Dale S. Bloomquist

The effect of mandibular osteotomy in three patients with hypersomnia sleep apnea

Hypersomnia sleep apnea (HSA) is characterized by apneic episodes during sleep and daytime hypersomnolence. Patients afflicted as a result of upper airway obstruction have been treated traditionally with permanent tracheostomy. Three patients with HSA and mandibular retrognathism are presented. Each patient had a retrognathic mandible that stemmed from a different cause. Surgical advancement of their underdeveloped mandibles corrected the symptoms of HSA rapidly. The literature concerning HSA is reviewed and the advantages of mandibular surgery in selected cases are discussed.

Orthognathic surgery and pulpal blood flow: A pilot study using laser doppler flowmetry

The purpose of this study was to analyze the effect of Le Fort I osteotomy on pulpal circulation. A laser Doppler flowmeter was used to measure pulpal blood flow of maxillary right and left central incisors and a randomly selected mandibular canine in 14 volunteers prior to surgery and at various intervals during the 6 months following surgery. Custom-made splints allowed accurate and reproducible positioning of the measurement probe. The data showed a significant reduction in vascular supply at the final observation. However, a high variability of individual blood flow patterns was found. In some patients, transient periods of ischemia were observed shortly after surgery. Also, numerous teeth demonstrated hyperemia at later intervals. One patient developed discoloration of a central incisor, and another lost marginal periodontal support around both central incisors. However, in none of the 14 subjects was pulpal blood flow found to be absent following surgery.

The posterior ilium as a donor site for maxillo-facial bone grafting

The anterior iliac crest has been the traditional source of pelvic bone for autogenous bone grafting in the maxillo-facial skeleton. Although the posterior iliac crest is frequently utilized by our orthopaedic colleagues, little attention has been given this site in the oral and maxillo-facial literature. As the posterior crest affords an almost unlimited amount of bone for autogenous grafting in the maxillo-facial region, we feel its use is indicated when very large amounts of bone are required. The techniques for removal of cancellous and cortico-cancellous posterior crest grafts are described in detail. Morbidity of the posterior crest donor site includes possible difficulties with patient positioning, injury to the sacro-iliac joint, injury to the sciatic or cluneal nerves, and severe haemorrhage. Ambulation following the use of the posterior crest has not been a problem. Significant blood loss can be adequately controlled with proper exposure, electrocautery, and bone wax.

Effects of Le Fort I osteotomy on human gingival and pulpal circulation

The maxillary blood flow during the first 24 h following Le Fort I osteotomy was evaluated by laser Doppler flowmetry. Pulpal blood flow was recorded from two maxillary incisors and gingival blood flow was assessed from a site slightly apical to the interdental papilla of the maxillary central incisors of 12 patients receiving Le Fort I osteotomy, nine control patients receiving mandibular osteotomy, and 10 nonsurgical control subjects without orthodontic appliances. Measurements were made before surgery and at time intervals between 0-8, 8-16, and 16-24 h after surgery. The nonsurgical controls were tested at similar intervals. Gingival and pulpal blood-flow measurements did not change over time in the nonsurgical control group. Presurgical blood-flow values did not differ between the two surgical groups. Following surgery, mean gingival (but not pulpal) blood flow was significantly lower for patients treated with Le Fort I osteotomy than for patients treated with mandibular osteotomy. Follow-up examinations revealed that one patient receiving Le Fort I osteotomy experienced loss of gingiva and bone around both central incisors. This patient had one of the largest reductions in gingival blood flow.

Cortical power spectrum analysis of hypnotic pain control in surgery

Cortical power spectrum (CPS) of brain potentials was recorded from the scalp between prefrontal and parietal regions in both right hemisphere (RH) and left hemisphere (LH). A pattern of laterality shift in CPS occurred at different stages during an extensive oral surgery, performed under hypnosis, in a young female patient. Video and audio recordings as well as psychophysiological recordings were obtained through the following 6 stages: Baseline, Hypnosis, Surgery (1 hr, no cortical recording), Immediate Postsurgery Procedure, Hypnotic Re-experience, Hypnotic Rest, and Posthypnotic Baseline. Indications of anxiety and pain scores were reported in writing by the patient through verbal command by the hypnotist. In each stage, 10 min of CPS (10 spectrum/stage, 8 epochs/spectrum, 6 seconds/epoch) were analyzed by a PDP-11 computer. The results of CPS analysis demonstrated significant large total power reduction at different stages. There was significant correlation between both hemispheres at baseline, but dissociation of hemispheric power output occurred during hypnosis stages. LH was more dominant than RH during baseline and presurgery hypnosis, but both were leveled-off immediately following the surgery procedure. However, RH became more dominant during all postsurgery hypnosis stages. Interestingly, this pattern shifted back to the original relationship during the posthypnotic baseline stage. Specific changes of spectral power in theta and alpha of EEG activities in both hemispheres also occurred in conjunction with hypnosis.

Stability of mandibular constriction with a symphyseal osteotomy

The purposes of this study are to determine the stability of surgical mandibular constriction with a midline osteotomy and to evaluate the periodontal and temporomandibular joint responses. A symphyseal osteotomy to facilitate mandibular construction was performed in 15 patients to correct transverse discrepancies. At the same time a surgical anterior or posterior repositioning of the mandible was done by using a bilateral sagittal osteotomy of the vertical ramus. Tomograms in the coronal plane including the mandibular second molars were taken preoperatively (T1), immediately postoperatively (T2) and 8 weeks postoperatively (T3). Linear measurements between the cortical borders of the mandible were assessed from the tomograms at each time period. Median surgical and postoperative changes in mandibular width were determined. When evaluating the entire group no statistically significant change in the surgical constriction was found postoperatively (T2 and T3), although there was some individual variability. An examination of the periodontal response at the osteotomy site revealed no statistically significant change between the initial and the 5-month postoperative examinations. No changes in joint noise were detected postoperatively, and all mandibular joint movements returned to preoperative values except for excursive movements. Mandibular constriction with a midline osteotomy on conjunction with a bilateral sagittal osteotomy was found to be a stable modality for correcting transverse disharmonies.

Stability of mandibular lengthening using bicortical screw fixation

The mandibular lengthening procedure performed with the use of rigid internal fixation yields more stable results than previously demonstrated when nonrigid fixation is used. Twenty patients with Class II malocclusion who had undergone this procedure were examined retrospectively to assess postoperative skeletal change. The mean postoperative interval was 15.7 months. Although there was individual variability, no significant mean postoperative horizontal change was found, which indicated excellent stability.

Long-term stability of anterior open-bite closure with bilateral sagittal split osteotomy

INTRODUCTION Maxillary impaction and bimaxillary osteotomies are used to treat anterior open-bite malocclusions but can have adverse soft-tissue effects. Correcting an anterior open bite with a single mandibular procedure avoids these undesirable soft-tissue effects, but the stability of this procedure is unknown. The purpose of this study was to assess the long-term stability of anterior open-bite correction with bilateral sagittal split osteotomy and rigid internal fixation. METHODS Orthognathic surgical records of 1 oral surgeon were searched for all patients treated for anterior open bite with bilateral sagittal split osteotomy and surgical closing rotation of the mandible with rigid internal fixation. Cephalometric films from initial consultation, presurgery, postsurgery, orthodontic appliance removal, and a mean of 4.5 years after orthodontic appliance removal were collected, traced, and measured. RESULTS Thirty-one patients fit the inclusion criteria for this study and had an initial mean open bite of -2.6 mm (SD, 1.1 mm). The patients experienced an average mandibular closing rotation of 3.7° (SD, 2.4°) with surgery. By orthodontic appliance removal, the mandible rotated open 1.1°, and incisor overlap was 1.4 mm (SD, 1.0 mm). Approximately 4.5 years after orthodontic appliance removal, the mean incisor overlap was maintained at 1.0 mm (SD, 1.0 mm), yet the mandible rotated open an additional 1.1°. Only 3 patients relapsed to no incisor overlap in the long term, and only 3 patients experienced relapse greater than 1 mm in the long term. CONCLUSIONS Approximately 90% of the treated patients had a positive incisor overlap 4.5 years after orthodontic appliance removal. Despite a 60% loss of mandibular surgical closing rotation, only 10% of the patients relapsed to no incisor overlap in the long term. Bilateral sagittal split osteotomy and surgical closing rotation of the mandible by using rigid internal fixation should be considered a stable alternative in the treatment of mild-to-moderate anterior open-bite malocclusions.

Case Report MM: Surgical-orthodontic correction of bilateral buccal crossbite (Brodie Syndrome)

A surgical approach to treatment was required for this 35-year-old patient to correct a malocclusion characterized by a bilateral buccal crossbite. Surgical procedures included a LeFort 1 osteotomy to reduce maxillary width and correct the vertical asymmetry. The mandible was lengthened with a bilateral sagittal split osteotomy. Treatment options for the nongrowing patient are limited in the correction of severe skeletal disharmonies.

Long-term results of subperiosteal implants combined with cancellous bone grafts

Twenty-three subperiosteal implants combined with cancellous bone grafts were done at the University of Washington over a four-year period. A modification of the original technique as used with 19 of the patients is described, as well as the follow-up evaluation. The greatest problem occurred at the mucosal-metal junction, resulting in multiple infections and some failures. This technique appears to be comparable with simple subperiosteal implant but not significantly better.