Bibliography: leaves 342-392. I: Introduction. Ch. 1. The Le Fort I osteotomy for the correction of maxillary position in three dimensions -- II: Review of the literature. Ch. 2. Dentofacial discrepancies involving the maxilla -- Ch. 3. Cephalometry -- Ch. 4. Relapse following Le Fort I osteotomy -- Ch. 5. Factors associated with post surgical relapse following Le Fort I osteotomy -- Ch. 6. Biomechanics of fixation -- III: Materials and method. Ch. 7. Evaluation of post surgical relapse -- Ch. 8. Errors of method -- IV: Results. Ch. 9. Early, intermediate and long term dentoskeletal effect following Le Fort I osteotomy -- Ch. 10. Results: Errors of the method -- V: Discussion. Ch. 11. Discussion of experimental design -- Ch. 12. Discussion of factors in the relapse of Le Fort I osteotomy -- VI: Conclusion. Ch. 13. Conclusion. -- VII: Appendix. i. Bone grafts ; ii. Le Fort I osteotomy surgical technique ; iii. Bone plate removal protocol statement.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

Aim of study The aim of this clinical retrospective study is to evaluate the clinical outcomes of patients with transverse maxillary hypoplasia who underwent surgical assisted maxillary expansion (SARME) using a bone borne distractor in 2 different surgical centers. Patients and Methods This is a clinical retrospective cross‐sectional study of adult patients diagnosed with maxillary transverse hypoplasia and having had transpalatal distraction by SARME done in two surgical centers (Oral and Maxillofacial Surgery, The University of Hong Kong, Hong Kong and The Baruch Padeh Medical Center, Poriya, Israel) from January 2004 to December 2011. A total of 37 patients were identified. The mean age was 27.1. Each patient underwent a standard Le Fort I osteotomy with midline split with no mobilization under general anesthesia. A bone‐borne palatal distractor was fitted on the hard palate. The distractor was activated at a rate of 0.6mm per day following 5 ‐ 7 days of latency until the amount of expansion was reached according to plan. Occlusal radiographs and lateral cephalographs were obtained at pre‐expansion phase and regular postoperative intervals during the activation and consolidation period. Among the 37 patients, only 15 patients could be contacted by phone, mail or e‐mail and has agreed to participate in the cross‐sectional analysis. Clinical examination was performed and included the following: tooth vitality, tooth mobility, periodontal status and occlusion. Questionnaire was also given to patients to grade their experiences toward the treatment outcome. Results The mean transverse expansion achieved was 9.58mm. The TPD was removed from the patients in the ranged of 2 months to the longest 8 months (mean: 5.2 months). The distraction gap was gradually ossified by bone and then the teeth were aligned into the space achieving stable dental occlusion. No intra‐operative complications were recorded. Post‐operatively, 2 patients had to be re‐operated due to failure to activate the distractor. Others post‐operative complications encountered were pain, fixation screw loosening, insufficient distractor length, infection, asymmetric expansion and tooth migration into the distraction gap. These complications were well managed accordingly. Majority of the patients were satisfied with the treatment and will recommend it to others. Conclusions Correction of maxillary transverse hypoplasia using a transpalatal distractor can reliably achieve large bony expansion of the maxillary arch with few postoperative complications. / published_or_final_version / Dental Surgery / Master / Master of Dental Surgery

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / Dentistry / Master / Master of Dental Surgery

Background Maxillary defects subsequent to hemimaxillectomy have long been restored with a pedicled temporalis flap. Recently,the trend towards maxillary reconstruction using vascularized bone free flaps and soft tissue free flaps has been gaining popularity. However, the value in terms of functional rehabilitation of these surgical modalities remains unconclusive. Objective To ascertain and compare masticatory performance and quality-of-life in patients with surgically reconstructed maxillectomy Class 2 (subtype A) defects by vascularized bone free flaps, vascularized soft tissue free flaps and pedicled soft tissue flaps. Methods Eighteen patients divided into 3 groups (4 vascularized bone flap, 5 vascularized soft tissue flap, 9 pedicled soft tissue flaps) were evaluated for functional outcome and qualityof-life (QoL). All patients were objectively assessed using masticatory comminution test. Subjective evaluation was conducted using functional outcomes questionnaire and patient reported speech perception. Self image and body perception were assessed using Body Esteem Scale. Overall quality-of-life was assessed using University of Washington QoL questionnaires. Results Patients reconstructed with vascularized bone flaps and vascularized soft tissue flaps showed superior masticatory performance compared to patients reconstructed with pedicled soft tissue flaps. Speech, facial attractiveness and overall QoL were similar for all three groups. Conclusions Maxillectomy class 2 (subtype A) patients show comparable speech, facial attractiveness and quality-of-life levels after reconstruction with vascularized bone flaps, vascularized soft tissue flaps and pedicled soft tissue flaps. However, those reconstructed with pedicled soft tissue flaps achieved lowest masticatory performances amongst the three surgical reconstruction modalities. Thus, the choice of recontruction for maxillectomy class 2 (subtype A) defects should be guided by minimizing surgical time and long term morbidity given the apparent similarity in functional outcomes. / published_or_final_version / Dental Surgery / Master / Master of Dental Surgery

Background Distraction osteogenesis (DO) was first applied on the human craniofacial skeleton in 1992 by McCarthy et al.1 who performed lengthening of the mandible in patients with hemifacial microsomia and Nager’s syndrome. Further advances in this field have since then led to the widespread use of this modality for the treatment of numerous congenital and acquired craniofacial skeletal anomalies. In 2001, a review by Swennen et al2 concluded that up to year 1999, this form of treatment was gaining intense popularity but that the main drawbacks included insufficient data on long term results and relapse. A systematic review of the last decade on functional outcomes and long term complications following distraction osteogenesis of the facial skeleton is presented. Methods A structured systematic literature search, with predefined inclusion and exclusion criteria from relevant computer databases and journals were performed. The journals were evaluated and critically appraised by 2 reviewers separately in 3 rounds. Papers were categorized according to the level of evidence, the quality of methodology and the specific field of functional outcomes and long term complications. Results were then categorized according to the type of distraction movements, ie maxillary advancement and mandibular lengthening. Results A total of 42 papers comprising of 16 studies for maxillary advancement and 26 studies for mandibular lengthening were included in this review. Maxillary advancement was found to be beneficial in patients with cleft maxillary hypoplasia in terms of achieving aesthetic outcome but the risk for velopharyngeal insufficiency remains uncertain. The achieved maxillary advancement was stable if performed on adult patients while a recurrence of midface retrusion was noted if DO was performed on growing patients. Overcorrection was recommended in these cases to an estimated value of 20-50%. Mandibular lengthening was 99% successful in relieving respiratory obstruction in patients with isolated Pierre Robin Sequence (PRS) or syndromic micrognathic infants preventing the need for tracheostomy in the long term, and in 89% successfully decannulating infants with pre-existing tracheostomy. However, feeding and growth outcomes after airway obstruction was relieved remain unknown due to lack of sufficient evidence. Unilateral mandibular DO was successful in achieving aesthetic symmetrical facial balance in patients with hemifacial microsomia however a total loss of corrected distraction length was noted by the end of growth period if DO was performed during growth. Conclusions DO achieved stable results in terms of lengthening the maxilla and mandible but was also noted to cause restricted growth potential of the distracted bone. Hence, the benefits of performing DO during active growth should be weighed against the likely need for a second surgery due to a growth deficit of distracted bone and future surrounding bone growth. However DO in adults remains an alternative to conventional orthognathic surgery and choice of treatment should be patient centred. / published_or_final_version / Dental Surgery / Master / Master of Dental Surgery

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / Dental Surgery / Master / Master of Dental Surgery

published_or_final_version / Dental Surgery / Master / Master of Dental Surgery