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Dive into the research topics where Michael Mars is active.

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Featured researches published by Michael Mars.


The Cleft palate journal | 1990

A preliminary study of facial growth and morphology in unoperated male unilateral cleft lip and palate subjects over 13 years of age

Michael Mars; William J. B. Houston

This paper investigates the effects of surgery on facial growth and morphology in Sri Lankan males with unilateral cleft lip and palate who were over 13 years of age at the time of study with cephalometry and dental study models. Three separate subgroups were analyzed: those who had totally unrepaired cleft lip and palate, those who received lip repair in infancy but not palatal repair, and those who had lip and palate repair in infancy. Twenty-three healthy noncleft Sri Lankan males over 13 years formed a control group from the same racial background. The results show that subjects who had no surgery had a potential for normal maxillary growth. Subjects who have had lip repair in early infancy show relatively normal maxillary growth, but maxillary hypoplasia is common when the palate has also been repaired early.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 3. Dental Arch Relationships

Michael Mars; Catherine Asher-McDade; Viveca Brattström; Erik Dahl; John McWilliam; Kirsten Mølsted; Dennis A. Plint; Birte Prahl-Andersen; Gunvor Semb; William C. Shaw

One hundred and forty-nine dental casts of subjects with complete unilateral clefts of the lip and palate from six European cleft palate centers were assessed by means of the Goslon Yardstick. The Yardstick proved capable of discriminating between the quality of the dental arch relationships between the six centers. Two centers showed especially poor results. Three centers obtained satisfactory results although differing surgical techniques were used in these centers. One of the centers showing satisfactory dental arch relationships employed a more complex and expensive treatment program than the other two centers, which both used simpler centralized treatment regimens.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 2. Craniofacial form and soft tissue profile.

Kirsten Mølsted; Catherine Asher-McDade; Viveca Brattström; Erik Dahl; Michael Mars; John McWilliam; Dennis A. Plint; Birte Prahl-Andersen; Gunvor Semb; William C. Shaw

The craniofacial morphology and the soft tissue profile were evaluated in this part of the intercenter study of the European Cleft Lip and Palate Research Group. The sample was comprised of cephalometric x-rays of the full cohort of 151 cases from the six European cleft palate centers. The facial morphology in complete unilateral cleft lip and palate patients was evaluated by means of roentgen cephalometry. Approximately 25 consecutive cases from each of six European cleft palate centers were compared. Only one center showed notable and consistent differences from the others. A contributing factor for these differences may be an inconsistent treatment regimen with many surgeons involved. Analysis of the soft tissue profile between the centers showed more pronounced differences than analysis of the skeletal profile. The treatment outcome in centers with more complex or expensive programs was no better than those centers using simpler management approaches.


The Cleft Palate-Craniofacial Journal | 1993

Timing of Hard Palate Closure and Dental Arch Relationships in Unilateral Cleft Lip and Palate Patients: A Mixed-Longitudinal Study

Alexis E. M. Noverraz; Anne Marie Kuijpers-Jagtman; Michael Mars; Martin A. van't Hof

In a mixed longitudinal study, dental arch relationships of 88 consecutive UCLP patients treated at the Nijmegen Cleft Palate Centre were evaluated using the Goslon Yardstick. On the basis of timing of hard palate closure, the patients were divided into four groups. Mean age of hard palate closure the patients were divided into four groups. Mean age of hard palate closure in group A (n = 18) was 1.5 years, in group B (n = 26) 4.6 years and in group C (n = 18) 9.4 years. In group D (n = 26, no patient older than 10 years) the hard palate was still open. Four stages of dental development were distinguished; deciduous dentition, early mixed dentition, late mixed dentition and permanent dentition. Reproducibility of scoring with the Goslon Yardstick was good for all stages of dental development. No differences in dental arch relationships were found between the four groups. In 86% of the cases, the dental arch relationships of UCLP patients treated in Nijmegen were acceptable. Pharyngeal flap surgery had minor unfavorable effects on dental arch relationships.


The Cleft Palate-Craniofacial Journal | 2005

Long-Term Effects of Clefts on Craniofacial Morphology in Patients With Unilateral Cleft Lip and Palate

Yu-Fang Liao; Michael Mars

OBJECTIVE To identify the long-term effects of clefts (intrinsic and functional) on craniofacial growth and to evaluate the possible association between the sizes of the cleft maxillary segment (intrinsic) and alveolar cleft (functional) and the craniofacial morphology in patients with unilateral cleft lip and palate (UCLP). DESIGN Retrospective case-control study. SETTING Sri Lankan Cleft Lip and Palate Project. SUBJECTS Thirty unoperated adult patients with UCLP and 52 normal controls. MAIN OUTCOME MEASURES Maxillary dental cast was used to measure the sizes of the cleft maxillary segment and alveolar cleft. Cephalometry was used to determine craniofacial morphology. RESULTS Patients with UCLP had shorter height of the basal maxilla, shorter posterior length of the basal maxilla, and less protruded basal maxilla at the zygomatic level than did control subjects. In patients with UCLP, the posterior height of the basal maxilla was related to the size of the cleft maxillary segment, and there was a tendency toward significant association between the anterior height of the basal maxilla and the size of the alveolar cleft. CONCLUSION The adverse effects of clefts on the growth of the maxilla in patients with UCLP are restricted to the basal maxilla in size. This growth inhibition is major in height and minor in length. The reduced posterior height of the basal maxilla in unoperated patients with UCLP might be primarily attributed to intrinsic effects, whereas the reduced anterior height of the basal maxilla might be attributed to functional effects.


The Cleft Palate-Craniofacial Journal | 2006

Analysis of Dental Arch Relationships in Swedish Unilateral Cleft Lip and Palate Subjects: 20-Year Longitudinal Consecutive Series Treated With Delayed Hard Palate Closure

Jan Lilja; Michael Mars; Anna Elander; Lars Enocson; Catharina Hagberg; Emma Worrell; Puneet Batra; Hans Friede

Objective: To evaluate the dental arch relationships for a consecutive series from Goteborg, Sweden, who had delayed hard palate closure. Design: Retrospective study. Setting: Sahlgrenska University Hospital, Goteborg, Sweden. Patients: The dental study models of 104 consecutive unilateral cleft lip and palate subjects. The study cohort was born between 1979 and 1994. Longitudinal records were available at ages 5 (n = 94), 10 (n = 97), 16 (n = 59), and 19 years (n = 46). Five assessors rated models according to the GOSLON Yardstick on two separate occasions each. Interventions: These patients had been operated upon according to the Goteborg protocol of delayed hard palate closure (at age 8 years). Results: 85% of subjects were rated in groups 1 and 2 (excellent or very good outcome), 12% were rated in group 3 (satisfactory), and 3% were assigned to group 4 (poor). No patients presented in Group 5 (very poor). Weighted kappa statistics for double determination of Yardstick allocation for five assessors demonstrated values between .65 and .90 for interrater agreement (good/very good) and between .70 and .90 for intrarater agreement (very good). Conclusions: Delayed hard palate closure as practiced in Goteborg since 1979 has produced the best GOSLON Yardstick ratings in a consecutive series of patients ever recorded worldwide, since the Yardstick was first used in 1983. However, it is noteworthy that a new protocol has been introduced in Goteborg since 1994, in which hard palate closure is done at 3 years due to concerns regarding speech.


The Cleft Palate-Craniofacial Journal | 2007

The Nature of Feeding in Infants With Unrepaired Cleft Lip and/or Palate Compared With Healthy Noncleft Infants

A. G. Masarei; Debbie Sell; Alex Habel; Michael Mars; Brian C. Sommerlad; A. Wade

Objective: Feeding difficulties are reported widely in infants with cleft lip and/ or palate. There is, however, a paucity of objective information about the feeding patterns of these infants. This study compared patterns of feeding in infants with unrepaired cleft lip and palate with healthy noncleft infants of a similar age. Setting: North Thames Regional Cleft Centre. The noncleft cohort was recruited from West Middlesex University Hospital, a general hospital with similar demographics. Participants: Fifty newborn infants with nonsyndromic complete unilateral cleft lip and palate or a cleft of the soft and at least two thirds of the hard palate who were referred to the North Thames Regional Cleft Centre participated. Parents of 20 randomly selected, noncleft infants agreed to participate. Main Outcome Measures: Feeding patterns were rated using the Neonatal Oral Motor Assessment Scale. Additional objective information was collected using the Great Ormond Street Measurement of Infant Feeding (Masarei et al., 2001; Masarei, 2003). Results: Infants with nonsyndromic complete unilateral cleft lip and palate or a cleft of the soft and at least two thirds of the hard palate had less efficient sucking patterns than their noncleft peers had. They used shorter sucks (mean difference, 0.30 second; p < .0005), a faster rate of sucking (mean difference, 34.20 sucks/second; p < .0005), higher suck-swallow ratios (mean difference, 1.87 sucks/swallow; p < .0005), and a greater proportion of intraoral positive pressure generation (mean difference, 45.97% positive pressure; p < .0005). Conclusions: This study demonstrated that the sucking patterns of infants with nonsyndromic complete unilateral cleft lip and palate or a cleft of the soft and at least two thirds of the hard palate differ from those of their noncleft peers.


The Cleft Palate-Craniofacial Journal | 2006

Hard Palate Repair Timing and Facial Growth in Unilateral Cleft Lip and Palate: A Longitudinal Study

Yu-Fang Liao; T. J. Cole; Michael Mars

Objective: To investigate whether timing of hard palate repair had a significant effect on facial growth in patients with unilateral cleft lip and palate (UCLP). Design: Retrospective longitudinal study. Setting: Sri Lankan Cleft Lip and Palate Project. Patients: A total of 104 patients with nonsyndromic UCLP who had hard palate repair by age 13 years, with their 290 cephalometric radiographs taken after lip and palate repair. Main Outcome Measures: Clinical notes were used to record surgical treatment histories. Cephalometry was used to determine facial morphology and growth rate. Results: Timing of hard palate repair had a significant effect on the length and protrusion of the alveolar maxilla (PMP-A and SNA, respectively) and the anteroposterior alveolar jaw relation (ANB) at age 20 years but not on their growth rates. Conclusion: Timing of hard palate repair significantly affects the growth of the maxilla in patients with UCLP. Late hard palate repair has a smaller adverse effect than does early hard palate repair on the growth of the maxilla. This timing effect primarily affects the anteroposterior development of the maxillary dentoalveolus and is attributed to the development being undisturbed before closure of the hard palate.


The Cleft Palate-Craniofacial Journal | 1996

The Goslon Yardstick Applied to a Consecutive Series of Patients with Unilateral Clefts of the Lip and Palate

Iain Hathorn; Dai Roberts-Harry; Michael Mars

First described in 1987, the Goslon yardstick has been used since as a reliable and reproducible means of measuring dental arch relationships and, therefore, the quality of facial growth. The dental study models of a group of 32 consecutively treated patients with unilateral clefts of lip and palate, from the Frenchay Hospital, Bristol, U.K., were analyzed using the Goslon yardstick. More than 50% of the sample were in the unfavorable Goslon groups IV and V. Because of these results, we at Frenchay Hospital now base our related surgical procedures on the early vomerine closure of the anterior hard palate without nasal or alveolar repair at 3 months, followed by primary hard and soft palate closure at 6 months.


The Cleft Palate-Craniofacial Journal | 2006

Hard palate repair timing and facial growth in cleft lip and palate: a systematic review.

Yu-Fang Liao; Michael Mars

Objective: To evaluate the effect of timing of hard palate repair on facial growth in patients with cleft lip and palate, with special reference to cranial base, maxilla, mandible, jaw relation, and incisor relation. Design: A systematic review. Methods: The search strategy was based on the key words “facial growth,” “cleft lip palate,” and “timing of (hard) palate repair.” Case reports, case-series, and studies with no control or comparison group in the sample were excluded. Results: Fifteen studies met the selection criteria. All the studies were retrospective and nonrandomized. Five studies used cephalometry and casts, seven used cephalometry, and three used casts. Methodological deficiencies and heterogeneity of the studies prevented major conclusions. Conclusion: The review highlights the importance of further research. Prospective well-designed, controlled studies, especially targeting long-term results, are required to elucidate the effect of timing of hard palate repair on facial growth in patients with cleft lip and palate.

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Debbie Sell

Great Ormond Street Hospital

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Yu-Fang Liao

Great Ormond Street Hospital

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Alex Habel

Great Ormond Street Hospital

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Brian C. Sommerlad

Great Ormond Street Hospital

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Emma Worrell

Great Ormond Street Hospital

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Gunvor Semb

University of Manchester

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Puneet Batra

Great Ormond Street Hospital

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Birte Prahl-Andersen

Academic Center for Dentistry Amsterdam

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