Three-Dimensional Analysis of Craniofacial Structures of Individuals With Nonsyndromic Unilateral Complete Cleft Lip and Palate.

ABSTRACT: Cleft lip and palate (CLP) is one of the most common congenital deformities. Primary surgeries at an early age result in scar formation, which may impede the growth of craniofacial structures of the maxilla. Orthodontist's role in the management of individuals with CLP is important and starts from the time of birth. The knowledge of craniofacial structures in individuals with a cleft is essential for treatment planning. The purpose of this study was to analyze and compare craniofacial structures of cleft and noncleft side of individuals with non-syndromic unilateral complete cleft lip and palate (NSUCCLP) using cone-beam computed tomography (CBCT). CBCT scans of individuals with NSUCCLP (n = 42) were retrieved from the databases of two cleft centers, which followed the same protocols for timing and type of primary surgeries and secondary alveolar bone grafting (SABG). DICOM files of CBCT scans were integrated into Dolphin 3D software, and analysis was carried out in multiplanar views. The craniofacial structures of individuals with NSUCCLP were analyzed using fourteen parameters. Measurements were also recorded between the cleft and noncleft sides for comparison. The volume of the maxilla was generated by isolating it from adjacent structures on a 3D reconstructed model. MAWC, MAWPM1, MAWPM2, MAWM1, and MV of the cleft side was less than noncleft side (P < 0.05). MHP @ N Aper is less on the noncleft side (P < 0.05). There is an asymmetry of structures around the dentoalveolar and nasal region; however, asymmetries were not affected at deeper structures of the craniofacial region of individuals with NSUCCLP.

Three-dimensional finite element analysis of initial displacement and stress on the craniofacial structures of unilateral cleft lip and palate model during protraction therapy with variable forces and directions.

Maxillary protraction and expansion is recommended to treat midfacial deficiency in patients with cleft lip and palate (CLP), where amount and direction of forces can change displacement and stress. This study assessed the initial displacement and stresses using Facemask and Maxgym forces with and without RME at +20∘, 0∘, and -20∘ angulation using a finite element (FE) model of unilateral cleft lip and palate (UCCLP). The Initial displacement and stress were more for protraction with expansion as compared to only protraction. Asymmetric displacement was observed with more on cleft than on noncleft side and more on dental than skeletal structures. Palatal plane rotated less upward, increased arch width and decreased arch length was observed with protraction with expansion.

Three-dimensional assessment of transverse displacement with Facemask and Maxgym in unilateral cleft lip and palate model.

BACKGROUND: Growing patients with cleft lip and palate (CLP) exhibit maxillary deficiency due to early surgical intervention. Maxillary protraction with expansion is the recommended treatment modality for deficient maxilla. Facemask is a conventional protraction appliance, and Maxgym is a new protraction appliance. The purpose of this study is to compare the efficacy of Maxgym with Facemask using finite-element analysis. METHODS: A three-dimensional finite-element model consisting of 49,807 nodes and 185,620 tetrahedral-shaped elements was created using computed tomography scan of a patient with unilateral CLP. F1, F2, and F3 represent different protraction forces of facemask, and M1, M2, and M3 represent different protraction forces of Maxgym. E1 represents slow maxillary expansion (SME) force, and E2 represents rapid maxillary expansion (RME) force. Facemask and Maxgym forces were applied parallel to the occlusal plane from the middle of the clinical crown on the buccal side of the first premolars. The forces E1 and E2 were also applied on the middle of the crown height on the lingual side of the first premolars and the first molars to simulate expansion. The amount of displacement for Maxgym and Facemask forces in transverse direction was analyzed designating specific nodes to represent dental and skeletal structures. RESULTS: The dental and skeletal structures were displaced in transverse direction under all loading conditions. Only expansion or protraction force resulted in transverse displacement of nodes. RME produces greater transverse displacement as compared to SME. Maxgym forces produce greater transverse displacement as compared to facemask. Maxgym with RME produces greater transverse displacement as compared to Maxgym with SME, whereas facemask with RME produces greater transverse displacement as compared to facemask with SME. CONCLUSIONS: Maxgym forces produce greater transverse displacement as compared to facemask with or without expansion.

Management of Class II malocclusion with ectopic maxillary canines.

Correction of Class II relationship, deep bite and ectopically erupting canines is an orthodontic challenge for the clinician. A 13-year-old male patient presented with Class II malocclusion, ectopically erupting canines, and cross bite with maxillary left lateral incisor. He was treated with a combination of Headgear, Forsus™ fatigue resistant device [FFRD] with fixed mechanotherapy for the management of space deficiency and correction of Class II malocclusions. Headgear was used to distalize upper first molars and also to prevent further downward and forward growth of the maxilla. Then Forsus™ FFRD was used for the advancement of the mandible. The molar and canine relationship were corrected from a Class II to a Class I. The objectives were to establish good occlusion and enable eruption of unerupted canines. All these objectives were achieved and remained stable.

Second premolar extraction: Not always a second choice.

Extraction is a recognized and widely accepted procedure in orthodontic treatment. The selection of teeth for orthodontic extraction is an important decision and they are modified according to the individual patient. This case report describes the management of 18-year old female patient with moderate crowding which was treated with second bicuspid extraction. At the end of treatment, patient had pleasing profile, good intercuspation, ideal overjet, and overbite. The occlusion remained stable even 3 years after orthodontic treatment.

Clinical application of micro-implant anchorage in initial orthodontic retraction.

Micro-implant is a device that is temporarily fixed to bone for the purpose of enhancing orthodontic anchorage either by supporting the teeth of the reactive unit or by obviating the need for the reactive unit altogether, and which is subsequently removed after use. The purpose of this study was to evaluate the clinical efficiency of micro-implants in reinforcing anchorage during the initial retraction of anterior teeth, check the rate of initial retraction for 8 weeks, and assess the stability of micro-implants during this period. Eighteen micro-implants were placed (10 in the maxilla and 8 in the mandible) and immediately loaded with 200-250 g of force using 9-mm closed coil Nitinol springs. The amount of space closure was measured every 2 weeks until the eighth week. Cephalometric measurements were made at the end of the study to evaluate anchor loss, if any. Micro-implant stability was also assessed. The rate of initial retraction in the maxilla at the end of 8 weeks was 1.65 mm/quadrant and 1.51 mm/quadrant in the mandible. The amount of retraction on the left side of the arches was 1.66 mm/quadrant and 1.49 mm/quadrant on the right side. The average initial retraction for both arches per month was 0.78 mm. An anchor loss of 0.1 mm (0.06%) was observed in the maxilla while no mandibular anchor loss was recorded. The rate of initial retraction observed in the maxilla was more than that achieved in the mandible. Initial retraction was also more on the left side of the arches. There was no anchor loss in the mandible. The micro-implant-reinforced anchorage was helpful in minimizing anchor loss and accepted heavy traction forces but did not bring about a faster rate of retraction.

Estimation of soft- and hard-tissue thickness at implant sites.

INTRODUCTION: Anchorage control is a critical consideration when planning treatment for patients with dental and skeletal malocclusions. To obtain sufficient stability of implants, the thickness of the soft tissue and the cortical-bone in the placement site must be considered; so as to provide an anatomical map in order to assist the clinician in the placement of the implants. OBJECTIVE: The aim of this study is to evaluate the thickness of soft- and hard-tissue. MATERIALS AND METHODS: To measure soft tissue and cortical-bone thicknesses, 12 maxillary cross-sectional specimens were obtained from the cadavers, which were made at three maxillary mid-palatal suture areas: The interdental area between the first and second premolars (Group 1), the second premolar and the first molar (Group 2), and the first and second molars (Group 3). Sectioned samples along with reference rulers were digitally scanned. Scanned images were calibrated and measurements were made with image-analysis software. We measured the thickness of soft and hard-tissues at five sectional areas parallel to the buccopalatal cementoenamel junction (CEJ) line at 2-mm intervals and also thickness of soft tissue at the six landmarks including the incisive papilla (IP) on the palate. The line perpendicular to the occlusal plane was made and measurement was taken at 4-mm intervals from the closest five points to IP. RESULTS: (1) Group 1:6 mm from CEJ in buccal side and 2 mm from CEJ in palatal side. (2) Group 2:8 mm from CEJ in buccal side and 4 mm from CEJ in palatal side. (3) Group 3:8 mm from CEJ in buccal side and 8 mm from CEJ in palatal side. CONCLUSIONS: The best site for placement of implant is with thinnest soft tissue and thickest hard tissue, which is in the middle from CEJ in buccal side and closest from CEJ in palatal side in Group 1 and faraway from CEJ in buccal side and closest from CEJ in palatal side in Group 2 and faraway from CEJ in buccal side and faraway from CEJ in palatal side in Group 3.

Assessment of clinical outcomes of Roth and MBT bracket prescription using the American Board of Orthodontics Objective Grading System.

BACKGROUND: There is always a need to assess whether small changes in bracket prescription can lead to visually detectable differences in tooth positions. However, with little clinical evidence to show advantages of any of the popularly used bracket systems, orthodontists are forced to make clinical decisions with little scientific guidance. AIM: To compare the orthodontic cases finished with Roth and MBT prescription using American Board of Orthodontics-Objective Grading System (ABO-OGS). SETTINGS AND DESIGN: Department of Orthodontics, Post-graduate dental college, retrospective cross-sectional study. MATERIALS AND METHODS: Forty patients selected were divided into two groups of 20 patients each finished with straight wire appliance using Roth and MBT prescription, respectively. The examiner ability was assessed and calibrated by one of the ABO certified clinician to grade cases using the OGS. STATISTICAL ANALYSIS: Unpaired student t-test was used and P < 0.05 was accepted as significant. RESULTS AND CONCLUSIONS: MBT bracket group had a lower score of 2.60 points in buccolingual inclination and lower score of 1.10 points in occlusal contact category that was statistically significant when compared with Roth group. The difference in total ABO-OGS score was 2.65 points showing that the outcome for the MBT prescription was better than that of the Roth prescription, which is statistically significant, but with little or no clinical significance. It can be concluded that use of either one of the Roth and MBT bracket prescriptions have no impact to the overall clinical outcome and quality of treatment entirely depends on clinician judgment and experience.

A comparision of Twin-block and Forsus (FRD) functional appliance--a cephalometric study.

UNLABELLED: The aim was to compare the effects of Twin-block & Forsus (FRD) functional appliances in the correction of Angles Class II division 1 malocclusions. MATERIALS AND METHODS: Pre- and post-treatment lateral cephalograms of 25 patients who underwent treatment with twin block for the correction of class II div 1 were compared with 25 patients who underwent treatment with Forsus appliance. These were again compared with the pre follow up and post follow up lateral cephalograms of 25 patients who have not undergone any treatment during this period. All the 3 group patients were compared for skeletal, dental and soft tissue parameters. RESULTS: Cephalometric analysis revealed that both Twin-block & Forsus Fatigue Resistant Device (FRD) appliances stimulated mandibular growth. Statistically significant differences between the two groups were found. Twin-block patients showed statistically very high significant (p < 0.001) increase in mandibular length (6.02 mm) whereas Forsus appliance patients showed significant (p < 0.05) increase in mandibular length (1.6 mm) when compared with control group (0.3 mm). No significant restriction of maxillary growth was found in either of the two experimental groups when compared to control group. Significant increase in lower anterior facial height & posterior facial height was observed in both experimental groups in relation to control group. Significant reduction of overjet and overbite was observed in both experimental groups. Class I molar relationship and improvement in the soft tissue profile were achieved in both treatment groups compared with control group. CONCLUSIONS: Both Twin Block and Forsus were effective in the treatment of Class II Div 1 malocclusion. Class II correction with Twin-block is more due to mandibular skeletal and dentoalveolar changes whereas in Forsus, it is more due to dentoalveolar changes and less skeletal changes.

Facial talon in mandibular incisor: An unusual occurrence.

Talon cusp, also known as an eagle's talon, is a dental anomaly that occurs on the lingual aspect of teeth commonly, but occurrence on the facial aspect has rarely been reported. It is an extra cusp on an anterior tooth, which arises as a result of evagination on the surface of a crown before calcification has occurred. The incidence of talon cusp on lingual side is less than 6% and is even lesser on the facial aspect. Commonly involved teeth are maxillary incisors, usually unilateral but in some instances bilateral. The classical radiographical feature of talon cusp is double teeth appearance. The anomaly has been reported to be unusual in the mandibular dentition and extremely rare on the facial aspect. We report one such extremely rare case of facial talon cusp in mandibular central incisor.

Evaluation of the power arm in bringing about bodily movement using finite element analysis.

AIM: To evaluate the effectiveness of the power arm in bringing about bodily movement and to determine the ideal length and location of the power arm. METHODS: A geometric model of the maxillary right canine was constructed and subsequently converted to a finite element model. Material property data were represented, boundary conditions were defined, and force was applied. Different situations were simulated in which a power arm of varying vertical lengths were attached at different locations on the tooth--namely, the incisal, middle, and cervical thirds. RESULTS: The amount of bodily movement is maximum when the force is delivered directly at the cervical third. It decreases at the middle third and is least when attached at incisal third. The varying lengths of the power arm for a particular site of attachment does not bring about any change in the movement. CONCLUSION: The attachment of the power arm at the cervical third brought about maximum bodily movement, followed by the middle and incisal thirds. Variations in length of the power arm at different sites of attachment did not bring any change in the outcome. Thus, the point of attachment is critical in bringing about bodily movement.

Treatment of mandibular anterior crowding with incisor extraction using lingual orthodontics: a case report.

A 20-year-old woman presented with a labially displaced mandibular right central incisor with severe attrition. Her maxillary dentition was well-aligned, and she had a straight profile. The respective central incisor was extracted. Subsequently, all teeth were aligned and the extraction space was closed with 2D lingual brackets. The result was esthetically pleasing.

A new sagittal dysplasia indicator: the YEN angle.

AIM: To develop a new cephalometric measurement to evaluate the sagittal relationship between the maxilla and mandible. MATERIAL AND METHODS: Seventy-five pretreatment lateral cephalograms (25 each of Class I, II, and III) were subdivided based on ANB, Wits appraisal, and Beta angle into skeletal Class I, II, and III. The same cephalograms were again classified into skeletal Class I, II, and III based purely on Beta angle. The new measurement is based on the landmarks S, M (midpoint of the anterior maxilla), and G (center at the bottom of the symphysis), which form the YEN angle measured at M. RESULTS: The mean and standard deviation for the YEN angle were calculated in all three skeletal groups. After using one-way analysis of variance (ANOVA) and Newman Keuls test, receiver-operating characteristic curves were obtained for the YEN angle in both types of classifications. The results showed that a patient with a YEN angle from 117 to 123 degrees could be considered to have a Class I skeletal relationship. CONCLUSIONS: The YEN angle was developed to assess more reliably the sagittal relationship between both jaws. Subjects with a YEN angle between 117 and 123 degrees have a skeletal Class I pattern. With an angle less than 117 degrees, patients are considered to have a skeletal Class II relationship, and with an angle greater than 123 degrees, patients have a skeletal Class III.