Use of 3-d stereolithographic models in oral and maxillofacial surgery

OBJECTIVE

To assess the feasibility of the use of 3-dimensional (3-D) stereolithographic (SLA) technology in complex maxillofacial reconstructive surgery.

MATERIALS AND METHODS

3-D SLA technology was used in the treatment planning of complex maxillofacial procedures performed by the Department of Oral and Maxillofacial Surgery at Boston University. Specialized 3-D models were ordered and utilized for surgical treatment of a variety of indications including trauma surgery, temporomandibular joint surgery, orthognathic surgery, secondary correction of facial and skull deformities, and extensive jaw pathology. This technology was also used in one patient for jaw reconstruction using novel bone and tissue engineering techniques.

RESULTS

The use of 3-D models in Oral and Maxillofacial Surgery significantly improved predictability of clinical outcomes when compared to similar treatments without its use. Total operating time was reduced which had the benefit of decreasing the duration of general anesthesia and reducing wound exposure time. They allowed for assessment of extensive traumatic and pathologic defects in three-dimensions prior to surgical reconstruction. The models were also useful in the design and fabrication of custom prostheses, sizing of bone grafts and allowed for manufacturing of scaffolds for bone regeneration.

CONCLUSIONS

3-D SLA models can be very effectively used in oral and maxillofacial surgery for multiple indications and diverse clinical scenarios. Successful incorporation of this technology for jaw bone regeneration using tissue engineering techniques offers exciting new prospects for the future.

Phase 2, randomized, double-blind, dose-ranging study evaluating the safety, tolerability, population pharmacokinetics, and efficacy of oral torezolid phosphate in patients with complicated skin and skin structure infections

Torezolid (TR-700) is the active moiety of the prodrug torezolid phosphate ([TP] TR-701), a second-generation oxazolidinone with 4- to 16-fold greater potency than linezolid against Gram-positive species including methicillin-resistant Staphylococcus aureus (MRSA). A double-blind phase 2 study evaluated three levels (200, 300, or 400 mg) of oral, once-daily TP over 5 to 7 days for complicated skin and skin structure infections (cSSSI). Patients 18 to 75 years old with cSSSI caused by suspected or confirmed Gram-positive pathogens were randomized 1:1:1. Of 188 treated patients, 76.6% had abscesses, 17.6% had extensive cellulitis, and 5.9% had wound infections. S. aureus, the most common pathogen, was isolated in 90.3% of patients (139/154) with a baseline pathogen; 80.6% were MRSA. Cure rates in clinically evaluable patients were 98.2% at 200 mg, 94.4% at 300 mg, and 94.4% at 400 mg. Cure rates were consistent across diagnoses, regardless of lesion size or the presence of systemic signs of infection. Clinical cure rates in patients with S. aureus isolated at baseline were 96.6% overall and 96.8% for MRSA. TP was safe and well tolerated at all dose levels. No patients discontinued treatment due to an adverse event. Three-stage hierarchical population pharmacokinetic modeling yielded a geometric mean clearance of 8.28 liters/h (between-patient variability, 32.3%), a volume of the central compartment of 71.4 liters (24.0%), and a volume of the peripheral compartment of 27.9 liters (35.7%). Results of this study show a high degree of efficacy at all three dose levels without significant differences in the safety profile and support the continued evaluation of TP for the treatment of cSSSI in phase 3 trials.

Ameloblastic carcinoma of the mandible with metastasis to the skull and lung: advanced imaging appearance including computed tomography, magnetic resonance imaging and positron emission tomography computed tomography

Ameloblastic carcinoma is a very rare malignant odontogenic tumour with characteristic histopathological and clinical features, which requires aggressive surgical treatment and surveillance and, therefore, differs from ameloblastoma. Metastasis typically occurs in the lung. Only one patient with metastasis to the skull has previously been described and no prior case reports have presented MRI and positron emission tomography-CT (PET-CT) imaging findings. We describe a case of ameloblastic carcinoma with metastasis to the skull and lung with emphasis on imaging features including MRI and PET-CT.

Changes in quality of life after surgical removal of impacted mandibular third molar teeth

BACKGROUND

The decision to get impacted teeth removed is not straightforward because of the concerns about its possible outcome. Assessment of quality of life is now regarded as an essential component for assessing outcomes of dental health care. The purpose of this paper is to assess the effect of impacted third molar teeth surgery on a number of health related outcomes.

PATIENTS AND METHODS

A total of 72 patients undergoing surgical removal of their unilateral impacted mandibular third molar teeth were recruited to participate in this study. Patients were asked to complete two questionnaires, 14-item Oral Health Impact Profile (OHIP-14) and the 16-item UK Oral Health related Quality of Life measure questionnaire (OHQOLUK-16) daily for one week following surgery.

RESULTS

There was significant decrease in the mean OHQOLUK-16 score and OHIP-14 scores for the first five postoperative days. There were no significant differences in changes in the mean OHIP-14 scores or OHQOLUK-16 scores on postoperative day 6 and 7.

CONCLUSION

There was a significant deterioration in oral health related quality of life in the immediate postoperative period, which slowly returned to preoperative level by day 6. This information may be useful in creating realistic expectation for patients who are considering third molar surgery.

Maxillary sinusitis of odontogenic origin

Odontogenic etiology accounts for 10% to 12% of cases of maxillary sinusitis. Although uncommon, direct spread of dental infections into the maxillary sinus is possible due to the close relationship of the maxillary posterior teeth to the maxillary sinus. If a periapical dental infection or dental/oral surgery procedure violates the schneiderian membrane integrity, infection will likely spread into the sinus, leading to sinusitis. An odontogenic source should be considered in individuals with symptoms of maxillary sinusitis and a history of dental or jaw pain; dental infection; oral, periodontal, or endodontic surgery; and in those people resistant to conventional sinusitis therapy. An odontogenic infection is a polymicrobial aerobic-anaerobic infection, with anaerobes outnumbering the aerobes. Diagnosis requires a thorough dental and clinical evaluation, including radiographs. Management of sinus disease of odontogenic origin often requires medical treatment with appropriate antibiotics, surgical drainage when indicated, and treatment to remove the offending dental etiology.

Surgical management of obstructive sleep apnea

Obstructive sleep apnea (OSA) syndrome is a common disorder that has recently received much attention by the medical community due to its potentially serious physiological consequences. The clinical significance of OSA results from hypoxemia and sleep fragmentation caused by collapse of the airway, which leads to apnea or hypopnea during sleep. This paper reviews common surgical techniques used for clinical management of OSA patients, with emphasis on jaw advancement surgical procedures.

Maxillary sinus disease of odontogenic origin

Odontogenic sinusitis is a well-recognized condition and accounts for approximately 10% to 12% of cases of maxillary sinusitis. An odontogenic source should be considered in patients with symptoms of maxillary sinusitis who give a history positive for odontogenic infection or dentoalveolar surgery or who are resistant to standard sinusitis therapy. Diagnosis usually requires a thorough dental and clinical evaluation with appropriate radiographs. Common causes of odontogenic sinusitis include dental abscesses and periodontal disease perforating the Schneidarian membrane, sinus perforations during tooth extraction, or irritation and secondary infection caused by intra-antral foreign bodies. The typical odontogenic infection is now considered to be a mixed aerobic-anaerobic infection, with the latter outnumbering the aerobic species involved. Most common organisms include anaerobic streptococci, Bacteroides, Proteus, and Coliform bacilli. Typical treatment of atraumatic odontogenic sinusitis is a 3- to 4- week trial of antibiotic therapy with adequate oral and sinus flora coverage. When indicated, surgical removal of the offending odontogenic foreign body (primary or delayed) or treatment of the odontogenic pathologic conditions combined with medical therapy is usually sufficient to cause resolution of symptoms. If an oroantral communication is suspected, prompt surgical management is recommended to reduce the likelihood of causing chronic sinus disease.

Changes in temporomandibular joint dysfunction after orthognathic surgery

PURPOSE

We sought to evaluate the effects of orthognathic surgery on temporomandibular joint (TMJ) dysfunction in patients with known presurgical TMJ internal derangement who underwent double-jaw surgery for the treatment of dentofacial deformities.

PATIENTS AND METHODS

Treatment records of 25 patients with magnetic resonance imaging and clinical verification of preoperative TMJ articular disc displacement who underwent double-jaw surgery only were retrospectively evaluated, with an average follow-up of 2.2 years. Signs and symptoms of TMJ dysfunction, including pain, range of mandibular motion, and presence/absence of TMJ sounds, were subjectively (visual analog scales) and objectively evaluated at presurgery (T1), immediately postsurgery (T2), and at longest follow-up (T3). Surgical change (T2-T1) and long-term stability of results (T3-T2) were calculated using the superimposition of lateral cephalometric and tomographic tracings.

RESULTS

Presurgery, 16% of the patients had only TMJ pain, 64% had only TMJ sounds, and 20% had both TMJ pain and sounds. Postsurgery, 24% of the patients had only TMJ pain, 16% had only TMJ sounds, and 60% has both TMJ pain and sounds. Thus, presurgery 36% of the patients had TMJ pain, and postsurgery, 84% had pain. Average visual analog scale pain scores were significantly higher postsurgery and none of the patients with presurgery TMJ pain had relief of pain postsurgery. In addition, 6 patients (24%) developed condylar resorption postsurgically, resulting in the development of Class II open bite malocclusion.

CONCLUSIONS

Patients with preexisting TMJ dysfunction undergoing orthognathic surgery, particularly mandibular advancement, are likely to have significant worsening of the TMJ dysfunction postsurgery. TMJ dysfunction must be closely evaluated, treated if necessary, and monitored in the orthognathic surgery patient.

Stability of maxillary advancement using rigid fixation and porous-block hydroxyapatite grafting: cleft palate versus non-cleft patients

This study was undertaken to evaluate the stability of maxillary advancement using bone plates for skeletal stabilization and porous block hydroxyapatite (PBHA) as a bone graft substitute for interpositional grafting in cleft and non-cleft patients. The records of 74 patients (41 females, 33 males) who underwent Le Fort I maxillary advancement using rigid fixation and PBHA interpositional grafting were evaluated retrospectively. All patients also underwent simultaneous sagittal split mandibular ramus osteotomies. Patients were divided into 2 groups for study purposes: group 1 consisted of 17 cleft palate patients and group 2 consisted of 57 non-cleft patients. Each group was further subdivided into 2 subgroups based on the concurrent vertical positioning of the maxillary incisors: groups 1a and 2a, where the maxilla underwent 3 mm or more of inferior repositioning, and groups 1b and 2b, where the maxilla underwent minimal vertical change (< or = 1 mm). Presurgery, immediate postsurgery, and longest follow-up lateral cephalometric tracings were superimposed and analyzed to calculate surgical change and long-term stability of results by assessing horizontal and vertical changes at point A, incisor superius, and the mesial cusp tip of maxillary first molar. The average follow-up time in group 1 was 37.9 months (range 12 to 136) and in group 2 was 28.77 months (range 17 to 88). Average maxillary advancement at point A was: group 1a, 5.4 mm; group 1b, 5.25 mm; group 2a, 5.48 mm; group 2b, 5.46 mm. Average relapse at point A was: group 1a, -0.75 mm; group 1b, -1 mm; group 2a, -0.47 mm; group 2b, -0.48 mm. Average horizontal and/or vertical relapse at the central incisors and first molars was 1 mm or less in group 1 and less than 0.5 mm in group 2. Although there was a slightly greater relapse in group 1, no statistically significant difference was observed between the groups. Maxillary advancement with Le Fort 1 osteotomies using rigid fixation and interpositional PBHA grafting during bimaxillary surgery is a stable procedure with good predictability in cleft and non-cleft patients, regardless of the direction of vertical maxillary movement.

Stability of the Le Fort I osteotomy for maxillary advancement using rigid fixation and porous block hydroxyapatite grafting

PURPOSE

The purpose of this study was to evaluate the stability of maxillary advancement using bone plates for skeletal stabilization and porous block hydroxyapatite (PBHA) as a bone graft substitute for interpositional grafting.

PATIENTS AND METHODS

The records of 78 patients (55 female, 23 male) with a diagnosis of anteroposterior maxillary hypoplasia were retrospectively evaluated. All patients underwent greater than 5 mm Le Fort I maxillary advancement with rigid fixation and PBHA interpositional grafting. The study sample was divided into 3 groups on the basis of the concurrent superior or inferior positioning of the maxillary incisors. Presurgery (T1), immediately postsurgery (T2), and longest follow-up (T3) lateral cephalometric tracings were superimposed to analyze for horizontal and vertical changes at the following landmarks: (1) point A, (2) incisal edge of the maxillary incisor, and (3) mesial cusp tip of maxillary first molar.

RESULTS

The maxilla was inferiorly repositioned in 27 patients, superiorly repositioned in 21 patients, and advanced horizontally without a significant vertical change in 30 patients. All groups showed 0.5 mm or less horizontal and vertical relapse. There was no statistically significant difference between the 3 groups.

CONCLUSIONS

Maxillary advancement with Le Fort 1 osteotomies by using rigid fixation and interpositional PBHA grafting is a stable and predictable procedure regardless of the direction of vertical maxillary movement.

Concomitant temporomandibular joint and orthognathic surgery: a preliminary report

PURPOSE

In the present study, we evaluated the outcome of concomitant temporomandibular joint (TMJ) and orthognathic surgery in patients with TMJ articular disc dislocation and coexisting dentofacial deformities.

PATIENTS AND METHODS

The records of 70 patients treated with TMJ articular disc-repositioning surgery and concomitant orthognathic surgery (double jaw or only mandibular surgery) were retrospectively evaluated. Patients were divided into the following 3 groups: group 1 patients had mandibular advancement, group 2 patients had mandibular setback, and group 3 patients had a mandible that remained in the original position. Lateral cephalometric radiographs and lateral cephalometric tomograms were assessed at the following intervals: before surgery (T1), immediately after surgery (T2), 6 to 12 months after surgery (T3), and at the longest follow-up (T4). Lateral cephalometric tracings were superimposed to calculate surgical change (T2 - T1), short-term stability (T3 - T2), and long-term stability (T4 - T3) of the orthognathic surgery procedures. Maximum interincisal opening (MIO) and subjective TMJ pain (visual analog scales) were comparatively evaluated at T1 and T4.

RESULTS

Subjective TMJ pain levels and MIO improved in all 3 groups after surgery. Before surgery, 56 of 70 patients (80%) had pain and 14 of 70 patients (20%) had no pain. At the longest follow-up, 42 of 70 patients (60%) reported complete relief of TMJ pain. Only 5 of 70 patients (7%) had severe pain after surgery compared with 37 of 70 patients (53%) before surgery. At the longest follow-up, 6 of 70 patients (9%) showed less than 35 mm MIO, residual severe pain, or both. One patient had significant condylar resorption after surgery. The orthognathic procedures were found to be stable in the long term. Concomitant TMJ and orthognathic surgery had an overall success rate of 91.4% based on a greater than 35 mm MIO and a decrease in pain.

CONCLUSIONS

When indicated, TMJ and orthognathic surgery can be concomitantly performed with predictable results and a good success rate. Strong consideration should be given to early surgical intervention because the success rate decreases significantly with pre-existing TMJ dysfunction of greater than 48 months' duration.

Use of conservative condylectomy for treatment of osteochondroma of the mandibular condyle

PURPOSE

The aim of the present study was to present a conservative condylectomy technique (condylectomy performed below the condylar head but high in the condylar neck) and articular disc repositioning as the surgical treatment approach for management of osteochondroma of the head of the mandibular condyle.

PATIENTS AND METHODS

Six patients (4 females and 2 males) with an average age of 22.3 years (range, 13 to 32 years) and with an osteochondroma of the mandibular condyle were treated with conservative condylectomy. The remaining condylar neck stump was recontoured, and the articular disc was repositioned and stabilized over the "new" condyle. Any indicated orthognathic surgical procedures were then performed to optimize occlusion, function, and aesthetics. Clinical and radiographic evaluation was performed before surgery (T1), immediately after surgery (T2), and at the longest follow-up (T3).

RESULTS

Average follow-up for the patients was 51 months (range, 22 to 108 months). No recurrence of the tumor was encountered in any of the cases. Subjective and objective evaluations of postsurgical temporomandibular joint function and range of mandibular motion were normal. Associated maxillary and/or mandibular orthognathic procedures were found to be stable in the long term.

CONCLUSION

Conservative condylectomy with recontouring of the residual condylar neck to function as a condyle and repositioning of the articular disc is a viable option for treatment of osteochondromas of the mandibular condyle. The use of this method of treatment permits effective removal of the tumor and eliminates the need for autogenous grafts or total joint prostheses for temporomandibular joint reconstruction.