Orthognathic surgery case of metal allergy applied orthodontic appliances made of organic polymer

This case report presents a case that underwent orthognathic treatment with non-metallic appliances made of organic polymer. The patient was a 19-year-old female with mandibular protrusion and maxillary anterior crowding. The overbite was +3.0 mm, and the overjet ?3.0 mm. She was allergic to nickel (Ni³⁺), cobalt (Co³⁺) and cobalt–chrome (Co–Cr³⁺). The pre-surgical orthodontic treatment included the extraction of the maxillary right-and-left second premolars and mandibular right third molar. An orthodontic appliance made of organic polymer was employed. Orthognathic surgery with bilateral sagittal split ramus osteotomy was carried out. After 32 months pre-surgical orthodontic treatment, the left and right sides were set back 9 and 7 mm, respectively. Rigid fixation of the splitted mandible was employed using two absorbency screws in each side, and the inter-maxillary fixation was performed with elastic threads for 8 days. Total treatment period was 42 months. For retention, a non-metal retainer was employed for the upper and lower dentition. The consistent non-metal treatment on orthognathic case of metal allergy was attained successfully. However, the maxillary molars and the mandibular anterior teeth appeared elongated. This was considered to be caused by the low rigidity of a plastic material.     

Orthognathic treatment case after severe root resorption in the early treatment stage

This article presents an orthognathic treatment case after severe apical root resorption of maxillary anterior teeth using anterior segmental osteotomy.This case involved a 20-year-old female with the chief complaint of maxillary protruding and irregularly aligned mandibular anterior teeth. Her medical history showed no allergies or medical problems. The overbite was +3.0 mm, and the overjet +3.0 mm. After extraction of the four first premolars, a multi-bracket treatment was started. A severe root resorption of the maxillary anterior teeth was found 12 months after active treatment. The maxillary anterior segmental osteotomy was chosen as the compensatory treatment. The total treatment period was 2 years and 7 months. The post-retention panoramic radiograph showed no developmental root resorption.     

Considerations in correction of mandibular protrusion by intra-oral vertical ramus osteotomy

This case report presents a case that underwent orthognathic treatment with intra-oral vertical ramus osteotomy (IVRO). The patient was a 19-year-old female with mandibular protrusion and severe maxillary anterior crowding. The overbite was +0.5 mm and the overjet −1.5 mm. She had orofacial pain and tenderness of the temporomandibular joints (TMJ) and surrounding muscles. The pre-surgical orthodontic treatment included the extraction of the maxillary right lateral incisor, maxillary right second premolar, maxillary left canine, mandibular left second molar and mandibular right second premolar. After 18 months of pre-surgical orthodontic treatment, the left and right sides of the mandible were set back 8 and 6 mm, respectively, via IVRO to improve mandibular protrusion. The total treatment period was 26 months. The patient showed the backward reaction of the mandible, which occurred after release of the maxillo-mandibular fixation. The usage of the Class II elastics during the post-surgical phase to maintain the overjet made the inclination of the maxillary incisors more lingual.     

Anterior maxillary segmental distraction for correction of maxillary hypoplasia and dental crowding in cleft palate patients: a preliminary report

To evaluate the feasibility of anterior maxillary segmental distraction (AMSD) to correct maxillary hypoplasia and severe dental crowding in cleft lip and palate (CLP) patients, 7 patients (average age 16.4 years) with maxillary hypoplasia, shortened maxillary dental arch length and severe anterior dental crowding secondary to CLP were selected for this study. After anterior maxillary segmental osteotomy, 3 patients were treated using bilateral internal distraction devices, and 4 patients were treated using rigid external distraction devices. Photographs and radiographs were taken to review the improvement in facial profile and occlusion after distraction. An average 10.25 mm anterior maxillary advancement was obtained in all patients after 10–23 days of distraction and 9–16 weeks of consolidation. The sella–nasion–point A (SNA) angle increased from 69.5° to 79.6°. Midface convexity was greatly improved and velopharyngeal competence was preserved. The maxillary dental arch length was greatly increased by 10.1 mm (P < 0.01). Dental crowding and malocclusion were corrected by orthodontic treatment. These results show that AMSD can effectively correct the hypoplastic maxilla and severe dental crowding associated with CLP by increasing the midface convexity and dental arch length while preserving velopharyngeal function, and dental crowding can be corrected without requiring tooth extraction.     

Skeletal,dental and facial aesthetic changes following anterior maxillary segmental distraction by tooth-borne device in patients with cleft lip and palate

Maxillary skeletal deficiency secondary to cleft lip and palate (CLP) remains a significant challenge. The aim of this study was to present the comprehensive skeletal, dental and facial aesthetic outcomes of anterior maxillary segmental distraction osteogenesis (AMSDO) for treatment of maxillary hypoplasia in patients with CLP. Twelve patients with maxillary hypoplasia treated with AMSDO by a customized tooth-borne distractor were included. Three-dimensional changes of anterior maxillary segment, upper incisor and pharyngeal space were measured by three-dimensional reconstruction derived from cone beam computed tomography (CBCT) data. Length and width of dental arch during distraction were determined in dental casts. Nasolabial angle, soft-tissue convexity and patient’s subjective satisfaction were assessed to evaluate facial aesthetic improvements. Nasopharyngoscopic evaluation and speech assessment were also performed before and after distraction. All patients successfully received AMSDO without serious complications. Following AMSDO, the anterior maxillary segments moved forward 5.56 ± 0.28 mm and slightly upward 1.15 ± 0.13 mm. AMSDO significantly lengthened maxillary dental arch, generated new bone to relieve dental crowding and improved patients’ facial aesthetic without worsening velopharyngeal closure and speech quality. AMSDO by tooth-borne distractor is an effective surgical alternative for the advancement in patients with cleft maxillary hypoplasia.     

Segment tilting associated with surgically assisted rapid maxillary expansion

This study aimed to evaluate, via computed tomography, the direction and magnitude of the segmental tilting that may occur after surgically assisted rapid maxillary expansion (SARME) in patients with a transverse maxillary deficiency. Thirty adult patients with a transverse maxillary deficiency greater than 5 mm were treated by SARME. The procedures consisted of bilateral zygomatic buttress and midpalatal osteotomies combined with the use of a tooth-borne orthopaedic device postoperatively. Axial and coronal images were obtained before and 6 months after SARME to evaluate the segment tilting. The greatest expansion occurred in the most inferior (5.4 ± 1.1 mm) and anterior (4.0 ± 1.3 mm) regions of the maxilla. The expanded segment tilted outward inferiorly and anteriorly in coronal and axial images, respectively. The segment tilting was 2.0 mm (2.3%) inferiorly and 3.1 mm (12.8%) anteriorly. It can be concluded that an outward tilting occurs in the most inferior and anterior portions of the maxilla during SARME procedures. Hence the direction and magnitude of such segmental tilting must be considered preoperatively when determining the surgical objectives.     

Changes in lip and cheek pressure due to simulated maxillary dental arch expansion

Changes in labial and buccal soft tissue pressure are considered to affect the post-treatment stability of dental arch expansion. The purpose of the present study was to investigate changes in lip and cheek pressure in simulated maxillary dental arch expansion using a hydraulic capillary infusion system. Thirteen subjects (8 males and 5 females, mean age 27.7 ± 2.7 years) with normal occlusion were examined. Manometric catheters connected to pressure transducers were mounted on intra-oral stents of 0.7 mm thickness. The areas measured were the right and left maxillary central incisors, canines, and first molars. Three types of stents were fabricated with 3.0 mm and 5.5 mm thickness for simulation of anterior expansion, lateral expansion, and combined anterior and lateral expansion. The results showed that in all areas, lip and cheek pressure significantly increased with an increase in the thickness of the stent. At all stent thicknesses, the canine area showed significantly higher pressure than the other areas. In expansions of both 0.7–3.0 mm and 0.7–5.5 mm, the combined expansion showed lower pressure than the anterior or lateral expansion alone in all areas of the dental arch. These results suggest that combined anterior and lateral expansion may be more advantageous for post-treatment stability than anterior expansion or lateral expansion alone performed to create space for tooth alignment.     

Bimaxillary protrusion trait in the Indian population: A cephalometric study of the morphological features and treatment considerations

PurposeThe orthodontic literature is discordant with the diagnosis of bimaxillary protrusion with no single anatomic answer and the anomaly has been referred in the literature with protean characteristics. The trait denotes a particular facial configuration and its cephalometric representation in certain ethnic and racial groups revealed a mixed pattern with individual variations. The present study was aimed at analyzing the dento-skeletal characteristics of bimaxillary protrusion in a sample of Indian men and women.Materials and methodsForty-six Indian subjects (28 women and 18 men; 19 ± 3.6 years of age) with Class I malocclusion and interincisal angle ≤110°, who attended orthodontic clinics for a comprehensive fixed orthodontic treatment were included for the study. The lateral films were hand traced and 27 parameters were measured. The data were imported to SPSS version 13 US package and statistical manipulation included means, standard deviation, and coefficient of variation (%). Male and female data were compared by Student's t-test (unpaired). Correlation and regression analysis were performed to assess any relationship between different parameters.ResultsThere was a marked increase in proclination of the maxillary incisors both to the maxillary plane (125.3 ± 5.7°), the NA line (35.1 ± 5.0°) and to sella–nasion (117.7 ± 5.5°). The positional relationship of the mandible to the maxilla with reference to the cranial base was within the normal limits (ANB = 3.1 ± 1.3°) and the skeletal pattern was Class I. The effective lengths of maxilla and mandible did not correlate significantly with sagittal skeletal discrepancy.ConclusionUnlike in other ethnic and racial groups, bimaxillary protrusion in Indian subjects is likely a bidental protrusion over normal dento-alveolar bases. The skeletal characteristics suggested a normal relationship of the functional components of the face. The condition could be treated successfully with orthodontic mechanotherapy alone.     

Two-point nasomaxillary fixation of the Le Fort I osteotomy: assessment of stability at one year postoperative

The purpose was to assess maxillary position among patients undergoing Le Fort I maxillary advancement with internal fixation placed only at the nasomaxillary buttresses. This was a retrospective study of patients undergoing a Le Fort I osteotomy for maxillary advancement, with internal fixation placed only at the nasomaxillary buttresses. Demographic and cephalometric measures were recorded. The outcome of interest was the change in maxillary position between immediately postoperative (T1), 6 weeks postoperative (T2), and 1 year postoperative (T3). Fifty-eight patients were included as study subjects (32 male, 26 female; mean age 18.4 ± 1.8 years). Twenty-five subjects (43.1%) had a diagnosis of cleft lip and palate. Forty-three subjects (74.1%) had bimaxillary surgery, 16 (27.6%) had bone grafts, and 18 (31.0%) had segmental maxillary osteotomies. At T3, there were no subjects with non-union, malunion, malocclusion, or relapse requiring repeat surgery. Mean linear changes between T1 and T3 were ≤1 mm. Mean angular changes between T1 and T3 were <1°. There was no significant difference in stability in multi-segment maxillary osteotomies (P =  0.22) or with bone grafting (P =  0.31). In conclusion, anterior fixation alone in the Le Fort I osteotomy results in a stable maxillary position at 1 year postoperative.     

Prevalence of malocclusions and orthodontic treatment need in 8- to 12-year-old schoolchildren in Casablanca,Morocco

ObjectivesThe purpose of this work was to evaluate the prevalence of malocclusions and orthodontic treatment need among schoolchildren in Casablanca, Morocco.Materials and methodsA sample of 1000 children aged between 8 and 12 years, with no history of orthodontic treatment, was chosen at random in state schools in different administrative areas of the city of Casablanca. Data was registered using the method of Bjork et al. (1964). Orthodontic treatment need was assessed with the index used by the Swedish National Board of Health (SweNBH).ResultsWe found Angle Class I malocclusions in 61.4%, Class II in 24%, Class III in 10% and an indeterminate molar class with one or more missing molars in 4.6% of the children. Overjet was 1–4 mm in 63.8%, 4–6 mm in 17.2% and >6 mm in 10%. Bite was normal in 65.4%, 23.6% presented an overbite greater than 4 mm, 1.7% an anterior open bite ≤3 mm, 1.2% an anterior open bite >3 mm and 0.2% a bilateral open bite. Half of the sample presented anterior crowding, while only 2.5% presented posterior crowding. In all, 84.2% of the subjects needed some orthodontic treatment, and 15.8% needed no treatment. No statistically significant difference was found between sex or age and orthodontic treatment need (P>0.05).ConclusionsThis study found a strong need for orthodontic treatment, confirming the utility of implementing a programme of bucco-dental prevention and screening for malocclusion.     

Calvarial graft resorption index in the reconstruction of the maxillary sinus in patients with atrophic maxillas: a prospective clinical study

The objective of this study was to assess the resorption index of particulate calvarial grafts in maxillary sinuses of patients undergoing total reconstruction of an atrophic maxilla with residual alveolar bone that was less than, or equal to, 3 mm thick. Twenty-one maxillary sinus floor elevations were carried out using particulate calvarial grafts in 11 individuals with totally edentulous maxillas. All patients had computed tomography (CT) before (T0), and 48 hours (T1) and six months after surgery (T2). For each CT scan, linear measurements were taken of sections of the anterior, medial, and posterior regions of the maxillary sinus. There was a significant increase in the height of the maxillary sinus floor when T0 was compared with T1 (p = 0.001). There was a statistically significant reduction in all maxillary sinus measurements when T1 was compared with T2; the mean height reduction being 2.36 mm (16.87%) in the anterior region, 3.53 mm (22.47%) in the medial region, and 2.21 mm (22.78%) in the posterior region (p = 0.001). Mean resorption was 20.7%. Autogenous calvarial bone used alone is an option for graft material in pneumatised maxillary sinuses and in cases where there is limited alveolar bone.     

One-year assessment of surgical outcomes in Class III patients using cone beam computed tomography

The purpose of this study was to apply a novel method to evaluate surgical outcomes at 1 year after orthognathic surgery for Class III patients undergoing two different surgical protocols. Fifty patients divided equally into two groups (maxillary advancement only and combined with mandibular setback) had cone beam computed tomography (CBCT) scans taken pre-surgery, at splint removal, and at 1-year post-surgery. An automatic cranial base superimposition method was used to register, and shape correspondence was applied to assess, the overall changes between pre-surgery and splint removal (surgical changes) and between splint removal and 1-year post-surgery at the end of orthodontic treatment (post-surgical adaptations). Post-surgical maxillary adaptations were exactly the same for both groups, with 52% of the patients having changes >2 mm. Approximately half of the post-surgical changes in the maxilla for both groups were vertical. The two-jaw group showed significantly greater surgical and post-surgical changes in the ramus, chin, and most of the condylar surfaces (P < 0.05). Post-surgical adaptation on the anterior part of the chin was also more significant in the two-jaw group (P < 0.05). Regardless of the type of surgery, marked post-surgical adaptations were observed in the regions evaluated, which explain the adequate maxillary–mandibular relationship at 1-year post-surgery on average, with individual variability.     

Safe placement techniques for self-drilling orthodontic mini-implants

Self-drilling mini-implants are being used more frequently as an orthodontic anchorage, but the placement torque of self-drilling mini-implants can easily become excessive in the thick, mandibular cortical bone. The purpose of this study is to examine a safe self-drilling placement technique that provides adequate placement torque for orthodontic mini-implants. The mini-implants were placed using self-drilling and pre-drilling methods into the ribs of pigs. Specimens were classified into two groups, thin and thick, with cortical bone thicknesses of 1.2 ± 0.02 and 2.0 ± 0.03 mm, respectively, and used to model the human maxillary and the mandibular bones. The peak mini-implant placement torque value was measured and the surrounding cortical bone was observed histologically. In the mandible model, the torque in the self-drilling and pre-drilling groups exceeded 10 N cm, except in one case which had a 1.3 mm diameter pilot hole. Histology revealed cracks in the surrounding cortical bone in the groups whose torque value was 10 N cm or more. Therefore, when using the self-drilling technique to place a 1.6 mm diameter mini-implant in the mandibular alveolar bone, it is preferable to drill a 1.3 mm diameter pilot hole first.     

Lip changes after premolar extraction in Class I bimaxillary protrusion: A retrospective study in Thai female adults

Purpose

To determine the ratios of dental and lip changes and develop the predictive equations of lip changes in Class I bimaxillary protrusion in Thai female adults after orthodontic treatment with 4 premolars extraction.

Transverse maxillary stability assisted by a transpalatal device: A retrospective pilot study of 9 cases

This retrospective pilot study assessed the transverse stability of an original surgical approach in nine patients with moderate transverse maxillary deficiency associated with a sagittal and/or vertical skeletal anomaly. During the one-stage surgical procedure, bi- or three-dimensional anomalies were corrected. Maxillary expansion was guided by a transpalatal bone-anchored device (TPD?). Expansion measurements were made 1-2 months before surgery, 6 and at least 12 months after surgery. The transverse occlusion was corrected in all cases. After 12 months the gingival landmarks revealed an expansion range from ?0.83 to +2.92 mm for the cuspids, +1.66 to +6.23 mm for the bicuspids and from +2.68 to +4.80 mm for the molars. For the occlusal landmarks, expansion ranged from -2.01 to +3.15 mm (cuspids), from +1.11 to +7.13 mm (bicuspids) and from +2.70 to +6.26 mm (molars). Cuspid expansion was significantly smaller than that of bicuspids and molars. This more posterior expansion was achieved through the surgical procedure. The transverse stability obtained with the aid of the bone-anchored TPD? was satisfying. This preliminary study supports the principle of an original surgical approach, called ‘Le Fort I – TPD’, which combines a Le Fort I osteotomy with a controlled maxillary expansion.     

Changes in soft tissue profile after mandibular setback surgery in Class III subjects

The aim of this study was to investigate changes in hard and soft tissue profile after mandibular setback surgery. Lateral cephalograms of 25 Class III subjects were assessed before and 1.5 ± 0.4 years after mandibular setback surgery. Paired t test, Pearson correlation test and linear regression analysis were used to evaluate the changes in soft tissue profile. Significant changes were found in skeletal (SNB ?3.6 ± 0.9°, ANB 3.7 ± 1.0°, overjet 5.0 ± 1.2 and overbite 2.5 ± 1.1 mm, P < 0.001), soft tissue (facial convexity 5.9 ± 1.6°, P < 0.001; labiomental fold 0.6 ± 0.6 mm, P < 0.001; upper and lower lip protrusion 0.5 ± 0.8 mm, P < 0.01; ?3.3 ± 1.2 mm, P < 0.001), and upper and lower lip lengths (0.9 ± 1.2 mm, P < 0.01; ?1.8 ± 2.1 mm, P < 0.001). Correlations were found between facial convexity and SNB and ANB angles and between upper lip length and SNB and ANB angles. The change in lower lip length was correlated with SNB, ANB, overjet and overbite. Lower lip retrusion was correlated with overjet and a significant correlation was found between the retrusion of lower incisor and lower lip. Mandibular setback surgery was effective in producing an orthognathic profile in adult Class III subjects with mandibular prognathism.     

Posterior maxillary alveolar vertical distraction osteogenesis by bi-directional distractor

A patient with severe posterior maxillary hypoplasia was simulated using a 3-dimensional model by rapid prototyping, and segmental vertical distraction osteogenesis was planned to advance the posterior maxillary segment. The bi-directional distractor was adapted to the alveolar ridge and zygomatic buttress. After a 7-day latency period, we started distraction at a rate of 0.35 mm every 12 h. 12 mm of advancement of the posterior maxillary segment was achieved. This distraction osteogenesis using a bi-directional distractor with proper therapeutic planning and good surgical technique will help ensure adequate vector control to predictably regenerate the hard and soft tissues during alveolar distraction.     

Assessment of gingival biotype and facial hard/soft tissue dimensions in the maxillary anterior teeth region using cone beam computed tomography

ObjectiveThis study sought to assess the relationship between facial gingival and bone dimensions in maxillary anterior teeth region using cone beam computed tomography (CBCT).DesignThis study assessed 621 maxillary anterior teeth in 144 patients. In the sagittal plane, facial bone thickness (BT) and gingival thickness (GT) were measured at the crestal level and at 2, 4 and 6 mm apical to the cementoenamel junction (CEJ). The dentogingival complex (DGC) dimensions and the distance from the CEJ to bone crest were also measured on CBCT scans. To determine the gingival biotype, GT at 2 mm apical to the gingival margin was measured and GT <1.5 mm was categorized as thin while GT ≥1.5 mm was categorized as thick. The data were analyzed using SPSS version 21 via repeated measures ANOVA and the Cochrane’s Q, chi-square and independent samples t-tests.ResultsThe BT around the maxillary central and lateral incisors and canine teeth at 4 and 6 mm apical to the CEJ was significantly different in thick and thin gingival biotypes (P < 0.05). The mean GT at 2 and 4 mm apical to the CEJ was significantly different around central and lateral incisors (P < 0.05). Thickness of crestal bone was significantly different between the two gingival biotypes around central and lateral incisors (P < 0.05).ConclusionThe two gingival biotypes had significantly different mean BT; different biotypes and their relationship to BT varied around anterior maxillary teeth.     

Comparison between the classical and a modified trans-septal technique of alar cinching for Le Fort I osteotomies: a prospective randomized controlled trial

The aim of this prospective randomized control trial was to analyse the efficacy of a new trans-septal alar base cinch suture in controlling alar width in patients undergoing maxillary intrusion and setback by comparing it with the traditional cinch suture. Statistical evaluation was carried out in 62 of 76 patients. Group I (31 patients) received the traditional alar base cinch suture, and group II (31 patients) received the alar base cinch suture with an anchoring bite taken through the nasal septum 10 mm behind its anterior edge. In both groups the accurate identification of alar fibroareolar tissue was facilitated by an 18 gauge green needle passed extra orally. Alar base width was measured before and 6 months after surgery using Vernier callipers. Preoperative alar base width for group I was 29.76 mm (1.901 SD) and for group II 29.79 mm (3.141 SD); the postoperative values were 32.42 mm (1.858 SD) and 29.94 mm (2.568 SD), respectively. Mean alar base widening was 2.661 mm (0.800 SD) in group I and 0.145 mm (2.050) in group II. The difference in alar widening was statistically significant (p < 0.001). In conclusion, the trans-septal modified alar cinch suture offers better control of alar base architecture in maxillary intrusion and setback.     

Simple removable appliances to correct anterior and posterior crossbite in mixed dentition: Case report

Different techniques have been used to correct anterior and posterior crossbites in mixed dentition. This case report illustrates the treatment of anterior and unilateral posterior crossbites during the mixed dentition. The patient was a 9-year-old boy with a crossbite of the maxillary right permanent central incisor and a unilateral right posterior crossbite, both expressed by a functional shift in the sagittal and transverse dimensions. Two upper acrylic removable appliances, each with an expansion jackscrew, were used to correct the crossbites. The total active treatment time was 4 months; the treatment outcomes were successfully maintained for the subsequent 4 months. General and pediatric dentists, as well as orthodontists, may find this technique useful in managing crossbite cases of the mixed dentition and utilizing the discussion and illustrations for further clinical guidance.