Two-year follow-up of distraction osteogenesis: its effect on mandibular ramus height in hemifacial microsomia.

Distraction osteogenesis has been used to lengthen the mandible in patients with hemifacial microsomia. Questions regarding soft tissue and skeletal growth after distraction osteogenesis have not been clearly elucidated in the literature. In this case report, a 2-year follow-up of distraction osteogenesis in a 7 year old boy is documented with lateral and posterior/anterior cephalometric analysis. The analysis was performed preoperatively and at specific postsurgical periods to evaluate the facial soft tissue and skeletal growth patterns. Objective analysis of this growing patient after distraction osteogenesis clearly demonstrates that the anteroposterior elongation of the mandible is relatively stable, whereas the vertical lengthening and soft tissue effects are minimal. Critical evaluation of other patients who have undergone distraction osteogenesis is needed to determine if this was an isolated incident or the expected result in similar patients.

Sinus slot technique for simplification and improved orientation of zygomaticus dental implants: a technical note.

The zygomaticus dental implant, designed by Nobel Biocare for the Brånemark System, is indicated primarily for the severely resorbed maxilla. Though the zygomaticus implant has had a remarkable success rate in a very difficult patient population, there are some shortcomings to the protocol for placement. The sinus slot technique described herein provides a simplified approach to zygomaticus implant placement, as compared to the currently recommended protocol.

An algorithm for determination of ideal location of interdental osteotomies in presurgical orthodontic treatment planning.

Treatment-planning patients with dentofacial deformities begins with the desired final occlusal results in mind. Examination of occlusal models and subsequent feasibility model surgery determine whether segmentalization of one or both arches is necessary to accomplish the final occlusal scheme desired. Segmentalization of the maxilla and/or mandible may be used to resolve transverse or arch configuration discrepancies, level occlusal plane(s), correct dentoalveolar inclination, and/or remove extraction spaces by osteotomy. With so many variables to consider, it is often difficult even for an experienced clinician to systematically evaluate and select the ideal location of interdental osteotomies prior to presurgical orthodontics. This manuscript describes an algorithmic approach to diagnosis and treatment planning that will assist the clinician in determining the most favorable location(s) for interdental osteotomy(ies).

The predictability of inferior medial canthus as a stable external vertical reference point in maxillary repositioning surgery.

The purpose of this study was to investigate the predictability of using the inferior medial canthus as a stable external reference point for establishment of the vertical dimension in maxillary orthognathic surgery. Ten consecutive patients with skeletal Class II malocclusion and open bite who underwent orthognathic reconstructive surgery were included in the study. Prediction tracings were completed preoperatively and superimposed on an immediate postoperative lateral cephalometric radiograph. In 7 patients, the vertical positioning of the maxillary incisal edge on the immediate postoperative lateral cephalometric radiograph showed no difference from the superimposed preoperative prediction tracing. One patient showed 1 mm difference and 2 patients showed 2 mm difference from the preoperative prediction tracings. All cases resulted in acceptable maxillary incisal exposure relative to upper lip stomion. It is concluded that the inferior medial canthus can be used as a reproducible external vertical reference for orthognathic surgery when the technique described herein is used.

Predictability of bimaxillary orthognathic surgery using "piggyback" intermediate splints.

Ten consecutive patients underwent bimaxillary surgery including segmental Le Fort I and bilateral sagittal split ramus osteotomies. All 10 patients were symmetric skeletal Class II malocclusion with an anterior open bite. Asymmetry cases were excluded. Dimensional changes depicted on the cephalometric prediction tracing were reproduced in the model surgery and then transferred to the patient during the operative procedure using a "piggyback" intermediate splint. All dimensional changes, except vertical, were transferred from the model surgery to the patient intraoperatively by using a "piggyback" intermediate splint. The accuracy of this transfer and final skeletal result was examined. All the data clearly showed that in no case was any discrepancy greater than 2 mm, which demonstrates the predictable results that can be achieved by using a "piggyback" intermediate splint in bimaxillary orthognathic surgery.

An innovative method for accurate positioning of the proximal segment in sagittal split osteotomies.

Ten patients underwent bilateral sagittal split ramus osteotomy for the correction of mandibular retrognathia. Prior to the surgery, predictive cephalometric tracings were completed, utilizing horizontal and vertical reference guides. The anticipated horizontal and vertical changes were determined from the predictive tracings, and these results were recorded on the prediction tracing. During surgery, corresponding reference marks were made on the lateral surface of the mandible. These reference marks were utilized to position the proximal segment during surgery, prior to placement of stabilization screws. A postoperative lateral cephalometric radiograph was taken within 24 hours in each case. The positions of the proximal segments were compared pre- and postsurgically. The results of this study indicate that this simple method results in accurate positioning of the proximal segments.

Geometric considerations when planning an asymmetric genioplasty.

The sliding osteotomy of the inferior border of the mandible, otherwise known as genioplasty, has often been described in the world literature with regard to diagnosis and treatment planning. However, the treatment of the asymmetric chin has received little attention. Moreover, diagnosis and treatment planning of asymmetric chins with concomitant orthognathic surgery is completely lacking from the literature. The complexity of surgically correcting asymmetric chins, compounded with complex, bimaxillary orthognathic surgery, is an extremely challenging task. This article looks at geometric considerations when planning the surgical correction of an asymmetric chin following a protocol of data collection, model surgery, diagnosis, and treatment planning. Clinical experience in the form of a case presentation will demonstrate the millimetric precision that can be achieved when planning corrective genioplasty in an asymmetric patient undergoing concomitant orthognathic surgery.

Modification of sagittal split ramus osteotomy to avoid unfavorable fracture around impacted third molars.

The dental literature recognizes that performing sagittal ramus osteotomy when impacted third molars are present significantly increases the risk of unfavorable fractures of both the proximal and distal segments. Many articles have described how to repair unfavorable fractures of sagittal split segments, but few to date specifically address how to modify the osteotomy design to reduce the potential for unfavorable fractures. Moreover, techniques for removal of impacted third molars after the completion of a sagittal split ramus osteotomy have received little attention in the literature, yet it is obviously a common occurrence. This paper describes a modification of the sagittal split ramus osteotomy when a fully formed impacted third molar is present at the time of the sagittal ramus osteotomy. A technique is also described for removing the impacted third molar after the sagittal split is completed. Clinical experience has demonstrated these techniques to have several advantages.

Anthropometric profile evaluation of the midface in patients with cleft lip and palate.

This study was done to determine those profile anthropometric measurements that are abnormal in the midface profile in patients with cleft lip and palate. The sample population consisted of 30 randomly selected skeletally mature white patients with cleft lip and palate who had been treated by the same team who were accredited by the American Cleft Palate-Craniofacial Association. Twenty patients had unilateral and 10 had bilateral complete clefts. None of these patients had previously undergone orthognathic surgery or definitive rhinoplasty surgery. Fifteen facial anthropometric features were measured on each person's face. The result from this study showed that in patients with cleft lip and palate right versus left side differences did not exist and only four statistically significant differences existed between the unilateral and bilateral cases. However, in all patients, four of these esthetic facial features were consistently and significantly abnormal: obtuse nasofrontal angle: obtuse nasomental angle; a posteriorly positioned infraorbitale relative to globe; and an obtuse general facial angle. Several other features were abnormal in a high percentage of persons in this study. These were lack of supratip break, flat to concave paranasal contour, increased subnasale-alargroove:subnasale-pronasale ratio, decreased nasal protrusion:nasal length ratio, decreased nasolabial angle ratio, decreased maxillary length ratio, increased nasal bridge projection:nasal protrusion ratio, and deficient cheek contour. This data indicates that the major deformity in persons with adult cleft lip and palate exist in the nose and secondarily in other components of the midface.

Cephalometric profile evaluations in patients with cleft lip and palate.

This study was done to determine those abnormal cephalometric features found in adult cleft lip and palate patients. The sample population consisted of 30 randomly selected white patients with cleft lip and palate who were treated by the same team that had been accredited by the American Cleft Palate-Craniofacial Association. Twenty patients had unilateral complete clefts, and 10 had bilateral complete clefts. Thirteen different cephalometric parameters were measured and compared with normal. The results from this study showed that there were few statistically significant differences between the unilateral and bilateral cleft palate patient populations. There were only three measurements that had statistically significant differences between the unilateral cleft patients and the bilateral cleft patients: subnasale-stomion, subnasale-stomion: stomion-soft-tissue menton, and subnasale-lower lip vermillion: lower lip vermillion-soft tissue menton. However, 10 of the 13 measurements had statistically significant variations from normal. These measurements included subnasale=stomion; stomion=soft tissue menton, subnasale=lower lip vermillion; lower lip vermillion=soft tissue menton, interlabial distance, subnasale-perpendicular to upper lip, subnasale-perpendicular to lower lip, subnasale-perpendicular to chin, angle formed between sella turcica=nasion and nasion=A=point, maxillary depth angle, A-point to nasion-pogonion, and angle formed between A=point=nasion and nasion=B=point. The data indicated that a multiplicity of vertical and horizontal abnormalities exist in the person with cleft lip and palate in addition to the well-known transverse deficiencies, and that cephalometric abnormalities are not limited to anteroposterior maxillary deficiency.

Changes in condylar position following bilateral sagittal split ramus osteotomy with setback.

The purpose of this study was to evaluate the changes in condylar position following bilateral sagittal split ramus osteotomy with 5- and 10-mm setback in 1 symmetric human cadaver mandibles. A Plexiglas device was constructed to determine the mandibular morphology and the movements of the condyle and the proximal segments before and after surgery. There was no statistically significant relationship between mandibular morphology or the magnitude of setback and changes in condylar position postsurgery. All condyles and rami tipped in a highly variable fashion in the coronal plane. In the axial plane, the lateral pole of the condyles rotated predominantly anteriorly; the left side rotated significantly more than did the right. In the sample studied, the position of the condylar and proximal segments was altered in a highly variable and unpredictable manner, regardless of the magnitude of setback or the morphology of the mandible.

Facial anthropometrics versus cephalometry as predictors for surgical treatment in patients with Class III dentofacial deformities.

The purpose of this study was to determine statistically the relative importance of facial anthropometrics and cephalometry in diagnosing the specific jaw deformity in patients with Class III relationships, ie, the contribution that maxillary deficiency and/or mandibular prognathism made to the Class III deformity. Frontal and right profile photographic views and pretreatment lateral cephalometric radiographs of 20 randomly selected Class III patients were analyzed. Correlation and multiple-regression analyses were utilized to determine the relative importance of clinical diagnosis and cephalometric diagnosis in determining the actual surgery performed. In addition, these analyses determined the relative importance of the various facial anthropometrics and cephalometric parameters critical to making the specific diagnosis of maxillary deficiency and/ or mandibular prognathism. It was concluded that a jaw-specific diagnosis of the Class III population studied was best made with facial anthropometrics rather than cephalometry, and the most important predictive facial features on which to based this diagnosis were paranasal configuration and chin projection. Although the overall cephalometric diagnosis had no statistically significant correlation to the actual surgery preformed, two individual cephalometric parameters, maxillary first molar to pterygoid vertical and mandibular plane angle, were found to statistically correlate to the actual surgery performed. These cephalometric parameters should be scrutinized along with the facial anthropometric data when the jaw-specific surgery is selected.

Vascular transformation in cherubism.

Cherubism is a well-known disease entity that was first described by Jones in 1933. A case is presented in which the usual course of the lesion changed dramatically during treatment. The lesion demonstrated unilateral growth with a vascular proliferation after surgical recontouring. Vascular transformation and surgical activation of cherubism, as well as treatment considerations, are discussed.

The modified superiorly based pharyngeal flap. Part IV. Position of the base of the flap.

The modified superiorly based pharyngeal flap surgical technique developed by Epker et al. was performed on 13 patients with moderate to severe hypernasality. The flap base was attached close to the level of the palatal plane and was found to maintain a consistent longitudinal relationship to the level of the atlas. This technique corrected hypernasality in a range of patients with velopharyngeal incompetence, as predicted.

The modified superior based pharyngeal flap. Part III. A retrospective study.

A retrospective study of 31 patients who had diagnosed velopharyngeal incompetence and were surgically managed with the modified superior based pharyngeal flap was completed. The following were analyzed: age at time of operation, gender, physical status, diagnostic protocol, length of operation (length of total surgery) and length of superior based pharyngeal flap, length of postoperative hospital stay, length of total hospital stay, length of follow-up, speech results, complications, patient care, and medication. The result showed that the optimal timing for correction of velopharyngeal incompetence was between 3 and 6 years of age. The mean length of total hospital stay was 2.7 days, postoperative complications were minimal, and speech results were generally good.

A precise radiographic method to determine the location of the inferior alveolar canal in the posterior edentulous mandible: implications for dental implants. Part 1: Technique.

In severely atrophic or osteoporotic mandibles, the location of the inferior alveolar nerve may vary considerably, both superoinferiorly and mediolaterally. A clinician's ability to reliably locate this nerve within the mandible would permit the surgical planning of implant placement in the posterior edentulous mandible. Eight edentulous cadaver mandibles were studied. A technique that precisely locates the inferior alveolar nerve within the mandible is described. The technique will aid the surgeon in planning a surgical approach to the posterior mandible with reduced risk of injury to the inferior alveolar nerve.

A precise radiographic method to determine the location of the inferior alveolar canal in the posterior edentulous mandible: implications for dental implants. Part 2: Clinical application.

An analysis of implant placement in the posterior region of eight edentulous cadaver mandibles was performed. The results demonstrated that the radiographic technique developed can be employed to safely place implants adjacent to the inferior alveolar nerve in the posterior mandible by using radiographic laminography and a specially designed intraoral reference splint.

Reconstruction of frontal and frontal-nasal deformities with prefabricated custom implants.

The use of prefabricated custom silicone rubber implants for frontal and nasofrontal deformities produces predictable esthetic results with minimal operative and postoperative morbidity and/or complications in selected patients. Over the past 8 years, 15 custom silicone rubber implants have been placed with good to excellent results. Only one implant was removed due to postoperative infection. This implant was successfully replaced upon resolution of the infection.

Transoral submental lipectomy: an adjunct to orthognathic surgery.

Individuals undergoing the surgical correction of dentofacial deformities are becoming both older and more discriminating. Consequently, they often request specific esthetic improvements. To meet the desires of such patients, adjunctive surgical procedures to the planned orthognathic surgery are becoming more commonplace. One of the more frequent procedures performed is the transoral submental lipectomy. This article discusses the evaluation of the submental region, the indications for transoral submental lipectomy, and the surgical technique. Several case indications illustrate the results of this procedure.