Short-term condylar and glenoid fossa changes in infants with Pierre Robin sequence undergoing mandibular distraction osteogenesis.

The purpose was to evaluate short-term changes in condylar and glenoid fossa morphology in infants with Pierre Robin sequence (PRS) undergoing early (age <4 months) mandibular distraction osteogenesis (MDO) for the management of severe airway obstruction. Computed tomography data from infants with PRS who had MDO were compared to those of age-matched control infants without facial skeletal dysmorphology. Surface/volume, linear, and angular measurements of the condyle and glenoid fossa were obtained and compared between infants with PRS and controls. Eleven infants with PRS met the inclusion criteria. There were five female and six male subjects with a mean age at the time of MDO of 41±32 days. Prior to MDO, PRS mandibles had a smaller condylar articulating surface area and volume than age-matched control mandibles, with a more laterally positioned condylar axis (P≤0.05). Following MDO, there were significant increases in condylar articulating surface area and volume, approaching those of normal controls, with further lateral translation of the condylar axis (P≤0.05). Condyle and glenoid fossa morphology is largely normalized following early MDO in infants with PRS. The condylar axis translates laterally as a result of MDO; this change is not observed with mandibular growth in infants without PRS.

Two-point nasomaxillary fixation of the Le Fort I osteotomy: assessment of stability at one year postoperative.

The purpose was to assess maxillary position among patients undergoing Le Fort I maxillary advancement with internal fixation placed only at the nasomaxillary buttresses. This was a retrospective study of patients undergoing a Le Fort I osteotomy for maxillary advancement, with internal fixation placed only at the nasomaxillary buttresses. Demographic and cephalometric measures were recorded. The outcome of interest was the change in maxillary position between immediately postoperative (T1), 6 weeks postoperative (T2), and 1 year postoperative (T3). Fifty-eight patients were included as study subjects (32 male, 26 female; mean age 18.4±1.8 years). Twenty-five subjects (43.1%) had a diagnosis of cleft lip and palate. Forty-three subjects (74.1%) had bimaxillary surgery, 16 (27.6%) had bone grafts, and 18 (31.0%) had segmental maxillary osteotomies. At T3, there were no subjects with non-union, malunion, malocclusion, or relapse requiring repeat surgery. Mean linear changes between T1 and T3 were ≤1mm. Mean angular changes between T1 and T3 were <1°. There was no significant difference in stability in multi-segment maxillary osteotomies (P= 0.22) or with bone grafting (P= 0.31). In conclusion, anterior fixation alone in the Le Fort I osteotomy results in a stable maxillary position at 1 year postoperative.

Is alteration of the occlusal plane stable with isolated nasomaxillary fixation of the Le Fort I osteotomy?

The purpose of this work was to evaluate the stability of maxillary position in the setting of occlusal plane rotations in bimaxillary surgery with rigid fixation of the mandible and bilateral nasomaxillary fixation at the Le Fort I level. This was a retrospective assessment of patients undergoing bimaxillary surgery for the correction of dentofacial deformities with occlusal plane alterations. Demographic measures assessed included age, sex, history of craniofacial anomaly, segmental maxillary osteotomy, and maxillary bone grafting. Cephalometric measures assessed included occlusal plane rotation (clockwise (CWR) or counterclockwise (CCWR)), angular measurements of maxillary and mandibular position (SNA, SNB, and ANB), and occlusal plane angle (occlusal plane to corrected Frankfort horizontal); these were assessed preoperatively (T0) and immediately (T1), 6 weeks (T2), and 1year postoperative (T3). Descriptive and bivariate statistics were computed; P≤0.05 was considered significant. Thirty-six patients were included as study subjects (mean age 18.6±1.8 years; 17 (47.2%) female); 27 (75%) had a primary diagnosis of craniofacial anomaly. Eleven patients (30.6%) had segmental maxillary osteotomies; 10 patients (27.8%) had simultaneous maxillary bone grafting. Twelve patients underwent CCWR; 24 patients underwent CWR. No patient required repeat surgery for malocclusion or relapse; there were no malunions or non-unions during follow-up. For CCWR patients, the mean occlusal plane change from preoperative to postoperative was 5.8±2.8°, remaining stable at 1 year postoperative (ΔT3-T1 1.6±1.0°, P>0.05). For CWR patients, the mean occlusal plane rotation was 4.5 ± 2.2°, remaining stable at 1 year postoperative (ΔT3-T1 1.1±0.9°, P>0.05). In patients undergoing bimaxillary surgery for occlusal plane rotation, two-point fixation of the Le Fort I osteotomy resulted in a stable maxillary position at 1 year postoperative.

What are the defining characteristics of the most cited publications in orthognathic surgery?

The purpose of this study was to identify the characteristics associated with highly cited papers in orthognathic surgery. This was a cohort study of articles published in the English-language literature from 1900 to 2017. Citation databases were searched for papers related to orthognathic surgery and the most frequently cited papers were identified. For each paper, the following variables were collected: region of origin, time-period of publication, corresponding author specialty, journal of publication, topic area, study design, and number of citations. The outcome variable was the citation index (citations per year). North American investigators published 70% of the 100 most-cited articles in orthognathic surgery. The majority of papers were from oral and maxillofacial surgeons. Frequent content areas were diagnosis, virtual planning, fixation/stability, and complications. The majority (54%) of studies were cohort or case report/series. The mean number of citations was 235.0±126.5; the mean citation index was 9.9±6.1 citations per year. Time-period, content area, and study design were associated with the citation index (all P<0.001). Time-period, content area, and study design predicted the citation index (all P≤0.009). Among frequently cited papers in orthognathic surgery, oral and maxillofacial surgeons had the highest volume of contributions. Diagnosis, treatment planning, and complications were the most common topics studied.

The matricellular protein periostin contributes to proper collagen function and is downregulated during skin aging.

BACKGROUND: Periostin is a secreted 90kDa matricellular protein, which is predominantly expressed in collagen-rich tissues. Collagen is the most abundant protein in mammals and has great tensile strength. Recent investigations have shown that periostin influences collagen fibrillogenesis and biomechanical properties of murine connective tissues. OBJECTIVE: We investigated the function of periostin concerning collagen homeostasis during intrinsic and extrinsic skin aging. For this purpose, human skin samples of young and old donors as well as samples of photoaged and sun-protected skin areas were analyzed for periostin expression. Using in vitro models, we determined the cell types responsible for periostin expression and performed functional analyses with periostin knockdown cells. METHODS: TaqMan Real-Time PCR, UV irradiation, knockdown experiments, immunostaining, electron microscopy, collagen degradation assay, collagen crosslink analysis. RESULTS: Periostin expression is highest in the papillary dermis and downregulated during skin aging. Fibroblasts and non-follicular skin derived precursors were identified as main source for periostin expression in human skin. Periostin knockdown in fibroblasts has no effect on collagen expression, but results in an increased fibril diameter and aberrant collagen structure. This leads to an increased susceptibility of collagen toward proteases, whereas recombinant periostin protects collagen fibrils from degradation. CONCLUSION: Our data show that periostin plays an important role for proper collagen assembly and homeostasis. During skin aging periostin expression decreases and contributes to the phenotype of aged skin.

The effects of tooth extraction on alveolar bone biomechanics in the miniature pig, Sus scrofa.

OBJECTIVE: This study investigated the role of occlusion in the development of biomechanical properties of alveolar bone in the miniature pig, Sus scrofa. The hypothesis tested was that the tissues supporting an occluding tooth would show greater stiffness and less strain than that of a non-occluding tooth. DESIGN: Maxillary teeth opposing the erupting lower first molar (M(1)) were extracted on one side. Occlusion developed on the contralateral side. Serially administered fluorochrome labels tracked bone mineralisation apposition rate (MAR). A terminal experiment measured in vivo buccal alveolar bone strain on occluding and non-occluding sides during mastication. Ex vivo alveolar strains during occlusal loading were subsequently measured using a materials testing machine (MTS/Sintech). Whole specimen stiffness and principal strains were calculated. RESULTS: MAR tended to be higher on the extraction side during occlusion. In vivo buccal shear strains were higher in the alveolar bone of the occluding side vs. the extraction side (mean of 471 microvarepsilon vs. 281 microvarepsilon, respectively; p=0.04); however, ex vivo shear strains showed no significant differences between sides. Stiffness differed between extraction and occlusion side specimens, significantly so in the low load range (344 vs. 668 MPa, respectively; p=0.04). CONCLUSIONS: Greater in vivo shear strains may indicate more forceful chews on the occluding side, whereas the similarity in ex vivo bone strain magnitude suggests a similarity in alveolar bone structure and occlusal load transmission regardless of occlusal status. The big overall change in specimen stiffness that was observed was likely attributable to differences in the periodontal ligament rather than alveolar bone.

Semantic priming effects in normal versus poor readers.

The authors studied sensitivity to semantic priming, as distinct from semantic judgment, in poor readers. Association strength (high vs. low semantic association) was manipulated factorially with semantic association type (categoric vs. thematic association). Participants were 11-year-old poor readers (n = 15) who were matched with a group of chronological-age controls (n = 13), and also matched with a group of reading-age controls (n = 15). Three priming conditions were used: related, unrelated, and neutral prime. Neutral primes consisted of a row of hash marks. Related primes elicited shorter decision latencies than did unrelated primes. Neutral primes elicited the slowest responses in all groups. Poor readers showed an additional delay in the neutral prime condition. No effects of association type (categorical vs. thematic) or association strength (high vs. low) were found, nor were any relationship with reading ability found. The delayed performance of the poor readers on neutral primes is explained in terms of orthographic processing and dependency on grapheme phoneme relationships. The findings are discussed with reference to F. R. Vellutino, D. M. Scanlon, and D. Spearing's (1995) work on semantic processing and reading ability.

Contrasting effects of age of acquisition in lexical decision and letter detection.

Two experiments studied attention in beginning and skilled readers of Dutch to letter information in function words and content words. Early and late acquired nouns and function words were presented to third-grade students and skilled adolescent readers. Target words were presented in short story contexts, as in the study of Greenberg, Koriat, and Vellutino (1998). Target nouns were matched on word frequency. Predictions of the structural account hypothesis of letter detection (Koriat, Greenberg, & Goldshmid, 1991) were confirmed. No age-of-acquisition effect was found. In contrast, a separately conducted lexical decision experiment using the same content word stimulus sets showed shorter decision latencies for early acquired words. The combined results suggest that during silent reading, when attention is focused on meaning, phonological processes may play a less prominent role than in lexical decision tasks that demand explicit control of phonological codes. The letter detection results confirmed predictions of the structural account hypothesis for both beginning and skilled readers. Taken together, these studies demonstrate that phonological processes in silent reading may play a less prominent role and that the structural account of letter processing is valid for languages other than Hebrew and English but probably is not the unique mechanism involved in letter detection.

Age-of-acquisition effects in native speakers and second-language learners.

Two lexical decision experiments were conducted to study the locus of age-of-acquisition (AoA) effects in skilled readers with English or Dutch as their first language. AoA effects have generally been explained in terms of phonological processing. In Experiment 1, Dutch elementary school and secondary school students were presented with words factorially manipulated on surface frequency and AoA). Two main effects and an interaction were found, confirming findings reported for English speakers by Gerhand and Barry (1999). In addition, a language development effect was established: AoA effects decreased with reading age. Elementary school students showed the largest AoA effects. Experiment 2 used two groups of subjects. The first group consisted of Dutch students enrolled in a master's degree program in English. The second group consisted of native speakers of English. All subjects were presented with the experimental set of words used by Gerhand and Barry (1999). British subjects showed the same response pattern as reported by Gerhand and Barry (1999). The question of interest was whether Dutch subjects would show an AoA effect on the English set or not. The answer was affirmative. Dutch subjects produced identical response patterns as the British group, showing only an overall 94-msec latency delay. This result challenges predictions of the phonological completeness hypothesis. Alternative accounts in terms of semantic processing are discussed.

Outcome analysis of minimally invasive repair of pectus excavatum: review of 251 cases.

BACKGROUND/PURPOSE: Since the first report in 1997 by Dr Nuss of the technique for minimally invasive repair of pectus excavatum (MIRPE), the popularity and demand for this operation has increased dramatically. Many pediatric surgeons became familiarized with MIRPE and have applied it to a large number of patients. Outcomes and complications have not yet been defined. METHODS: A comprehensive survey of APSA members was conducted to review technical problems, complications, and outcomes of this new technique. RESULTS: Of the 74 survey responders, 31 (42%) currently use the MIRPE as their procedure of choice, and 251 cases were reviewed. A total of 74.2% of surgeons relied on direct observation and written documentation to obtain training in MIRPE. Less than 60% used the chest index in the preoperative assessment. A total of 98% used the Walter Lorenz bar for the MIRPE. The most common complication was bar displacement or rotation requiring reoperation (9.2%). Pneumothorax requiring tube thoracostomy was reported in 4.8%. Less common problems included infectious complications (2%), pleural effusion (2%), thoracic outlet obstruction (0.8%), cardiac injury (0.4%), sternal erosion (0.4%), pericarditis (0.4%), and anterior thoracic artery pseudoaneurysm (0.4%). Three patients (1.2%) required early strut removal. Reoperation using the open modified Ravitch approach was performed in 2 patients (0.8%). Most surgeons indicated that teenaged patients (>15 years old) were at higher risk for complications. Thoracoscopy in combination with MIRPE was used by 61% of the surgeons. Overall patient satisfaction was rated as excellent or good (96.5%). CONCLUSIONS: The relatively high incidence of problems with MIRPE is probably related to the learning curve associated with the introduction of this new technique. Awareness of technical details, careful patient selection, use of a stabilizing bar, and thoracoscopy likely will result in decreased complications. Long-term results are yet to be determined. The development of a national registry is of great importance for further outcome analysis of MIRPE.

One-stop surgery: evolving approach to pediatric outpatient surgery.

PURPOSE: Maximizing patient satisfaction is of prime importance in today's competitive outpatient surgery market. The authors recently devised a system, one-stop surgery, which simplifies outpatient surgery for pediatric patients and their families by combining the traditionally separate preoperative evaluation and subsequent operation into one visit. This report describes our initial experience with one-stop surgery. METHODS: Umbilical hernia repair, circumcision, and portacath removal were considered surgical procedures appropriate for our one-stop surgery pilot study. Medical information obtained by phone or fax from referring physicians was used to identify potential candidates. Families were contacted, precertified for their surgical procedure, and given nothing by mouth instructions. The day of surgery the child was evaluated by the attending pediatric surgeon. If the diagnosis was confirmed, and no contraindications to surgery were identified, the child immediately underwent the prescheduled surgical procedure. RESULTS: From April through October 1997, 61 children were scheduled for one-stop surgery. Nine patients (15%) were no shows, and one additional family opted not to proceed with circumcision. The remaining 51 children (83%) underwent their one-stop surgical procedure: umbilical hernia repair (n = 23), circumcision (n = 19), portacath removal (n = 8), and inguinal hernia repair (n = 1). No child had an anesthetic contraindication to surgery, and only one minor postoperative complication (wound hematoma) occurred. CONCLUSIONS: This pilot study has demonstrated that with appropriate patient screening and cooperation of the entire surgical team, a variety of outpatient surgical procedures can be handled using this one-stop surgery method. By combining one-stop surgery with our previously reported phone follow-up system, many minor surgical procedures can be managed with only one visit to the hospital. Decreasing the "hassle factor" of outpatient surgery for children and their families, who frequently live far from their closest children's hospital, while providing the highest quality of specialized surgical and anesthetic care, may potentially be a very powerful marketing tool for pediatric surgical specialists.

Unusual presentations of injuries associated with the mandibular condyle in children.

Condylar fractures are sustained commonly by children and are readily diagnosed in the main. Three case histories serve to illustrate the intricate anatomy of the area and how damage to it can produce unusual signs and symptoms which can mislead the unwary. Supplemental images, in particular coronal CTs, can be instrumental in arriving at the correct diagnosis and treatment.

Pain following iliac crest bone grafting of alveolar clefts.

The purpose of this study was to investigate pain following iliac crest bone grafting of alveolar clefts. The study involved 34 consecutive patients requiring secondary alveolar bone grafting. The study population consisted of 21 males and 13 females with a mean age of 11 years (SD = 3.4). Twenty-three patients had unilateral and 11 patients bilateral clefts. The patients were treated in a like manner with harvesting of an iliac crest cortico-cancellous block concurrently with the raising of flaps and cleft closure. All surgery was performed by combinations of the authors. Eighteen patients were placed on postoperative intravenous ketorolac and the remainder were not. All patients received patient controlled analgesia at a dose of 0.015 mg/kg of morphine with an 8 min exclusion period before re-dosing. Total narcotic usage averaged 0.18 mg/kg (SD = 0.19) with 31 patients using less than 0.4 mg/kg. Regular ketorolac did not influence narcotic usage, nor did sex, age or nature of the cleft. Thirty-one patients began ambulating on the first postoperative day and 27 were discharged within 2 days of surgery. No long-term donor site morbidity was observed. Our results suggest that pain following iliac crest bone grafting of alveolar clefts is not severe and is readily alleviated with small quantities of analgesic drugs. It would appear that short-term morbidity following these procedures is frequently overstated and is in itself not a valid reason to change to calvarial or mandibular donor sites.

Stability of Le Fort I osteotomy with maxillary advancement: a comparison of combined wire fixation and rigid fixation.

PURPOSE: This study compares two types of fixation: intraosseous wires, skeletal suspension wiring, and maxillomandibular fixation (combined wire fixation; CWF) with rigid internal fixation (RIF) in patients who underwent Le Fort I osteotomy to correct maxillary hypoplasia. MATERIALS AND METHODS: All patients were operated on by the same surgeon using a standard technique, which included bone grafting. The 12 patients in group A were treated with CWF for 4 weeks. Group B was made up of 13 patients who had RIF and training elastics for 4 weeks. Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T1), 1 day postoperatively (T2), and at least 1 year postoperatively (T4). The position of the maxilla in relation to the cranial base and Frankfort plane at each time interval was compared. RESULTS: Postsurgical horizontal change (maxillary position change from T2 to T4) for both groups was in the posterior direction. In group A, six patients had less than 1 mm change, three had 1 to 2 mm change, and three had > 2 mm change. In group B, 10 patients had less than 1 mm change, three had 1 to 2 mm change and 0 had > 2 mm change. Comparison of mean values of groups A and B suggested improved stability with rigid versus wire fixation in the horizontal plane; however, statistical analysis of adjusted mean values showed no significant difference. Vertical changes in maxillary position were also measured from postoperatively to 1 year (T2 to T4). The vertical changes were minimal in those cases of maxillary advancement where no vertical changes were planned; however, there was a statistically significant (P = .0024) improved stability with RIF versus combined wire fixation cases. Comparison of adjusted means showed double the amount of vertical setting 1 year postoperatively in the CWF group. CONCLUSION: Overall, 22 of 25 patients with horizontal maxillary advancement had excellent stability at 1 year. Observed trends suggest that RIF may have improved stability over CWF.

Craniofacial fractures. An algorithm to optimize results.

The aim of treatment of combined injuries of the cranium and face is the correct anatomic restoration of the maxilla in relation to the cranial base above and the mandible below and the reconstruction of any associated craniofacial, naso-orbitoethmoidal, and zygomatic fractures. The plethora of techniques described in this article for the management of these injuries attests to the controversy and confusion surrounding the management of these patients.

Orbital abscess of odontogenic origin. Case report and review of the literature.

A case is discussed of a patient with an orbital cellulitis and a post septal abscess secondary to infection from an upper molar tooth. Spread of infection was to the maxillary sinus and thence to the orbit via a defect in the orbital floor. The clinical presentation, differential diagnosis, value of CT scanning, treatment and possible complications are reviewed.

The "three-piece" osteotomy and interpositional bone graft for augmentation of the atrophic mandible.

A study of 20 patients who underwent augmentation of an atrophic mandible by a "three-piece" osteotomy and interpositional bone graft technique is presented. The results show a reduced rate of bone resorption in the posterior regions and a reduced incidence of sensory nerve disturbances in comparison with previous visor/sandwich techniques.