at the canine and molar areas, respectively. The amount of relapse measured between T2 and T3 was minimal (a mean value of 0.35 and 0.8mm at the canine and molar areas, respectively). Asymmetric expansion was performed in 6 patients who exhibited unilateral skeletal constriction at the initial assessment and these cases appeared stable at T3. The surgical approach described in the current study enabled rapid maxillary expansion of unilateral and bilateral skeletal constriction cases effectively and with good stability.

Applications of 3D imaging in orthodontics: part I.

Part I of this paper describes the background, general concepts, available techniques and the clinical applications of recording external craniofacial morphology in three dimensions. Part II explores the different 3D techniques of imaging the dental arches, and their possible uses in orthodontic diagnosis and treatment.