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Biomedical subjects

T A Turvey

Publications and source records attributed to T A Turvey.

At least 19 recordsLinked to original sources
PubMed1998

A retrospective analysis of lingual nerve sensory changes after mandibular bilateral sagittal split osteotomy.

PURPOSE: The purpose of this retrospective study was to determine the patient-reported incidence, duration, and perceived deficit in daily activities associated with lingual nerve (LN) sensory changes after bilateral sagittal split osteotomy (BSSO) of the mandible and to compare them with inferior alveolar nerve (IAN) sensory changes in the same study population. MATERIALS AND METHODS: Questionnaires were mailed to 316 patients who had undergone BSSO procedures between 1980 and 1993. The patients were queried for perceived sensory changes in the distribution of the IAN and LN; duration of these sensory changes; and alteration in daily activities caused by these sensory changes. The same questionnaire was mailed to 47 patients who had undergone isolated genioplasty (GP) to control for the normal variance of non-BSSO surgery on perceived LN sensory changes. RESULTS: Forty-three percent of the BSSO patients and 38% of the GP patients returned the questionnaires. Within the BSSO group, 19.4% reported LN sensory changes, of which 69.3% reported that these changes resolved within 1 year; 88% reported altered daily activities. By comparison, 95.5% reported a perceived IAN sensory change, of which 27.3% reported that these changes resolved within 1 year; 57% reported altered daily activities. Within the GP control group, 11% reported LN sensory changes; none of the reported sensory changes lasted longer than 1 month. CONCLUSIONS: A small percentage of patients report LN sensory changes after BSSO. When compared with IAN reported sensory changes, LN sensory changes resolve more frequently and sooner, but they are associated with greater perceived deficits in daily activity. The interpretation of the reported incidence of LN change must be critically reviewed because control subjects also responded positively.

Activities of Daily Living↗
PubMed1996

Orthognathic surgery: a hierarchy of stability.

The stability and predictability of orthognathic surgical procedures varies by the direction of surgical movement, the type of fixation, and the surgical technique employed, largely in that order of importance. The most stable orthognathic procedure is superior repositioning of the maxilla, closely followed by mandibular advancement in patients in whom anterior facial height is maintained or increased. (If facial height is decreased by upward rotation of the chin, stability is compromised). The combination of moving the maxilla upward and the mandible forward is significantly more stable when rigid internal fixation is used in the mandible. Forward movement of the maxilla is reasonably stable, with or without rigid internal fixation, but mandibular setback often is not stable, and downward movement of the maxilla that creates downward rotation of the mandible is unstable. For mandibular setback, the inclination of the ramus at surgery appears to be an important influence on stability. It has been suggested that both interpositional synthetic hydroxyapatite grafting and simultaneous ramus osteotomy improve the stability of downward movement of the maxilla, but this has not been well documented. In two-jaw Class III surgery, the stability of each jaw appears to be quite similar to that of isolated maxillary advancement or mandibular setback. The least stable orthognathic procedure is transverse expansion of the maxilla. Although surgically assisted rapid palatal expansion has been suggested as a more stable alternative to segmental Le Fort I osteotomy, the patterns of movement resulting from the two procedures are different, and differences in stability have not been established.

Humans↗
PubMed1995

Long-term stability of two-jaw surgery for treatment of mandibular deficiency and vertical maxillary excess.

Changes in cephalometric landmark positions and relationships were evaluated more than 5 years postsurgically in 26 patients whose long-face condition had been treated with a combination of superior repositioning of the maxilla and mandibular advancement. All the patients had a least 2-mm surgical intrusion of the maxilla and 2-mm lengthening of the mandible with wire osteosynthesis, maxillomandibular fixation, and skeletal suspension wires. On the average, a small amount of downward and backward rotation of the mandible occurred long term. The mean change in overjet was less than 1 mm. Most of the changes occurred in a minority of the patients: 20% of the group had 2 to 4-mm downward movement of menton, and the mandibular plane angle increased more than 2 degrees in 25% of the patients. On clinical evaluation, a tendency toward opening of the bite beyond 1 year postsurgery was noted in 5 of the 26 patients (19%), and one patient had a greater than 4-mm decrease in overbite. The condylion-pogonion distance decreased 2 to 4 mm in three patients, two of whom had shown greater than 4-mm shortening of this distance during the first postsurgical year. It appears that long-term shortening of the condylar process is not a highly prevalent problem, but changes of 2 to 4 mm in condylion-pogonion associated with modest clinical relapse may occur beyond 1 year postsurgery in 5 to 10% of these two-jaw surgery patients.

Adolescent↗
PubMed1994

Stability following superior repositioning of the maxilla by Le Fort I osteotomy: five-year follow-up.

Changes in dental and skeletal relationships were evaluated 5 years postsurgically in 49 patients whose maxilla had been superiorly repositioned by a Le Fort I osteotomy. All of the patients had at least 2 mm of intrusion at the maxillary incisor and molar; none had a mandibular ramus osteotomy or other osteotomy except genioplasty. Only 6.5% had 2 mm or greater of net vertical change in skeletal or dental landmarks at 1 year postsurgery. From 1 to 5 years postsurgery, minimal changes in skeletal and dental landmarks occurred in the majority of the patients, but approximately 25% of the patients showed 2 mm or more of downward movement of the maxilla and/or eruption of maxillary teeth, leading to downward-backward rotation of the mandible. Only one patient had more than 1 mm of open bite on long-term follow-up. An increase in overbite, resulting from incisor eruption, was noted in 14%, and an increase in overjet occurred in 12% as the mandible rotated. It appears that modest long-term skeletal and dental changes occur in some surgically treated long-face patients. The likelihood of long-term change was not related to the age of the patient, stability during the first postsurgical year, or segmentation of the maxilla at surgery.

Adolescent↗
PubMed1993

Recovery following orthognathic surgery: mandibular bilateral sagittal split osteotomy and Le Fort I osteotomy.

Thirty-eight patients, who underwent orthognathic surgery, reported their recovery period upon returning to work or school and returning to full activity. Twenty-six patients had isolated bilateral sagittal split osteotomies (BSSO) and 12 had isolated Le Fort I osteotomies (LFI). At 1 to 2 weeks postoperatively, 50% of the BSSO group had returned to work or school while none of the LFI group had returned. By 3 to 4 weeks, 81% of the BSSO group had returned to work or school while nearly one half of the LFI group still had not returned. The BSSO group returned to full activity earlier than the LFI group, although the differences were not statistically significant. Hemoglobin, hematocrit, weight, and vital signs were determined preoperatively and for 6 weeks postoperatively. The LFI group had a larger mean estimated blood loss, length of operation, and weight loss.

Absenteeism↗
PubMed1992

Superior repositioning of the maxilla combined with mandibular advancement: mandibular RIF improves stability.

Postsurgical changes in 24 patients who had rigid internal fixation (RIF) of the mandible with screws after combined superior repositioning of the maxilla and mandibular advancement were compared with 53 patients who underwent the same surgery but who had intraosseous wire fixation, skeletal suspension wires, and 8 weeks of maxillomandibular fixation (MMF). During the first 8 weeks after surgery, the mean posterior relapse of the mandible was greater in the MMF group than in the RIF group (for example, -1.1 mm versus 0.15 mm at B point), and the percentage of patients with clinically significant vertical and horizontal changes was greater in the MMF group. By 1 year, there had been slight additional mean relapse in the MMF group (-1.5 mm net relapse at B point, with 42% of the patients showing 2 mm or more relapse). In the RIF group, the mandible was more likely to be repositioned forward than posteriorly (net mean change at B point, 0.7 mm forward; 33% had 2 mm or more forward movement). In the RIF group, all but one of the patients (96%) were judged to have an excellent clinical result; in the MMF group, the corresponding figure was 60%.

Adult↗
PubMed1992

Surgical-orthodontic correction of mandibular deficiency: five-year follow-up.

Changes in dental and skeletal relationships at 5 years postsurgery were evaluated in a group of 35 patients whose mandibular deficiency had been corrected by the same surgeon, using sagittal split osteotomy of the mandibular ramus. From 1 to 5 years postsurgery, there was a small (0.9-mm) but statistically significant mean decrease in mandibular length (condylion to point B). In six patients, the decrease in mandibular length was 2 to 4 mm, and in two it was more than 4 mm, but only one of these individuals had more than a 2-mm increase in overjet. There was no mean change in overjet, but three patients had a 2 to 4-mm increase. Of these, one had 3.2 mm shortening of the mandible, one had 1.4 mm shortening of the mandible, and one had no change in mandibular length but repositioning of the incisors. Most patients had a deep overbite initially, and there was a tendency for the bite to deepen between the first and fifth years postoperatively, more as a result of extrusion of incisors than of mandibular rotation. Remodeling of the gonial angle area, with vertical and/or horizontal repositioning of gonion, was noted in more than half the subjects. It appears that morphologic changes related to continued skeletal remodeling, often compensated for by small changes in mandibular posture or tooth positions, continue after 1 year postsurgery for many patients.

Adolescent↗
PubMed1991

The effect of orthognathic surgery on head posture.

Changes in resting head and neck posture were studied in 201 patients following five different orthognathic surgery procedures: (1) LeFort I osteotomy for superior repositioning (intrusion) of the maxilla (n = 45); (2) bilateral sagittal split ramus osteotomy for mandibular advancement (n = 78); (3) mandibular setback (n = 19); (4) combined maxillary intrusion and mandibular advancement (n = 46); (5) combined maxillary intrusion and mandibular setback (n = 13). Head and neck posture were measured on standardized serial cephalograms taken in natural head position prior to, immediately after, and 1 year after surgery for each subject. Immediately after surgery, there was flexion of the head as measured by the craniovertical and craniocervical angles in all of the groups except the mandibular setback group, which showed little change. By 1 year post-surgery, the mean craniovertical and craniocervical angles were approximately the same as before surgery in the groups with one-jaw surgery. Statistically significant head flexion at 1 year (P less than 0.05) was observed in the combined maxillary intrusion and mandibular advancement group, and with maxillary intrusion plus mandibular setback, there was a trend toward persistent flexion. Neck posture showed no significant short- or long-term changes in any of the surgical groups.

Adult↗
PubMed1991

Stability after surgical-orthodontic correction of skeletal Class III malocclusion. 2. Maxillary advancement.

Nearly half the patients with skeletal Class III malocclusion have maxillary deficiency as the major component of their problem, and modern surgical techniques allow maxillary osteotomy to correct the deformity. Changes at surgery and postsurgically were studied in 49 patients who underwent isolated surgical maxillary advancement. Thirty-one had wire osteosynthesis and maxillomandibular fixation, and 18 had rigid fixation with bone plates. In nearly half the patients, the maxilla was moved down as well as forward, indicating that the patient had both vertical and anteroposterior deficiency. In the anteroposterior plane, 80% of the patients had excellent stability at 1 year, while 20% had 2 to 4 mm of posterior movement of anterior maxillary landmarks. There was no difference in anteroposterior stability between wire/maxillomandibular fixation and rigid internal fixation groups. When the maxilla was moved down as well as forward, there was a strong tendency for relapse upward in both fixation groups. As a result, the chin frequently became more prominent from immediate postsurgery to 1-year followup, as upward movement of the maxilla allowed the mandible to rotate upward and forward.

Adult↗
PubMed1991

Surgical mandibular advancement in adolescents: postsurgical growth related to stability.

Ten of 12 adolescents treated with surgical mandibular advancement showed postsurgical mandibular growth, as indicated by an increase in the distance from condylion to pogonion. In all cases, the growth was expressed vertically relative to the cranial base, so that the chin did not come forward. None of the patients had significant increments of anterior maxillary growth postsurgically. Several patients had vertical maxillary growth, which was compensated by vertical mandibular growth, so that the anteroposterior position of the chin was maintained. Forward growth of the maxilla is minimal after the peak of the adolescent growth spurt, and results of mandibular advancement surgery can be acceptably stable after that time.

Adolescent↗
PubMed1991

Stability after surgical-orthodontic corrective of skeletal Class III malocclusion. 3. Combined maxillary and mandibular procedures.

Stability after combined Le Fort I and bilateral sagittal split osteotomies was reviewed in 51 patients with skeletal Class III malocclusion. Because vertical changes in the position of the maxilla affect both the vertical and anteroposterior positions of the mandible, the sample was subdivided by the direction of vertical movement of the maxilla at surgery. Excellent postsurgical stability was observed in the long-face Class III patients in whom upward and forward movement of the maxilla was combined with ramus osteotomy to prevent excessive forward rotation of the mandible. When the maxilla was moved forward and the mandible set back with minimal vertical change, moderate relapse tendencies were observed in both jaws, but most of the correction was maintained at 1 year. When the maxilla was moved down and forward while the mandible was set back, moderate vertical relapse of the maxilla and anteroposterior relapse of the mandible followed. Stability of the downward movement of the maxilla was, on average, better than that resulting from maxillary surgery alone.

Adult↗
PubMed1991

Lag screw versus position screw techniques for rigid internal fixation of sagittal osteotomies: a comparison of stability.

Both lag screw and position screw techniques have potential advantages and disadvantages when used for securing sagittal osteotomies of the mandible. This study evaluated 56 patients undergoing bilateral sagittal split osteotomies for mandibular advancements. Osteotomies were fixed with either a position screw or lag screw technique using 2-mm self-threading screws. Five cephalometric points and two angles were used to evaluate skeletal changes. There were no statistically significant differences in the postsurgical movement of point B or the mandibular incisor. There were slight statistically significant differences in the horizontal and vertical movements of gonion. Overall, similar postoperative stability existed in both groups. Gonion and gonial angle changes were detected cephalometrically but had no effect on the clinical outcome.

Adult↗
PubMed1991

Stability after surgical-orthodontic correction of skeletal Class III malocclusion. I. Mandibular setback.

Postsurgical stability of mandibular setback to correct mandibular prognathism was compared for three approaches: transoral vertical ramus osteotomy, bilateral sagittal split osteotomy with wire osteosynthesis and maxillomandibular fixation, and bilateral sagittal split osteotomy with rigid internal fixation via bone screws. In the transoral vertical ramus osteotomy group, the mean postsurgical change in chin position was almost zero, but nearly 50% of the patients did have clinically significant changes in chin position; two thirds of these movements were posterior and one third anterior. In the bilateral sagittal split osteotomy groups, the chin either stayed in its immediately postsurgical position or moved anteriorly. In one fourth of the patients who received maxillomandibular fixation and in nearly half of the patients who received rigid internal fixation, the chin moved forward more than 4 mm.

Adult↗
PubMed1990

Effects of trauma to the mandibular nerve on human perioral directional sensitivity.

The capacity of 4 patients who had previously experienced trauma to their mandibular nerves to distinguish opposing directions of tactile motion over the distribution of the mental nerve was compared to that of 8 neurologically normal adults. Brushing stimuli were delivered to the perioral region and were precisely controlled for their velocity, the length of skin traversed, the width of skin contacted, and the orientation and direction of motion. A temporal, 2-alternative, forced choice method was used to obtain estimates of directional sensitivity, d'. It was discovered that impairment in cutaneous directional sensitivity could be readily detected within areas of hypaesthesia. Although directional sensitivity was found to increase linearly with the length of skin traversed for both the patients and the neurologically normal adults, the slope and the x-intercept of the linear relationship differed between the two groups. The difference in the slope suggests that direction discrimination within the hypaesthetic areas is relatively insensitive to changes in the length of skin traversed. The difference in the x-intercept suggests that a greater length of skin must be traversed before any information about direction is made available at the hypaesthetic sites. The dependency of the capacity of neurologically normal and impaired individuals to process information about direction of tactile motion on the length of skin traversed and the velocity of stimulation suggests that a high degree of stimulus control is required for the detection and quantification of subtle neurosensory deficits.

Adolescent↗
PubMed1990

Alterations in velopharyngeal function after maxillary advancement in cleft palate patients.

Velopharyngeal function was assessed aerodynamically prior to surgery and at least 1 year following surgery in 24 cleft palate patients who underwent maxillary advancement. In 5 patients (23%) deterioration and in 5 patients (23%) improvement of velopharyngeal function was observed. In those patients whose velopharyngeal function improved, a pharyngeal flap was in place at surgery. Of the 5 patients whose velopharyngeal function deteriorated, 4 had adequate and 1 borderline adequate velopharyngeal function prior to surgery. In the remaining 14 patients, velopharyngeal function was unchanged. No relationship between the amount of maxillary advancement or the "need ratio" and velopharyngeal function was observed.

Adolescent↗