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A comparative study of surgical techniques on the cervicomental angle in human cadavers.

BACKGROUND: The cervicomental (CM) angle is formed by the horizontal plane of the submental region and the vertical plane of the neck. OBJECTIVE: To compare the 2-dimensional effect of 4 surgical techniques on the CM angle in a human cadaver model. DESIGN: Anatomic presurgical and postsurgical comparative study performed on human cadavers preserved with ethylene glycol. SETTING: Academic medical research center in St Louis, Mo. SUBJECTS: Twelve cadaver specimens with obtuse CM angles with heads attached to the sternum and upper thorax. INTERVENTIONS: Standard superficial musculoaponeurotic system rhytidectomy techniques were performed on all cadaver heads. Four techniques were compared: (1) platysmal plication; (2) platysmal plication and plication of the anterior bellies of the digastrics; (3) platysmal plication, plication of the anterior bellies of the digastrics, and interlocking mastoid-to-mastoid sutures; and (4) platysmal plication and interlocking mastoid-to-mastoid sutures. MAIN OUTCOME MEASURES: The comparative changes in CM angle, the distance between the mentum and CM angle (mentum-CM distance), and the distance between the sternum and CM angle (sternum-CM distance) obtained with each of the 4 surgical techniques. Anatomic characteristics of the cadavers were also noted. RESULTS: On average, the CM angle was significantly reduced after all procedures (P<.001). The mean sternum-CM distance increased significantly (P =.01). A trend toward significance was observed in the change in mentum-CM distance (P =.10). The presence of a low hyoid was significantly associated with a smaller CM angle after surgery (P =.009) and demonstrated a trend toward significance with an increase in mentum-CM distance (P =.07), but it was not significantly associated with an increase in sternum-CM distance (P =.58). After controlling for the presence of a low hyoid, the mastoid-to-mastoid suture significantly reduced the CM angle by approximately 11.3 degrees (P =.002) and the sternum-CM distance by 1.15 cm (P<.001). CONCLUSIONS: The CM angle and the sternum-CM distance were significantly affected by all procedures. The addition of the mastoid-to-mastoid suture had the greatest effect on the CM angle, and the reduction in CM angle was strongly associated with an increase in the sternum-CM distance. Presence of a low hyoid was the only preoperative factor associated with a significant postoperative reduction in CM angle.

Aged↗
PubMed2005

Which is mightier, the tuning fork or the bone oscillator?

INTRODUCTION: It is important to differentiate cochlear implant candidates with profound sensorineural hearing loss from those with profound mixed hearing loss. The latter include patients with far advanced otosclerosis and chronic otitis media who may be better treated with ossiculoplasty and conventional amplification than with cochlear implantation. Otologists have observed that a dentally placed tuning fork can be heard by some patients whose sensorineural thresholds are beyond the limits of a bone oscillator placed on the mastoid. We hypothesized that tuning forks may be able to deliver a strongerintensity bone-conducted signal than a conventional mastoid-placed oscillator. OBJECTIVE: To measure the maximum bone-conduction signal intensities of a mastoid-placed bone oscillator and tuning forks placed on the forehead, mastoid, and teeth. METHOD: The maximum signal intensity of a mastoid-placed bone oscillator and tuning forks at various locations (mastoid, forehead, teeth) was measured using behavioural masking level differences at three frequencies (250, 500, and 1000 Hz). RESULTS: The peak intensity of a dental bone-conducted tuning fork signal is greater than that delivered by a mastoid-placed bone oscillator (at least 20.5 dB HL at 250 Hz, 16.5 dB HL at 500 Hz, and 8.5 dB HL at 1000 Hz; p <.001) at all three frequencies tested. At some frequencies, the bone oscillator's maximum perceived level is greater than the peak perceived level of the tuning fork when placed on the forehead or mastoid. CONCLUSIONS: In addition to pure-tone audiometry, all patients being considered for cochlear implantation should be evaluated with maximally vibrating tuning forks applied to the teeth. If the signal is audible, other surgical procedures may need to be considered before proceeding with cochlear implantation.

Adolescent↗
PubMed2002

[Endoscopic anatomy of the middle ear].

OBJECTIVE: To provide a detailed anatomic description of middle ear endoscopy via different approaches. METHOD: Using 0, 30 and 90 degree rigid endoscopes, 6 dry temporal bones and 11 temporal bone blocks were examined to define the average range of view obtained by three approaches: 1. via the external ear canal approach; 2. via a retroauricular incision: including two subdivided routes, the mastoid-tympanic antrum route and mastoid-retrotympanum route; 3. via the middle ear cranial fossa. Each region of the middle ear was chosen for inspection. RESULT: 1. via the external ear canal approach, all sites of the tympanic cavity structures were seen with 0, 30 and 90 degree rigid otoendoscopes, including the hidden areas such as the tympanic sinus, facial recess, anterior epitympanic recess, orifice of eustachian tube et al. 2. via the mastoid-tympanic antrum route, the structures of the mastoid cavity, tympanic antrum, epi-mesotympanum were clearly defined; via the mastoid-retrotympanum route, the structures of the mastoid cavity and meso-hypotympanum were also observed; 3. via the middle cranial fossa approach, the structures of the epitympanum, tympanic antrum, mastoid cavity and lateral wall were inspected, most mesotympanic structures were evaluated. CONCLUSION: Middle ear endoscopy through the different approaches provides the otosurgeons a clear view field of the middle ear structures, can therefore decrease the incidence of cholesteatoma recurrence and evaluate the state of the postoperative middle ear cavity. The 30 degree otoendoscope can provide a better visualization of the middle ear structures, via the three approaches, the 90 degree otoendoscope is suited for the inspection of the posterior epitympanum via the transmeatal approach and retrotympanum via mastoid cavity-tympanic antrum route.

Ear, Middle↗