Long-term hard and soft tissue relapse rate after genioplasty.

PURPOSE: The purpose of this study was to assess hard and soft tissue stability 12 months after advancement genioplasty. MATERIAL AND METHODS: This is a retrospective study of 20 patients who underwent either advancement genioplasty alone (n = 11) or in combination with bilateral sagittal split osteotomy for mandibular advancement (n = 9). Lateral cephalometric radiographs were traced and immediate postoperative changes and 12-month postoperative changes were defined. The relapse rate for the pogonion, the soft tissue pogonion, and the soft tissue B point (Bs) were evaluated. The results were compared for combined mandibular advancement plus genioplasty versus genioplasty alone. Relapse rates were also correlated with the amount of advancement. All patients were treated with rigid internal fixation. RESULTS: After 12 months, the pogonion, the soft tissue pogonion, and the soft tissue B point had a mean relapse rate of -0.38 mm, -1.2 mm, and -1.5 mm (negative value indicates a relapse, and a positive value indicates prolapse), respectively, which was not significant at probability values of.45,.069, and.054, respectively. Relapse was not statistically related to the amount of advancement. There was no significant difference between the relapse rate for genioplasty alone versus combined bilateral sagittal split osteotomy and genioplasty, even with different amounts of advancement. CONCLUSIONS: Advancement genioplasty is an important and reliable technique for the esthetic treatment of the lower facial skeleton. The results indicate that there is no significant relapse after genioplasty and bilateral sagittal split osteotomy or genioplasty alone after 12 months when rigid internal fixation is used. The changes were minimal and hard to detect clinically. Genioplasty, with or without mandibular advancement, is a stable surgical procedure when used in conjunction with rigid internal fixation.

Upper lip length after V-Y versus continuous closure for Le Fort I level maxillary osteotomy.

PURPOSE: The purpose of this report is to document changes in lip length and thickness after Le Fort I maxillary osteotomy by using continuous versus V-Y closure. MATERIALS AND METHODS: This is a retrospective analysis of 18 patients who underwent Le Fort I maxillary osteotomy. Ten patients had a single midline V-Y closure and 8 patients had simple continuous closure. Lateral cephalometric analysis was performed, and preoperative and 12-month postoperative changes in lip dimensions were calculated. Lip length and thickness were analyzed at 5 points: A-point (A), subnasale (Sn), cervical margin of incisor (C), stomion superius (Ss) and labrale superius (Ls). The lengths from A to Sn, C to Ls, and Sn to Ss were calculated. RESULTS: After 12 months, there was no significant difference in lip length (P =.39) or thickness of the upper lip in its upper (P =.75) or lower (P =.19) parts, between the 2 groups. CONCLUSION: Lip length and width show no significant differences before surgery versus after surgery with either closure technique after Le Fort I osteotomy.

Anatomy of the lateral canthal tendon.

OBJECTIVE: The purpose of this study was to clarify and describe the anatomy of the lateral canthal tendon. Knowledge of this anatomy is essential in selection of appropriate surgical procedures to restore orbital anatomy. STUDY DESIGN: Gross dissections were performed of the lateral orbital soft tissues from 21 preserved Caucasian cadaveric orbits. A block of the bony attachment of each lateral canthus was taken for histologic examination. After anatomical exposure, the following measurements of the lateral canthus were made: (1) the distance from the midpoint of insertion of the lateral canthus at the lateral orbit to the zygomaticofrontal suture; (2) the horizontal width of the lateral canthus, as measured from the lateral commissure to the lateral orbit; (3) the vertical difference in height between the medial canthal and lateral canthal insertions. RESULTS: The mean midpoint of the lateral canthus insertion was 10. 24 mm inferior to the zygomaticofrontal suture (range, 5-15 mm). The mean horizontal length of the lateral canthus from the lateral commissure to the lateral orbit was 7.52 mm (range, 2-12 mm). The mean vertical difference in height between the insertions of the medial canthus and the lateral canthus was 1.35 mm (range, -2-4 mm), the lateral canthus being at a more superior point. Histologic examination of hematoxylin-eosin-stained slides showed that the fibers of the lateral canthus inserted into the periosteum but not beyond it. CONCLUSIONS: The lateral canthal tendon attaches the upper and lower tarsal plates to Whitnall's tubercle inside the orbital rim deep to the septum. A precise knowledge of the periorbital anatomy will assist the surgeon in the selection of appropriate surgical techniques that will provide for restoration of this delicate anatomical configuration.

Anatomy of the structures medial to the temporomandibular joint.

OBJECTIVE: To define the relationship of the branches of the trigeminal nerve and the infratemporal vessels to the zygomatic arch and medial capsular ligament of the temporomandibular joint (TMJ). MATERIAL AND METHOD: In a study of 20 cadaveric dissections of the infratemporal fossa, measurements were obtained in anterior-posterior and transverse directions to identify the relationship of the trigeminal nerve, carotid artery, internal jugular vein, and middle meningeal artery to the zygomatic arch. The distance from the lateral to the medial aspect of the glenoid fossa was measured to further delineate the proximity of these structures to the medial portion of the capsule of the TMJ. RESULTS: The mean transverse distance from the zygomatic arch to the middle meningeal artery was 31 mm (range, 21 mm to 43 mm). The mean anterior-posterior distance from the height of the glenoid fossa to the middle meningeal artery was 2.4 mm (-2 mm to 8 mm). The transverse distance from the carotid artery to the zygomatic arch was a mean of 37.5 mm (29 mm to 48 mm) with the mean anterior-posterior distance of -6.5 mm (-21 mm to 6 mm). The mean distance from the internal jugular vein to the zygomatic arch was 38.3 mm (31 mm to 49 mm). The mean anterior-posterior distance was -8.7 mm (-20 mm to 7 mm). The transverse distance from the trigeminal nerve to the arch was a mean distance of 35 mm (24 mm to 46 mm). The mean anterior-posterior distance was 9.2 mm (1 mm to 25 mm). The mean medial to lateral width of the glenoid fossa was 18.7 mm (16 mm to 23 mm). CONCLUSION: The arteries, nerves, and veins are close to the medial aspect of the TMJ. A knowledge of these relationships can guide the surgeon on the medial aspect of the TMJ and can help to prevent complications associated with these structures.

The less than 7-mm edentulous mandible: the implant/overdenture reconstructive option.

The edentulous patient with a severely atrophic mandible (less than 7 mm in height) can be successfully restored with two endosseous implants and a clip-bar overdenture, with minimal morbidity. Two of the three cases reported illustrate the long-term potential of this treatment modality.

Comparative cell targeting in vitro using the CO2 laser.

In keeping with current interest in bactericidal effects of lasers to treat localized infection, we examined the effect of CO2 laser light on three bacterial species. Cell monolayers were placed atop filters minimizing the presence of extracellular water. Samples were exposed to irradiance values between 0 and 520 W/cm2 for 0.1 s. Cell survival was determined by colony counts. There was logarithmic killing of the bacteria with increasing irradiance; 90% kill was effected at 180 W/cm2 for Escherichia coli, 350 W/cm2 for Streptococcus mutans, and 250 W/cm2 for Bacillus stearothermophilus. However, standard deviations suggest no significant difference between cell types. Our results show the bactericidal effect of the CO2 laser with no remarkable difference between Gram types. However, substantial cell kill was achieved at relatively low irradiance. Whereas selectivity of damage may not be afforded by the CO2 laser, it may minimize collateral damage.

Diagnosis of facial neuralgias and headaches.

Although the above disorders are not common, the dentist's ability to diagnose and differentiate them from other facial pains is essential. Many patients suffering from these afflictions have been seen by numerous dentists and physicians before appropriate diagnosis and treatment is provided; therefore, it is essential for dentists to be aware of these conditions and immediately refer the patient to a neurologist for further treatment if necessary.