B.D. Tiner

Short-term changes of condylar position after sagittal split osteotomy for mandibular advancement.

OBJECTIVE The goal of this study was to quantify condylar position changes after mandibular advancement surgery with rigid fixation (screws). Radiographic changes in condylar position were determined in all planes (X, Y, and Z). Computed tomography with image reconstruction was used. STUDY DESIGN A consecutive population of patients who elected to have rigid fixation for surgical stabilization method were studied (n = 21). Computed tomography data were acquired in the axial plane through use of abutting 1.5-mm-thick slices. Data acquisition occurred 1 week preoperatively and 8 weeks postoperatively. Measurements were made from 2-dimensional reconstructions. RESULTS The averages were as follows: lateral displacement from midline, 1.2 mm (55% of patients); medial displacement from midline, 1.5 mm (45% of patients; range, 3.2 mm); condyle angle increase from coronal plane, 3.5 degrees (60% of patients); condyle angle decrease from coronal, 4.3 degrees (40% of patients; range, 8.5 degrees); superior rotation of proximal segment, 3.2 degrees (39% of patients); inferior rotation of proximal segment, 8.6 degrees (61% of patients; range, 15.6 degrees); superior displacement, 1.2 mm (60% of patients); inferior displacement, 1.0 mm (40% of patients; range, 2.5 mm); anterior displacement, 1.6 mm (33% of patients); posterior displacement, 1.6 mm (67% of patients; range, 2.8 mm). CONCLUSIONS Changes occurred in all planes, but the most common postoperative condyle position was more lateral; with increased angle, the coronoid process was higher and the condyle was more superior and posterior in the fossa.

Technical factors accounting for stability of a bilateral sagittal split osteotomy advancementWire osteosynthesis versus rigid fixation

OBJECTIVE Relapse after bilateral sagittal split osteotomy has been attributed to various technical factors that are inherent in the surgical procedure. The purpose of this article was to analyze technical factors that predispose to relapse when wire or rigid fixation is used. STUDY DESIGN Patients were randomized to either rigid or wire osteosynthesis. Cephalometric radiographs were obtained and digitized at multiple time periods before and after surgery. Data were analyzed through use of 2-sample t tests and stepwise regression analyses. RESULTS Multivariate analysis indicated that the following factors correlated with relapse: initial advancement, change in ramus in inclination, change in the mandibular plane, and fixation type. CONCLUSIONS Relapse increased with the amount of initial advancement and, to a lesser extent, with control of the proximal segment and change in the mandibular plane. These factors are similar for wire osteosynthesis and rigid fixation.

Effects of hypesthesia on oral behaviors of the orthognathic surgery patient

PURPOSE The purpose of this study was to compare orthognathic surgery patients with and without significant hypesthesia with respect to perceived problems with specific oral behaviors. PATIENTS AND METHODS Data from 116 patients 6 months after bilateral sagittal split osteotomy (BSSO) and mandibular advancement were analyzed. Tactile sensation in the right and left mental nerve areas was determined using monofilaments and brush strokes (von Frey hairs). The right infraorbital region was used as a control. A difference of 450 mg of force between the control and test sites was considered significant hypesthesia. Patients rated their level of subjective problems with swallowing liquids or solids, smiling, spitting, kissing, speaking, eating, and drooling on a scale from 1 (none to mild) to 7 (extreme). A value of 5 or greater was considered significant impairment. RESULTS Hypesthesia was shown in 23 patients (19.8%) with the monofilaments and in 29 patients (25.0%) using brush stroke direction. In each of these two groups, a significant correlation was observed between hypesthesia and difficulty in chewing and kissing. No correlation was observed between any of the remaining seven oral behaviors and hypesthesia. CONCLUSION These findings suggest that only certain oral behaviors are affected by hypesthesia of the mental nerve.

Clinical evaluation of hydroxyapatite-coated titanium plasma-sprayed and titanium plasma-sprayed cylinder dental implants

OBJECTIVE The purpose of this article was to present the preliminary results of a prospective clinical trial comparing titanium plasma-sprayed versus hydroxyapatite-coated titanium plasma-sprayed cylinder (press fit) implants in different regions of the mouth. STUDY DESIGN Sixty-five subjects met the inclusion requirements. Surgery was done in two phases by four experienced surgeons. Implant placement and abutment connection were separated by 3 to 4 months in the mandible, 6 to 7 months in the maxilla. Patients were assigned to either titanium plasma-sprayed or hydroxyapatite-coated implants on the day of surgery. Implant placement was not stratified for the region of the jaws. Outcome assessment was failure (loss) of an implant before or within 3 months of second phase surgery. RESULTS Three hundred fifty-two implants equally distributed between titanium plasma-sprayed and hydroxyapatite-coated titanium plasma-sprayed implants were placed in four different sites; anterior maxilla, posterior maxilla, anterior mandible, and posterior mandible. There were a total of 15 failures (4.26%). Overall, titanium plasma-sprayed implants showed a higher but not significant failure rate compared with hydroxyapatite-coated implants (p = 0.06). Although not statistically significant, we believe that a smoking history played an important role in the failure of implants. CONCLUSION This study suggests that an hydroxyapatite-coating of an implant allows superior initial integration when compared with a titanium plasma-sprayed surface.

Hard and soft tissue predictability with advancement genioplasties

Variability in soft tissue response to genial advancements has been noted in the literature. Although many factors may influence the results, little attention has been paid to bony vertical movement in conjunction with the bony horizontal movement of the chin and its effect on horizontal soft tissue movement. Eighteen patients who underwent isolated genial advancements were studied preoperatively and for at least 6 months after surgery. It was noted that the further the chin was advanced the less the soft tissue followed the advancement. In addition, vertical movement of the chin greatly influenced the overall result. The more the bony chin is shortened, the thicker the soft tissue chin becomes; the reverse is true when it is lengthened. Finally, horizontal resorption/stability appears to be influenced by the amount of dissection rather than the amount of advancement.

Cost of a genioplasty under deep intravenous sedation in a private office versus general anesthesia in an outpatient surgical center.

The cases of twenty-four patients who underwent genioplasties either under deep intravenous (IV) sedation in a dental office or under general anesthesia in a surgical center were reviewed. A cost comparison of this operation in these two environments showed that it was twice as expensive to have the same procedure done in an outpatient surgical suite under general anesthesia as it was in a private office under IV sedation.

Rigid fixation of the intraoral inverted ‘L’ osteotomy

Several articles have been written on the use of intraoral vertical subcondylar or inverted “L” osteotomies. le4 Although these procedures have been popular with surgeons to set the mandible back, a disadvantage is the necessary use of maxillomandibular fixation for 6 to 12 weeks. Paulus and Steinhauser’ have described lag screw fixation of vertical subcondylar osteotomies. However, they noted the difficulty in placing more than two screws. Kraut6 discussed placing “T” plates on vertical subcondylar osteotomies. This was followed by maxillomandibular fixation for 1 to 5 days postoperatively. Generally the reasons why rigid fixation has not been popular for vertical subcondylar osteotomies are the inability to position the condylar segment and difficulty controlling the segments. The purpose of this report is to describe a technique used by the authors for the last year to treat mandibular setbacks by an inverted L osteotomy and rigid fixation.

Stability of simultaneous modified LeFort III/LeFort I osteotomies

The objective of this study was to examine maxillary skeletal stability after simultaneous modified LeFort III/LeFort I osteotomy in patients who presented for the simultaneous correction of midface and maxillary hypoplasia. Eleven patients underwent simultaneous modified LeFort III/LeFort I osteotomies using transoral and transconjunctival surgical approaches. The mean net surgical movement at A point (A pt) was 5.2 mm anteriorly and 2 mm inferiorly. Titanium mini-plates were used to stabilize both the midface component and the LeFort I segment; iliac crest or calvarial bone grafts as well as freeze-dried cancellous blocks were used at the zygoma and lateral orbital rim regions. All patients had lateral cephalometric radiographs taken immediately postoperatively, and at their sixth week, sixth month, and one year follow-up visits. Five maxillary landmarks (CI, A pt, ANS, PNS, and 2M) were used to examine the horizontal and vertical changes occurring at each time period. The central incisor relapsed vertically 2.8 mm at six months, A pt relapsed vertically 2.3 mm at six months, ANS relapsed posteriorly 1.6 mm at 6 weeks, PNS relapsed 1.5 mm anteriorly at one year. This study demonstrated that the maxilla moved anteriorly 1.5 mm and superiorly 2.8 mm in simultaneous modified LeFort III/LeFort I osteotomies performed with mini-plate fixation and bone grafts. This movement should be considered when planning and performing simultaneous surgical movement of the maxilla and midface using modified LeFort II/LeFort I osteotomies. Appropriate occlusal overcorrection at the time of surgery is necessary.

Subpalpebral SMAS Suspension as an Adjunct to Midface Osteoplasty during Orthognathic and Craniofacial Surgery

A method of suspending the subpalpebral SMAS at the time of skeletal reconstruction to improve midface augmentation and enhance soft tissue bulk over skeletal fixation devices is presented. Concepts borrowed from refinements in rhytidectomy that improve soft tissue redraping in patients undergoing extensive midface subperiosteal dissection are described.

Painful Preauricular Mass

In early January 199 1, a 22-year-old white woman presented to the Facial Pain Clinic at the University of Texas Health Science Center at San Antonio with a l-month history of increasing swelling and tenderness in the left preauricular area. The patient denied any history of trauma to the region but had recently been treated with antibiotics for an external ear infection and an episode of conjunctivitis. The patient’s past medical history was remarkable for an ovarian cyst, removed in 1986, and intermittent temporomandibular disorders. She admitted to being under unusually high amounts of stress recently, and had been taking ibuprofen for headaches, fever, and general malaise, which she believed were residual symptoms from the flu. Present symptoms included constant headaches in the anterior temporal regions bilaterally, which the patient described as throbbing and more common in the afternoon. The patient also complained of left preauricular pain that was constant and worse in the mornings. Pain was also present in the cervical and trapezius regions bilaterally, which was constant and most intense in the mornings. The patient limited her diet to soft foods because of the facial pain and she perceived an inability to open her mouth as wide as normal. She denied any systemic signs and symptoms, but acknowledged sleep disruption for the past 6 months. The patient had experienced an episode of extreme trismus 1 year earlier, which occurred on awakening. She reported facial muscle soreness every morning and was aware of diurnal clenching. Her pain improved with moist heat and simple analgesics and worsened with eating. The patient denied having joint sounds or ear pain. Physical examination revealed a rubbery, mobile, erythematous, tender mass in the left preauricular area measuring 3 X 2 cm, and an ipsilateral granulomatous lesion extending from the medial palpebral commissure onto the side of the nose (Fig 1). The patient stated that the preauricular lesion had begun approximately 2 weeks earlier and had be-