Maxillomandibular Advancement for the Treatment of Obstructive Sleep Apnea in Patients With Normal or Class I Malocclusion.

BACKGROUND: Maxillomandibular advancement is an effective surgical option for obstructive sleep apnea (OSA) that achieves enlargement of the upper airway by physically expanding the facial skeleton. The authors sought to determine whether an advancement of 10 mm predicts surgical success and if any correlation existed between the magnitude of mandibular/maxillary advancement and improvement in polysomnography metrics using aggregated individual patient data from multiple studies. METHODS: A search of the PubMed database was performed to identify relevant articles that included preoperative and postoperative polysomnography data and measurements of the advancement of both the maxillary and mandibular portions of the face in patients with normal or class I malocclusion. Each patient was stratified into "Success" or "Failure" groups based on criteria defining a "Success" as a 50% preoperative to post-operative decrease in AHI or RDI and a post-operative AHI or RDI <20. RESULTS: A review of the PubMed database yielded 162 articles. Review of these resulted in 9 manuscripts and a total of 109 patients who met the inclusion criteria. There was no statistically significant difference in the amount of anterior advancement of either the mandible (P = 0.96) or the maxilla (P = 0.23) between the "Success" or "Failure" groups. CONCLUSIONS: While there is a paucity of individual data available, the current data does not support an ideal amount of maxillary or mandibular advancement that is required to obtain a surgical success in the treatment of OSA. Until a multicenter, prospective, randomized trial is performed, surgical planning should be tailored to patient-specific anatomy to achieve the desired result.

A novel 3D-printed computer-assisted piezocision guide for surgically facilitated orthodontics.

Surgical interventions on the alveolar ridges aimed at facilitating orthodontic tooth movement have been extensively reported. However, unexpected events or complications still occur in daily practice. The purpose of this report was to present a novel 3-dimensional (3D) computer-assisted piezocision guide (CAPG) designed to be translucent for increased visibility, rigid for enhanced support during guidance, and porous for profuse irrigation during procedure. Such a design can function to minimize the risk of surgical complications. In this case, we present a novel 3D-printed CAPG to facilitate a minimally invasive periodontal accelerated osteogenic orthodontics (PAOO) procedure with a guide that provides accuracy, adequate visibility, and greater access for the coolant to reach the surgery site. By navigating the cone-beam computed tomography data, we precisely know the cortical bone thickness, root direction, and interrelations between anatomic structures in an individual situation, which allows us to design our cutting slot for the required length and depth according to the operator's knowledge. Finally, 3D printing was applied, transferring our surgical plan to fabricate the CAPG. Moreover, the well designed pores on the CAPG allow effective irrigation during the piezocision procedure. This minimally invasive procedure was uneventful, and no devitalized tooth or alveolar bone was found.

Correcting severe scissor bite in an adult.

Scissor bite often remains unnoticed by patients although it can adversely affect facial symmetry, jaw growth, and mastication. This case report illustrates the efficacy of temporary skeletal anchorage devices (TSADs) and a modified lingual arch in correcting severe scissor bite. A 28-year-old woman presented with severe scissor bite in the mandibular right posterior segment. To treat this condition, TSADs were used for maxillary posterior intrusion and a modified lingual arch for buccally uprighting mandibular posterior teeth. Long-term retention records demonstrate stable treatment results.

Maxillary Corticotomies With Bone-to-Bone Retraction and Mandibular Segmental Osteotomy for Correcting an Anterior Double Protrusion.

BACKGROUNDS: This article presents maxillary corticotomies with bone-to-bone retraction and anterior segmental osteotomy (ASO) as an alternative to 2-jaw orthognathics in the bimaxilary protrusion patient with partially anchylosed maxillary anterior tooth. METHODS: The 18-year-old male, complaining of anterior protrusion, with a trauma history to the maxillary central incisor, and requesting rapid treatment, was treated with maxillary corticotomies in 2 stages and ASO in the mandible. The mandibular ASO and palatal corticotomy were done under local anesthesia and 2 weeks later, labial corticotomy followed. The anterior segment was retracted bodily using buccal C-tubes and a combination of the C-lingual retractor and palatal C-plate. RESULTS: Due to a concern about ankylosis of the maxillary right central incisor, retraction of the anterior bone/tooth segment was chosen over any attempt to move teeth through the bone. After bone-to-bone retraction, the remaining extraction space was closed by protraction of posteriors. The total treatment period was 18 months. There was good retraction of the anterior segment and retrusion of the lips. CONCLUSIONS: A combination of maxillary corticotomies with skeletal anchorage for bone-to-bone retraction and a mandibular ASO under local anesthesia might be an alternative treatment option for excellent profile change in a short treatment period.

Arch-width changes in extraction vs nonextraction treatments in matched Class I borderline malocclusions.

INTRODUCTION: The aims of this study were to identify a sample of borderline Class I extraction and nonextraction patients and to investigate posttreatment changes in arch-width and perimeter measurements. METHODS: A parent sample of 580 Class I patients was subjected to discriminant analysis, and a borderline subsample of 62 patients, 31 treated with extraction of 4 first premolars and 31 treated without extractions, was obtained. The patients' plaster casts were digitally scanned, and the maxillary and mandibular intercanine and intermolar widths and perimeters were assessed. RESULTS: The extraction group showed increases in maxillary and mandibular intercanine widths (P <0.001) and decreases in mandibular intermolar width and in maxillary and mandibular perimeters (P <0.001). The nonextraction group showed increases in all 4 arch-width measurements (P ≤0.003), whereas the maxillary and mandibular perimeters were maintained. The posttreatment differences between the 2 groups showed significant differences in the maxillary (P <0.001) and mandibular intermolar widths (P <0.001). Also, the comparison of the arch perimeters between the 2 treatment groups showed adjusted differences of -8.51 mm (P <0.001) and -8.44 mm (P <0.001) for the maxillary and mandibular arches, respectively. The intercanine widths showed no changes between the 2 treatment groups. CONCLUSIONS: Borderline Class I patients treated with extraction of 4 first premolars had decreased maxillary and mandibular intermolar and perimeter measurements compared with nonextraction patients. The maxillary and mandibular intercanine widths showed no significant difference between the 2 treatment groups.

Prevalence of extraction space reopening in different orthodontic treatment protocols.

INTRODUCTION: In this study, we aimed to compare the amount and frequency of extraction space reopening after 2- and 4-premolar extraction treatments in Class II and 4-premolar extractions in Class I malocclusion patients. METHODS: The sample comprised 105 subjects with full-cusp Class II and Class I malocclusions, divided into 3 groups. Group 1 consisted of 33 full-cusp Class II malocclusion patients treated with a 2-premolar extraction protocol. Group 2 had 34 full-cusp Class II malocclusion patients treated with 4-premolar extractions, and group 3 included 38 Class I malocclusion patients treated with 4-premolar extractions. The Peer Assessment Rating index was used to assess initial malocclusion severity and quality of the occlusal outcome, measured on dental casts. The amounts of extraction spaces were measured with a digital caliper on the final and long-term posttreatment dental casts, after an average of 9.79 years posttreatment. Intergroup comparisons were performed by analysis of variance, followed by Tukey tests and chi-square tests. RESULTS: There were no significant differences regarding the amount and frequency of extraction space reopening among the groups. CONCLUSIONS: Two- and 4-premolar extractions in Class II and 4-premolar extraction treatment in Class I malocclusion patients show similar reopening of extraction spaces in the long term.

Improvement in Peer Assessment Rating scores after nonextraction, premolar extraction, and mandibular incisor extraction treatments in patients with Class I malocclusion.

INTRODUCTION: Different treatment protocols implemented for correction of Class I malocclusion aim at achieving ideal occlusal characteristics. This study was planned to evaluate the improvement in the occlusal characteristics of Class I patients treated with nonextraction (NE), all first premolar extractions (PME), and mandibular incisor extraction (MIE) as assessed by the percentage of improvement in Peer Assessment Rating (PAR) scores. METHODS: This retrospective cross-sectional study was conducted on the pretreatment and posttreatment dental casts of 108 subjects with Class I malocclusion. The total sample was divided into 3 equal groups according to the treatment protocol implemented: NE, PME, and MIE. The mean pretreatment and posttreatment PAR scores, and the percentages of improvement were compared among the 3 treatment modalities using Kruskal-Wallis and post-hoc Dunnett T3 tests. RESULTS: The mean percentages of improvement in the PAR score were 75.8% ± 25.8% in the NE group, 73.1% ± 19.4% in the PME group, and 70.6% ± 24.1% in the MIE group. There was no significant difference (P = 0.351) in the percentages of improvement in PAR scores among the 3 treatment modalities. However, the mean pretreatment and posttreatment PAR scores varied significantly (P <0.001) in the 3 groups. The average pretreatment and posttreatment PAR scores were highest in the MIE group and lowest in the NE group. CONCLUSIONS: The comparable percentages of improvement in PAR scores among the 3 groups denote that equivalent occlusal corrections were achieved in Class I patients treated with the NE, PME, and MIE protocols.

Efficiency of piezosurgery technique in miniscrew supported en-masse retraction: a single-centre, randomized controlled trial.

BACKGROUND: Piezoelectric surgery is a newly introduced technique for rapid tooth movement. However, the efficiency of this technique has not been investigated on en-masse retraction cases yet. OBJECTIVE: To investigate the efficiency of piezosurgery technique in accelerating miniscrew supported en-masse retraction and study the biological tissue response. In addition, to show if this technique induces a difference in dental, skeletal and soft tissue changes on lateral cephalograms, and in canine and molar rotations, besides intercanine and intermolar widths on dental casts. DESIGN, SETTING, PARTICIPANTS: We conducted a randomized, single-centred, parallel-group, controlled trial, requiring upper right and left first premolar extractions on 30 patients above the minimum age of 14 years at the beginning of retraction. INTERVENTIONS: Piezosurgery-assisted versus conventional en-masse retraction anchored from miniscrews placed between second premolars and first molars, bilaterally. OUTCOMES: The main outcome was the en-masse retraction rate. Secondary outcomes were gingival crevicular fluid (GCF) volume and GCF content of receptor activator of nuclear factor κß ligand (RANKL), changes regarding cephalometric and dental cast variables, and miniscrew success rates. RANDOMIZATION: Accomplished with opaque, sealed envelopes. BLINDING: Applicable for data assessment only. RECRUITMENT: Commenced in February 2013 and ended in October 2014. RESULTS: Thirty-one patients were included in the study and divided into 2 groups of piezosurgery (n = 16) and control (n = 15). After 9.3 months of follow-up, no statistically significant difference was observed between groups for neither retraction rates (P = 0.958) nor GCF parameters (P > 0.05). Changes in lateral cephalometric and dental cast variables, and miniscrew success rates did not show significant differences either. CONCLUSION: Based on the results of this study, piezosurgery technique was found to be ineffective in accelerating en-masse retraction, and promoting a difference in the studied GCF parameters, skeletal and dental variables. REGISTRATION: The trial was not registered. PROTOCOL: The full protocol of this PhD thesis study can be accessed from tez.yok.gov.tr. FUNDING: This work was supported by Baskent University Research Fund. No conflict of interest was declared.

[Efficiency of cephalometry in orthodontic treatment planning: cephalometric parameters and their age-related changes]. / Éffektivnost' tsefalometrii v planirovanii ortodonticheskoi korrektsii: tsefalometricheskie parametry i ikh vozrastnye izmeneniia (chast' 1).

The aim of the study was to evaluate the efficiency of cephalometry in orthodontic treatment planning in patients with teeth crowding and Angle Class I molars relation. Cephalometric parameters were analyzed in 70 patients that completed orthodontic treatment in 'Orthodont' dental clinic (Samara). Cephalometric X-rays were taken at baseline examination and after treatment. In patients with crowding and Class I molars relationship treated with extraction of all four first premolars correlation between N-Se and mandibular and maxillary length was disturbed. These patients showed higher N-Se and reduced jaws length than patients with no extraction or extraction of 2 premolars. The observed increase of G angle with reduced mandibular length assumes compensatory changes of mandible position. These disproportions were aggravated by facial growth. In certain cases cephalometric assessment is inefficient for treatment strategy choice.

Surgical and orthodontic management of maxillary canine-lateral incisor transpositions.

Transposition of the maxillary canine and the lateral incisor is a complex dental anomaly to treat. The difficulty increases if the treatment aims to correct the transposition. These case reports describe 2 patients with transposition of the maxillary lateral incisor and canine. The first case involves bilateral incomplete transpositions, and the second is a complete transposition. The radiographic appearance of the canine was similar in the 2 patients. However, the treatments were distinct because of the 3-dimensional positions of the teeth. The first case involved palatally placed lateral incisor roots. To prevent resorption of the lateral incisors, the canines were moved into position buccally. In the second case, the lateral incisor root had a buccal position, and the canine crown was tractioned palatally. The position of the lateral incisor root was critical when electing the correct treatment and mechanics for each patient.

The effect of teeth extraction for orthodontic treatment on the upper airway: a systematic review.

PURPOSE: The purpose of this study was to evaluate the effect of teeth extraction for orthodontic treatment on the upper airway. METHODS: Relevant trials assessing the effect of orthodontic extractions on the upper airway were retrieved electronically through PubMed, Embase, Medline, Web of Knowledge, and the Cochrane Library. The processes of literature search, selection, quality assessment, and data extraction were performed by two authors independently. RESULTS: Seven articles were included in this systematic review. They were categorized into three groups according to their indications for extractions, namely anteroposterior discrepancy (group 1), crowding (group 2), and unspecified indications (group 3). In group 1, enrolled patients were diagnosed with class I bimaxillary protrusion and had four first premolars extracted, with a significant decrease in upper airway dimension. In group 2, increase in the upper airway dimension was reported in patients who were diagnosed with class I crowding and four first premolars extracted. In group 3, all patients were adolescents and no significant change in the upper airway dimension was observed. CONCLUSIONS: Currently, it is difficult to draw evidence-based conclusions because of the exceeding heterogeneity among included studies, and more qualified trials are required to provide reliable evidence. Extractions followed by large retraction of the anterior teeth in adult bimaxillary protrusion cases could possibly lead to narrowing of the upper airway. Mesial movement of the molars appeared to increase the posterior space for the tongue and enlarge the upper airway dimensions. Although the effect of teeth extraction on upper airway dimension seems to be related to indications for extraction, accepted scientific evidence is still insufficient owing to the limited number of included studies. The relationship between the upper airway size and the respiratory function has not been demonstrated. While there may be a decrease in the upper airway volume, there is no evidence that this would turn an airway more collapsible. None of the studies assessed in this review had actual functional assessment of breathing. Additional qualified trials are necessary to verify reliability.

Surgery Versus Nonsurgery Option for Scissors Bite Treatment.

BACKGROUND: This article compared the use of temporary skeletal anchorage devices (TSADs) and orthognathic surgery for scissors bite correction. METHODS: To correct the scissors bite without orthognathic surgery, a cross-type titanium miniplate was placed with 3 miniscrews (1.5 mm in diameter and 5 mm in length) in the midpalatal area, without a surgical incision and under local anesthesia. In addition, a 1 miniscrew was placed on the buccal alveolar bone to avoid molar extrusion during uprighting. In the surgical case, a 3-piece Le Fort osteotomy was performed to decrease maxillary arch width for transverse correction, and to close the extraction space by anterior retraction. The maxilla was stabilized with 4 L-shaped plates at the zygomatic buttresses and the pyriform aperture, as well as 2 straight plates between the 3 segments. RESULTS: After 15 months of treatment in the nonsurgery case, the scissors bite was successfully resolved by decreasing maxillary arch width and uprighting the molars. In the mandibular arch, correction of the crowding was aided by extraction of # 41. In the surgery case, after 24 months of treatment in the orthognathic surgery case, the bilateral scissors bite was successfully resolved and the facial asymmetry was corrected. The molar occlusion finished in Class II and the facial profile was improved. CONCLUSIONS: In scissors bite cases, a good diagnosis will help the clinician to decide whether treatment should involve orthognathic surgery. The authors have shown a case that was corrected with surgery and a case that was corrected using TSAD anchors. Treatment planning must include evaluation of the basal arch width of maxilla and mandible in class I occlusion, any skeletal asymmetry concomitant with a mandibular shift, the inclinations or atypical eruption degree of the posterior teeth, and the number of teeth involved in the scissors bite.

Change in the Upper Airway of Patients With Obstructive Sleep Apnea Syndrome Using Computational Fluid Dynamics Analysis: Conventional Maxillomandibular Advancement Versus Modified Maxillomandibular Advancement With Anterior Segmental Setback Osteotomy.

OBJECTIVE: The aim of the study was to compare the effect of conventional maxillomandibular advancement (MMA) and modified MMA with anterior segmental setback osteotomy (MMA-ASSO) on the airway changes in patients with obstructive sleep apnea syndrome (OSAS) using three-dimensional computational fluid dynamics (3D-CFD) analysis. METHODS: Two adult male patients with Class I malocclusion, lip protrusion, acute nasolabial angle, and OSAS were treated with conventional MMA (Case 1) and modified MMA-ASSO (Case 2). Individualized 3D airway models were fabricated using computed tomography data obtained 1 month before (T0) and at least 6 months after surgery (T1). A total of 7 cross-sectional areas of the airway were established, starting just above the hard palate (plane 1) with interval of 1 mm caudally. Airflow velocity and negative pressure were investigated using CFD analysis, and polysomnography studies were performed at T0 and T1. RESULTS: There were improvement of apnea-hypoapnea index and the lowest O2 level (T0 versus T1; 43.2 versus 15.2, 79% versus 90% in Case 1; 61.0 versus 6, 89% versus 92% in Case 2). At plane 2 (retropalatal area) in Cases 1 and 2, there were increase in the smallest cross-sectional areas (57.9% versus 28.4%), decrease in the airflow velocity and increase in the negative pressure at the peak of expiration (49.5% versus 31.7%; 88.4% versus 54.3%), end after expiration (53.2% versus 32.2%; 83.2% versus 47.9%), and peak of inspiration (53.1% versus 29.2%; 75.3% versus 48.2%). CONCLUSION: Modified MMA-ASSO method might be an effective treatment option for OSAS patients with improvement of airway problems and esthetic facial profile.

Bacteremia after piezocision.

INTRODUCTION: The aim of this study was to investigate the presence of transient bacteremia after a piezocision procedure. METHODS: The sample consisted of 30 subjects (24 women, 6 men; mean age, 19.6 ± 0.7 years; range, 18.1-22.4 years) with the American Society of Anesthesiologists' physical status I. All patients had Class I skeletal and dental relationships and had fixed orthodontic treatment with the Damon system. The piezocision surgery was performed 1 week after the placement of the orthodontic appliances in all patients. Two 20-mL venous blood samples were collected before and 30 to 60 seconds after the first microincision using an aseptic technique. The samples were inoculated into BACTEC Plus aerobic and anaerobic blood culture bottles and were assessed in the BACTEC blood culture analyzer (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md). The results were analyzed statistically using the McNemar test, with P <0.05 indicating statistical significance. RESULTS: No significant difference between the preoperative and postoperative samples was determined with respect to transient bacteremia (P = 0.250). No bacteremia was detected in the pretreatment samples, although Gemella sanguinis, Streptococcus pluranimalium, and Streptococcus mitis/oralis were detected in 3 postoperative blood samples. CONCLUSIONS: The piezocision procedure might be related to transitory bacteremia. Hence, orthodontists should consider the possibility of bacterial endocarditis in at-risk patients when piezocision is part of the treatment plan.

Correction of facial asymmetry and maxillary canting with corticotomy and 1-jaw orthognathic surgery.

Although 2-jaw orthognathic surgery is a typical recommendation for the treatment of facial asymmetry, another good treatment alternative is maxillary corticotomy with temporary skeletal anchorage devices followed by mandibular orthognathic surgery. The corticotomy procedure described here can achieve unilateral molar intrusion and occlusal plane canting correction with potentially fewer complications than 2-jaw orthognathic surgery. The approach allows movement of dentoalveolar segments in less time than with conventional dental intrusion using temporary skeletal anchorage devices. A 2-jaw asymmetry with occlusal plane canting might be corrected using maxillary corticotomy and mandibular orthognathics rather than 2-jaw orthognathics. Two patients with facial asymmetry are presented here. In each one, the maxillary cant was corrected over a period of 2 to 3 months with 3.5 mm of intrusion of the unilateral buccal segment. After the preorthognathic cant correction, orthognathic surgery was done to correct the mandibular asymmetry.

Can cone-beam computed tomography superimposition help orthodontists better understand relapse in surgical patients?

This case report describes the interdisciplinary treatment of a 19-year-old Brazilian man with a Class I malocclusion, a hyperdivergent profile, an anterior open bite, and signs of temporomandibular joint internal derangement. The treatment plan included evaluation with a temporomandibular joint specialist and a rheumatologist, orthodontic appliances, and maxillomandibular surgical advancement with counterclockwise rotation. Cone-beam computed tomography images were taken before and after surgery at different times and superimposed at the cranial base to assess the changes after orthognathic surgery and to monitor quantitatively the internal derangement of the temporomandibular joints and surgical relapse. Our protocol can improve the orthodontist's understanding of surgical instability, demonstrate the clinical value of cone-beam computed tomography analysis beyond the multiplanar reconstruction, and guide patient management for the best outcome possible.

Smile attractiveness in patients with Class II division 1 subdivision malocclusions treated with different tooth extraction protocols.

The aim of this study was to compare smile attractiveness between one, three, and four premolar extraction protocols in patients with Class II division 1 subdivision malocclusions and to analyse the aesthetic influence of buccal and posterior corridor widths on smile attractiveness. The sample consisted of posed smile photographs obtained from 66 subjects, divided into three groups according to the treatment-extraction protocol. Group 1 was treated with one maxillary premolar extraction included 23 subjects, group 2 was treated with four premolar extractions included 23 subjects, and 20 patients in group 3 were treated with three premolar extractions. Buccal and posterior corridor widths of each photograph were measured in proportion to the smile width. To rate the posed smile photographs, panels of 70 orthodontists and 46 laypeople used a 10-point scale. There were no significant differences in smile attractiveness scores between the three groups and between orthodontists and laypeople. Also buccal and posterior corridor widths did not differ between the groups and they did not influence the aesthetic scores. It was concluded that smile attractiveness is similar in treatment protocols of one, three, and four premolar extractions and that widths of buccal and posterior corridors do not influence smile attractiveness in these groups.

Advancement of the premaxilla with distraction osteogenesis.

OBJECTIVES: The aim of this study was to evaluate the effects of premaxillary advancement with distraction osteogenesis (DO) on the skeletal, dental, and soft tissues. MATERIALS AND METHODS: A total of 21 cases with Angle class I molar relationship and negative overjet or edge-to-edge incisor relationship were included. Due to patient relocation during fixed orthodontic treatment the results of 19 patients (9 females, 10 males) were reported. Their average chronological age was 16.18 ± 3.10 years. An individual tooth-borne distraction appliance was used. Skeletal, dental, and soft tissue changes were evaluated on cephalograms obtained before treatment (T1), at the end of the consolidation period (T2) and fixed orthodontic treatment (T3). Friedman and Wilcoxon tests were applied to determine the significant differences during T1-T2, T2-T3, and T1-T3 periods. RESULTS: At T2 forward movements of ANS, A, and upper incisors were significant. Significant increases of SNA, ANB, and overjet were obtained. The soft tissue points of Pn, Sn, Ss, Ls showed significant anterior movement. Arch length increase of 10.76 mm was significant. At T3 the decreases of SNA and ANB angles, and FH ┴ N-A distance were significant. Pn point showed significant anterior movement. Total treatment time showed significant anterior movement of points ANS, A, and upper incisors. Significant increase of SNA and ANB angles was noted. The soft tissue points followed the movement of the underlying hard tissue. LIMITATION: A class III control group could not be established for ethical reasons. CONCLUSIONS: The facial profile was improved and space was obtained to solve the maxillary anterior crowding with premaxillary advancement through DO.

Severity and outcome assessments of patients undertaking surgical orthodontic treatment.

BACKGROUND: Combined orthognathic-orthodontic treatment can be lengthy and expensive. It is therefore important to evaluate the effectiveness of proposed treatment and the likely outcomes. OBJECTIVES: To determine the demographic and surgical details of patients who received orthognathic-orthodontic treatment at Christchurch Hospital, New Zealand, and to assess treatment using the Severity and Outcome Index (SOI). METHODS: An observational and retrospective study was conducted of patients who received surgical orthodontic treatment between 2005 and 2012 at Christchurch Hospital. Pre- and post-treatment lateral cephalometric radiographs of 93 patients were evaluated. Seven cephalometric parameters were assessed using the Severity and Outcome Index. A severity score ranged from 0 for the most severe to 7 for the least severe, while the outcome score ranged from 0 for the worst to 7 for the best outcome. RESULTS: Class II patients had a severity score of 3.4 and the best outcome score of 6.2. Class III patients had a severity score of 3.3 and an outcome score of 6.1. Patients with an anterior open bite (AOB) had the worst severity score of 3.0, and the worst outcome score of 5.9. The overall treatment outcome scores for all groups were statistically significantly greater than the severity scores, which increased from 3.4 to 6.1 (p < 0.05). CONCLUSIONS: Favourable outcomes were achieved for a group of patients with a high need for treatment. Christchurch Hospital appeared to be treating cases of increased severity and gained better treatment outcomes when compared with a United Kingdom (UK) national audit.

Effects of extraction of four premolars on vermilion height and lip area in patients with bimaxillary protrusion.

The purpose of this study was to evaluate the effects of orthodontic treatment, involving the extraction of four premolars, on vermilion height and lip area. Twenty-eight female patients (mean 21.9 ± 3.1 years) who were diagnosed with bimaxillary protrusion were selected for this study to be treated by extraction of four premolars. The control group consisted of 28 female volunteers (mean 25.0 ± 3.0 years) with Angle Class I normal occlusion. Frontal photographs of the patients were taken both before and after the orthodontic treatment in resting position. Thirty-five landmarks on the upper and lower lips were identified for the measurements of vermilion height and lip area. Lateral cephalograms were taken before and after active orthodontic treatment, and linear and angular measurements were performed. The mean pre-treatment values of vermilion height and lip area were significantly greater in the treatment group than those of the control group and decreased significantly after the orthodontic treatment towards the values in the control group. There were no significant differences in the vermilion height and lip area between the post-treatment and the control groups, except for lower lip area values. Significant correlations found between the changes in incisor position and the changes in vermilion height were few in number for the upper lip but greater in number for the lower lip. Thus, the results of this study show that bimaxillary protrusion cases can be treated by the extraction of four premolars to produce an aesthetic improvement in frontal facial features.