Melih Motro

Dimensional changes of maxillary sinuses and pharyngeal airway in Class III patients undergoing bimaxillary orthognathic surgery

OBJECTIVE To evaluate the pharyngeal airway and maxillary sinus volume changes after mandibular setback surgery combined with maxillary advancement and/or impaction surgery. MATERIALS AND METHODS Seventeen Class III skeletal patients (11 females, 6 males) who required bimaxillary orthognathic surgery were selected. Volumetric measurements were performed using cone beam computed tomography (CBCT) scans preoperatively and 3.9 ± 0.87 months postoperatively. All the CBCT scans were assessed and analyzed using MIMICS 14.0 software. Preoperative and postoperative volumes of pharyngeal airway and maxillary sinuses and the relationship between the amounts of surgical movement of the jaws and the above volumes were statistically evaluated. RESULTS The pharyngeal airway area presented no significant change except for the lower and total pharyngeal airway volumes in males, in whom a significant decrease was observed (4196.27 ± 2061.11 mm(3) and 3375.53 ± 3624.67 mm(3), respectively). No significant change was observed in the minimal cross-sectional area of the pharyngeal airway. There was a significant decrease in the volume of the maxillary sinuses after the surgery by 3448.09 ± 3315.56 mm(3). No correlation was found between the amount of skeletal movement and the change in the volume of pharyngeal airway or maxillary sinuses. CONCLUSION There was a significant decrease only for lower and total pharyngeal airway volumes in males and a significant decrease in the volume of the maxillary sinuses.

A Novel Vector Control Device in Horizontal Bone Transport

Bone grafting is the most frequently used technique for cleft palate repair. The major shortcoming of this method is the difficulty of achieving complete soft tissue coverage in cases with large defects. Buccal or tongue flaps are used most commonly in such cases, but the outcome is not always ideal. Alveolar distraction may be a more promising method for overcoming such problems. 1-4 This article describes a new method developed to treat cases with large defects and presents a case to illustrate the use of this protocol. Materials and Methods Chromium-cobalt crowns with double tubes for the molars and semicircular tubes for other teeth were prepared separately for each segment. Care was taken to orient the tubes in the same horizontal plane. The cast segments were connected by two 1.5-mm stainless steel arch wires. The arches were extended distally from the tubes to accommodate the planned anterior movement of the distraction segments. To avoid mucosal irritation, double tubes were placed as mesially as possible on the molar crowns. The anchoring segments were connected by a transpalatal bar. A custom-designed tooth-borne distractor was positioned occlusally on the arch (Fig 1). Case Report A 16-year-old female patient presented with absence of the premaxilla and bilateral complete cleft lip and palate. The etiology was uncertain. The treatment plan was reconstruction of the premaxilla and correction of the sagittal jaw relationship, using the alveolar distraction protocol to improve the patient’s facial profile and appearance (Fig 2). Treatment started with leveling and alignment of the dental arches, leaving a space of 3 mm between the maxillary second premolar and first molar to avoid root exposure during osteotomy. SURGICAL METHOD First, a cast metal appliance was cemented. The next day, surgery was performed under general anesthesia. The segments were mobilized by making vertical incisions between the maxillary second premolars and first molars, followed by horizontal osteotomies above the roots. During this process, the palatal mucosa was left intact. Arches and distractors were inserted intraoperatively, and the distractors were activated with five full turns (5 mm) to observe the mobility of the discs. The distractors were then closed, the segments were ligated tightly, and the flaps were sutured. After a 5-day latency period, activation was started at a rate of one half turn (0.5 mm) twice a day. The patient was monitored weekly until the 2 segments contacted at the midline. Activation was continued bilaterally until the desired amount of premaxillary augmentation, including 30% overcorrection, was achieved (Fig 3).

Hounsfield Units: a new indicator showing maxillary resistance in rapid maxillary expansion cases?

OBJECTIVE To determine if density measurements of several maxillary regions in Hounsfield Units (HU) and outcomes of rapid maxillary expansion (RME) are correlated. Is correlation powerful enough to give us direct information about maxillary resistance to RME? MATERIALS AND METHODS Twenty-two computed tomographic (CT) scans (14 years) are used in this archive study. Two CT records were collected, one before RME (T1) and one after 3 months of retention period (T2). Maxillary measurements were made using dental and skeletal landmarks in first molar and first premolar slides to measure the effects of RME. Density of midpalatal suture (MPSD) and segments of maxillary bone is measured in HU at T1. Correlation analysis was conducted between density measurements and maxillary variables. Regression analysis was then performed for variables that showed positive correlation. RESULTS There was no correlation between density and skeletal measurements. Intermolar angle (ImA) in molar slice showed statistically significant correlation with density measurements. The ImA variable showed the highest correlation with MPSD in frontal section (r  =  0.669, P < .01). CONCLUSIONS There is correlation of 32.1-43.3% between density measurements and ImA increase. Our density measurements explain a certain percentage of ImA increase, but density is not the only and definitive indicator of changes after RME.

Simultaneous Alveolar Cleft Closure and Dental Midline Correction With Curvilinear Intraoral Distraction

This article describes a new method that enables vector control during alveolar distraction osteogenesis in the treatment of a cleft palate patient. The patient presented with unilateral complete cleft lip and palate, and the alveolar part of the defect was covered by a mobile buccal flap. The distraction was performed by sliding the surgically released tooth segment with the help of an intraoral distractor over 1.5-mm stainless steel archwires held by metal crowns. This vector-controlled method enabled new bone and attached gingiva formation in harmony with the proper alveolar shape.

Expansion maxillaire rapide assistée chirurgicalement. Évaluation de différentes techniques chirurgicales et de leur effet sur le complexe dento-squelettique maxillaire par tomographie volumique à faisceau conique (CBCT). Rapport préliminaire

AIM To evaluate and compare the dentoskeletal effects associated with surgically assisted rapid maxillary expansion (SARME) performed with (+) and without (-) pterygomaxillary disjunction (PD), utilizing cone beam computed tomography (CBCT). MATERIALS AND METHODS A retrospective study of 9 patients (1 male, 8 females, mean age 18.9 years) undergoing SARME who were divided into two groups. In group (-PD) the surgical technique followed involved bilateral LeFort I type of osteotomy plus midline osteotomy. In group (+PD) same protocol was followed and pterygoid disjunction was performed additionally. Three-dimensional CBCT scans were obtained preoperatively and 3-6 month postretention. A Hyrax type acrylic bonded expander was used. MIMICS 14.0 (Materialise Europe, Belgium) software was used to evaluate transverse expansion at skeletal, dentoalveolar and dental level. Additionally dental inclinations, alveolar bending and the pattern of expansion sagittally were assessed. Wilcoxons and Mann Whitney U tests were used for comparisons. RESULTS AND DISCUSSION All linear transverse measurements at dental and dentoalveolar level were found to have a statistically significant increase (P < 0.05) in both treatment groups. No statistically significant differences were found between the two groups as well as within groups on skeletal level (except of the anterior expansion of maxilla between piriform rims bilaterally). In -PD group significant buccal tipping of the 1(st) premolar was observed as well as increased buccal bending of the alveolar crest. CONCLUSION This study confirms that SARME is an effective treatment of maxillary transverse deficiency. CBCT is an adequate tool to assess dentoskeletal treatment effects.

Postoperative Positional and Dimensional Changes of Mandibular Canal after Bilateral Sagittal Split Set-Back Osteotomy

Objective This preliminary study was planned to provide information about preoperative mandibular canal (MC) position and the postoperative positional changes of MC and length in three dimensions, with the purpose of providing some assistance in reducing inferior alveolar neurosensory disturbance (IAND). Methods MC was examined on CBCT data using SimPlant Pro Standalone 13.0. MC locations were measured in all dimensions, with respect to mandibular bony borders. Results The results showed that MC is frequently located in the midthird of the ramus anteroposteriorly and superoinferiorly and in the midthird of the corpus superoinferiorly. Postoperatively, ramus width was increased, ramus length was decreased significantly, and MC was repositioned laterally and inferiorly. MC length was decreased on both sides, non-correlated with the set-back amounts. Conclusion Preoperative results may be beneficial for the prediction of MC position for surgeons, and postoperative results will be used for the following studies to correlate postoperative positional changes with IAND.

Orthodontics and Temporomandibular Disorders. Are They Related

ABSTRACT The aim of this review was to evaluate associations between different orthodontic treatment techniques, the role of malocclusion types, and signs and symptoms of temporomandibular disorders (TMDs). Associations between different orthodontic treatment techniques and TMD were found in some studies, whereas most of the reviewed articles failed to identify significant associations. Based on the presently available research, because it has not been demonstrated that malocclusions cause TMDs, it is incorrect to claim that orthodontic approaches can treat or prevent TMDs. Moreover, there is no evidence that any orthodontic treatment causes TMD signs or symptoms. Longitudinal studies are still needed. (Turkish J Orthod 2015;28:71–76)

Prevalence and characteristics of non-syndromic hypodontia among Turkish orthodontic patient population.

Background: Hypodontia is often used as a collective term for congenital absence of primary or secondary teeth, although specifically it describes the absence of one to six teeth excluding third molars. The prevalence of hypodontia varies from 0.03 to 10.1% in various populations. Materials and Methods: In this retrospective study, we reviewed the records of Turkish orthodontic patients treated between 1994 and 2003. A total of 1236 orthodontic patients (507 girls, 729 boys) were included in this study. The age of the patients ranged from 11 to 20 years. Data were collected and entered into the SPSS 20 program for statistical analysis. The Chi-square test was used to analyze differences in the distribution of hypodontia, sex, and malocclusion type. Results: In the total sample of 1236 patients who were orthodontically treated, hypodontia was found in 82 children, including 45 girls and 37 boys. The prevalence of hypodontia was 7%. Patients with more severe hypodontia showed a tendency to exhibit a class II relationship. The mandibular second premolar were the most commonly missing teeth in 48 girls and 26 boys. Conclusion: Hypodontia may lead to some clinical problems including malocclusions, esthetic and functional complaints, and also psychological problems. All cases should be evaluated by an interdisciplinary approach for appropriate treatment choice. Our data emphasize the importance of detailed and careful radiographic examination. This helps in long-term and effective treatment planning according to a child′s individual requirements.

Does the Bone Cement Affect Miniscrew Stability

ABSTRACT Objective: The purpose of this study was to determine whether bone cement increased the resistance of miniscrews against pull-out and shear forces. Materials and Method: Sixty commercially available miniscrews were placed into bovine bone samples (one each) at a 90° angle, using a custom-made orientation jig and controlling torque (30 N-cm) and rotation (20 rpm) with a rechargeable screwdriver. The miniscrews were inserted using three different methods: self-drilling, predrilling, and predrilling with bone cement application. Pull-out strengths and shear tests were performed using a universal testing machine. Results: Nonparametric Kruskal-Wallis tests were used for comparisons between groups, and Bonferroni-adjusted Mann-Whitney U tests were used to detect different group(s) (α/3=0.016). There was a statistically significant difference between the pull-out strengths of the groups (p<0.01). The self-drilling group had a significantly lower pull-out strength at failure than the other groups (p<0.0...