Behnam Aghabeigi talks on the Rehabilitation of resorbed maxilla

The zygomatic implant placement procedure does not require any adjunctive procedures. Furthermore, the ability to immediately use existing dentures and the lack of need for bone grafting and prolonged hospitalisation makes this treatment modality more acceptable to the patient. Four cases are reported that demonstrate the successful treatment of a severely atrophic maxilla with either a fixed prosthesis supported by two zygomatic and a minimum of three standard dental implants or an over-denture supported by two zygomatic and one standard dental implant.

According to Behnam aghabeigi Birmingham placement of dental implants in the posterior maxilla is often jeopardised by the size and extension of the sinus cavities and inadequate amounts of bone. Atrophic processes can be accelerated by removable dentures as well. Surgical procedures were therefore developed to elevate the floor of the sinus and fill the hereby created cavity with bone or a substitute material, in order to subsequently install dental implants. Autogenous bone, harvested from the iliac crest, remains the optimum bone grafting procedure including maxillary sinus augmentation techniques. In view of the extreme maxillary atrophy, the conventional surgical approach would have been maxillary augmentation with or without a titanium mesh and particulate cancellous bone marrow graft from the iliac bone. Another option could have been a Le Fort osteotomy with an interpositional iliac corticocancellous block graft.

Extraoral bone harvesting necessitates increased hospitalisation, financial costs, donor site morbidity and functional limitations. Moreover, there is up to 8.6%5 risk of complications following iliac crest bone graft harvesting. Even higher morbidity rates6 including pain (14%) and neurosensory deficits (26%) have been reported lately. Finally, unpredictable reduction in size of the bone graft, because of resorption, is a frequent finding.

The acceptance of this approach is low by both patients and clinicians due to the following reasons:

1. The psychological fear of being subjected to a relatively major surgical procedure

2. The need for hospitalisation and morbidity associated with a distant donor site, particularly the restricted mobility associated with an iliac bone graft

3. Inability to use the existing denture during the graft healing period. This precaution is intended to minimise graft resorption by eliminating transmission of occlusal loads to the grafted site during the healing phase

4. Increased costs of the procedure including the cost of hospital stay, use of in-patient operating facilities and a second surgical team for the bone harvest

5. Extended treatment time with delayed implant placement four to six months following the grafting procedure.

Simultaneous placement of dental implants at the time of bone grafting is avoided due to a lower success rate than delayed placement.

An alternative treatment for this group of patients is the zygomaticus implant, introduced by Branemark. The implant is a titanium endosteal implant ranging in length from 30 mm to 52.5 mm. The surgical procedure is carried out under general anaesthesia as described elsewhere.9 Briefly, following bilateral elevation of the buccal mucoperiosteal tissue, removal of the lateral sinus bony window posteriorly and reflection of the antral mucosal lining, two zygomatic implants are inserted engaging the dense bone of the body of zygomatic arch, emerging intraorally in the upper premolar region just palatal to the alveolar crest. Each implant is introduced into the second premolar area, traversing the maxillary sinus, and is placed into the body of the zygomatic bone.

Synchronous placement of a minimum of four dental implants in the canine and the central incisor maxillary area, allows for fabrication of fixed hybrid prosthesis. Alternatively, placement of two zygomatic implants and at least two standard dental implants at the pyriform buttresses allows construction of a bar to support a maxillary overdenture without the need for any bone grafting. In case more root form dental implants can be placed in the pre-maxilla a fixed prosthesis could be fabricated.

For more information about Behnam Aghabeigi visit here : http://benaghabeigi.com

Differences examined by Behnam Aghabeigi in assessment and self-assessment

This particular description of a paper aims to examine the difference of assessment and self assessment scores in oral and maxillofacial surgery trainees and MSc postgraduates following the surgical removal of lower third molar teeth.

Subjects and Methods

A total of 17 trainees and MSc postgraduates were assessed when surgically removing lower third molar teeth under general anesthesia. The teeth were selected on the basis that their removal would necessitate raising of a flap and removal of bone. Assessors were members of staff of the department. One assessor was scrubbed, assisting and, where necessary, training the operator; the second observed the procedure closely. Where necessary, the assessor/trainer instructed and/or took over the procedure in the normal way.

Operators were shown the assessment forms prior to the surgery. They were told that the assessment would not count in any way towards their continuous assessment.

Methods of assessment were:

1.An objective assessment of whether 20 components of the procedure were correctly or incorrectly performed. In cases where the trainer corrected the operative technique or took over, the relevant parts of the procedure were judged incorrectly performed.

2.An operative global rating scale (1-5). The scale is anchored by descriptors and measures different aspects of performance, i.e. respect for tissue, time and motion, instrument handling, knowledge of instruments, flow of operation, use of assistants, knowledge of procedure, overall performance.

Both types of assessment were marked by the two assessors during or immediately postoperatively. The operator was asked to assess his performance using the same assessment form immediately postoperatively. The results were correlated using standard statistical techniques.

Results

A total of 22 lower third molar teeth were removed by 17 different operators. There were 8 different assessors using both the objective checklist and global rating scales. In 18 cases, operators assessed their performance using both scales.

There was no evidence of a difference between the marks of the two assessors. Using a two-way analysis of variance P = 0.70 and P = 0.68 for the objective and global rating scales, respectively. The level of agreement between assessors was 86.36% (kappa = 0.79, P <0.001) in the objective checklist scale and 90.91% (kappa = 0.83, P<0.001) in the global rating scale.

Two-way analysis of variance shows that there was evidence of a difference between assessors’ and self-assessment marks using both types of scores (objective checklist score, P < 0.001; global rating score, P < 0.001).

Discussion

Although there was evidence of good agreement between assessors, there was poor agreement between assessors and operators when using both the objective checklist and global rating scales. Operators almost invariably scored themselves higher than the assessors. Some of these differences were substantial and some operators who were scored very low by assessors scored themselves extremely high. In the objective scale scores were up to 10.5 marks higher (maximum 20) than those of the assessors. They were up to 12.5 marks higher (maximum 40) in the global scale.

These results suggest that some operators have poor judgment and over-rate their surgical ability even when assessed for a specific procedure and given rigid criteria against which to mark.

Little work appears to have been done on self-assessment of specific clinical procedures, especially when marking the self-assessment after the procedure concerned was performed. There have, however, been reports45 of relatively poor agreement between external measures of medical students’ clinical performance and students’ self-assessment of their performance. Additionally, lower performing medical students tended to rate their clinical performances higher than did their peers at initial self-assessment.

In the present study, objective checklist scores although having very rigid criteria tended to be overscored more than the global rating scale where operators were perhaps reluctant to give themselves marks at the extremes of the scale. Certainly over-scoring of checklist criteria suggests that either operators did not know what was expected of them or in some cases exhibited a considerable degree of self-deception. Alliteratively, they may have scored potential or ideal performance or even tried to compensate for poor performance as a defense mechanism.

Conclusions

The results of this study found evidence of a surprising and worrying over-rating of their own surgical skills by many trainees and postgraduates in oral and maxillofacial surgery. There can be little doubt that there is a need to evaluate further the accuracy of self-assessment of operative skills. In conjunction with this, we must train surgeons to evaluate critically their performance and self-assessment can form an excellent basis for constructive feedback between trainer and trainee.

It may be found that some individuals will never develop the judgment to assess accurately their performance. It would be invaluable to have a way to identify these individuals so that they could be redirected at an early stage in their careers.

For more information about Behnam Aghabeigi visit here : http://benaghabeigi.com

Behnam Aghabeigi talks on measures for anterior open bite

According to Behnam Aghabeigi a retrospective survey of 83 patients with an anterior open bite who underwent orthognathic surgery was carried out. Records were examined for the prevalence of abnormal TMJ signs and symptoms, including pain. A survey was mailed to these patients that consisted of: (1) the TMJ Scale, (2) the Symptom Checklist 90 (SCL90), (3) the Spielberger State-Trait Anxiety Inventory (STAI), and (4) a visual analog scale on which patients indicated their degree of satisfaction with the procedure. Thirty-seven (42%) patients responded to the survey, and 13 (15%) also attended a clinical and radiographic examination.

Multiple regression analysis was used for statistical analysis of the factors contributing to the presence and/or persistence of pain. In the preoperative group, the prevalence of pain was 32%, dysfunction 40%, and limitation of opening 7%. Age and gender were significantly associated with the presence of pain. The overall prevalence of abnormal TMJ signs and symptoms was not significantly different after orthognathic surgery. An abnormal psychologic profile was the most significant factor associated with the presence and/or persistence of pain. It is concluded that that the prevalence of temporomandibular disorders in anterior open bite patients increases with age, is significantly higher in females, and is not influenced by other occlusal variables. Furthermore, orthognathic surgery does not significantly influence temporomandibular disorders in patients with anterior open bite. Female patients, particularly those with an abnormal psychologic profile, are at a higher risk of persistent

Behnam Aghabeigi told us that it is generally agreed that the etiology of temporomandibular disorders (TMD) is multifactorial. Various emotional and mechanical factors have been implicated. There has been debate as to whether peripheral factors, such as occlusal disharmony, are of primary importance or whether central factors, such as psycho-logic variables, play the key role. Depending on the different concepts of etiology, different treatment regimens have been advocated. The dental profession historically has favored the peripheral factors and therefore embraced treatment modalities directed toward correction of occlusal dis-crepancies. Some authors1,2 even advocated orthognathic surgery for cases of TMD in combination with dysgnathia. However, it is unclear whether any association exists between the maxillomandibular relationship and TMD.3,4 Certain types of malocclusion have been reported as more likely to be associated with TMD5,6 and therefore such patients are more likely to benefit from treatment strategies addressing the occlusal disharmony. However, to date there is no randomized controlled prospective study demonstrating the efficacy of occlusal therapy in the manage-ment of TMD. Part of the difficulty in epidemiologic studies and clinical trials in relation to patients with TMD is the het-erogenous nature of the patients with regard to etiologic factors, such as occlusal or psychometric variables.

Pullinger and Seligman5 compared the role of occlusal variables between a large group of TMD patients and control subjects. They found that, except for anterior open bite (AOB), overbite and overjet char-acteristics did not distinguish the TMD patient group. Anterior open bite was rare among control subjects, and the authors reported the complete absence of AOB in the asymptomatic non-patients, as did several other authors.8–10 However, the low incidence of AOB in the general population could lead to sampling errors in such studies; this precipitates a need to study the prevalence of TMD in AOB patients.

Furthermore, the influence of orthognathic surgery on the temporomandibular joint (TMJ) has attracted a considerable amount of interest. Symptoms of TMJ disorders before and after orthognathic surgery have been documented in several clinical studies, but the reported incidence varies widely. There are reports of various degrees of improvement or deterioration, or no change at all in TMJ symptoms after orthognathic surgery. It has been suggested that orthognathic surgery may stimulate the progress of joint disease by microbleeding in the upper joint space, increased loading, disc displacement, and immobilization. Differences in the type of malocclusion, method and duration of post-operative fixation, type of osteotomy (eg, Le Fort I versus bimaxillary osteotomy15), and choice of mandibular setback procedure (eg, subcondylar versus sagittal split ramus procedure16) are among the factors that have been cited to account for the differences in TMJ symptoms after orthognathic surgery.
It has been suggested that the condyles of patients with anterior open bite may be very sensitive to functional loading, and their adaptive capacity is probably lower than in patients with deep bites. However, an analysis of the data published in relation to mixed patient groups reveals that in relation to correction of AOB, the published literature is contradictory. There are reports of significant improvement in TMD17 as well as reports of development of a significant number of new TMD cases after orthognathic surgery. Therefore, this study was carried out to assess the influence of orthognathic surgery on the TMJ in a relatively large number of patients with AOB.

Materials and methods

The clinical records of patients with an AOB who underwent orthognathic surgery during a 6-year period were examined; all patients had at least a 1-year post-operative follow-up period. The majority of cases were treated with a Le Fort I maxillary impaction, either alone (46%) or in combination with a mandibular procedure such as bilateral intraoral oblique (37%) or bilateral sagittal split osteotomy (14%). Only a very small number underwent segmental procedures (2%). In bimaxillary procedures, maxillomandibular fixation was used for a period of 4 to 6 weeks. Permission was granted by the Massachusetts General Hospital Human Studies Committee to review patient records, administer a mailed questionnaire, and recall patients for a review examination.

For more information about Behnam Aghabeigi visit here : http://benaghabeigi.com